TISSUE CHARACTERIZATION TO DIFFERENTIATE PATHOLOGICAL FROM PHYSIOLOGICAL HYPERTROPHY IN PATIENTS WITH HYPERTENSION AND ATHLETES

Precedents: In pathological left ventricular (LV) hypertrophy (H) of hypertensive patients (P) there is a deposition of collagen. Myocardial fibrosis is one of the factors responsible for systolic and diastolic dysfunction. Athletes increase their ventricular mass as physiological ventricular H. Integrated backscatter (IB) demonstrates changes in myocardial acoustic properties, depending upon their composition and function.
Objectives: (1).Assess the capability of IB to differentiate physiological from pathological H. (2).Correlate IB with overall and regional systolic and diastolic functions.
Methods: Group I(GI):13 hypertensive P with an LV mass index (LVMI)>124 gr/m², Group II(G2):11 athletes, Group III(G3): 8 volunteers. We determined overall systolic and diastolic functions and regional function of the basal septum, IB and cyclic variation of the IB (CVIB) of the posterior wall.
Results: Age (years): G1:52 ± 15, G2:28 ± 8 G3:35 ± 8 p = 0.000; Sex: G1:m/f 12/1, G2: m/f 9/2, G3: m/f 4/4, LVMI: G1: 180.1 ± 58 gr/m², G2:130.2 ± 20 gr/m² G3: 90.2 ± 16 gr/m² p = 0.000. Left atrial area (LAA): G1: 22 ± 4 cm², G2: 18.8 ± 1.8 cm², G3: 15.8 cm² p = 0.001, mid-wall shortening fraction (MWSF): G1:26.9 ± 3.5, G2:27.5 ± 4 G3:25 ± 3 p = NS; CVIB: G1:5,3 ± 2,5 G2:7.6 ± 2,1 G3:6.4 ± 1.1 P = 0.048.Correlation of IB and MWSF, p = NS; IB and MWSF p = NS, IB and CVIB:-0.56 p = 0.005.  

  TABLE     

2.

Normal Values in Children for Myocardial Ultrasonic Tissue Characterization by Integrated Backscatter     

Shibuya K  Bigras JL  McCrindle BW  Newman A  Smallhorn JF 《Echocardiography (Mount Kisco, N.Y.)》1998,15(4):353-361

Normal values in adults for ultrasonic tissue characterization by integrated backscatter have been reported previously and subsequently applied to patients with specific diseases. Factors influencing integrated backscatter values in a pediatric population are not clearly defined. To obtain normal values for myocardial ultrasonic integrated backscatter in a pediatric population, we studied 72 children with normal cardiac anatomy using an ultrasonic integrated backscatter imaging system. The parameters measured were at peak, nadir, and end-diastole in eight different regions with two different settings: fixed and variable. We subsequently calculated cyclic variation, the ratios of cyclic variation to end-diastole and to peak. Age ranged from 1 day to 17.4 years (median 4.4 years). More than 90% of data curves from the two regions in the left ventricular posterior wall in long-axis view had normal patterns, whereas more than 50% of curves for the other regions had abnormal patterns. Comparing the two posterior wall positions, there were no differences in cyclic variation between the two regions, with little effect of setting. Less effect of regions and settings was noted for the ratios of cyclic variation to end-diastole or peak. There was no relation between backscatter variables and age, gender, or height, and some variables correlated weakly with body surface area. The assessment of integrated backscatter in children is optimal with interrogation of the left ventricular posterior wall imaged in the long-axis view. More stable estimates are obtained when the cyclic variation is related to the peak or end-diastolic value.     

3.

Ten-Year Echo/Doppler Determination of the Benefits of Aerobic Exercise after the Age of 65 Years     

Alexander J. Muster  M.D.  Hyunggun Kim  Ph.D.  †  Bonnie Kane  B.S.  R.D.C.S.  David D. McPherson  M.D.  † 《Echocardiography (Mount Kisco, N.Y.)》2010,27(1):5-10

As the human lifespan becomes progressively extended, potential health-related effects of intense aerobic exercise after age 65 need evaluation. This study evaluates the cardiovascular (CV), pulmonary, and metabolic effects of competitive distance running on age-related deterioration in men between 69 (±3) and 77 (±2) years (mean ± SD). Twelve elderly competitive distance runners (ER) underwent oxygen consumption and echo/Doppler treadmill stress testing (Balke protocol) for up to 10 years. Twelve age-matched sedentary controls (SC) with no history of CV disease were similarly tested and the results compared for the initial three series of the study. CV data clearly separated the ER from SC. At entry, resting and maximal heart rate, systolic/diastolic blood pressure, peak oxygen consumption (VO_2max), and E/A ratio of mitral inflow were better in the ER (P < 0.05 vs. SC). With aging, ER had a less deterioration of multiple health parameters. Exceptions were VO_2max and left ventricular diastolic function (E/A, AFF, IVRT) that decreased (P < 0.05, Year 10 vs. Year 1). Health advantages of high-level aerobic exercise were demonstrated in the ER when compared to SC. Importantly, data collected in ER over 10 years confirm the benefit of intensive exercise for slowing several negative effects of aging. However, the normative drop of exercise capacity in the seventh and eighth decades reduces the potential athleticism plays in prevention of CV events. (Echocardiography 2010;27:5-10)     

4.

Hemodynamic Predictors of Atherosclerosis in the Thoracic Aorta   总被引：12，自引：0，他引：12  

Sukernik MR  West OD  Chittivelu B  Vanderbush EJ  Francis CK 《Echocardiography (Mount Kisco, N.Y.)》1998,15(2):157-161

We sought to identify atherosclerotic plaques and measured flow parameters in the descending aorta (DA) of 83 consecutive patients (40 years and older) studied with transesophageal echocardiography. Patients with atherosclerotic plaques in the DA were older (68 ± 10 vs 58 ± 12 years [P = 0.0001]), had a higher proportion of spontaneous echo contrast in the DA (15/46 [33%] vs 3 of 37 [8%] P = 0.02), had larger aortic diameters (2.52 ± 0.35 vs 2.37 ± 0.36 cm [P = 0.06]), had a lower maximal velocity in the DA (54.2 ± 21.5 vs 73.8 ± 33.0 cm/sec [P = 0.02]), and had a lower calculated maximal shear rate (SR) (88.0 ± 37.6 vs 129.0 ± 67.0 sec⁻¹ [P = 0.002]). There was no significant difference between groups with respect to sex, hypertension, diabetes, total cholesterol, and smoking. In multivariate analysis only age (P = 0.002) and maximal SR (P = 0.03) were identified as independent predictors of atherosclerosis in the DA. We conclude that low SR is associated with aortic atherosclerosis.     

5.

背向散射技术与彩色室壁运动技术在高血压左室重构中的应用     

刘晓宁  夏稻子 《高血压杂志》2003,11(6):535-539

目的 探讨背向散射和彩色室壁运动参数评估原发性高血压不同左室构型心肌病变程度和局部室壁运动的临床价值。方法 测定70例原发性高血压病患者和31例正常对照者室间隔及左室后壁的背向散射参数和局部室壁收缩期位移。共收入正常构型组18例，向心重构组17例，向心肥厚组23例，离心肥厚组12例。结果 高血压各组室间隔超声背向散射(IB％)均不同程度地增大，以向心性肥厚组和离心性肥厚组为著；左室后壁IB％在向心性肥厚组和离心性肥厚组增高，以离心性肥厚组为著；室间隔周期变化幅度(cvlB)在向心性肥厚组和离心性肥厚组减低；左室后壁的CVIB在离心性肥厚组显著减低；高血压各组均未出现明显的背向散射跨壁梯度的改变。室间隔和左室后壁的SEM在离心性肥厚组显著减低，其余各组间虽无明显统计学差异，但在向心性肥厚组呈现增加的趋势。在离心性肥厚组，收缩期CK色带变薄或消失，色带不完整。结论 心肌超声背向散射参数可用于判断高血压不同左室构型心肌病变的程度；彩色室壁运动技术可用于评估高血压不同左室构型局部室壁运动状态。     

6.

Assessment of the relationship between functional capacity and right ventricular ultrasound tissue characterization by integrated backscatter in patients with isolated mitral stenosis     

Yildirim N  Saricam E  Ozbakir C  Bozboga S  Ocal A 《International heart journal》2007,48(1):87-96

AIM: The aim of the present study was to investigate right ventricular (RV) myocardial textural properties in asymptomatic and symptomatic mitral stenosis (MS) patients with normal RV systolic function using integrated backscatter (IBS). METHODS: The study included 40 patients with MS of moderate or severe degree. Patients were classified into 2 groups according to NYHA class (asymptomatic group, NYHA class I, symptomatic group, NYHA class II-III). RV pulsed-wave tissue Doppler imaging (TDI) and IBS analyses were performed in all patients. Isovolumic contraction time (IVCT), systolic wave velocity (S), isovolumic relaxation time (IVRT), early diastolic wave velocity (E), and late diastolic wave velocity (A) were measured by TDI. IBS amplitude (IB) and cyclic variation (CV) of the RV lateral wall in the parasternal long-axis view were measured by IBS. CV was calculated by subtracting systolic IB from diastolic IB. RESULTS: IVRT (54.2 +/- 11.9 ms versus 86.2 +/- 16.2 ms, P < 0.001) and A wave amplitude (10.2 +/- 2.1 cm/s versus 13.6 +/- 1.8 cm/s, P < 0.05) were higher whereas E wave amplitude (11.7 +/- 1.6 cm/s and 10.3 +/- 1.5 cm/s, P < 0.05) and E/A ratio (1.3 +/- 0.3 versus 0.7 +/- 0.1, P < 0.001) were lower in group 2. Symptomatic patients had a lower CV value of RV (9.5 +/- 3.4 dB versus 6.7 +/- 1.9 dB, P = 0.004). There was a positive correlation between CV and E/A (r = 0.964, P < 0.001) CONCLUSION: Symptomatic isolated MS patients had RV echo texture changes and diastolic dysfunction in comparison to asymptomatic ones with similar mitral valve areas in the presence of normal RV systolic function. In isolated MS, both pulsed-wave TDI and IBS may aid in the detection of RV diastolic pathology.     

7.

Quantitative Texture Analysis in Two-Dimensional Echocardiography     

FABIO LATTANZI  M.D.    PAOLO BELLOTTI  M.D.  EUGENIO PICANO  M.D.    FRANCESCO CHIARELLA  M.D.  MARCO PATERNI  GIANLUCA FORNI  M.D.  LUIGI LANDINI  Ph  .D.  ALESSANDRO DISTANTE  M.D.  CARLO VECCHIO  M.D. 《Echocardiography (Mount Kisco, N.Y.)》1996,13(1):9-20

Background: Myocardial reflectivity is abnormally increased in patients with thalassemia major under transfusion treatment, probably due to myocardial iron deposits and / or secondary structural changes. Such increased reflectivity has been detected by both qualitative and subjective analysis of two-dimensional echocardiographic (2-D echo) images and quantitative assessment of integrated backscatter amplitude with noncommercially available ultrasound prototypes. The purpose of this study was to assess the acoustic properties of myocardium in patients with beta-thalassemia major and iron overload by means of quantitative computerized offline textural analysis of conventionally recorded 2-D echo images, and to compare textural data with other qualitative (visual assessment) and quantitative (ultrasound backscatter analysis) approaches for myocardial ultrasound tissue characterization simultaneously applied to these patients. Methods and Results: Thirty-five young patients with thalassemia major, without clinical signs of cardiac failure, and 20 age and sex matched normal controls were studied by echocardiography. Each patient was receiving blood transfusion every 2-3 weeks. Two-dimensional echo images, obtained with a commercially available echocardiograph using the parasternal long-axis view, were digitized offline and analyzed by first and second order texture algorithms applied to regions of interest in the myocardium (septal and posterior wall). The mean gray level value was higher in thalassemic patients than in controls on both the septum (110 ± 25 vs 57 ± 13, arbitrary units on a 0-255 scale; P > 0.01) and posterior wall (91 ± 25 vs 67 ± 18; P > 0.01). Among second order statistical parameters, contrast and angular second moment significantly (P > 0.01) differentiated septal and posterior walls of patients and controls. In thalassemic patients, no consistent correlation was found between wall texture parameters and hematologic (years of transfusions and chelation, number of transfusions), 2-D echo (posterior wall thickness, left ventricular end-diastolic diameter), and Doppler (transmitral E/A waves ratio) parameters. Myocardial walls with visually assessed increased echo reflectivity showed a trend toward higher values of mean gray level when compared with myocardial segments with qualitatively assessed normal reflectivity (septum: 121 ± 26 vs 106 ± 24; posterior wall: 105 ± 23 vs 87 ± 23). Although radiofrequency integrated backscatter has been demonstrated to be capable of identifying thalassemic patients, no significant correlation was found between mean gray level (by texture analysis) and radiofrequency data (septum: r = 0.03; posterior wall: r = 0.09; P = NS for both). Conclusions: Myocardial walls affected by hemochromatosis show ultrasound image texture alterations that may be quantified with digital image analysis techniques and appear mostly unrelated to hematologic and conventional, as well as radiofrequency-based, echocardiographic parameters. These changes in quantitatively evaluated echo reflectivity are present even before the development of clinical and echocardiographic signs of cardiac dysfunction.     

8.

Ultrasonic tissue characterization of normal and ischemic myocardium   总被引：2，自引：0，他引：2  

Sagar KB  Pelc LR  Saeian K  Rhyne TL  Wann LS  Warltier DC 《Echocardiography (Mount Kisco, N.Y.)》1990,7(1):11-19

Cardiac ultrasonic tissue characterization is designed to use the alterations in acoustic signals from the myocardium to differentiate normal from ischemic or infarcted tissue due to their characteristic backscatter attenuation. Various approaches such as use of a gray scale, color display, or quantitative image analysis have been used for tissue characterization, but all depend on subjective assessments and are not necessarily reproducible. The most promising method has been the use of "raw" radiofrequency signals and measure changes in the ultrasonic attenuation with an index of backscatter to distinguish normal from abnormal myocardium called "integrated backscatter" (IB). Various studies have demonstrated the changes in the ultrasonic backscatter with ischemia or infarction. In this review we summarize our experience with a research prototype instrument in tissue characterization and differentiation of normal, ischemic, infarcted, and post ischemic reperfused myocardium in anesthetized open chest dogs. Currently we are investigating the role of ultrasonic tissue characterization to estimate infarct size and plan to apply these observations to patients in order to detect viable myocardium and quantitate infarct size.     

9.

Noninvasive quantitative tissue characterization and two-dimensional color-coded map of human atherosclerotic lesions using ultrasound integrated backscatter: comparison between histology and integrated backscatter images   总被引：15，自引：0，他引：15  

Kawasaki M  Takatsu H  Noda T  Ito Y  Kunishima A  Arai M  Nishigaki K  Takemura G  Morita N  Minatoguchi S  Fujiwara H 《Journal of the American College of Cardiology》2001,38(2):486-492

OBJECTIVES: The purpose of the present study was to define clinicopathologically whether integrated backscatter (IB) combined with conventional two-dimensional echo (2DE) can differentiate the tissue characteristics of calcification (CL), fibrosis (FI), lipid pool (LP) with fibrous cap, intimal hyperplasia (IH) and thrombus (TH) and can construct two-dimensional tissue plaque structure in vivo. BACKGROUND: It is difficult to characterize the components of plaque using conventional 2DE techniques. METHODS: Integrated backscatter values of plaques were measured in the right common carotid and femoral arteries (total 24 segments) both during life and after autopsy in 12 patients (age 68 to 84 years, 10 men and two women). Integrated backscatter values were determined using a 5-12 MHz multifrequency transducer, setting the region of interests (ROIs) (11 x 11 pixels) on the echo tomography of the entire arterial wall (55 +/- 10 ROI/segment) and comparing it with histologic features in the autopsied arterial specimens. RESULTS: Corrected IB values obtained before death and at autopsy were significantly correlated (r = 0.93, p < 0.01). Corresponding to the histologic features, corrected IB values on the rectangle ROIs obtained during life were divided into five categories: category 1 (TH) 4 < IB < or = 6; category 2 (media and IH or LP in the intima) 7 < IB < or = 13; category 3 (FI) 13 < IB < or = 18, category 4 (mixed lesion) 18 < IB < or = 27 and category 5 (CL) 28 < IB < or = 33. In category 2, media and intima were differentiated using conventional 2DE. Under the above procedures, color-coded maps constructed with IB-2DE obtained during life precisely reflected the histologic features of media and intima. CONCLUSIONS: Integrated backscatter with 2DE represents a useful noninvasive tool for evaluating the tissue structure of human plaque.     

10.

Relationship between myocardial collagen and echo amplitude in non-fibrotic hearts   总被引：2，自引：0，他引：2  

LYTHALL  D. A.; BISHOP  J.; GREENBAUM  R. A.; ILSLEY  C. J. D.; MITCHELL  A. G.; GIBSON  D. G.; YACOUB  M. H. 《European heart journal》1993,14(3):344-350

The aim of the study was to investigate the relationship betweenmyocardial collagen and regional echo amplitude in humans withnon-fibrotic myocardium. The ratio of myocardial collagen to total myocardial proteinwas determined as the hydroxyproline/leucine ratio in endoniyocardialbiopsies obtained from the right ventricular side of the interventricularseptum in orthotopically transplanted hearts. Regional echoamplitude was measured in the interventricular septum. Patientswere studied prospectively. Twenty-five patients (five female, 20 male) who had undergoneorthotopic cardiac transplantation were studied 355 to 2939days (1009±718, mean±SD) post-transplantationat the time of annual cardiac catheterization and endomyocardialbiopsy. Patient ages varied from 22 to 62 years (46±11).Donor ages were 14 to 47 years (25±8) and the ischaemictime, 90 to 245 min (151±42). Cardiac transplantationwas performed for end-stage cardiac failure in all patients.The aetiology of cardiac failure was valvular heart diseasein three, dilated cardiomyopathy in eight and ischaemic heartdisease in the remainder. Echo amplitude studies were performedwithin 24 h of endomyocardial biopsy. All but one patient wereon an immunosuppressive regime consisting of cyclosporine Aand azathioprine with additional steroids in three. The remainingpatient, who was the longest surviving patient in the studygroup, had never been treated with cyclosporine. This patientwas maintained on steroids and azathioprine alone. No patienthad clinical or histological evidence for acute cardiac rejectionand all were clinically well. Five patients had angiographicevidence of coronary artery disease. All subject studies were performed at Harefield Hospital. Echoamplitude analysis was performed at the Royal Brompton Hospital.Myocardial collagen analysis was performed in the BiochemistryUnit at the National Heart and Lung Institute. End-diastolic echo amplitude was measured in the interventricularseptum. A micro-analytical technique was used to measure themyocardial hydroxyproline/leucine ratio. There was a weak but significant correlation between the estimateof myocardial collagen measured by the hydroxyproline/leucmneratio and end-diastolic echo amplitude (r = 0.41, P = 0.04,y = 3.66x + 4.24). If the five patients with angiographicallydocumented coronary artery disease were excluded from analysisthe correlation was substantially improved (r = 0.51, P = 0.02,y=4.19x+3.89). These findings suggest that the variation in collagen in themyocardium is responsible for approximately 20% of the observedvariation in myocardial backscatter signal in non-fibrotic hearts.This supports clinical studies which have shown increases inmyocardial ultrasonic backscatter in conditions where myocardialfibrosis occurs and also indicates the importance of myocardialcollagen in determining the ultrasonic backscatter signal innormal hearts.     

11.

Impact of pulmonary regurgitation and age at surgical repair on textural and functional right ventricular myocardial properties in patients with tetralogy of Fallot.     

Giuseppe Pacileo  Giuseppe Limongelli  Marina Verrengia  Tiziana Miele  Giulia Cesare  Paolo Calabrò  Giovanni Di Salvo  Fabiana Cerrato  Roberta Ancona  Raffaele Calabrò 《Italian heart journal》2005,6(9):745-750

BACKGROUND: The aim of this study was to identify non-invasively the potential impact of pulmonary regurgitation and age at surgical repair on the right ventricular (RV) textural and functional myocardial properties in patients operated on for tetralogy of Fallot (TOF). METHODS: We assessed the average intensity (Int.(1B)) and the cyclic variation (CV(IB)) of the echocardiographic backscatter curve in 30 TOF patients (mean age 16.2 +/- 8.3 years), who had undergone corrective surgery (mean age at repair 3.2 +/- 2.6 years, range 0.2-11 years). They were divided into three age- and body surface area (BSA)-matched subgroups according to the results of the surgical repair: 12 patients had no significant postsurgical sequelae (group I), 12 patients had isolated moderate-severe pulmonary regurgitation (group II), and 6 patients had pulmonary regurgitation associated with significant (> 30 mmHg) RV outflow tract obstruction (group III). In addition, 30 age-, sex- and BSA-matched normal subjects were identified as the control group. RESULTS: In our study population, CV(IB) was lower (7.86 +/- 2.5 vs 10.6 +/- 1.4 dB, p < 0.001) and Int.IB higher (-18.6 +/- 4.1 vs -21 +/- 2.8 dB, p = 0.01) compared to the control group. Comparison between the control group and each subgroup of TOF patients showed: a) comparable values of CV(IB) and Int.(IB) in group I (10.6 +/- 1.4 vs 9.4 +/- 2.3 dB, p = 0.07; and -21 +/- 2.8 vs -21.4 +/- 2.3 dB, p = 0.7, respectively); b) Int.(IB) was significantly different only in group III (-21 +/- 2.8 vs -13.3 +/- 4.6 dB, p < 0.0001), c) CV(IB) was different either in group II or III (10.6 +/- 1.4 vs 7.42 +/- 2, p < 0.001; and 10.6 +/- 1.4 vs 5.56 +/- 1.8, p < 0.001, respectively). In addition, comparison of integrated backscatter indexes among the TOF subgroups revealed significant differences of CV(IB) between group I and II (9.4 +/- 2.4 vs 7.4 +/- 2, p = 0.03) and between group I and III (9.4 +/- 2.4 vs 5.56 +/- 1.8, p = 0.004), and of Int.(IB) between group I and III (-21.4 +/- 2.3 vs -13.3 +/- 4.66, p < 0.001) and between group II and III (-21.4 +/- 2.3 vs -18.6 +/- 2.8, p = 0.006). Group III patients, who had the most significant RV dilation, expressed as the ratio between RV and left ventricular end-diastolic diameter (0.55 +/- 0.8) compared to group II (0.67 +/- 0.11, p = 0.038) and group I (0.55 +/- 0.87, p < 0.001), showed the lowest values of CV(IB) (5.56 +/- 1.8 dB) and the highest values of Int.(IB) (-13.3 +/- 4.6 dB) Finally, in our study population, both the degree of RV dilation and the age at surgical repair significantly correlated with Int.(IB) (r = 0.49 and r = 0.4, p = 0.06 and p = 0.033, respectively) and inversely correlated with CV(IB) (r = -0.55 and r = -0.53, p = 0.002 and p = 0.003, respectively). CONCLUSIONS: In patients operated on for TOF: a) integrated backscatter analysis may identify patients with significant RV myocardial abnormalities related to postsurgical sequelae; b) residual pulmonary regurgitation, particularly if associated with pulmonary stenosis, appears to affect RV myocardial properties; c) an earlier repair of TOF may result in better preservation of myocardial characteristics.     

12.

Ultrasonic tissue characterization of human hypertrophied hearts in vivo with cardiac cycle-dependent variation in integrated backscatter   总被引：4，自引：0，他引：4  

T Masuyama  F G St Goar  T L Tye  G Oppenheim  I Schnittger  R L Popp 《Circulation》1989,80(4):925-934

Integrated ultrasonic backscatter (IB) is a noninvasive measure of the acoustic properties of myocardium. Previous experimental studies have indicated that altered acoustic properties of the myocardium are reflected by the magnitude of variation of IB during the cardiac cycle. In our study, cardiac cycle-dependent variation of IB was noninvasively measured using a quantitative IB imaging system in 12 patients with uncomplicated pressure-overload hypertrophy and 13 patients with hypertrophic cardiomyopathy. Sixteen normal subjects served as a control. The magnitude of cardiac cycle-dependent variation of IB for the posterior wall was 6.0 +/- 0.9 dB in normal subjects, 5.7 +/- 0.8 dB in the patients with uncomplicated pressure-overload hypertrophy, and 6.7 +/- 2.1 dB in the patients with hypertrophic cardiomyopathy. There were no significant differences among any of these groups. In contrast, the magnitude of cardiac cycle-dependent variation of IB for the septum was significantly smaller in the patients with uncomplicated pressure-overload hypertrophy (2.8 +/- 1.3 dB) and in the patients with hypertrophic cardiomyopathy (3.1 +/- 2.3 dB) than in normal subjects (4.9 +/- 1.0 dB). The magnitude of cardiac cycle-dependent variation of IB was smaller as the wall-thickness index increased (r = -0.53, p less than 0.01, n = 82 for all data). This IB measure also correlated with percent-systolic thickening of the myocardium (r = 0.67, p less than 0.01, n = 82). Thus, alteration in the magnitude of cardiac cycle-dependent variation of IB was observed in hypertrophic hearts and showed apparent regional myocardial differences.     

13.

Lack of prognostic value of normalized integrated backscatter analysis of myocardium in patients with thalassemia major: a long-term follow-up study     

Jambrik Z  Derchi G  Picano E  Ait-Ali L  Forni G  Bellotti P 《Echocardiography (Mount Kisco, N.Y.)》2005,22(3):239-244

BACKGROUND: Patients with beta-thalassemia major often present with severe anemia and must undergo continuous transfusion therapy, consequently developing iron overload leading to hemochromatosis. Because of these the iron deposits and/or secondary structural changes, patients develop an increase in myocardial integrated backscatter (IB). AIM: To investigate the prognostic value of analyzing acoustic quantitative properties of the myocardium in patients with beta-thalassemia major. PATIENTS AND METHODS: Between 1989 and 1990, 38 patients (mean age: 18 years, range: 7-26, 21 males) with beta-thalassemia major and without clinical signs of cardiac failure were enrolled prospectively. All patients were on chelation therapy (desferroxiamine). To obtain quantitative operator-independent measurement of the IB signal of the left ventricular septum and posterior wall, the ultrasonic radiofrequency signal integrated values were normalized to the pericardial interface and expressed in percentage (IB%). RESULTS: Follow-up was 122 +/- 36 months, during which 15 events (7 cardiac deaths and 8 heart failures) occurred. The event-free survival was comparable in patients with normal and abnormal IB%. Septal IB% was 33 +/- 14 in the 15 patients with events, and 33 +/- 12 in the 25 patients without events (P = ns). The %IB had no prognostic value in this population. A prognostic value was found in multivariate analysis for patient refusal/noncompliance of chelation therapy (P = 0.02, OR: 4.37, 95% CI: 1.72-16.9) and also body mass index (P = 0.04, OR: 1.2, 95% CI: 1.0-1.4). CONCLUSION: Analysis of end-diastolic IB% of myocardium in patients with beta-thalassemia and iron overload was not predictive of adverse cardiac events during long-term follow-up in this study.     

14.

Myocardial integrated ultrasonic backscatter in patients with dilated cardiomyopathy: prediction of response to beta-blocker therapy     

Suwa M  Ito T  Kobashi A  Yagi H  Terasaki F  Hirota Y  Kawamura K 《American heart journal》2000,139(5):905-912

BACKGROUND: Myocardial integrated backscatter (IB) imaging has been reported to be useful for ultrasonic tissue characterization and delineation of myocardial viability or fibrosis. beta-Blocker therapy has beneficial effects for patients with dilated cardiomyopathy (DCM), but there are no clear findings that indicate which patients with DCM will respond to this therapy. This study was performed to evaluate whether myocardial IB analysis can predict the response to beta-blocker therapy. METHODS AND RESULTS: We prospectively performed echocardiographic examination with IB analysis in 29 patients with DCM (20 men, 9 women) before starting bisoprolol therapy and in 15 normal subjects. Standard echocardiographic examination and IB analysis in the left ventricular wall in the 2-dimensional short-axis view were performed and the magnitude of cyclic variation (CV) of IB and calibrated myocardial IB intensity (subtracted pericardial) were obtained from the interventricular septum and the left ventricular posterior wall. Sixteen patients responded to bisoprolol therapy and 13 did not respond after 12 months of full-dose therapy. Calibrated myocardial IB intensity was lower in responders relative to nonresponders in both the interventricular septum (responders, -20.1 +/- 3.6 dB vs nonresponders, -9.8 +/- 5.1 dB, P <.0001; controls, -20.1 +/- 4.4 dB) and posterior wall (responders, -20.6 +/- 3.6 dB vs nonresponders, -14.6 +/- 4.2 dB, P =.0002; controls, -22.7 +/- 3.3 dB). Also, the lower the myocardial intensity in the interventricular septum or posterior wall, the better left ventricular systolic function improved after beta-blocker therapy. However, CV was lower in both DCM groups than in the controls, and CV in the interventricular septum was lower in nonresponders than in responders (responders, 4.0 +/- 4.1 dB vs nonresponders, -0.8 +/- 6. 1 dB, P <.02; controls, 8.3 +/- 2.4 dB). In addition, CV in the posterior wall showed no difference between the 2 DCM groups (responders, 5.6 +/- 1.3 dB vs nonresponders, 5.1 +/- 3.5 dB, P = not significant; controls, 9.6 +/- 2.5 dB). Also, the percent fibrosis on right ventricular endomyocardial biopsy specimens showed no distinctions between these 2 groups (responders, 25.1% +/- 16.1% vs nonresponders, 24.9% +/- 15.0%, P = not significant). CONCLUSIONS: These findings suggest that left ventricular myocardial IB data, especially IB intensity, provide useful information for predicting the response to beta-blocker therapy in patients with DCM. However, right ventricular endomyocardial biopsy findings do not appear to contribute to discriminating between the 2 groups.     

15.

Supplemental Oxygen During Endoscopic Variceal Ligation: Effects on Arterial Oxygenation and Cardiac Arrhythmia     

Tadashi Iwao  M.D.    Atsushi Toyonaga  M.D.    Hiroyuki Shigemori  M.D.    Michihiro Sumino  M.D.    Kazuhiko Oho  M.D.    Kyuichi Tanikawa  M.D. 《The American journal of gastroenterology》1995,90(12):2186-2190

Objectives: Endoscopic variceal ligalion may affect cardiopulmonary function. The aim of this study was to determine the effect of either nasal oxygen (2 L/min) or no oxygen on arterial oxygenation and cardiac arrhythmia during variceai ligation.
Methods: A prospective, endoscopy team-blinded, randomized, cross-over study (first session vs second session) was conducted in 30 cirrhotic patients undergoing variceal ligation. Oxygen saturation (SaO₂) and cardiac arrhythmia were assessed by a pulse oximeter. In this study, 15 patients received supplemental oxygen in the first sessions, and 15 received oxygen in the second sessions.
Results: Oxygen desaturation (nadir SaO₂ < 90%) occurred in 23% of patients breathing room air but was prevented hy oxygen ( p < 0.01), and the nadir SaO₂ was significantly lower in patients breathing room air than in those receiving oxygen (93.2 ± 0.7% vs 98.3 ± 0.3%, p < 0.01). During the procedure, premature ventricular contraction was more frequently observed in patients breathing room air than in those receiving oxygen (14.0 ± 3.2/h vs 5.4 ± 1.5/r, p < 0.05).
Conclusions: These data suggest that oxygen desaturation and cardiac arrhythmia are common in patients undergoing variceal ligation and that low flow nasal oxygen can alleviate these events. Supplemental oxygen is therefore advisable to avoid potential serious cardiopulmonary accidents in patients undergoing variceal ligalion.     

16.

Assessment of Mitoxantrone-Induced Cardiotoxicity in Patients with Multiple Sclerosis: A Tissue Doppler Echocardiographic Analysis   总被引：1，自引：0，他引：1  

Paolo Pattoneri  M.D.  Fabiola Sozzi  M.D.  Ph.D.  †  Giovanna Pelà  Ph.D.  †  Enrico Montanari  M.D.  ‡  Paolo Moruzzi  M.D.  §  Alberico Borghetti  M.D.  §  Maria Domenica Cappellini  M.D.  ¶ 《Echocardiography (Mount Kisco, N.Y.)》2009,26(4):397-402

Aim: Tissue Doppler echocardiography was investigated for its applicability in detecting subtle myocardial involvement in multiple sclerosis patients receiving a low dose of mitoxantrone. Methods and Results: Twenty Caucasian patients with multiple sclerosis (mean age 43.9 ± 9.3 years, 12 males and 8 females) treated with mitoxantrone (mean cumulative dose 35.4 ± 21.6 mg/m²), were compared to 20 healthy subjects (mean age 45.4 ± 15.3 years, 11 males and 9 females) matched for age and gender. All subjects underwent conventional and Tissue Doppler echocardiography. Patients with heart failure, life-threatening arrhythmias, and other prominent manifestations of heart disease were excluded. No differences were observed in blood pressure, heart rate, and conventional systolic and diastolic echocardiographic parameters. At Tissue Doppler echocardiography, patients with multiple sclerosis showed differences of the systolic mechanic expressed by a significant lower S-wave peak velocity at the lateral site of mitral annulus (11.4 ± 2.5 cm/sec vs. 15.0 ± 4.1 cm/sec, P < 0.02). Such S-wave peak velocity significantly correlated with a cumulative dose of mitoxantrone (r =−0.37, P < 0.05). Conclusion: Tissue Doppler echocardiography suggests an early involvement of the systolic myocardial function at the low dose of mitoxantrone. Therefore, Tissue Doppler echocardiography may be used as a noninvasive method for monitoring subclinical cardiotoxicity in multiple sclerosis patients receiving mitoxantrone.     

17.

Quantitative ultrasonic tissue characterization with real-time integrated backscatter imaging in normal human subjects and in patients with dilated cardiomyopathy   总被引：5，自引：0，他引：5  

Z Vered  B Barzilai  G A Mohr  L J Thomas  R Genton  B E Sobel  T A Shoup  H E Melton  J G Miller  J E Pérez 《Circulation》1987,76(5):1067-1073

We have shown previously that the physical properties of myocardium in dogs can be characterized with quantitative ultrasonic integrated backscatter and that interrogation of the tissue with ultrasound can delineate cardiac cycle-dependent changes in ultrasonic backscatter in normal tissue that disappear with ischemia and reappear with reperfusion if functional integrity is restorable. To determine whether this approach can be applied to man, we implemented an automatic gain compensation and continuous data acquisition system to characterize myocardium with quantitative ultrasonic backscatter and to detect cardiac cycle-dependent changes in real time. We developed a two-dimensional echocardiographic system with quantitative integrated backscatter imaging capabilities for use in human subjects that can automatically differentiate ultrasonic signals from blood as opposed to those obtained from tissue and adjust the slope of the gain compensation appropriately. Real-time images were formed from a continuous signal proportional to the logarithm of the integrated backscatter along each A-line. In our initial investigation, 15 normal volunteers (ages 17 to 40 years, heart rates 44 to 88 beats/min) and five patients with dilated cardiomyopathy (ages 22 to 52, heart rates 82 to 120 beats/min) were studied with conventional parasternal long-axis echocardiographic views. Diastolic-to-systolic variation of integrated backscatter in the interventricular septum and left ventricular posterior wall was seen in each of the normal subjects averaging 4.6 +/- 1.4 dB (SD) and 5.3 +/- 1.5 dB (n = 127 sites), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

18.

Echocardiography with angiotensin administration in the diagnosis of adriamycin-induced cardiomyopathy     

N G?ldel  G Autenrieth  K Werdan  P Knesewitsch  W Wilmanns 《Zeitschrift für Kardiologie》1989,78(5):320-327

Noninvasive assessment of early cardiotoxicity of doxorubicin is still a problem of clinical concern. We studied whether echocardiography during afterload stress induced by angiotensin II (1,000-3,000 ng/min) allows earlier detection of left ventricular impairment than echo at rest. We compared 30 normals (N) to 30 patients with carcinoma, who had received doxorubicin at a cumulative dose of at least 360 mg/sqm. At rest echocardiograms of patients were either normal (P1; n = 24) or abnormal (P2; n = 6; fractional shortening less than 28%, distance of mitral E-point to septum greater than 7 mm). Best parameter for separation of P1 vs N was the slope K of the regression line of the relation between endsystolic diameter and systolic blood pressure (cuff-method). 38% of P1 and 100% of P2 had K-values below the range of N (less than 4.7 mm Hg/mm). Four of five patients with reduced ejection fraction assessed by scintigraphy (less than 55%) after continued therapy with doxorubicin have had, in previous echocardiographic studies, normal resting parameters but abnormal K-values. We conclude that afterload-stress increases the sensitivity of echocardiography in detecting cardiotoxicity due to doxorubicin.     

19.

Defibrillation Energy Requirements Differ Between Anesthetic Agents     

MICHELE WANG  M.Sc.  PAUL DORIAN  M.D.  M.Sc. 《Journal of cardiovascular electrophysiology》1989,3(2):86-94

We examined the effect of anesthesia on the energy requirements for internal defibrillation (DF) in dogs anesthetized with pentobarbital (30 mg/kg IV followed by 2–3 mg/kg/hr constant infusion) (n = 20), fentanyl (25 μg/kg/hour) (n = 25), and enflurane (0.5%–1.5%) (n = 8). Multiple shocks of varying energies were applied through left and right ventricular epicardial patch electrodes to relate delivered energy to percent success in DF. The energies required for 50% success (E₅₀) and 80% success (E₈₀) in DF were estimated using logistic regression. E₅₀ in fentanyl anesthetized animals (3.8 ± 2.3 J) was significantly lower than in those given pentobarbital (6.9 ± 3.0 J) (P < 0.01), and lawer than those given enflurane (5.7 ± 2.8 J) (NS). E₈₀ with fentanyl (6.5 ± 4.0 J) was also lower than that of pentobarbital (10.4 ± 4.9 J) (P < 0.01) and enflurane (7.6 ± 4.3 J) (NS) animals. lawer defibrillation energy requirements (DER) with fentanyl anesthesia, when compared with pentobarbital, were associated with significantly longer ventricular effective refractory periods (VERP) (171 ± 20 versus 142 ± 15 msec: P < 0.01), lower mean arterial pressures (114 ± 20 vs 136 ± 25 mmHg: P < 0.01), and Iower heart rates (90 ± 37 versus 164 ± 19 b/m; P < 0.01).
Anesthetic agents may modify DER; their effects need to be taken into account in the assessment of DER in patients receiving implanted defibrillators and in the evaluation of the results of defibrillation research in anesthetized animals.     

20.

Ultrasonic backscatter and collagen in normal ventricular myocardium   总被引：12，自引：0，他引：12  

R M Hoyt  D J Skorton  S M Collins  H E Melton 《Circulation》1984,69(4):775-782

Integrated ultrasonic backscatter has been related to collagen deposition in fibrotic myocardium. The purpose of our study was to measure the integrated ultrasonic backscatter in the right and left ventricles of 10 normal freshly excised canine hearts and five normal formalin-fixed human hearts. A 2.25 MHz, 50% fractional bandwidth transducer was positioned at the transducer focal distance from the epicardium. The radio frequency backscatter signal, excluding specular reflections, was digitized, squared, and integrated to yield the integrated ultrasonic backscatter (in decibels down from a 100% reflector). The segment of myocardium corresponding to the integrated ultrasonic backscatter sample volume was excised and assayed for hydroxyproline, a marker for collagen. A second purpose of our study was to evaluate the influence of fixation with formalin on the backscatter. Regional integrated ultrasonic backscatter was therefore measured in 10 freshly excised canine left ventricles, which were fixed in 10% formalin for 2 weeks. Integrated ultrasonic backscatter measurements were then repeated. In freshly excised canine hearts, the integrated ultrasonic backscatter from right ventricle was higher than that from left ventricle (-60.4 +/- 1.6 [SEM] vs -66.9 +/- 1.0 dB; p less than .001). The collagen content of right ventricle was also higher than that of left ventricle (4.40 +/- 0.26 [SEM] vs 3.58 +/- 0.13 micrograms/mg dry weight; p less than .005). Similar results were obtained in human hearts. There were no correlations between integrated ultrasonic backscatter and collagen content (r = .28 and .32 for dogs and humans, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)     

Normal Values in Children for Myocardial Ultrasonic Tissue Characterization by Integrated Backscatter

Normal values in adults for ultrasonic tissue characterization by integrated backscatter have been reported previously and subsequently applied to patients with specific diseases. Factors influencing integrated backscatter values in a pediatric population are not clearly defined. To obtain normal values for myocardial ultrasonic integrated backscatter in a pediatric population, we studied 72 children with normal cardiac anatomy using an ultrasonic integrated backscatter imaging system. The parameters measured were at peak, nadir, and end-diastole in eight different regions with two different settings: fixed and variable. We subsequently calculated cyclic variation, the ratios of cyclic variation to end-diastole and to peak. Age ranged from 1 day to 17.4 years (median 4.4 years). More than 90% of data curves from the two regions in the left ventricular posterior wall in long-axis view had normal patterns, whereas more than 50% of curves for the other regions had abnormal patterns. Comparing the two posterior wall positions, there were no differences in cyclic variation between the two regions, with little effect of setting. Less effect of regions and settings was noted for the ratios of cyclic variation to end-diastole or peak. There was no relation between backscatter variables and age, gender, or height, and some variables correlated weakly with body surface area. The assessment of integrated backscatter in children is optimal with interrogation of the left ventricular posterior wall imaged in the long-axis view. More stable estimates are obtained when the cyclic variation is related to the peak or end-diastolic value.     

Ten-Year Echo/Doppler Determination of the Benefits of Aerobic Exercise after the Age of 65 Years

As the human lifespan becomes progressively extended, potential health-related effects of intense aerobic exercise after age 65 need evaluation. This study evaluates the cardiovascular (CV), pulmonary, and metabolic effects of competitive distance running on age-related deterioration in men between 69 (±3) and 77 (±2) years (mean ± SD). Twelve elderly competitive distance runners (ER) underwent oxygen consumption and echo/Doppler treadmill stress testing (Balke protocol) for up to 10 years. Twelve age-matched sedentary controls (SC) with no history of CV disease were similarly tested and the results compared for the initial three series of the study. CV data clearly separated the ER from SC. At entry, resting and maximal heart rate, systolic/diastolic blood pressure, peak oxygen consumption (VO_2max), and E/A ratio of mitral inflow were better in the ER (P < 0.05 vs. SC). With aging, ER had a less deterioration of multiple health parameters. Exceptions were VO_2max and left ventricular diastolic function (E/A, AFF, IVRT) that decreased (P < 0.05, Year 10 vs. Year 1). Health advantages of high-level aerobic exercise were demonstrated in the ER when compared to SC. Importantly, data collected in ER over 10 years confirm the benefit of intensive exercise for slowing several negative effects of aging. However, the normative drop of exercise capacity in the seventh and eighth decades reduces the potential athleticism plays in prevention of CV events. (Echocardiography 2010;27:5-10)     

Hemodynamic Predictors of Atherosclerosis in the Thoracic Aorta

We sought to identify atherosclerotic plaques and measured flow parameters in the descending aorta (DA) of 83 consecutive patients (40 years and older) studied with transesophageal echocardiography. Patients with atherosclerotic plaques in the DA were older (68 ± 10 vs 58 ± 12 years [P = 0.0001]), had a higher proportion of spontaneous echo contrast in the DA (15/46 [33%] vs 3 of 37 [8%] P = 0.02), had larger aortic diameters (2.52 ± 0.35 vs 2.37 ± 0.36 cm [P = 0.06]), had a lower maximal velocity in the DA (54.2 ± 21.5 vs 73.8 ± 33.0 cm/sec [P = 0.02]), and had a lower calculated maximal shear rate (SR) (88.0 ± 37.6 vs 129.0 ± 67.0 sec⁻¹ [P = 0.002]). There was no significant difference between groups with respect to sex, hypertension, diabetes, total cholesterol, and smoking. In multivariate analysis only age (P = 0.002) and maximal SR (P = 0.03) were identified as independent predictors of atherosclerosis in the DA. We conclude that low SR is associated with aortic atherosclerosis.     

背向散射技术与彩色室壁运动技术在高血压左室重构中的应用

目的 探讨背向散射和彩色室壁运动参数评估原发性高血压不同左室构型心肌病变程度和局部室壁运动的临床价值。方法 测定70例原发性高血压病患者和31例正常对照者室间隔及左室后壁的背向散射参数和局部室壁收缩期位移。共收入正常构型组18例，向心重构组17例，向心肥厚组23例，离心肥厚组12例。结果 高血压各组室间隔超声背向散射(IB％)均不同程度地增大，以向心性肥厚组和离心性肥厚组为著；左室后壁IB％在向心性肥厚组和离心性肥厚组增高，以离心性肥厚组为著；室间隔周期变化幅度(cvlB)在向心性肥厚组和离心性肥厚组减低；左室后壁的CVIB在离心性肥厚组显著减低；高血压各组均未出现明显的背向散射跨壁梯度的改变。室间隔和左室后壁的SEM在离心性肥厚组显著减低，其余各组间虽无明显统计学差异，但在向心性肥厚组呈现增加的趋势。在离心性肥厚组，收缩期CK色带变薄或消失，色带不完整。结论 心肌超声背向散射参数可用于判断高血压不同左室构型心肌病变的程度；彩色室壁运动技术可用于评估高血压不同左室构型局部室壁运动状态。     

Assessment of the relationship between functional capacity and right ventricular ultrasound tissue characterization by integrated backscatter in patients with isolated mitral stenosis

AIM: The aim of the present study was to investigate right ventricular (RV) myocardial textural properties in asymptomatic and symptomatic mitral stenosis (MS) patients with normal RV systolic function using integrated backscatter (IBS). METHODS: The study included 40 patients with MS of moderate or severe degree. Patients were classified into 2 groups according to NYHA class (asymptomatic group, NYHA class I, symptomatic group, NYHA class II-III). RV pulsed-wave tissue Doppler imaging (TDI) and IBS analyses were performed in all patients. Isovolumic contraction time (IVCT), systolic wave velocity (S), isovolumic relaxation time (IVRT), early diastolic wave velocity (E), and late diastolic wave velocity (A) were measured by TDI. IBS amplitude (IB) and cyclic variation (CV) of the RV lateral wall in the parasternal long-axis view were measured by IBS. CV was calculated by subtracting systolic IB from diastolic IB. RESULTS: IVRT (54.2 +/- 11.9 ms versus 86.2 +/- 16.2 ms, P < 0.001) and A wave amplitude (10.2 +/- 2.1 cm/s versus 13.6 +/- 1.8 cm/s, P < 0.05) were higher whereas E wave amplitude (11.7 +/- 1.6 cm/s and 10.3 +/- 1.5 cm/s, P < 0.05) and E/A ratio (1.3 +/- 0.3 versus 0.7 +/- 0.1, P < 0.001) were lower in group 2. Symptomatic patients had a lower CV value of RV (9.5 +/- 3.4 dB versus 6.7 +/- 1.9 dB, P = 0.004). There was a positive correlation between CV and E/A (r = 0.964, P < 0.001) CONCLUSION: Symptomatic isolated MS patients had RV echo texture changes and diastolic dysfunction in comparison to asymptomatic ones with similar mitral valve areas in the presence of normal RV systolic function. In isolated MS, both pulsed-wave TDI and IBS may aid in the detection of RV diastolic pathology.     

Quantitative Texture Analysis in Two-Dimensional Echocardiography

Background: Myocardial reflectivity is abnormally increased in patients with thalassemia major under transfusion treatment, probably due to myocardial iron deposits and / or secondary structural changes. Such increased reflectivity has been detected by both qualitative and subjective analysis of two-dimensional echocardiographic (2-D echo) images and quantitative assessment of integrated backscatter amplitude with noncommercially available ultrasound prototypes. The purpose of this study was to assess the acoustic properties of myocardium in patients with beta-thalassemia major and iron overload by means of quantitative computerized offline textural analysis of conventionally recorded 2-D echo images, and to compare textural data with other qualitative (visual assessment) and quantitative (ultrasound backscatter analysis) approaches for myocardial ultrasound tissue characterization simultaneously applied to these patients. Methods and Results: Thirty-five young patients with thalassemia major, without clinical signs of cardiac failure, and 20 age and sex matched normal controls were studied by echocardiography. Each patient was receiving blood transfusion every 2-3 weeks. Two-dimensional echo images, obtained with a commercially available echocardiograph using the parasternal long-axis view, were digitized offline and analyzed by first and second order texture algorithms applied to regions of interest in the myocardium (septal and posterior wall). The mean gray level value was higher in thalassemic patients than in controls on both the septum (110 ± 25 vs 57 ± 13, arbitrary units on a 0-255 scale; P > 0.01) and posterior wall (91 ± 25 vs 67 ± 18; P > 0.01). Among second order statistical parameters, contrast and angular second moment significantly (P > 0.01) differentiated septal and posterior walls of patients and controls. In thalassemic patients, no consistent correlation was found between wall texture parameters and hematologic (years of transfusions and chelation, number of transfusions), 2-D echo (posterior wall thickness, left ventricular end-diastolic diameter), and Doppler (transmitral E/A waves ratio) parameters. Myocardial walls with visually assessed increased echo reflectivity showed a trend toward higher values of mean gray level when compared with myocardial segments with qualitatively assessed normal reflectivity (septum: 121 ± 26 vs 106 ± 24; posterior wall: 105 ± 23 vs 87 ± 23). Although radiofrequency integrated backscatter has been demonstrated to be capable of identifying thalassemic patients, no significant correlation was found between mean gray level (by texture analysis) and radiofrequency data (septum: r = 0.03; posterior wall: r = 0.09; P = NS for both). Conclusions: Myocardial walls affected by hemochromatosis show ultrasound image texture alterations that may be quantified with digital image analysis techniques and appear mostly unrelated to hematologic and conventional, as well as radiofrequency-based, echocardiographic parameters. These changes in quantitatively evaluated echo reflectivity are present even before the development of clinical and echocardiographic signs of cardiac dysfunction.     

Ultrasonic tissue characterization of normal and ischemic myocardium

Cardiac ultrasonic tissue characterization is designed to use the alterations in acoustic signals from the myocardium to differentiate normal from ischemic or infarcted tissue due to their characteristic backscatter attenuation. Various approaches such as use of a gray scale, color display, or quantitative image analysis have been used for tissue characterization, but all depend on subjective assessments and are not necessarily reproducible. The most promising method has been the use of "raw" radiofrequency signals and measure changes in the ultrasonic attenuation with an index of backscatter to distinguish normal from abnormal myocardium called "integrated backscatter" (IB). Various studies have demonstrated the changes in the ultrasonic backscatter with ischemia or infarction. In this review we summarize our experience with a research prototype instrument in tissue characterization and differentiation of normal, ischemic, infarcted, and post ischemic reperfused myocardium in anesthetized open chest dogs. Currently we are investigating the role of ultrasonic tissue characterization to estimate infarct size and plan to apply these observations to patients in order to detect viable myocardium and quantitate infarct size.     

Noninvasive quantitative tissue characterization and two-dimensional color-coded map of human atherosclerotic lesions using ultrasound integrated backscatter: comparison between histology and integrated backscatter images

OBJECTIVES: The purpose of the present study was to define clinicopathologically whether integrated backscatter (IB) combined with conventional two-dimensional echo (2DE) can differentiate the tissue characteristics of calcification (CL), fibrosis (FI), lipid pool (LP) with fibrous cap, intimal hyperplasia (IH) and thrombus (TH) and can construct two-dimensional tissue plaque structure in vivo. BACKGROUND: It is difficult to characterize the components of plaque using conventional 2DE techniques. METHODS: Integrated backscatter values of plaques were measured in the right common carotid and femoral arteries (total 24 segments) both during life and after autopsy in 12 patients (age 68 to 84 years, 10 men and two women). Integrated backscatter values were determined using a 5-12 MHz multifrequency transducer, setting the region of interests (ROIs) (11 x 11 pixels) on the echo tomography of the entire arterial wall (55 +/- 10 ROI/segment) and comparing it with histologic features in the autopsied arterial specimens. RESULTS: Corrected IB values obtained before death and at autopsy were significantly correlated (r = 0.93, p < 0.01). Corresponding to the histologic features, corrected IB values on the rectangle ROIs obtained during life were divided into five categories: category 1 (TH) 4 < IB < or = 6; category 2 (media and IH or LP in the intima) 7 < IB < or = 13; category 3 (FI) 13 < IB < or = 18, category 4 (mixed lesion) 18 < IB < or = 27 and category 5 (CL) 28 < IB < or = 33. In category 2, media and intima were differentiated using conventional 2DE. Under the above procedures, color-coded maps constructed with IB-2DE obtained during life precisely reflected the histologic features of media and intima. CONCLUSIONS: Integrated backscatter with 2DE represents a useful noninvasive tool for evaluating the tissue structure of human plaque.     

Relationship between myocardial collagen and echo amplitude in non-fibrotic hearts

The aim of the study was to investigate the relationship betweenmyocardial collagen and regional echo amplitude in humans withnon-fibrotic myocardium. The ratio of myocardial collagen to total myocardial proteinwas determined as the hydroxyproline/leucine ratio in endoniyocardialbiopsies obtained from the right ventricular side of the interventricularseptum in orthotopically transplanted hearts. Regional echoamplitude was measured in the interventricular septum. Patientswere studied prospectively. Twenty-five patients (five female, 20 male) who had undergoneorthotopic cardiac transplantation were studied 355 to 2939days (1009±718, mean±SD) post-transplantationat the time of annual cardiac catheterization and endomyocardialbiopsy. Patient ages varied from 22 to 62 years (46±11).Donor ages were 14 to 47 years (25±8) and the ischaemictime, 90 to 245 min (151±42). Cardiac transplantationwas performed for end-stage cardiac failure in all patients.The aetiology of cardiac failure was valvular heart diseasein three, dilated cardiomyopathy in eight and ischaemic heartdisease in the remainder. Echo amplitude studies were performedwithin 24 h of endomyocardial biopsy. All but one patient wereon an immunosuppressive regime consisting of cyclosporine Aand azathioprine with additional steroids in three. The remainingpatient, who was the longest surviving patient in the studygroup, had never been treated with cyclosporine. This patientwas maintained on steroids and azathioprine alone. No patienthad clinical or histological evidence for acute cardiac rejectionand all were clinically well. Five patients had angiographicevidence of coronary artery disease. All subject studies were performed at Harefield Hospital. Echoamplitude analysis was performed at the Royal Brompton Hospital.Myocardial collagen analysis was performed in the BiochemistryUnit at the National Heart and Lung Institute. End-diastolic echo amplitude was measured in the interventricularseptum. A micro-analytical technique was used to measure themyocardial hydroxyproline/leucine ratio. There was a weak but significant correlation between the estimateof myocardial collagen measured by the hydroxyproline/leucmneratio and end-diastolic echo amplitude (r = 0.41, P = 0.04,y = 3.66x + 4.24). If the five patients with angiographicallydocumented coronary artery disease were excluded from analysisthe correlation was substantially improved (r = 0.51, P = 0.02,y=4.19x+3.89). These findings suggest that the variation in collagen in themyocardium is responsible for approximately 20% of the observedvariation in myocardial backscatter signal in non-fibrotic hearts.This supports clinical studies which have shown increases inmyocardial ultrasonic backscatter in conditions where myocardialfibrosis occurs and also indicates the importance of myocardialcollagen in determining the ultrasonic backscatter signal innormal hearts.     

Impact of pulmonary regurgitation and age at surgical repair on textural and functional right ventricular myocardial properties in patients with tetralogy of Fallot.

BACKGROUND: The aim of this study was to identify non-invasively the potential impact of pulmonary regurgitation and age at surgical repair on the right ventricular (RV) textural and functional myocardial properties in patients operated on for tetralogy of Fallot (TOF). METHODS: We assessed the average intensity (Int.(1B)) and the cyclic variation (CV(IB)) of the echocardiographic backscatter curve in 30 TOF patients (mean age 16.2 +/- 8.3 years), who had undergone corrective surgery (mean age at repair 3.2 +/- 2.6 years, range 0.2-11 years). They were divided into three age- and body surface area (BSA)-matched subgroups according to the results of the surgical repair: 12 patients had no significant postsurgical sequelae (group I), 12 patients had isolated moderate-severe pulmonary regurgitation (group II), and 6 patients had pulmonary regurgitation associated with significant (> 30 mmHg) RV outflow tract obstruction (group III). In addition, 30 age-, sex- and BSA-matched normal subjects were identified as the control group. RESULTS: In our study population, CV(IB) was lower (7.86 +/- 2.5 vs 10.6 +/- 1.4 dB, p < 0.001) and Int.IB higher (-18.6 +/- 4.1 vs -21 +/- 2.8 dB, p = 0.01) compared to the control group. Comparison between the control group and each subgroup of TOF patients showed: a) comparable values of CV(IB) and Int.(IB) in group I (10.6 +/- 1.4 vs 9.4 +/- 2.3 dB, p = 0.07; and -21 +/- 2.8 vs -21.4 +/- 2.3 dB, p = 0.7, respectively); b) Int.(IB) was significantly different only in group III (-21 +/- 2.8 vs -13.3 +/- 4.6 dB, p < 0.0001), c) CV(IB) was different either in group II or III (10.6 +/- 1.4 vs 7.42 +/- 2, p < 0.001; and 10.6 +/- 1.4 vs 5.56 +/- 1.8, p < 0.001, respectively). In addition, comparison of integrated backscatter indexes among the TOF subgroups revealed significant differences of CV(IB) between group I and II (9.4 +/- 2.4 vs 7.4 +/- 2, p = 0.03) and between group I and III (9.4 +/- 2.4 vs 5.56 +/- 1.8, p = 0.004), and of Int.(IB) between group I and III (-21.4 +/- 2.3 vs -13.3 +/- 4.66, p < 0.001) and between group II and III (-21.4 +/- 2.3 vs -18.6 +/- 2.8, p = 0.006). Group III patients, who had the most significant RV dilation, expressed as the ratio between RV and left ventricular end-diastolic diameter (0.55 +/- 0.8) compared to group II (0.67 +/- 0.11, p = 0.038) and group I (0.55 +/- 0.87, p < 0.001), showed the lowest values of CV(IB) (5.56 +/- 1.8 dB) and the highest values of Int.(IB) (-13.3 +/- 4.6 dB) Finally, in our study population, both the degree of RV dilation and the age at surgical repair significantly correlated with Int.(IB) (r = 0.49 and r = 0.4, p = 0.06 and p = 0.033, respectively) and inversely correlated with CV(IB) (r = -0.55 and r = -0.53, p = 0.002 and p = 0.003, respectively). CONCLUSIONS: In patients operated on for TOF: a) integrated backscatter analysis may identify patients with significant RV myocardial abnormalities related to postsurgical sequelae; b) residual pulmonary regurgitation, particularly if associated with pulmonary stenosis, appears to affect RV myocardial properties; c) an earlier repair of TOF may result in better preservation of myocardial characteristics.     

Ultrasonic tissue characterization of human hypertrophied hearts in vivo with cardiac cycle-dependent variation in integrated backscatter

Integrated ultrasonic backscatter (IB) is a noninvasive measure of the acoustic properties of myocardium. Previous experimental studies have indicated that altered acoustic properties of the myocardium are reflected by the magnitude of variation of IB during the cardiac cycle. In our study, cardiac cycle-dependent variation of IB was noninvasively measured using a quantitative IB imaging system in 12 patients with uncomplicated pressure-overload hypertrophy and 13 patients with hypertrophic cardiomyopathy. Sixteen normal subjects served as a control. The magnitude of cardiac cycle-dependent variation of IB for the posterior wall was 6.0 +/- 0.9 dB in normal subjects, 5.7 +/- 0.8 dB in the patients with uncomplicated pressure-overload hypertrophy, and 6.7 +/- 2.1 dB in the patients with hypertrophic cardiomyopathy. There were no significant differences among any of these groups. In contrast, the magnitude of cardiac cycle-dependent variation of IB for the septum was significantly smaller in the patients with uncomplicated pressure-overload hypertrophy (2.8 +/- 1.3 dB) and in the patients with hypertrophic cardiomyopathy (3.1 +/- 2.3 dB) than in normal subjects (4.9 +/- 1.0 dB). The magnitude of cardiac cycle-dependent variation of IB was smaller as the wall-thickness index increased (r = -0.53, p less than 0.01, n = 82 for all data). This IB measure also correlated with percent-systolic thickening of the myocardium (r = 0.67, p less than 0.01, n = 82). Thus, alteration in the magnitude of cardiac cycle-dependent variation of IB was observed in hypertrophic hearts and showed apparent regional myocardial differences.     

Lack of prognostic value of normalized integrated backscatter analysis of myocardium in patients with thalassemia major: a long-term follow-up study

BACKGROUND: Patients with beta-thalassemia major often present with severe anemia and must undergo continuous transfusion therapy, consequently developing iron overload leading to hemochromatosis. Because of these the iron deposits and/or secondary structural changes, patients develop an increase in myocardial integrated backscatter (IB). AIM: To investigate the prognostic value of analyzing acoustic quantitative properties of the myocardium in patients with beta-thalassemia major. PATIENTS AND METHODS: Between 1989 and 1990, 38 patients (mean age: 18 years, range: 7-26, 21 males) with beta-thalassemia major and without clinical signs of cardiac failure were enrolled prospectively. All patients were on chelation therapy (desferroxiamine). To obtain quantitative operator-independent measurement of the IB signal of the left ventricular septum and posterior wall, the ultrasonic radiofrequency signal integrated values were normalized to the pericardial interface and expressed in percentage (IB%). RESULTS: Follow-up was 122 +/- 36 months, during which 15 events (7 cardiac deaths and 8 heart failures) occurred. The event-free survival was comparable in patients with normal and abnormal IB%. Septal IB% was 33 +/- 14 in the 15 patients with events, and 33 +/- 12 in the 25 patients without events (P = ns). The %IB had no prognostic value in this population. A prognostic value was found in multivariate analysis for patient refusal/noncompliance of chelation therapy (P = 0.02, OR: 4.37, 95% CI: 1.72-16.9) and also body mass index (P = 0.04, OR: 1.2, 95% CI: 1.0-1.4). CONCLUSION: Analysis of end-diastolic IB% of myocardium in patients with beta-thalassemia and iron overload was not predictive of adverse cardiac events during long-term follow-up in this study.     

Myocardial integrated ultrasonic backscatter in patients with dilated cardiomyopathy: prediction of response to beta-blocker therapy

BACKGROUND: Myocardial integrated backscatter (IB) imaging has been reported to be useful for ultrasonic tissue characterization and delineation of myocardial viability or fibrosis. beta-Blocker therapy has beneficial effects for patients with dilated cardiomyopathy (DCM), but there are no clear findings that indicate which patients with DCM will respond to this therapy. This study was performed to evaluate whether myocardial IB analysis can predict the response to beta-blocker therapy. METHODS AND RESULTS: We prospectively performed echocardiographic examination with IB analysis in 29 patients with DCM (20 men, 9 women) before starting bisoprolol therapy and in 15 normal subjects. Standard echocardiographic examination and IB analysis in the left ventricular wall in the 2-dimensional short-axis view were performed and the magnitude of cyclic variation (CV) of IB and calibrated myocardial IB intensity (subtracted pericardial) were obtained from the interventricular septum and the left ventricular posterior wall. Sixteen patients responded to bisoprolol therapy and 13 did not respond after 12 months of full-dose therapy. Calibrated myocardial IB intensity was lower in responders relative to nonresponders in both the interventricular septum (responders, -20.1 +/- 3.6 dB vs nonresponders, -9.8 +/- 5.1 dB, P <.0001; controls, -20.1 +/- 4.4 dB) and posterior wall (responders, -20.6 +/- 3.6 dB vs nonresponders, -14.6 +/- 4.2 dB, P =.0002; controls, -22.7 +/- 3.3 dB). Also, the lower the myocardial intensity in the interventricular septum or posterior wall, the better left ventricular systolic function improved after beta-blocker therapy. However, CV was lower in both DCM groups than in the controls, and CV in the interventricular septum was lower in nonresponders than in responders (responders, 4.0 +/- 4.1 dB vs nonresponders, -0.8 +/- 6. 1 dB, P <.02; controls, 8.3 +/- 2.4 dB). In addition, CV in the posterior wall showed no difference between the 2 DCM groups (responders, 5.6 +/- 1.3 dB vs nonresponders, 5.1 +/- 3.5 dB, P = not significant; controls, 9.6 +/- 2.5 dB). Also, the percent fibrosis on right ventricular endomyocardial biopsy specimens showed no distinctions between these 2 groups (responders, 25.1% +/- 16.1% vs nonresponders, 24.9% +/- 15.0%, P = not significant). CONCLUSIONS: These findings suggest that left ventricular myocardial IB data, especially IB intensity, provide useful information for predicting the response to beta-blocker therapy in patients with DCM. However, right ventricular endomyocardial biopsy findings do not appear to contribute to discriminating between the 2 groups.     

Supplemental Oxygen During Endoscopic Variceal Ligation: Effects on Arterial Oxygenation and Cardiac Arrhythmia

Objectives: Endoscopic variceal ligalion may affect cardiopulmonary function. The aim of this study was to determine the effect of either nasal oxygen (2 L/min) or no oxygen on arterial oxygenation and cardiac arrhythmia during variceai ligation.
Methods: A prospective, endoscopy team-blinded, randomized, cross-over study (first session vs second session) was conducted in 30 cirrhotic patients undergoing variceal ligation. Oxygen saturation (SaO₂) and cardiac arrhythmia were assessed by a pulse oximeter. In this study, 15 patients received supplemental oxygen in the first sessions, and 15 received oxygen in the second sessions.
Results: Oxygen desaturation (nadir SaO₂ < 90%) occurred in 23% of patients breathing room air but was prevented hy oxygen ( p < 0.01), and the nadir SaO₂ was significantly lower in patients breathing room air than in those receiving oxygen (93.2 ± 0.7% vs 98.3 ± 0.3%, p < 0.01). During the procedure, premature ventricular contraction was more frequently observed in patients breathing room air than in those receiving oxygen (14.0 ± 3.2/h vs 5.4 ± 1.5/r, p < 0.05).
Conclusions: These data suggest that oxygen desaturation and cardiac arrhythmia are common in patients undergoing variceal ligation and that low flow nasal oxygen can alleviate these events. Supplemental oxygen is therefore advisable to avoid potential serious cardiopulmonary accidents in patients undergoing variceal ligalion.     

Assessment of Mitoxantrone-Induced Cardiotoxicity in Patients with Multiple Sclerosis: A Tissue Doppler Echocardiographic Analysis

Aim: Tissue Doppler echocardiography was investigated for its applicability in detecting subtle myocardial involvement in multiple sclerosis patients receiving a low dose of mitoxantrone. Methods and Results: Twenty Caucasian patients with multiple sclerosis (mean age 43.9 ± 9.3 years, 12 males and 8 females) treated with mitoxantrone (mean cumulative dose 35.4 ± 21.6 mg/m²), were compared to 20 healthy subjects (mean age 45.4 ± 15.3 years, 11 males and 9 females) matched for age and gender. All subjects underwent conventional and Tissue Doppler echocardiography. Patients with heart failure, life-threatening arrhythmias, and other prominent manifestations of heart disease were excluded. No differences were observed in blood pressure, heart rate, and conventional systolic and diastolic echocardiographic parameters. At Tissue Doppler echocardiography, patients with multiple sclerosis showed differences of the systolic mechanic expressed by a significant lower S-wave peak velocity at the lateral site of mitral annulus (11.4 ± 2.5 cm/sec vs. 15.0 ± 4.1 cm/sec, P < 0.02). Such S-wave peak velocity significantly correlated with a cumulative dose of mitoxantrone (r =−0.37, P < 0.05). Conclusion: Tissue Doppler echocardiography suggests an early involvement of the systolic myocardial function at the low dose of mitoxantrone. Therefore, Tissue Doppler echocardiography may be used as a noninvasive method for monitoring subclinical cardiotoxicity in multiple sclerosis patients receiving mitoxantrone.     

Quantitative ultrasonic tissue characterization with real-time integrated backscatter imaging in normal human subjects and in patients with dilated cardiomyopathy

We have shown previously that the physical properties of myocardium in dogs can be characterized with quantitative ultrasonic integrated backscatter and that interrogation of the tissue with ultrasound can delineate cardiac cycle-dependent changes in ultrasonic backscatter in normal tissue that disappear with ischemia and reappear with reperfusion if functional integrity is restorable. To determine whether this approach can be applied to man, we implemented an automatic gain compensation and continuous data acquisition system to characterize myocardium with quantitative ultrasonic backscatter and to detect cardiac cycle-dependent changes in real time. We developed a two-dimensional echocardiographic system with quantitative integrated backscatter imaging capabilities for use in human subjects that can automatically differentiate ultrasonic signals from blood as opposed to those obtained from tissue and adjust the slope of the gain compensation appropriately. Real-time images were formed from a continuous signal proportional to the logarithm of the integrated backscatter along each A-line. In our initial investigation, 15 normal volunteers (ages 17 to 40 years, heart rates 44 to 88 beats/min) and five patients with dilated cardiomyopathy (ages 22 to 52, heart rates 82 to 120 beats/min) were studied with conventional parasternal long-axis echocardiographic views. Diastolic-to-systolic variation of integrated backscatter in the interventricular septum and left ventricular posterior wall was seen in each of the normal subjects averaging 4.6 +/- 1.4 dB (SD) and 5.3 +/- 1.5 dB (n = 127 sites), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Echocardiography with angiotensin administration in the diagnosis of adriamycin-induced cardiomyopathy

Noninvasive assessment of early cardiotoxicity of doxorubicin is still a problem of clinical concern. We studied whether echocardiography during afterload stress induced by angiotensin II (1,000-3,000 ng/min) allows earlier detection of left ventricular impairment than echo at rest. We compared 30 normals (N) to 30 patients with carcinoma, who had received doxorubicin at a cumulative dose of at least 360 mg/sqm. At rest echocardiograms of patients were either normal (P1; n = 24) or abnormal (P2; n = 6; fractional shortening less than 28%, distance of mitral E-point to septum greater than 7 mm). Best parameter for separation of P1 vs N was the slope K of the regression line of the relation between endsystolic diameter and systolic blood pressure (cuff-method). 38% of P1 and 100% of P2 had K-values below the range of N (less than 4.7 mm Hg/mm). Four of five patients with reduced ejection fraction assessed by scintigraphy (less than 55%) after continued therapy with doxorubicin have had, in previous echocardiographic studies, normal resting parameters but abnormal K-values. We conclude that afterload-stress increases the sensitivity of echocardiography in detecting cardiotoxicity due to doxorubicin.     

Defibrillation Energy Requirements Differ Between Anesthetic Agents

We examined the effect of anesthesia on the energy requirements for internal defibrillation (DF) in dogs anesthetized with pentobarbital (30 mg/kg IV followed by 2–3 mg/kg/hr constant infusion) (n = 20), fentanyl (25 μg/kg/hour) (n = 25), and enflurane (0.5%–1.5%) (n = 8). Multiple shocks of varying energies were applied through left and right ventricular epicardial patch electrodes to relate delivered energy to percent success in DF. The energies required for 50% success (E₅₀) and 80% success (E₈₀) in DF were estimated using logistic regression. E₅₀ in fentanyl anesthetized animals (3.8 ± 2.3 J) was significantly lower than in those given pentobarbital (6.9 ± 3.0 J) (P < 0.01), and lawer than those given enflurane (5.7 ± 2.8 J) (NS). E₈₀ with fentanyl (6.5 ± 4.0 J) was also lower than that of pentobarbital (10.4 ± 4.9 J) (P < 0.01) and enflurane (7.6 ± 4.3 J) (NS) animals. lawer defibrillation energy requirements (DER) with fentanyl anesthesia, when compared with pentobarbital, were associated with significantly longer ventricular effective refractory periods (VERP) (171 ± 20 versus 142 ± 15 msec: P < 0.01), lower mean arterial pressures (114 ± 20 vs 136 ± 25 mmHg: P < 0.01), and Iower heart rates (90 ± 37 versus 164 ± 19 b/m; P < 0.01).
Anesthetic agents may modify DER; their effects need to be taken into account in the assessment of DER in patients receiving implanted defibrillators and in the evaluation of the results of defibrillation research in anesthetized animals.     

Ultrasonic backscatter and collagen in normal ventricular myocardium

Integrated ultrasonic backscatter has been related to collagen deposition in fibrotic myocardium. The purpose of our study was to measure the integrated ultrasonic backscatter in the right and left ventricles of 10 normal freshly excised canine hearts and five normal formalin-fixed human hearts. A 2.25 MHz, 50% fractional bandwidth transducer was positioned at the transducer focal distance from the epicardium. The radio frequency backscatter signal, excluding specular reflections, was digitized, squared, and integrated to yield the integrated ultrasonic backscatter (in decibels down from a 100% reflector). The segment of myocardium corresponding to the integrated ultrasonic backscatter sample volume was excised and assayed for hydroxyproline, a marker for collagen. A second purpose of our study was to evaluate the influence of fixation with formalin on the backscatter. Regional integrated ultrasonic backscatter was therefore measured in 10 freshly excised canine left ventricles, which were fixed in 10% formalin for 2 weeks. Integrated ultrasonic backscatter measurements were then repeated. In freshly excised canine hearts, the integrated ultrasonic backscatter from right ventricle was higher than that from left ventricle (-60.4 +/- 1.6 [SEM] vs -66.9 +/- 1.0 dB; p less than .001). The collagen content of right ventricle was also higher than that of left ventricle (4.40 +/- 0.26 [SEM] vs 3.58 +/- 0.13 micrograms/mg dry weight; p less than .005). Similar results were obtained in human hearts. There were no correlations between integrated ultrasonic backscatter and collagen content (r = .28 and .32 for dogs and humans, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)