Three-dimensional echocardiographic measurement of left and right ventricular mass and volume: in vitro validation

Introduction: Three-dimensional (3D) echocardiography has been shown to offer highly accurate measurements of left ventricular (LV) volume and mass. The present study evaluated the accuracy of 3D surface reconstruction by the piecewise smooth subdivision method in measuring volume and mass not only in the LV but also in the more complexly shaped right ventricle (RV). Methods: 3D echo scans were obtained of in vitro LV's (n = 15) and RVs (n = 10). From digitized images, ventricular borders were traced and used in surface reconstructions. Mass and volume determined from the reconstructions were compared to true volume and mass determined prior to imaging. Additionally casts of two RVs were made and laser-scanned. Distances between the laser-identified points on the RV surface and the corresponding 3D echo reconstructions were measured. Results: 3D LV volume agreed well with the true volume (y = 0.99x + 1.73, r = 0.99, SEE = 3.35 ml, p < 0.0001), as did 3D LV mass (y = 0.99x – 4.71, r = 0.99, SEE = 9.85 g, p < 0.0001). 3D RV volume overestimated true volume (y = 1.11x + 1.77, r = 0.99, SEE = 3.36 ml, p < 0.001) by 6.23 ± 3.70 ml (p < 0.0001). 3D mass agreed well with RV mass (y = 0.78x + 17.32, r ² = 0.93, SEE = 3.54 g, p < 0.0001). 3D echo reconstructions matched the laser-scanned RV closely with residual distances of 1.1 ± 0.9 and 1.4 ± 1.2 mm, respectively. Conclusions: 3D echo using freehand scanning combined with surface reconstruction by the piecewise smooth subdivision surface method enables accurate determination of LV mass and volume, of RV mass and volume, and of the RV's complex shape.     

Longitudinal systolic ventricular interaction in pediatric and young adult patients with TOF: a cardiac magnetic resonance and M-mode echocardiographic study

Aim of this prospective study was to evaluate longitudinal systolic left ventricular (LV)–right ventricular (RV) interaction using M-mode compared to magnetic resonance imaging (MRI) data in 146 pediatric and adults with operated tetralogy of Fallot (TOF). We determined biventricular measures of longitudinal M-mode echocardiography [i.e. tricuspid annular plane systolic excursion (TAPSE); the mitral annular plane systolic excursion (MAPSE)] compared to longitudinal function parameters using MRI. M-mode data were compared to established normal z-score values. We found a good correlation between MAPSE and LVEF values (r = 0.788; p < 0.001). Correlations between MRI derived MAPSE and M-mode guided MAPSE (r = 0.879, p < 0.001), and between MRI derived TAPSE and M-mode guided TAPSE were significant (r = 0.780, p < 0.001). While the LVEF was normal in patients with a normal RVEF, the LVEF was decreased in patients with significantly reduced RVEF. Patients with a significantly dilated RV (RVEDVi > 150 ml/m²) showed a significantly reduced mean MAPSE of 1.30 ± 0.26 cm. LV longitudinal function decreases below ?2 SD of normal MAPSE z-score values after a mean of 22 postoperative years. Our data confirm progressive adverse RV–LV interaction in the long-term follow-up of TOF. We show that simple M-mode measurement of the longitudinal LV function (i.e. MAPSE) is a sufficient surrogate for estimation of LVEF. Therefore determination of the MAPSE is a helpful additional tool for LV systolic function assessment late after TOF repair.     

三维体元模型超声重建法定量测量左室壁心肌重量的实验研究

为了评价三维体元模型超声重建法定量测量左室壁心肌重量的准确性，我们对７个左室模型和１７只离体猪心进行研究，并与二维法进行比较。结果显示：三维体元模型超声重地和二维法测量左室模型的重量与实测值均非常接近，相关系数以三维法最高。三维法和二维法对变形的猪左室模型重量的测量结果与实测的差别无显著意义，误差率为１．２６％。     

Rapid and accurate left ventricular surface generation from three-dimensional echocardiography by a catalog based method. Rapid LV surface generation by three-dimensional echo

Background: Quantitative analysis from three-dimensional (3D) echocardiography requires accurate reconstruction of left ventricular (LV) surfaces. This currently requires time-consuming manual image tracing. We describe and validate an alternative rapid method of generating LV surfaces. Methods: A 3D-image set is acquired using transthoracic scanning. Images from five standard echo views are displayed and border points selected where anatomic landmarks are well defined. A LV surface is reconstructed as a convex weighted sum of LVs from a catalog of 80 LVs. The intersections of the surface with the five views are presented on these images. The routine may be rerun until the LV surface matches the images. One LV surface is generated in 3 min ± 27 s. In 41 studies (19 normal, 15 previous infarction, seven cardiomyopathy) the volumes of the catalog-fit endocardial and epicardial surfaces were compared with volumes from surfaces reconstructed from full manual tracing. Results: Over a wide range of LV volumes and ejection fraction (EF), the catalog-fit results correlated closely to those from manual tracing: end-diastolic volume (194 ± 99 vs. 204 ± 110 ml, y = 0.93x, R ² = 0.99, SEE = 19 ml, p < 0.001), end-systolic volume (122 ± 95 vs. 131 ± 106 ml, y = 0.92x, R ² = 0.99, SEE = 13 ml, p < 0.001), EF (42 ± 16 vs. 42 ± 15%, y = x, R ² = 0.99, SEE = 4%, p < 0.001) and mass (220 ± 88 vs. 204 ± 86 g, y = 1.1x, R ² = 0.99, SEE = 24 g, p < 0.001). The endocardial catalog surface was generated from an average of 20 points and three computational runs for both end-diastole and end-systole. Conclusions: The catalog method of LV reconstruction from 3D-echo provides accurate measurement of volume, EF and mass. The speed of the method is a major advantage.     

Subclinical left ventricular systolic impairment in steady state young adult patients with sickle-cell anemia

Chronic volume overload in sickle-cell anemia (SCA) is associated with left ventricular (LV) enlargement and hypertrophy. The effect of the disease on LV systolic function remains debated. The aim of our study was to investigate LV systolic function in SCA patients using 2D speckle-tracking imaging. We compared 30 steady state asymptomatic adult SCA patients (17 women, mean age 24.7 ± 5.1 years) with 30 age and sex-matched healthy subjects (17 women, mean age 25.0 ± 4.9 years). In addition to conventional echocardiographic parameters including LV ejection fraction (LVEF) and LV mass index (LVMi), global longitudinal strain (GLS) and strain rate (GLSR) were measured. GLS (?17.9 ± 2.0 vs. ?19.7 ± 2.5 %, p = 0.004) and GLSR (?0.92 ± 0.09 vs. ?1.07 ± 0.17 s^?1, p < 0.0001) values were lower in SCA patients while LVEF values (60.1 ± 3.8 vs. 61.7 ± 4.7 %, p = 0.30) were not different. LVMi was increased in SCA patients (100.7 ± 23.5 vs. 72.4 ± 15.2 g/m², p = 0.0001) and GLSR was significantly lower in the subgroup of patients with LV hypertrophy (?0.88 ± 0.09 vs. ?0.96 ± 0.08 s^?1, p = 0.02). In SCA patients LVMi was correlated to GLS (r = 0.58, p = 0.001) and GLSR (r = 0.45, p = 0.015) pleading in favor of a pathological LV remodeling. Asymptomatic SCA patients exhibited a subclinical alteration of LV systolic function. Myocardial dysfunction appears to be linked to the degree of LV hypertrophy. 2D speckle-tracking imaging might be useful for long-term follow-up and to study the natural course of LV dysfunction in SCA patients.     

Discrepancies between echocardiographic measurements of left ventricular mass in a healthy adult population.

Increased left ventricular (LV) mass is associated with increased cardiovascular morbidity and mortality. LV mass is commonly estimated from echocardiography according to the Penn or ASE (American Society of Echocardiography) conventions. No formal statistical test of agreement between these methods has been published. Therefore we compared M-mode echocardiographic LV mass estimates by the Penn and ASE methods in a normal adult population. M-mode echocardiographic tracings were obtained in 169 healthy volunteers and used to calculate LV mass using the Penn and ASE methods. Median values of the estimates were similar [Penn, 126 g (interquartile range 96-170 g); ASE, 129 g (105-164 g); P=0.08] and were highly intercorrelated (r=0.98, P<0.0001). However, the Bland-Altman analysis of agreement revealed significant inconsistencies between Penn and ASE LV mass values. The difference between Penn and ASE values was correlated significantly with heart size (P<0.0001), such that, for small hearts, the Penn LV mass was lower than the ASE LV mass; in contrast, for large hearts, Penn estimates were greater than ASE values. In the upper 5% of the LV mass distribution, the median value for the Penn LV mass index was 132.4 g/m(2), compared with 116.5 g/m(2) for ASE values (2P=0.017). Thus the two most common methods of echocardiographic estimation of LV mass differ significantly at the upper and lower ends of the heart size distribution. These results have important implications for both cardiac research and clinical evaluation.     

超声心动图评价左室部分切除成形术的血流动力学变化

目的应用超声心动图评价左心室部分切除成形术治疗终末期扩张型心肌病血流动力学变化。方法自1998年4月至12月,12例经末期扩张型心肌病患者接受了左心室部分切除术治疗。术前及术后1个月内行经胸超声心动图,术中行经食管超声心动图检查,取左室长轴切面测量左室内径,以双面面积长轴法测量左室收缩功能,用9段记分法定量评价室壁运动。结果左室心肌平均切除重量44.8±12.5g。超声心动图检查左室舒张末期、收缩末期内径显著减少(81.5±11.53至65.9±10.29mm);(72.67±11.28至58.16±10.27mm),P<0.05。左心射血分数增加(19.4%±7.4%至29.73%±8.17%),P<0.01;每搏量和左室整体及局部室壁运动得分无明显改变,P>0.05。结论左室部分切除治疗晚期扩张型心肌病近期能显著减少心腔内径、心室容积,每搏量无增加,室壁运动幅度无明显改变,远期效果并不象人们所期盼的那样,心功能改善不明显。射血分数的提高可能仅仅依赖于舒张末期容积的减低和二尖瓣返流的矫正。     

Assessment of the normal adult right ventricular diastolic function using M-mode echocardiographic measurement of tricuspid ring motion

Right ventricular function can be evaluated echocardiographically by assessing the longitudinal motion of the tricuspid ring recorded in the apical four chamber view. In this study, we applied this technique to assess the right ventricular diastolic function in 10 healthy Japanese men (mean age : 28±6 years; age range : 20–43 years). Echocardiographic studies were performed with a phased-array imaging system using a 2.5 MHz probe. Tricuspid ring motion was measured by two-dimensional echo guided M-mode echocardiogram of the right lateral tricuspid ring. The excursion of the tricuspid ring during early diastole (dS; mm) and the peak rate of change of the excursion (dS/dt; mm/sec) were measured. We also assessed the right ventricular function by cine magnetic resonance imaging (MRI). Cine gradient echo images were obtained along the short axis of the right ventricle. The right ventricular volume at each phase of the cardiac cycle was calculated by Simpson's method and time–volume curves were constructed. The peak filling rate (dV/dt; ml/s) was determined from these time–volume curves. The dS was 12.8±2.5 mm, dS/dt was 132±27 mm/sec and dV/dt was 269±66 ml/s. There were significant positive correlations between dS and dV/dt (r=0.80, P<0.01), and between dS/dt and dV/dt (r=0.45, P<0.05). Based on our results, M-mode echocardiographic measurements of tricuspid ring motion may be used to assess the right ventricular diastolic function.     

Detection of radiotherapy-induced myocardial changes by ultrasound tissue characterisation in patients with breast cancer

Radiotherapy (RT) in the thoracic region is associated with an increased risk of late cardiovascular morbidity and mortality. Ultrasonic tissue characterisation (UTC) is a non-invasive method of identifying changes in myocardial tissue, such as increased fibrosis. The aim of this study was to assess whether UTC can detect early RT-induced myocardial alterations. Seventy-eight eligible patients with early stage breast cancer were evaluated before and immediately after RT. Twenty patients had right-sided and 58 left-sided breast cancer. None received chemotherapy. A comprehensive echocardiographic examination included 3D measurements and UTC of the right ventricular (RV) free wall, ventricular septum and left ventricular (LV) posterior wall. Integrated backscatter calibration was done for the pericardium (cpIBS) and LV cavity (ccIBS). RT for left-sided breast cancer was associated with increased echodensity in the UTC analysis. RV free wall and ventricular septum cpIBS increased from ?15.0 ± 7.3 to ?13.7 ± 7.9 dB (p = 0.079) and from ?18.2 ± 5.1 to -16.0 ± 6.4 dB (p = 0.002), respectively. Likewise, ccIBS in the RV free wall increased from 20.4 ± 5.9 to 22.1 ± 5.6 dB (p = 0.046), and in the LV septum from 17.3 ± 5.2 to 19.8 ± 5.5 dB (p < 0.001). In 3D echocardiography, LV mass increased from 102 ± 18 to 107 ± 18 g (p = 0.005). Patients receiving RT for right-sided breast cancer did not display these changes. Left-sided RT increased myocardial echodensity, particularly in the structures receiving the highest radiation dose. Considering the progressive nature of the RT induced damage, these early changes may help us with individual risk stratification and serve as a tool for screening.     

Usefulness of free-angle M-mode echocardiography in assessing left ventricular dimension and left ventricular systolic function

Objectives To assess the usefulness of free-angle M-mode echocardiography in measuring left ventricular (LV) dimension and global systolic function. Background The validity of conventional M-mode echocardiography in assessing LV dimension and global systolic function is well known; the incidental angle between the M-mode cursor and true LV minor axis diameter, however is a potential cause of measurement error. Free-angle M-mode echocardiography may overcome the limitation of M-mode cursor arrangement in conventional M-mode echocardiography. Methods Thirteen normal volunteers and 10 patients in whom abnormal left ventricular wall motion was not detected by echocardiography (mean age, 53±17 years) were enrolled in this study. Conventional and free-angle M-mode echocardiographic images of the LV were obtained by echocardiography (ALOKA SSD-5500) using a 2.5-MHz transducer, and the LV end-diastolic (LVDd) and end-systolic (LVDs) dimensions were measured by the leading edge method. LV end-diastolic and end-systolic volumes were calculated using a formula by Teichholz, and the LV ejection fraction (LVEF) was obtained. Data from conventional M-mode echocardiography and free-angle M-mode echocardiography were then compared. Results Measurements obtained with conventional M-mode and free-angle M-mode echocaardiography were strongly correlated. Correlation coefficients for LVDd, LVDs, and LVEF were 0.98, 0.98, and 0.96, respectively (p<0.001 in each case). Conclusions Assessment of left ventricular dimension, and global systolic function with free-angle M-mode can be as accurate as conventional M-mode in subjects in whom left ventricular wall motion abnormality is not detectable by echocardiogram. Moreover, when there is improper M-mode cursor direction in conventional echocardiography, free-angle M-mode echocardiography can assess global left ventricular systolic function more accurately and conveniently than conventional M-mode echocardiography.     

Abnormal Global Left Ventricular Relaxation Occurs Early During the Development of Pharmacologically Induced Ischemia

In animal and human models, left ventricular (LV) diastolic function has been observed to be highly sensitive to myocardial ischemia. The response of LV diastolic parameters to pharmacologically induced ischemia, however, has not been characterized and might be important in the interpretation of dobutamine stress echocardiography. Eight mongrel dogs, in which were inserted a high-fidelity micromanometer LV catheter, coronary sinus sampling catheter, and ultrasonic coronary artery flow probe, underwent intravenous dobutamine infusion at escalating doses both before (control protocol) and after (ischemia protocol) creation of left anterior descending coronary artery stenosis with a hydraulic cuff occluder adjusted to maintain resting coronary artery flow but attenuate reactive hyperemia. At each dobutamine dose, epicardial short-axis 2-dimensional echocardiographic images and hemodynamic measurements were obtained. LV diastolic function was examined by calculation of peak (–)dP/dt and the time constant of isovolumic relaxation (τ). The dobutamine infusion protocol was terminated on the earliest recognition of an anterior wall motion abnormality. Peak (+)dP/dt normalized for developed isovolumetric pressure was calculated as a relatively load-independent index of global LV contractile function. Dobutamine infusion with and without ischemia resulted in comparable changes in heart rate and (+)dP/dt/IP, with no change in LV end-diastolic or -systolic pressure. The magnitude of peak (-)dP/dt increased less during the ischemia (1231 ± 109 to 1791 ± 200 mm Hg/sec) versus the control (1390 ± 154 to 2432 ± 320 mm Hg/sec) protocol (P < .05). Similarly, the observed decrease in τ was less during the ischemia (53 ± 3 to 38 ± 4 msec) than the control (51 ± 5 to 23 ± 3 msec) protocol, corresponding to a slower rate of relaxation (P < .05). In addition, the smaller decrease in τ was observed at the dobutamine dose before the dose at which an echocardiographic wall motion abnormality was first recognized. Dobutamine-induced ischemia is associated with abnormal LV diastolic function. In addition, these abnormalities seem to occur early in the development of ischemia. These observations extend to pharmacologically induced ischemia prior findings from other models of ischemia, suggesting the high sensitivity of LV diastolic function to the development of myocardial ischemia. (J Am Soc Echocardiogr 1999;12:113-20.)     

Acoustic cardiac triggering: a practical solution for synchronization and gating of cardiovascular magnetic resonance at 7 Tesla

Background

This study proposes and validates a method of measuring 3D strain in myocardium using a 3D Cardiovascular Magnetic Resonance (CMR) tissue-tagging sequence and a 3D optical flow method (OFM).

Methods

Initially, a 3D tag MR sequence was developed and the parameters of the sequence and 3D OFM were optimized using phantom images with simulated deformation. This method then was validated in-vivo and utilized to quantify normal sheep left ventricular functions.

Results

Optimizing imaging and OFM parameters in the phantom study produced sub-pixel root-mean square error (RMS) between the estimated and known displacements in the x (RMS_x = 0.62 pixels (0.43 mm)), y (RMSy = 0.64 pixels (0.45 mm)) and z (RMSz = 0.68 pixels (1 mm)) direction, respectively. In-vivo validation demonstrated excellent correlation between the displacement measured by manually tracking tag intersections and that generated by 3D OFM (R ≥ 0.98). Technique performance was maintained even with 20% Gaussian noise added to the phantom images. Furthermore, 3D tracking of 3D cardiac motions resulted in a 51% decrease in in-plane tracking error as compared to 2D tracking. The in-vivo function studies showed that maximum wall thickening was greatest in the lateral wall, and increased from both apex and base towards the mid-ventricular region. Regional deformation patterns are in agreement with previous studies on LV function.

Conclusion

A novel method was developed to measure 3D LV wall deformation rapidly with high in-plane and through-plane resolution from one 3D cine acquisition.     

Comparing a novel automatic 3D method for LGE-CMR quantification of scar size with established methods

Current methods for the estimation of infarct size by late-enhanced cardiac magnetic imaging are based upon 2D analysis that first determines the size of the infarction in each slice, and thereafter adds the infarct sizes from each slice to generate a volume. We present a novel, automatic 3D method that estimates infarct size by a simultaneous analysis of all pixels from all slices. In a population of 54 patients with ischemic scars, the infarct size estimated by the automatic 3D method was compared with four established 2D methods. The new 3D method defined scar as the sum of all pixels with signal intensity (SI) ≥35 % of max SI from the complete myocardium, border zone: SI 35–50 % of max SI and core as SI ≥50 % of max SI. The 3D method yielded smaller infarct size (?2.8 ± 2.3 %) and core size (?3.0 ± 1.7 %) than the 2D method most similar to ours. There was no difference in the size of the border zone (0.2 ± 1.4 %). The 3D method demonstrated stronger correlations between scar size and left ventricular (LV) remodelling parameters (LV ejection fraction: r = ?0.71, p < 0.0005, LV end-diastolic index: r = 0.54, p < 0.0005, and LV end-systolic index: r = 0.59, p < 0.0005) compared with conventional 2D methods. Infarct size estimation by our novel 3D automatic method is without the need for manual demarcation of the scar; it is less time-consuming and has a stronger correlation with remodelling parameters compared with existing methods.     

Color M-Mode Doppler Flow Propagation Velocity Is a Relatively Preload-Independent Index of Left Ventricular Filling

Standard Doppler indexes of transmitral filling vary in response to alterations in left ventricular (LV) relaxation or preload. To determine whether color M-mode Doppler flow propagation velocity (v_p ), a new index of LV relaxation, is affected by preload, we obtained LV volumes, standard Doppler filling indexes, and v_p in 20 patients at baseline, during Trendelenburg’s position, inverse Trendelenburg’s position, and after inhalation of amyl nitrite. LV end-diastolic volume decreased from 111 ± 41 mL at baseline and 116 ± 43 mL during Trendelenburg’s position, to 104 ± 40 during inverse Trendelenburg’s maneuver and 92 ± 33 mL after inhalation of amyl nitrite (P < .0001). Peak early filling velocity decreased from 79 ± 19 cm/s and 90 ± 20 cm/s to 73 ± 22 cm/s and 64 ± 20 cm/s, respectively (P < 0.0001). In contrast, no significant changes were found in v_p (48 ± 24 and 50 ± 26 cm/s vs 48 ± 25 and 48 ± 25 cm/s). We conclude that v_p is not affected significantly by preload. Thus v_p may provide a more reliable and independent assessment of LV relaxation. (J Am Soc Echocardiogr 1999;12:129-37.)     

Left ventricular remodeling and torsion dynamics in hypertensive patients

Left ventricular (LV) torsion is a fundamental component of wall motion and plays an important role to optimize ventricular ejection fraction. The aim of our study was to calculate by speckle tracking echocardiography LV twist angle in patients with hypertension and LV remodeling, analyzing torsional indices in all patterns of hypertrophy, in comparison to torsional dynamics of age-matched healthy subjects. Hypertensive patients (n = 202) were divided in three groups, patients with concentric remodeling (n = 70), concentric hypertrophy (n = 68) and eccentric hypertrophy (n = 64), in relation to the echocardiographic measurements of relative wall thickness and LV mass, analyzing their torsional patterns by speckle tracking in comparison to age-matched control group. Compared to healthy controls, LV twist angle was increased in patients with hypertension and concentric remodeling (15.2° ± 1.9° vs. 11.0° ± 1.6°; p < 0.001), reaching the highest value in patients with concentric hypertrophy (19.4° ± 2.6°); instead LV twist angle presented depressed in the group of patients that presented eccentric hypertrophy (5.0° ± 1.1°). Regarding LV untwisting rate, it was higher in the concentric remodeling and concentric hypertrophy groups (?123.1°/s ± 12.1°/s and ?145.1°/s ± 15.5°/s, respectively) in comparison with the controls (?90.0°/s ± 10.1°/s; p < 0.0001 for both). Instead, lower values of LV untwisting rate were observed in the eccentric remodeling group (?81.6°/s ± 8.1°/s), not significantly different to controls’ values (p = 0.09). Enhanced LV twist angle appears to be a compensatory mechanism in hypertensive patients during the earlier stages of concentric remodeling and concentric hypertrophy; this hyper-torsion is inevitably loss in the more advanced stage of eccentric hypertrophy.     

Adverse effects of permanent atrial fibrillation on heart failure in patients with preserved left ventricular function and chronic right apical pacing for complete heart block

Background

The impact of atrial fibrillation (AF) on heart failure (HF) was evaluated in patients with preserved left ventricular (LV) function and long-term right ventricular (RV) pacing for complete heart block.

Methods

Clinical, echocardiographic, and laboratory parameters of HF were assessed in 35 patients with established AF who had undergone ablation of the atrioventricular node and pacemaker implantation (Group A) and 31 patients who received dual-chamber pacing for spontaneous complete heart block (Group B).

Results

During a follow-up period of 12.7?±?7.5?years, New York Heart Association (NYHA) functional class increased from 1.3?±?0.5 to 2.1?±?0.6 (p?p?p?p?=?0,21) in Group B. At the end of follow-up, markers of LV function were moderately depressed in Group A compared with those in Group B: NYHA class 2.1?±?0.6 versus 1.6?±?0.7, p?=?0.001; LVEF 53.0?±?8.2 versus 56.9?±?7.0?%, p?p?p?10?%, increasing NYHA class ≥1, and NT-proBNP levels >1,000?pg/ml.

Conclusions

Permanent AF was associated with adverse effects on LV function and symptoms of HF in patients with long-term RV pacing for complete heart block, and appears to play an important role in the development of HF in this specific patient cohort.     

Semiautomatic three-dimensional CT ventricular volumetry in patients with congenital heart disease: agreement between two methods with different user interaction

To assess agreement between two semi-automatic, three-dimensional (3D) computed tomography (CT) ventricular volumetry methods with different user interactions in patients with congenital heart disease. In 30 patients with congenital heart disease (median age 8 years, range 5 days–33 years; 20 men), dual-source, multi-section, electrocardiography-synchronized cardiac CT was obtained at the end-systolic (n = 22) and/or end-diastolic (n = 28) phase. Nineteen left ventricle end-systolic (LV ESV), 28 left ventricle end-diastolic (LV EDV), 22 right ventricle end-systolic (RV ESV), and 28 right ventricle end-diastolic volumes (RV EDV) were successfully calculated using two semi-automatic, 3D segmentation methods with different user interactions (high in method 1, low in method 2). The calculated ventricular volumes of the two methods were compared and correlated. A P value <0.05 was considered statistically significant. LV ESV (35.95 ± 23.49 ml), LV EDV (88.76 ± 61.83 ml), and RV ESV (46.87 ± 47.39 ml) measured by method 2 were slightly but significantly smaller than those measured by method 1 (41.25 ± 26.94 ml, 92.20 ± 62.69 ml, 53.61 ± 50.08 ml for LV ESV, LV EDV, and RV ESV, respectively; P ≤ 0.02). In contrast, no statistically significant difference in RV EDV (122.57 ± 88.57 ml in method 1, 123.83 ± 89.89 ml in method 2; P = 0.36) was found between the two methods. All ventricular volumes showed very high correlation (R = 0.978, 0.993, 0.985, 0.997 for LV ESV, LV EDV, RV ESV, and RV EDV, respectively; P < 0.001) between the two methods. In patients with congenital heart disease, 3D CT ventricular volumetry shows good agreement and high correlation between the two methods, but method 2 tends to slightly underestimate LV ESV, LV EDV, and RV ESV.     

Reference values for echocardiographic measurements in urban and rural populations of differing ethnicity: the Strong Heart Study.

Discrepancies in reported reference values for left ventricular (LV) dimensions and mass may be due to imaging errors with early echocardiographic methods or effects of subject characteristics and inclusion criteria. To determine whether contemporary echocardiographic methods provide stable normal limits for left ventricular measurements in different populations, M-mode/2-dimensional echocardiography was applied in 176 American Indian participants in the Strong Heart Study and 237 New York City residents who were clinically normal. No consistent difference in any measure of LV size or function existed between populations. Upper normal limits (98th percentile) for LV mass were 96 g/m(2) in women and 116 g/m(2) in men and 3.27 cm/m for LV chamber diameter normalized for height. Thus contemporary M-mode/2D echocardiography provides reference ranges for LV measurements that approximate necropsy measurements and have acceptable stability in apparently normal white, African-American/Caribbean, and American Indian populations.     

Influence of propranolol infusion on cyclic variation of myocardial integrated backscatter in hypertrophic obstructive cardiomyopathy

It has been demonstrated that cyclic variation, assessed by myocardial integrated backscatter, reflects regional myocardial contractile function. The aim of this study was to investigate the influence of administration of β-blocker propranolol on cyclic variation in patients with hypertrophic cardiomyopathy and persistent left ventricular (LV) pressure gradient and to test the hypothesis that the reduction of LV pressure gradient would be related to the change in regional contractile function. Before and after 2 mg propranolol infusion, transthoracic echocardiography with integrated backscatter analysis was performed on 11 patients (8 men and 3 women, mean age 54 ± 12 years old). Integrated backscatter curves were obtained from the ventricular septum and LV posterior walls. With propranolol infusion, there was a significant reduction of LV fractional shortening (0.39 ± 0.08 to 0.34 ± 0.09, P < .01) and LV pressure gradient (83 ± 40 mm Hg to 42 ± 32 mm Hg, P < .001). In the posterior wall, the magnitude of cyclic variation significantly decreased (7.1 ± 2.2 dB to 5.6 ± 1.8 dB, P < .01), whereas in the septum, no apparent change in this parameter was observed (5.8 ± 2.1 dB to 4.7 ± 1.9 dB). Our findings suggest that in this form of cardiomyopathy, (1) the posterior wall myocardium is more susceptible to negative inotropic effects than the septum; (2) the reduction of LV pressure gradient is not related to that of regional wall motion; and (3) poor response of the ventricular septum is possibly because of more severe myocardial disarray and hypertrophy. (J Am Soc Echocardiogr 2002;15:1251-55.)     

Single-plane and biplane echocardiography: use of targeted scan planes improves the estimates of left ventricular volume and shape for analysis of postinfarction remodeling.

OBJECTIVE: Acute myocardial infarction and subsequent left ventricular (LV) remodeling induce complex geometric changes quantifiable by 3-dimensional (3D) echocardiography. Our objective was to determine accurate 2-dimensional echocardiographic techniques for analysis of diastolic and systolic LV volume and shape in remodeled hearts. METHODS: We obtained 3D apical scans from 16 patients at the acute stage, and at 1 and 6 months after acute myocardial infarction. LV volumes were calculated by 7 methods: (1) Teichholz; (2) Teichholz including the infarcted area; (3) single-plane area-length (AL) using a 2-chamber (2CH) view; (4) single-plane AL using a 4-chamber (4CH) view; (5) single-plane AL using a view including the infarcted area; (6) biplane AL using 2CH and 4CH views; and (7) biplane AL using a view including the infarction region and corresponding orthogonal view (method ALBMIO). LV shape was assessed by 5 methods: (1) a 2CH view; (2) a 4CH view; (3) a single-plane view including the infarcted area; (4) biplane (2CH and 4CH) views; and (5) biplane views including the infarction region and corresponding orthogonal view (method BMIO). RESULTS: For end-diastolic and end-systolic LV volume assessments, all 7 methods correlated with the 3D reference, but method ALBMIO performed best (end-diastolic: r = 0.931, bias = 17.4 mL; end-systolic: r = 0.946, bias = 11.2 mL). For LV shape assessments, method BMIO showed the smallest difference from the 3D reference. CONCLUSIONS: With 2-dimensional echocardiographic techniques, quantitative analysis of LV volume and shape is most accurate when a component scan plane is targeted through the infarcted myocardial region.