Two-dimensional Echocardiographic Studies during Sustained Ventricular Tachycardia

We evaluated left ventricular function in patients with recurrent sustained ventricular tachycardia (VT) using two-dimensional echocardiography (2DE). Thirteen patients, 11 men and 2 women, age range 42-77 (mean 62 +/- 12) years were studied in sinus rhythm (SR) and immediately after VT induction. 2DE parameters analyzed included wall motion, mitral valve leaflet motion, and ejection fraction (EF). In SR, 21 segments/walls in 12 patients showed wall motion abnormalities (WMA) ranging from hypokinesis to dyskinesis and one patient had generalized LV hypokinesis. In VT, new WMA were noted in 2 patients. Thirteen segments/walls in 8 patients showed further worsening of pre-existing WMA. In 1 patient there was worsening of generalized LV hypokinesis. Three patients showed apparent improvement in pre-existing WMA during VT. In 2 patients large apical aneurysms showed a reduction of dyskinesis in VT. Mitral valve opening was intermittent in patients with shorter VT cycle lengths and was maximal when atrial systole preceded or coincided with ventricular depolarization. Doppler echocardiography in 1 patient confirmed the pattern of intermittent mitral flow, with greatest flow occurring when mitral valve opening occurred well before the QRS peak. In 5 patients, 2DE permitted EF measurements. EF in SR ranged from 24-56% (mean 36 +/- 13), decreased to 6-33% (mean 21 +/- 11) within the first ten beats of VT and 6-25% (mean 19 +/- 8) after twenty beats of VT. EF decreased more in patients with shorter VT cycles as compared to those with longer VT cycle lengths.(ABSTRACT TRUNCATED AT 250 WORDS)     

Partial cut-off of the left ventricle: determinants and effects on volume parameters assessed by real-time 3-D echocardiography

A total of 44 patients with coronary artery disease underwent real-time three-dimensional (3-D) echocardiography for end systolic (ES) and end diastolic (ED) left ventricular (LV) volumetric analysis to assess the effect of partial cut-off of the left ventricular (LV) apex on volumetric analysis by apical transthoracic echocardiography. Patients with LV cut-off were assigned to either group 1 (ejection fraction, (EF) < 49%) or group 2 (EF > or = 49%). Patients were additionally classified as group A if they had anterior or apical wall motion abnormalities (WMA) or group B if they had only inferoposterior or lateral WMA. Partial LV cut-offs were found in 22 subjects (50%). The estimated end diastolic cut-off volumes were as follows: 8.6 +/- 3.2 mL (group 1), 4.3 +/- 2.4 mL (group 2), 9.1 +/- 3.3 mL (group A) and 1.4 +/- 0.8 mL (group B). In group 1, more patients with LV volume cut-off were found than in group 2: chi(2) = 4.52, p < 0.05; and in group A more than in group B: chi(2) = 8.08, p < 0.01. In all, partial LV cut-off led to underestimation of LV volumes: 5.9 +/- 4.7 ml (ED) vs. 2.1 +/- 1.3 ml (ES), p <0.02. In conclusion, LV cut-offs can potentially alter the accuracy of echocardiographic volumetric analysis, particularly in anterior or apical WMA.     

Segmental Wall Motion Abnormality Analyzed by Equilibrium Radionuclide Angiography and Improvement in Ventricular Function by Cardiac Resynchronization Therapy

Introduction: The purpose of this study was to determine the impact of the left ventricular (LV) segmental wall motion abnormalities detected by equilibrium radionuclide angiography (ERNA) on the improvement in LV and right ventricular (RV) function during biventricular (BIV) stimulation .
Results: We studied 28 patients in NYHA functional classes III or IV and QRS duration >150 ms on resting electrocardiogram. ERNA was performed before and during BIV stimulation at a 6-month follow-up. A significant shortening of QRS duration was observed during BIV stimulation (165 ± 5 ms before vs 133 ± 6 ms during, P < 0.01). Wall motion abnormalities (WMA) were observed in 16 patients (10 with nonischemic cardiomyopathies). In this group, LV and RV ejection fractions (EF) did not increase during BIV stimulation (LVEF = 22 ± 2% vs 20 ± 1.6%, ns; RVEF = 34 ± 3% vs 37 ± 3.8%, ns). Significant increases in RVEF (23 ± 3.2 %→ 38 ± 2.9%, P = 0.001) and LVEF (20 ± 2.5 %→ 30 ± 3%, P = 0.01) were observed in the group of patients without segmental WMA and with global hypokinesia (GH). In this group, a significant decrease in the dispersion in the phase of RV contraction was observed (SD = 39 ± 5 vs 26 ± 2 ms; P < 0.01). WMA predicted an increase in LVEF, in contrast to a baseline 6-minute-walk test, maximal oxygen consumption and LVEF, or amount of QRS shortening.
Conclusions: BIV stimulation increased in LV and RV EF in patients with ventricular dyssynchrony in absence of segmental WMA. ERNA was reliable in the selection of candidates for CRT.     

Clinical significance of right ventricular dysfunction in left ventricular non-compaction cardiomyopathy

Left ventricular non-compaction (LVNC) is described as the persistence of trabeculated myocardium in the left ventricle (LV) and is optimally assessed by cardiac magnetic resonance (CMR). Right ventricular (RV) involvement in LVNC remains poorly studied. Consecutive patients (N = 14) diagnosed with LVNC by CMR were studied. Their clinical data were analyzed. In addition, CMR assessment included quantification of LV and RV volumes, mass, ejection fraction (EF), LV wall motion score, LV non-compacted segments and non-compacted to compacted myocardium ratios. Average age of presentation was 33.1 ± 17.6 years old, with 9 males (64%). Of these patients, 7 (50%) presented with acute heart failure and 3 (21%) with syncope, including 1 documented ventricular tachycardia. RV EF < 35% was identified in 7 (50%) of these patients. Patients with RV EF < 35% presented at a higher median New York Heart Association class (1 [IQR 1-2] vs. 3 [IQR 2-4], P = 0.021) and had significantly lower LV EF (50.7% ± 15.4 vs. 21.8% ± 19.9, P = 0.029), higher LV end diastolic (100.9 ml/m(2) ± 22.3 vs. 159.1 ml/m(2) ± 36.0, P = 0.002) and systolic volume indices (52.0 ml/m(2) ± 25.8 vs. 129.1 ml/m(2) ± 48.4, P = 0.002), higher LV wall motion score index (1.3 ± 0.5 vs. 2.2 ± 0.6, P = 0.004) and higher ratio of LV non-compacted to compacted myocardium (3.3 ± 0.6 vs. 4.1 ± 0.8, P = 0.026). All 4 patients that had ventricular tachycardia also had RV dysfunction. RV dysfunction was present in half of patients with LVNC. Significant RV dysfunction seems to be a marker of advanced LVNC and may carry a worse prognosis. Further studies in a larger sample of patients are needed to confirm those observations.     

二维超声心动图推测国人心肌梗塞相关血管的初步研究

对40例急性心肌梗塞患者进行了二维超声心动图（ZDE）和冠状动脉（冠脉）造影检查。将左室分为16个节段进行分析，判定室壁运动异常（WMA）节段的部位和范围，分别统计冠脉各主支堵塞所致的WMA在各节段的发生率；据此推出左室各节段相对应供血的冠脉分支；并与国外报道的进行比较，发现国人的右冠脉供血区域较广于国外的报道；为应用2DE推测国人心肌梗塞的相关血管提供依据。     

Relationship of number of phases per cardiac cycle and accuracy of measurement of left ventricular volumes, ejection fraction, and mass.

In cine cardiac magnetic resonance imaging (MRI) studies, for any preset imaging parameters the number of phases per cardiac cycle for a single slice is proportional to breath-hold duration. We investigated the relationship between the accuracy of measurement of left ventricular (LV) end-diastolic and end-systolic volumes (EDV and ESV, respectively), mass and ejection fraction (EF), and the number of phases acquired per cardiac cycle. Twelve adult volunteers underwent cardiac MRI and five complete LV functional studies were obtained with 8, 11, 14, 17, and 20 phases per cardiac cycle. We calculated LV volumes, EF, and mass for each acquisition, and compared them using the 20-phase acquisition as the reference standard. The scan duration was proportional to the number of phases acquired. There was a systematic underestimation of LV, EDV, and EF, with decreasing number of phases. Differences from the reference standard became significant for the 8-phase acquisition (p<0.05). Subgroup analysis showed that only those with slower heart rates (<65/min) had significant differences in EDV, but not in EF, for the 8-phase acquisition. For those with faster heart rates, no differences were detected between the different acquisitions. There were no significant differences between all acquisitions for the LV ESV and mass. We conclude that at least 11 phases per cardiac cycle are needed to maintain accuracy for cine cardiac MRI studies. Decreasing the number of phases per cardiac cycle beyond this cutoff may introduce significant error of measurement, particularly for the left ventricular EDV and EF and especially for those with bradycardia, and should be avoided.     

Assessment of left ventricular volumes, ejection fraction and regional wall motion with retrospective electrocardiogram triggered 320-detector computed tomography: a comparison with 2D-echocardiography

Left ventricular (LV) volumes, ejection fraction (LVEF) and regional wall motion (LVRWM) have important treatment and prognostic implications in patients with coronary artery disease. We sought to determine the accuracy of 320-row multidetector computed tomography (MDCT) for the assessment of LV volumes, LVEF and LVRWM, using 2D-echocardiography as the reference standard. We evaluated 50 consecutive patients (mean age 60 ± 14 years, 66% male) who underwent 320-detector MDCT (dose-modulated retrospective electrocardiogram-triggering) and 2D-echocardiography within 14 days for investigation of known or suspected coronary artery disease. Two blinded readers measured LV volumes on MDCT and visually assessed LVRWM with a 3-point scale using a 17-segment model. A separate experienced echocardiologist, blinded to MDCT findings, assessed LVRWM on 2D-echocardiograms and determined LV volumes and LVEF using Simpson's biplane method. 2D-echocardiography served as the reference standard. Mean LVEF was 59 ± 9% (range 26-75%) on 2D-echocardiography and 60 ± 9% (range 27-76%) on MDCT. Using linear regression analysis, MDCT agreed very well with 2D-echocardiography for assessment of LVEDV (r(2) = 0.88; P < 0.001), LVESV (r(2) = 0.95; P < 0.001) and LVEF (r(2) = 0.90; P < 0.001). Mean differences (±standard deviation) of 14 ± 13 ml, 5 ± 7 ml and 1 ± 3% were observed between MDCT and 2D-echocardiography for LVEDV, LVESV and LVEF, respectively. On 2D-echocardiography, 81/850 (9.5%) segments had abnormal LVRWM. Agreement for assessment of LVRWM between 2D-echocardiography and MDCT was excellent (96%, k = 0.76). Accurate assessment of LV volumes, LVEF and LVRWM is feasible with 320-detector MDCT, with MDCT demonstrating slightly larger LV volumes than 2D-echocardiography.     

Mechanism of decreased sensitivity of dobutamine associated left ventricular wall motion analyses for appreciating inducible ischemia in older adults

Background

Dobutamine associated left ventricular (LV) wall motion analyses exhibit reduced sensitivity for detecting inducible ischemia in individuals with increased LV wall thickness. This study was performed to better understand the mechanism of this reduced sensitivity in the elderly who often manifest increased LV wall thickness and risk factors for coronary artery disease.

Methods

During dobutamine cardiovascular magnetic resonance (DCMR) stress testing, we assessed rate pressure product (RPP), aortic pulse wave velocity (PWV), LV myocardial oxygen demand (pressure volume area, PVA, mass, volumes, concentricity, and the presence of wall motion abnormalities (WMA) and first pass gadolinium enhanced perfusion defects (PDs) indicative of ischemia in 278 consecutively recruited individuals aged 69 ± 8 years with pre-existing or known risk factors for coronary artery disease. Each variable was assessed independently by personnel blinded to participant identifiers and analyses of other DCMR or hemodynamic variables.

Results

Participants were 80% white, 90% hypertensive, 43% diabetic and 55% men. With dobutamine, 60% of the participants who exhibited PDs had no inducible WMA. Among these participants, myocardial oxygen demand was lower than that observed in those who had both wall motion and perfusion abnormalities suggestive of ischemia (p = 0.03). Relative to those with PDs and inducible WMAs, myocardial oxygen demand remained different in these individuals with PDs without an inducible WMA after accounting for LV afterload and contractility (p = 0.02 and 0.03 respectively), but not after accounting for either LV stress related end diastolic volume index (LV preload) or resting concentricity (p = 0.31-0.71).

Conclusions

During dobutamine stress testing, elderly patients experience increased LV concentricity and declines in LV preload and myocardial oxygen demand, all of which are associated with an absence of inducible LV WMAs indicative of myocardial ischemia. These findings provide insight as to why dobutamine associated wall motion analyses exhibit reduced sensitivity for identifying inducible ischemia in elderly.

Trial registration

This study was registered with Clinicaltrials.gov ({"type":"clinical-trial","attrs":{"text":"NCT00542503","term_id":"NCT00542503"}}NCT00542503).     

Quantification of left ventricular volumes and ejection fraction using freehand transthoracic three-dimensional echocardiography: comparison with magnetic resonance imaging.

OBJECTIVES: Our aim was to validate 3-dimensional echocardiography (3DE) for assessment of left ventricular (LV) end-diastolic volume, end-systolic volume (ESV), stroke volume, and ejection fraction (EF) using the freehand-acquisition method. Furthermore, LV volumes by breath hold-versus free breathing-3DE acquisition were assessed and compared with magnetic resonance imaging (MRI). METHODS: From the apical position, a fan-like 3DE image was acquired during free breathing and another, thereafter, during breath hold. In 27 patients, 28 breath hold- and 24 free breathing-3DE images were acquired. A total of 17 patients underwent both MRI and 3DE. MRI contours were traced along the outer endocardial contour, including trabeculae, and along the inner endocardial contour, excluding trabeculae, from the LV volume. RESULTS: All 28 (100%) breath hold- and 86% of free breathing-3DE acquisitions could be analyzed. Intraobserver variation (percentual bias +/- 2 SD) of end-diastolic volume, ESV, stroke volume, and EF for breath-hold 3DE was, respectively, 0.3 +/- 10.2%, 0.3 +/- 14.6%, 0.1 +/- 18.4%, and -0.1 +/- 5.8%. For free-breathing 3DE, findings were similar. A significantly better interobserver variability, however, was observed for breath-hold 3DE for ESV and EF. Comparison of breath-hold 3DE with MRI inner contour showed for end-diastolic volume, ESV, stroke volume, and EF, a percentual bias (+/- 2 SD) of, respectively, -13.5 +/- 26.9%, -17.7 +/- 47.8%, -10.6 +/- 43.6%, and -1.8 +/- 11.6%. Compared with the MRI outer contour, a significantly greater difference was observed, except for EF. CONCLUSIONS: 3DE using the freehand method is fast and highly reproducible for (serial) LV volume and EF measurement, and, hence, ideally suited for clinical decision making and trials. Breath-hold 3DE is superior to free-breathing 3DE regarding image quality and reproducibility. Compared with MRI, 3DE underestimates LV volumes, but not EF, which is mainly explained by differences in endocardial contour tracing by MRI (outer contour) and 3DE (inner contour) of the trabecularized endocardium. Underestimation is reduced when breath-hold 3DE is compared with inner contour analysis of the MRI dataset.     

三维重建超声组织多普勒成像测量左室功能:活体动物实验研究

目的　用三维重建超声组织多普勒成像 ( 3DTDI)方法 ,研究左室壁运动特点及左室不同部分的射血分数(EF)。方法　用重建的 3DTDI的方法 ,对 8只心尖部心肌梗死的活体羊模型在四种不同的血流状态下进行左室壁运动的测定和左室不同部分的EF测量。结果　在四种不同的血流状态下 ,左室梗塞区域的室壁运动振幅明显低于正常部分 (P<0 .0 0 1) ,整个左室、左室正常部分的EF明显高于梗塞部分 (P <0 .0 0 1) ,左室正常部分的EF明显高于整个左室 ( 0 .0 0 0 1

相似文献   

Atrial and ventricular volume and function in persistent and permanent atrial fibrillation, a magnetic resonance imaging study.

Left atrial size is independently related to cardiovascular morbidity and mortality, and atrial fibrillation (AF) is strongly associated with atrial size. Our aims were to report atrial and ventricular dimensions in patients with AF evaluated with magnetic resonance imaging (MRI), and to assess the inter-study reproducibility of the measurements. Nineteen healthy volunteers, 19 patients with permanent AF, and 58 patients with persistent AF had cardiac dimensions evaluated by 6-mm cinematographic breath-hold MRI scans using a 1.5 Tesla Siemens Vision Magnetom scanner with a phased array chest coil. Intraobserver variability and inter-study reproducibility of the cardiac volumes and ejection fractions (EF) gave acceptable Bland-Altman plots, good correlations (R2: 0.80-0.99), and low reproducibility coefficients. The mean atrial volumes were similar in the two groups with AF [systolic vol. index (SVI): 75.9-80.3 mL/m2; diastolic vol. index (DVI): 77.4-82.1 mL/m2] and significantly different from the healthy volunteers (SVI: 30.3 mL/m2; DVI: 62.3 mL/m2; p < 0.0001). Mean left ventricular (LV) volumes and EF were significantly different in permanent AF (SVI: 34.2 mL/m2; DVI: 68.3 mL/m2; EF: 50.8%) compared to persistent AF [SVI: 44.0 mL/m2 (p = 0.02); DVI: 77.2 mL/m2 (p = 0.03); EF: 44.9% (p = 0.02)], and closer to the normal values (SVI: 22.4 mL/m2; DVI: 66.5 mL/m2; EF: 67.0%). MRI is a highly reproducible method for measurement of atrial and ventricular dimensions in healthy volunteers and in patients with AF. Our results suggest that atrial dilatation appears within the first months of AF and stays more or less unchanged thereafter. The LV appears to dilate early as a response to AF, but later seems to adapt.     

Sequential radial and circumferential strain and oxidative stress assessment in dogs with tachycardia-induced cardiac dysfunction

Quantitative analysis of left ventricular (LV) deformation based on two-dimensional speckle tracking echocardiography (2D STE) has increasingly been used to assess segmental and global function because conventional echocardiography is influenced by tethering effects of adjacent myocardium and cardiac translational motion. Hypothesis: (1) 2D STE can be useful to detect subtle regional changes in the LV contractility during development of tachycardia-induced cardiomyopathy (TIC) to heart failure in awake dog; (2) oxidized glutathione (GSSG) and reduced glutathione (GSH) levels are associated with the development of its respective segmental wall motion abnormalities (WMA). 6 healthy canine female Beagles were examined using 2D STE myocardial strain analysis before and for 8 weeks on week basis of rapid ventricular pacing (RVP) and at the end of study each myocardial segment were evaluated for oxidative status (GSH:GSSG ratio). 2D STE showed an initial peak of reduced global radial strain at 2 weeks of RVP in all three cardiac levels analyzed in which the affected segments showed a decreased transmural fiber shortening from anteroseptal to inferior segments distributed in helical pattern suggesting impaired contractility from part of left band to apical loop of spiral muscle band while global circumferential strain showed to be reduced since the fifth week of RVP particularly in the base and midventricular levels of ascending segment in clockwise direction from lateral to inferior segments. The most affected segments are localized in the lateral to posterior wall, however, segmental oxidative stress analysis did not show correlation with WMA detected by strain. 2D STE strain demonstrated to be a reliable tool for evaluation of LV myocardial deformation in TIC canine model showing an earlier significant WMA using radial strain and later using circumferential strain which may be of importance for improvement of diagnosis and therapy in naturally occurring canine cardiomyopathy and for earlier detection of WMA after suboptimal pacemaker lead placement.     

屏气磁共振电影成像对55岁以上健康成年人左心室功能的评价

目的采用屏气磁共振电影成像的方法,建立55岁以上健康成年人左心室功能参数的参考值范围.方法对55名55岁以上健康成年人行左心室短轴位电影成像,用心功能软件勾画心内外膜边界,计算左心室整体和局部功能指标.结果左心室整体功能指标:舒张末期容积:(74.4±11.3) ml; 收缩末期容积:(26.8±7.0) ml;每搏射血量:(47.5±7.0) ml;射血分数:(64.2±5.7)%;舒张末期质量:(51.5±11.8) g;收缩末期质量:(76.5±14.7) g.获得心尖层面前壁、侧下壁、室间隔和乳头肌、基底层面室壁、室间隔的舒张末期,收缩末期室壁厚度,室壁增厚率,室壁运动的参考值范围.结论建立了55岁以上健康成年人左心室整体和局部功能参数的参考值范围,为冠心病人心功能异常的判定提供参考标准.     

Patient motion compensation during transthoracic 3-D echocardiography

Bulk patient motion during transthoracic 3-D echocardiography (3DE) produces image plane misregistration and errors in left ventricular (LV) volume and ejection fraction (EF). To correct for patient motion, we used a magnetic locating system to track both the ultrasound transducer and the chest wall of the patient, so images could be registered in a patient-centered coordinate system ("correction"). Fourteen subjects each underwent 3DE, with deliberate patient motion, to measure LV volume and EF. Results were compared to magnetic resonance imaging (MRI). Without correction, 3DE differed significantly from MRI (EF: r = 0.78, SEE = 5.8%). Application of correction increased 3DE accuracy, despite patient motion (EF: r = 0.91, SEE = 3.7%), to a level comparable to that of 3DE in the absence of motion (EF: r = 0.93, SEE = 3.5%). Patient motion during 3DE examination can be corrected using a magnetic spatial location system.     

Relationship between acute strain pattern and recovery in tako-tsubo cardiomyopathy and acute anterior myocardial infarction: a comparative study using two-dimensional longitudinal strain

After acute-anterior myocardial infarction (AMI), left ventricular (LV) viable myocardial segments show some degree of active deformation (longitudinal shortening) despite wall motion abnormalities (WMA). Tako-tsubo cardiomyopathy (TTC) is characterized by myocardial stunning; however, it is unclear whether in TTC the strain pattern mimics AMI. To compare the strain-pattern in TTC and AMI using the 2D-longitudinal strain by speckle-tracking in segments with WMA, and its relationship with recovery of function at follow-up. 21 consecutive patients with typical TTC and 21 age-matched AMI patients treated by primary angioplasty had an analysis of LV-longitudinal strain at the acute-phase and at follow-up (1 and 6 months later for TTC and AMI respectively). The recovery of a segment was defined as normal wall motion at follow-up. Among the 706 analyzable LV-segments at the acute-phase, 406 had WMA (TTC 229, AMI 177). At follow-up, total recovery was observed for 45 % segments in AMI and 100 % in TTC, (p < 0.01). At the acute phase, systolic lengthening duration (47 ± 43 vs. 18 ± 33 %) and amplitude (0.25 ± 0.29 vs. 0.09 ± 0.19) and post systolic shortening (67 ± 53 vs. 39 ± 38 %) were higher in TTC, when compared to AMI-recovery (all, p < 0.01). In AMI, systolic lengthening duration was an independent predictor of poor recovery in multivariate analysis, linked to segmental longitudinal strain at follow-up (all, p ≤ 0.01). Furthermore, among the 57 % of segments exhibiting any systolic lengthening duration in AMI, only ¼ recovered, versus 62 % of such segments in TTC with 100 % recovery (p < 0.001). The systolic passive motion which is closely and inversely linked to recovery in AMI is paradoxically frequent and severe in TTC. This suggests that myocardial stunning in TTC and AMI is different according to longitudinal strain.     

Assessment of left atrial volumes in sinus rhythm and atrial fibrillation using the biplane area-length method and cardiovascular magnetic resonance imaging with TrueFISP.

OBJECTIVES: To determine whether the biplane area-length method can be used for the evaluation of left atrial volumes and ejection fraction with cardiovascular magnetic resonance imaging (CMR) by TrueFISP in normal subjects and patients with atrial fibrillation. BACKGROUND: Atrial fibrillation is the most common arrhythmia in elderly patients. Left atrial size and volumes play an important role in predicting short and long-term success after cardioversion. METHODS: Fifteen healthy subjects (mean age 65.6+/-6.4 years) and 18 patients (mean age 67.2+/-8.8 years) with atrial fibrillation were examined by CMR (Magnetom, Siemens, Erlangen, Germany). Images were acquired by TrueFISP using the horizontal and vertical long-axis plane to measure left atrial end-diastolic and end-systolic areas and longitudinal dimensions. Volumes were determined with commercially available software. Left atrial end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and ejection fraction (EF) were determined by the biplane area-length method and compared to findings obtained by the standard short-axis method. Images were acquired and analyzed a second time in the patients with atrial fibrillation. RESULTS: There was no difference in age between men and women (p=0.147) and healthy subjects and patients (p=0.128) included in the study. EDV and ESV were significantly higher and SV and EF significantly lower in patients with atrial fibrillation than in healthy subjects (p < or = 0.009), regardless of the method used. The values obtained for EDV and ESV by the biplane area-length method were significantly higher in both healthy subjects (p<0.001) and patients with atrial fibrillation (p<0.001) than those obtained by the standard short-axis approach, whereas SV (p> or = 0.057) and EF (p> or = 0.118) did not differ significantly. In the second investigation in patients with atrial fibrillation, ESV, SV, and EF did not differ significantly between the two methods (p> or =0.481). Assessment of interobserver variability revealed good agreement in the findings of the two observers, both in normal sinus rhythm and atrial fibrillation (overall variability 0.8+/-6.5%). CONCLUSIONS: The biplane area-length method can be used in CMR images obtained by TrueFISP to assess left atrial volumes and ejection fraction in normal subjects and patients with varying cardiac cycle length, as in atrial fibrillation.     

Adverse effect of increased left ventricular wall thickness on five year outcomes of patients with negative dobutamine stress

Background

To determine if patients without dobutamine induced left ventricular wall motion abnormalities (WMA) but an increased LV end-diastolic wall thickness (EDWT) exhibit a favorable cardiac prognosis.

Results

Between 1999 and 2001, 175 patients underwent a dobutamine stress cardiovascular magnetic resonance (DCMR) procedure utilizing gradient-echo cines. Participants had a LV ejection fraction >55% without evidence of an inducible WMA during peak dobutamine/atropine stress. After an average of 5.5 years, all participants were contacted and medical records were reviewed to determine the post-DCMR occurrence of cardiac death, myocardial infarction (MI), and unstable angina (USA) or congestive heart failure (CHF) warranting hospitalization.In a multivariate analysis, that took into account Framingham and other risk factors associated with cardiac events, a cine gradient-echo derived LV EDWT ≥12 mm was associated independently with an increase in cardiac death and MI (HR 6.0, p = 0.0016), and the combined end point of MI, cardiac death, and USA or CHF warranting hospitalization (HR 3.0, p = 0.0005).

Conclusion

Similar to echocardiography, CMR measures of increased LV wall thickness should be considered a risk factor for cardiac events in individuals receiving negative reports of inducible ischemia after dobutamine stress. Additional prognostic studies of the importance of LV wall thickness and mass measured with steady-state free precession techniques are warranted.     

Experience with an ultrasound stethoscope.

BACKGROUND: To test the diagnostic potential of the SonoHeart, a battery-powered hand-held ultrasound imaging device, in an outpatient clinic setting. METHODS: A total of 114 patients with a variety of cardiac diseases were examined by 2 independent cardiologists with the hand-held device using the standard echocardiographic system (SE) as a reference. Global right ventricular (RV) and left ventricular (LV) function (scored as normal, mildly to moderately, or severely reduced) and internal cavity dimensions were assessed. Regional wall motion of 6 segments using a 2-point score (1 = normal wall motion, 2 = abnormal wall motion) was evaluated in 34 patients on-line. RESULTS: There was a good agreement between the 2 imaging devices for evaluation of global LV (93%) and RV function (99%), regional wall motion (90%), dimensions of the LV (99%) and the RV (99%), and the left (96%) and right atria (99%). Furthermore, SonoHeart identified hypertrophic cardiomyopathy, pericardial effusion, and abnormalities of valves. CONCLUSION: The SonoHeart device allows rapid and accurate diagnosis, whenever needed in the outpatient clinic.     

定量组织速度成像技术评价急性心肌梗死后左室重构的左室功能

目的应用定量组织速度成像技术对心肌梗死后左室重构的左心功能进行评价,以探讨其应用价值.方法用定量组织速度成像技术测定22例健康者及临床确诊的29例心肌梗死后左室重构的冠心病患者的左室壁各节段的收缩期峰值速度(VS),舒张早期速度(VE),舒张晚期速度(VA)和VE/VA比值.测定二尖瓣口血流频谱的快速充盈速度(E),左房收缩充盈速度(A)和E/A值.容积法测左室射血分数,左室舒张末期容积指数(LVEDVI),左室收缩末期容积指数(LVESVI)及球形指数,并与正常组比较.结果心脏左室长轴方向上心梗组前壁,侧壁,下壁各节段,后间隔心尖段Vs明显下降(P＜0.01),后间隔基底段和中间段Vs无明显差异(P＞0.05);心梗组几乎各节段VE、VA、VE/VA与正常组相比有显著差异(P＜0.05).各节段平均VS与左室射血分数,球形指数等呈线性相关(r值分别为0.79,0.68,P＜0.01),舒张期功能参数平均VE/VA与二尖瓣E/A比值之间存在高度相关性(r=0.62,P＜0.01).心梗组LVEDVI和LVESVI明显增大(P＜0.01).结论定量组织速度成像可客观定位定量的反映心肌梗死局部心肌组织的收缩及舒张功能,又能体现心肌梗死后左室重构的整体功能,为心肌梗死后左室重构的心功能的评价提供了客观依据.     

A real-time three-dimensional echocardiographic validation of an intracardiac electrogram-based method for optimizing cardiac resynchronization therapy

INTRODUCTION: Although optimization of atrioventricular and interventricular delays has been demonstrated to improve hemodynamics in patients with cardiac resynchronization therapy (CRT), the required time-consuming procedure discourages its use in clinical practice. Recently, a new method for CRT optimization based on the intracardiac electrogram (IEGM) detected by the implanted leads, has been developed. We evaluated the effectiveness of this method in improving left ventricular (LV) asynchrony and performance using real-time 3D echocardiography (RT3DE). METHODS AND RESULTS: Twenty patients with CRT were prospectively studied. RT3DE was performed before and after IEGM optimization. The standard deviation of the time to the regional LV minimum systolic volume (Tmsv) for all 16 segments (Tmsv 16-SD), six basal and six mid segments (Tmsv 12-SD), and the six basal segments (Tmsv 6-SD) were assessed as a asynchrony indexes. LV end-diastolic and end-systolic volumes (EDV, ESV), stroke volume (SV), ejection fraction (EF), myocardial performance index (MPI), ejection time (ET), and filling time (FT), corrected by R-R interval, were also evaluated. After IEGM optimization, as compared with baseline Tmsv 12-SD and Tmsv 16-SD decreased (P = 0.01, P< 0.001, respectively), EF and SV improved (P < 0.001, P = 0.01 respectively), FT/RR and ET/RR increased (P = 0.02 for both), and MPI improved (P < 0.001). Tmsv 6-SD, EDV and ESV did not change. CONCLUSION: A simple IEGM-based method of CRT optimization decreased LV dyssynchrony and improved systolic function.