Real-time myocardial contrast echocardiography can predict functional recovery and left ventricular remodeling after revascularization in patients with ischemic heart disease.

BACKGROUND: Previous studies showed that preservation of microvascular integrity after myocardial ischemia was associated with myocardial viability. Real-time myocardial contrast echocardiography (RT-MCE) is a promising modality for non-invasive evaluation of microcirculation perfusion. Thus, it provides a unique tool to detect myocardial viability. We sought in this study to investigate the role of RT-MCE in predicting left ventricular (LV) functional recovery and remodeling after revascularization in patients with ischemic heart disease. METHODS: Thirty-one patients with ischemic heart disease and resting regional LV dysfunction were included. LV volume, global and regional function were evaluated by echocardiography before and 6 - 9 months after revascularization. RT-MCE was performed before revascularization using low mechanical index power modulation imaging. Myocardial contrast opacification of dysfunctional segments was scored on a 3-point scale and mean contrast score in dysfunctional segments was calculated. Patients were divided into 2 groups according to mean contrast score in dysfunctional segments: group A, patients with mean contrast score = 0.5 (n = 19); group B, patients with mean contrast score < 0.5 (n = 12). RESULTS: Wall motion improvement was found to be 94.5%, 45.5% and 16.1% respectively (P < 0.01) in homogenous, patchy and absent contrast opacification segments. At baseline, there was no significant difference in LV volume and global function between the two groups. After revascularization, group B had significantly larger LV end-diastolic volume (LVEDV) and LV end-systolic volume (LVESV), lower LV ejection fraction (LVEF) and higher wall motion score index (WMSI) than those of group A (all P < 0.05). Revascularization was followed by significant improvement of LV volume and recovery of global LV function in group A (all P < 0.01); however, in group B, after revascularization, deterioration of LVEDV (P < 0.05) was observed, moreover LVESV, WMSI and LVEF did not change significantly. CONCLUSIONS: The maintenance of myocardial microcirculation detected by RT-MCE can predict functional recovery and LV remodeling after revascularization in patients with ischemic heart disease, which might be helpful in clinical decision-making and risk stratification.

Assessment of left ventricular systolic synchronicity by real-time three-dimensional echocardiography in patients with dilated cardiomyopathy.

BACKGROUND: Recent advances in real-time three-dimensional echocardiography (RT3DE) offer the potential to assess the left ventricular (LV) dyssynchrony simultaneously by analyzing the 17 segments time-volume curves. The purpose of this study was to test the feasibility and accuracy of RT3DE for quantitative evaluation of left ventricular systolic synchronicity. METHODS: Twenty-four patients with dilated cardiomyopathy (DCM) and twenty-five healthy volunteers were enrolled in this study. Full volume RT3DE was performed by using Philips IE33 with X3-1 probe. The global and 17-segmental time-volume curves were obtained by the on-line Qlab software (version 4.2). The time to minimal systolic volume in each segment (T(msv)) was taken to derive the following indexes of systolic asynchrony: T(msv) 16-SD, T(msv) 16-Dif, T(msv) 12-SD, T(msv) 12-Dif, T(msv) 6-SD and T(msv) 6-Dif, which meant the standard deviation or the maximal difference of T(msv) among the 16, 12 and 6 segments of the left ventricle respectively. The software also provided with each of the above parameters as a percentage of the cardiac cycle. RESULTS: T(msv) 16-SD, T(msv) 12-SD and T(msv) 6-SD were all significantly larger in the DCM group than those of the control group [T(msv) 16-SD: (52.9 +/- 40.6) ms vs (8.8 +/- 6.2) ms; T(msv) 12-SD: (29.5 +/- 30.8) ms vs (6.9 +/- 4.0) ms; T(msv) 6-SD: (28.9 +/- 34.6) ms vs (7.0 +/- 4.7) ms, all P < or = 0.001]. T(msv) 16-Dif, T(msv) 12-Dif and T(msv) 6-Dif were also significantly larger in the DCM group. There were close negative relations between the LVEF determined by RT3DE and each of the indexes of systolic asynchrony, among which the indexes of T(msv)-16-SD% and T(msv)-16-Dif% correlated most closely (r = -0.703 and r = -0.701, respectively). The DCM patients had significantly larger EDV and ESV, with significantly reduced LVEF compared with the healthy subjects. CONCLUSION: RT3DE provides a simple, useful and unique approach to assess the systolic synchronicity of all the left ventricular segments simultaneously.

Quantification of left ventricular mechanics using vector-velocity imaging, a novel feature tracking algorithm, applied to echocardiography and cardiac magnetic resonance imaging.

BACKGROUND: Tagged magnetic resonance imaging (MRI) is the non-invasive golden standard to measure myocardial deformity. Tissue Doppler Imaging can be used to assess myocardial deformity, however, it has the limitation of angle-dependence. Our study aimed to compare left ventricular torsion and strains measured by velocity-vector imaging (VVI) using echocardiography (echo-VVI) and MRI (MRI-VVI), and to validate them against harmonic phase tagged MRI (HARP MRI). METHODS: A total number of 34 subjects (14 normal and 20 patients) were evaluated. Apical and basal image of left ventricular short axis view were acquired for measurements of apical and basal rotation, circumferential and radial strain using both echo-VVI and MRI-VVI. An apical four-chamber view was obtained for measuring the distance between the apical and basal levels. RESULTS: The correlations of segmental rotations, circumferential and radial strains were high between echo-VVI and HARP MRI, while the agreement of apical rotation was poor. Left ventricular torsion showed much better correlation and agreement between echo-VVI and HARP MRI than apical rotation: the coefficient was 0.97, P < 0.001. The correlation between MRI-VVI and HARP MRI in quantifying rotational parameters and strains was similar with echo-VVI and HARP MRI. Echo-VVI could discriminate normal and dysfunctional ventricles on either hypertensive or dilated cardiomyopathy. CONCLUSION: The data from this study show that (1) it is feasible to quantify left ventricular torsion and myocardial strain using echo-VVI and MRI-VVI in normal subjects, patients with left ventricular global systolic dysfunction and segment systolic dysfunction; (2) the agreement among all mechanical parameters derived from echo-VVI, MRI-VVI, and HARP MRI remained with clinically acceptable ranges.