Assessment Of The Systolic Synchrony Of Left Ventricular Wall In Chronic Heart Failure Patients By Tissue Velocity Imaging

PART one Preliminary study of the post-systolic shortening of left ventricular wall in chronic heart failure patientsObjective To study the post-systolic shortening (PSS) during isovolumic relaxation phase and its clinical meanings in regional myocardium in chronic heart failure (CHF) patients.Methods Left ventricular regional myocardium movement in 60 CHF patients (CHF group) and 30 normal persons (control group) were assessed by Tissue Velocity Imaging (TVI). Qlab software was used to measure the systolic peak velocity (Vs), regional systolic time (Ts), post-systolic shortening velocity (Vpss) and post-systolic shortening time (Tpss) at the basal and middle levels of left ventricle.Results In CHF group, the rate of isovolumic relaxation phase PSS was 34% both in basal and mid segments, the rates of pathological PSS were 29% and 30% respectively. The rates of isovolumic relaxation phase PSS in basal and mid segments in normal persons were 27% and 21%, none of them was pathological. Compared with the physiological PSS of control group, the pathological PSS of CHF group had a higher peak velocity and a longer time(P<0.05-0.01).Conclusion The pathological PSS of CHF group is obviously different from the physiological PSS of control group. The peak velocities of pathological PSS is higher and the duration is longer, it may be one of causes which lead to the asynchronous movement of left ventricle in CHF group.PART two Assessment of left ventricular systolic synchrony in heart failure patients with normal and wide QRS duration using tissue velocity imagingObjective To evaluate the prevalence of Synchrony in heart failure patients with difference QRS duration using tissue velocity imaging.Methods Forty heart failure patients with idiopathic dilated cardiomyopathy (23 with wide QRS complex , 17 with normal QRS complex) underwent standard tissue velocity imaging examinations. TVI was used to measure the standard deviation of the time to regional peak systolic velocity (Ts) of 12 LV segments in ejection phase (Ts-SD-12- ejection). Intraventricular dyssynchrony was defined as a delay of 32.6ms of Ts-SD-12.The incidence of dyssynchrony between two groups was compared.Results The study found that all the patients with different QRS duration had synchronized left ventricular systolic movement.Dyssynchrony was observed in 29.41% heart failure patients with normal QRS complex versus 78.26% patients with wide QRS complex.There was a significant difference between the prevalence of dyssynchrony derived from echo criteria in two groups ( P<0.05-0.01).Conclusion Dyssynchrony is commonly seen in patients with chronic heart failure regardless of QRS duration. The prevalence of dyssynchrony is significantly related to QRS duration. Tissue velocity imaging technique is more sensitive than the QRS duration to evaluate the dyssynchrony,and could be used to choose suitable patients for CRT.