Myocardial systolic synchrony measured by Doppler tissue imaging as a role of predictor of left ventricular ejection fraction improvement in severe congestive heart failure

Prognostic value of intraventricular dyssynchrony according to clinical stage of left ventricular impairment

Intraventricular dyssynchrony has prognostic implications in patients who have severe functional limitation and decreased ejection fraction. Patients with less advanced cardiac disease often exhibit intraventricular dyssynchrony, but there is little available information about its prognostic relevance in such patients. We investigated the prognostic effect of intraventricular dyssynchrony on outcome in 318 patients with known or suspected coronary artery disease who were classified according to the presence or absence of left ventricular dysfunction and heart failure symptoms. Mortality was considered the primary end point over a median follow-up of 56 months, and a Cox proportional hazards model was used for survival analysis. Despite a low prevalence (8%) of left bundle branch block, there was a high prevalence of intraventricular dyssynchrony even in patients without symptomatic heart failure. The magnitude of intraventricular dyssynchrony correlated poorly with QRS duration (r = 0.25), end-systolic volume index (r = 0.27), and number of scar segments (r = 0.25). There were 58 deaths during follow-up. Ventricular volume, ischemic burden, and magnitude of intraventricular dyssynchrony predicted outcome, but magnitude of intraventricular dyssynchrony was an independent predictor of survival only in patients with asymptomatic left ventricular dysfunction. In conclusion, patients with known or suspected coronary artery disease have a high prevalence of intraventricular dyssynchrony. Although ventricular volume, ischemic burden, and intraventricular dyssynchrony are potentially important prognostic markers, the relative importance of intraventricular dyssynchrony changes with the clinical setting and may be greatest in patients with preclinical disease.

Usefulness of Ventricular Longitudinal Contractility Assessed by Doppler Tissue Imaging in the Prediction of Reverse Remodeling in Patients with Severe Left Ventricular Systolic Dysfunction

OBJECTIVE

We sought to test if assessment of ventricular longitudinal contractility (LC) by Doppler tissue imaging (DTI) can predict reverse remodeling (RR) of left ventricular (LV) dysfunction resulting from medical treatment.

METHODS

DTI was performed in 35 patients with nonischemic LV dysfunction (ejection fraction 26 +/- 7%) and LC was assessed at the 4 different basal segments of the LV walls (septal, lateral, inferior, and anterior) using myocardial velocity curves and strain measurements; the peak systolic or delayed longitudinal contraction velocity of LV walls only with concomitant negative strain were measured and added to represent LC of each patient (LC by DTI). Successful RR was defined as a reduction of LV end-systolic volume of greater than 15%.

RESULTS

RR was observed in 13 patients (37%, group A). Initial LV ejection fraction was similar in patients who did and did not achieve RR (group B). Compared with group B, group A showed shorter QRS interval (110 +/- 36 vs 136 +/- 28 milliseconds, P = .022), shorter symptom duration (2.3 +/- 3.5 vs 4.2 +/- 3.4 years, P = .047), lower prevalence of left bundle branch block (23% vs 59%, P = .039), and higher value of LC by DTI (9.6 +/- 3.5 vs 6.3 +/- 3.6 cm/s, P = .011). Multivariate analysis revealed that symptom duration less than 2 years (odds ratio = 8.0, 95% confidence interval = 1.3-47.2, P = .022) and LC by DTI (odds ratio = 1.3, 95% confidence interval = 1.0-1.7, P = .019) were independent predictors of RR.

CONCLUSIONS

DTI provides a new index of LC, which is useful for predicting RR in patients with severe LV dysfunction.

Echocardiographic Assessment of Ventricular Asynchrony in Dilated Cardiomyopathy and Congenital Heart Disease: Tools and Hopes

Ventricular dyssynchrony is a relatively common problem in patients with heart failure, in particular those with wide QRS complex, and appears to have a deleterious effect on the natural history of heart failure, as it has been associated with increased mortality. Mechanistic studies, observational evaluations, and randomized trials have consistently demonstrated the beneficial effects of cardiac resynchronization therapy (CRT) in patients with moderate-to-severe chronic systolic heart failure and ventricular dyssynchrony who have failed optimal medical treatment. However, despite the promising results, it is estimated that in approximately 30% of patients undergoing CRT, the symptoms of heart failure do not improve or become even worse. One of the most important reasons for this failure is probably the lack of distinct mechanical dyssynchrony before implantation. A number of echocardiographic tools have been developed during the past 3 years for quantitative measurement of the severity of dyssynchrony before and after CRT. This review discusses the actual and potential role of different echocardiographic techniques in selection of patients and optimization of CRT and the value of some new clinical applications such as in congenital heart disease.