Clinical investigation
Heart failure/cardiomyopathy
Assessment of Longitudinal and Radial Ventricular Dyssynchrony in Ischemic and Nonischemic Chronic Systolic Heart Failure: A Two-Dimensional Echocardiographic Speckle-Tracking Strain Study

https://doi.org/10.1016/j.echo.2007.05.031Get rights and content

Background

Current guidelines recommend a QRS greater than or equal to 120 milliseconds to select candidates for cardiac resynchronization therapy. However, ischemic and nonischemic cardiomyopathies are two different entities and they might be selected following different approaches. We sought, thus, after a validation the new 2-dimensional (2D) speckle-tracking strain (STS) against color Doppler tissue imaging (DTI)-strain (S) to compare the different correlation between electrical and mechanical dyssynchrony (DYS) in ischemic and nonischemic cardiomyopathies.

Methods

We measured: (1) QRS duration; (2) mechanical interventricular DYS (the difference between preaortic and prepulmonary ejection times); (3) left intraventricular DYS (the SD of time-to-peak of longitudinal DTI-S); and (4) longitudinal and radial 2D-STS in the basal and middle segments of lateral and septal left ventricular walls in 95 patients with chronic heart failure caused by ischemic (n = 49) or nonischemic (n = 46) heart disease. Twelve healthy control subjects were also explored.

Results

Mechanical interventricular DYS was correlated (DTI-S: P < .001) with QRS-duration, but not in ischemic heart disease. DTI-S and 2D-STS measurements were correlated (R = 0.6, P < .001) in the overall population. Longitudinal 2D-S DYS was correlated with QRS duration in patients with nonischemic, (P = .003) but not with ischemic heart disease, whereas radial 2D-S DYS was correlated with QRS width in both subgroups (r = 0.48, P = .003, and r = 0.43, P = .003, respectively).

Conclusions

The profile of DYS is influenced by the underlying cause of heart failure. The 2D-STS is a new tool for cardiac DYS assessment. Its ability to measure both longitudinal and radial intraventricular DYS is noteworthy.

Section snippets

Methods

The study enrolled 95 patients in chronic, stable, NYHA functional class II to IV with a LV EF of 40% or less, and a LV end-diastolic diameter of 55 mm or greater. In all, 11 patients were excluded from the analysis because of suboptimal echocardiographic images. Patients were selected for the study in stable, optimally pharmacologically treated, condition. None of the patients were congestive at the time of the echocardiographic examination. The study was in compliance with the rules of the

Study Groups

Between May and September 2005, 95 consecutive patients presenting with chronic systolic HF (LV EF ≤40%, and LV end-diastolic diameter ≥55 mm) were included in this study. The underlying heart disease was ischemic cardiomyopathy (ICM) in 46 patients non-ICM (NICM) in 49 patients. The baseline characteristics of the two study groups are presented in Table 1, as are the characteristics of the control population.

Mean LV EF and QRS duration were similar in both groups. All patients were optimally

Discussion

This study showed that ventricular DYS can be assessed by analyzing longitudinal and radial 2D-STS from a single apical view. This new means of myocardial mechanical properties quantification is very promising. Different profiles of DYS were found, which were influenced by the underlying cause of HF. ICM and NICM appeared to have different myocardial contractile behaviors that resulted in different electromechanical correlates.

References (35)

Cited by (0)

View full text