Impacts of Mitral E/e′ on Myocardial Contractile Motion and Synchronicity in Heart Failure Patients With Reduced Ejection Fraction: An Exercise–Echocardiography Study

Abstract

The association between diastolic abnormality and postexercise contractile decompensation is uncertain in heart failure (HF) patients with reduced left ventricular ejection fraction (LVEF). The higher mitral E/annular early diastolic velocity (E/e') is relevant to postexercise regional myocardial contractile maladaptation. Seventy HF patients with LVEF <50 % (56 males, 58 ± 15 years) were studied pre- and postexercise using tissue Doppler echocardiography. We evaluated the mean and standard deviation of systolic myocardial velocity (Sm) and electromechanical delay (Ts) of 12 left ventricular segments, and further analyzed the corresponding changes of septal and posterolateral segments. The higher mitral E/e' was associated with more blunted heterogeneity of Sm and greater ventricular dyssynchrony after exercise. This is due to the posterolateral wall not being able to increase Sm with exercise to the same degree as the septum (decreased posterolateral/septal Sm ratio). Furthermore, the postexercise aggravated difference of Ts between septum and posterolateral segments leads to more dyssynchronous contraction in the higher E/e' groups. An E/e' ≥10 predicted a postexercise posterolateral/septal Sm ≤ 1 (odds ratio [OR]: 5.8, 95% confidence interval [CI]: 1.5-22.6, P = 0.011), and a difference of Ts between septum and posterolateral segments >65 ms (OR: 64, 95% CI: = 6-651, P < 0.001) in HF patients with reduced LVEF in multivariate analysis. The higher mitral E/e'-related postexercise maladaptation of myocardial contractile motion and synchronicity suggests the involvement of systolic abnormality in exercise pathophysiology in HF patients with reduced LVEF.