The Correlation between Strain and Strain Rate Left Ventricle with Functional Capacity in Post Myocardial Infarction Patients with Heart Failure

Myocardial infarction (MI) may alter left ventricular (LV) systolic function, which, in turn, may reflect on functional capacity. Objective systolic function assessment using 2D speckle-tracking echocardiography is promising to assess the correlation between LV longitudinal strain and strain rate with functional capacity in post-MI patients with heart failure. A cross-sectional study was done on 33 consecutive post-MI patients with class I-II NYHA heart failure visiting the cardiology outpatient clinic of Dr. Soetomo General Hospital, Surabaya. The resting echocardiogram was taken, followed by a treadmill stress test using Naughton protocol. Appropriate statistical analyses were used to determine the correlation of systolic longitudinal strain and strain rate with exercise capacity. Study subjects were 69.7% males with age 58.45±6.2 years old. EF by Biplane was 40.55±8.26%; with global peak longitudinal strain-12.23±5.19%, and strain rate-0.67±0.25s^-1; and peak exercise capacity 3.69±1.8 METs. Using Pearson's test, there was a strong negative correlation of systolic longitudinal strain and strain rate with functional capacity (r =-0.577, r =-0.607respectively; p<0.05). LV systolic longitudinal strain and strain rate were strongly correlated with functional capacity in post-MI patients with heart failure.