Systolic Strain Rate In Left Ventricular Dysfunction Caused By Rheumatic Chronic Severe Mitral Regurgitation.

BACKGROUND

In rheumatic severe mitral regurgitation, earlier detection of left ventricular dysfunction is very necessary in order to refer the patients for surgery at appropriate time. This study tried to find a correlation between conventional parameters of left ventricular dysfunction with systolic strain rate.

METHODS

A descriptive correlational study conducted from September 2016 to March 2018. One hundred and ninety-two patients of severe rheumatic MR and fifty-eight healthy controls were included. Left ventricular ejection fraction (LVEF), end diastolic dimension (LVEDD) and end systolic dimension (LVESD) were measured. Healthy controls were taken as group-I and patients were divided into group-II (ejection fraction ≥60% and LVESD ≤40 mm), group-III (ejection fraction ≥60% and LVESD ≤41-50 mm), and group-IV (ejection fraction <60%). Systolic strain rate at medial wall (SSR-med), at lateral wall (SSR-lat) and average of both (SSR-avg) were also measured by tissue doppler method for each study subject.

RESULTS

Out of 250 study subjects, males were 113 (45.2%) and females were 137 (54.8%). Means of the age, LVEF, LVEDD and LVESD were 30.8±9.1, 60.0±8.3, 58.5±7.8 and 37.4±9.9 respectively. Group I, II, III and IV contained 58, 69, 67 and 56 subjects respectively. Comparing these groups, mean LVEF progressively decreased from 63.9%±2.2 in group-I to 46.2±6.5 in group-IV while means of LVEDD and LVESD progressively increased from 45.9±3.5 and 23.2±2.3 in group-I to 64.3±3.6 and 49.0±2.9 in group-IV respectively. Average systolic strain rate (SSR-avg) decreased progressively from 1.57±0.06 in group-I to 0.83±0.08 in group-IV. All the strain rates, i.e., SSRmed, SSR-lat and SSR-avg showed significant negative correlation with left ventricular dysfunction, i.e., the group number (p<0.001).

CONCLUSIONS

Systolic strain rate measured by tissue doppler method have significant negative correlation with left ventricular dysfunction in patients having rheumatic chronic severe mitral regurgitation.