CORRELATION BETWEEN VENTRICULAR ACTIVATION TIME FROM 12-LEAD ECG AND LEFT VENTRICULAR SYSTOLIC FUNCTION IN PATIENTS DIAGNOSED WITH HYPERTENSION

Abstract

Background: Hypertension is a cardiovascular risk factor which could lead pressure overload in left ventricle then causing diastolic and systolic dysfunction. Echocardiography has important role to assess heart structure and function in hypertensive patients, still the myocardial changes actually has occurred before remodelling of left ventricle. Electrical changes of the heart would develop first, which ventricular activation time (VAT) duration from ECG increased in left ventricular hypertrophy. This condition is closely related to course of hypertensive disease. The aim of this study is to investigate correlation between VAT and left ventricular ejection fraction in hypertensive patients.

Method: Data were collected from 60 consecutive patients with hypertension whom visiting policlinic in Cardiac Centre Haji Adam Malik General Hospital Medan. Data of VAT (Q-T interval) from ECG and left ventricular ejection fraction (LVEF) form echocardiography were collected and analyzed. Then the duration of VAT and LVEF changed were assessed. Statistical analysis was performed using correlation and comparative test, including scatter-plot graphic.

Result: Among 60 hypertensive patients as total subject, divided to 30 subjects with diastolic heart failure and 30 subjects with systolic heart failure. Mean of VAT duration from total subject was 42 miliseconds and mean of LVEF was 45.71%, while mean of LVEF in diastolic heart failure group was 56% and mean of LVEF in systolic heart failure group was 35.43%. Spearman correlation test was used to assess relationship between VAT and LVEF, the result showed there was reverse correlation with p < 0.001 and had strong correlation with coefficient r = - 0.789. Then Mann-Whitney comparative test was performed to compare VAT between diastolic heart failure group and systolic heart failure group, the result showed statistically significant difference between 2 groups.

Conclusions: VAT duration from ECG in hypertensive patients and LVEF have reverse correlation, which means the increasing of VAT duration related to the decreasing of LVEF. Besides, there is a significant difference of VAT duration of hypertensive patients between diastolic heart failure and systolic heart failure with mean cut-off value is 44.68 miliseconds.