Validity of Electrocardiographic QT Interval in Predicting Left Ventricular Diastolic Dysfunction in Patients with Suspected Heart Failure.

OBJECTIVE To determine the validity of electrocardiographic QT interval in predicting left ventricular diastolic dysfunction in patients with suspected heart failure using echocardiogram as the gold standard. STUDY DESIGN Cross-sectional validation study. PLACE AND DURATION OF STUDY AFIC-NIHD, Rawalpindi, from December 2012 to June 2013. METHODOLOGY Patients with suspected heart failure undergoing 12-lead electrocardiogram and echocardiography were inducted. All electrocardiograms were analyzed by a single trained reader unaware of the echocardiographic findings. QTc interval was calculated according to the published guidelines. All patients underwent a complete M mode, 2 dimensional, Doppler, and tissue Doppler echocardiography using aiE33 ultrasound system and diastolic dysfunction was calculated. RESULTS Three hundred patients were studied. Descriptive statistics of age was 61.42 years ±10.43. Of all the patients 218 patients (72.7%) were male and 82 patients were female (27.3%). Mean QT interval (msec) was 427.29 ±54.69. One hundred and eighty patients (60.0%) had diastolic dysfunction and 120 patients (40%) had no diastolic dysfunction. The sensitivity of electrocardiographic QTc interval in predicting diastolic dysfunction was 71.11% and specificity was 88.11%. CONCLUSION Prolonged electrocardiographic QTc interval in patients with suspected heart failure is a useful tool in predicting diastolic dysfunction.