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.