Clinical investigation: Utility of left ventricular end diastolic diameter in the prediction of susceptibility to ventricular tachyarrhythmias

Background Prior studies have shown the utility of using both QRS duration and QT dispersion (QTd) as predictors of risk for ventricular tachyarrhythmias (VA). Lengthening of the QRS duration represents dyssynchrony of regional myocardial wall contraction, and increased QTd similarly represents variations in myocardial repolarization. We sought to examine the left ventricular end diastolic diameter (LVEDD) as a predictor of VA susceptibility. Methods Eighty-eight patients referred for electrophysiologic (EP) studies were evaluated. EP testing was performed using a standard protocol of up to three extrastimuli. QTd and QRS duration analyses were performed in a blinded manner. Values were defined as abnormal if QRS duration > 120 ms, QTd > 60 ms, and LVEDD > 6 cm. Results Of 88 patients (65 males; 23 females; mean age 67 ± 15 years), 33 were inducible by EP testing. Patients with either increased QRS duration or QTd are shown to be at greater risk for VA inducibility. LVEDD is a strong predictor of inducibility for VA (p < 0.02 between inducible and non-inducible patients). LVEDD in combination with QRS duration and QTd, further strengthens predictability for VA (p < 0.03 for QRS duration and p < 0.02 for QTd) with a trend towards inducibility as each value increases. Combination of the three parameters of QRS duration, QTd, and LVEDD was 91% sensitive for the identification of those patients inducible for VA. Conclusion The LVEDD is an echocardiographic value that strongly predicts VA inducibility, and when combined with QRS duration and QTd, identifies patients at higher risk for these tachyarrhythmias.