Value of the Paced QRS Duration

Background: The value for paced QRS duration (pQRSd) to detect left ventricular (LV) dysfunction in right ventricular apex (RVA)-paced patients has not been evaluated. Methods and Results: A total of 272 RVA-paced patients, including, 99 with LV systolic dysfunction (LVSD) and 173 without LVSD, were enrolled in this study. The pQRSd, echocardiographic variables, and plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) levels were measured. Relationships between pQRSd and echocardiographic variables, NT-proBNP levels, and New York Heart Association (NYHA) functional classification were analyzed. pQRSd was correlated with LV end-diastolic and end-systolic dimensions (beta = 1.59 and 1.54, respectively; all P < .001), NT-proBNP levels (beta = 12.98, P < .001) and LV ejection fraction (beta = -109.25, P < .001). There was a stepwise increase in pQRSd with increasing NYHA Class (all P < .001). The pQRSd cutoff value of 200 ms, derived from the receiver operator characteristic curve, had sensitivity of 71.72% and specificity of 86.71% to detect LVSD. pQRSd >= 240 ms gave a positive predictive value of 100%, whereas < 180 ms excluded > 97.3% of patients with LVSD. Conclusions: In RVA-paced patients, pQRSd is correlated with left ventricular structures and function and pQRSd of 200 ms is a satisfactory cutoff value in terms of sensitivity and specificity for detecting LVSD. (J Cardiac Fail 2009;15:347-352)