Coupling Interval Ratio to Predict the Beta-Blocker Response Against Premature Ventricular Complexes

Despite the wide-spread use of beta-blockers, unpredictable response and overall low efficacy are the major pitfalls of beta-blocker use for premature ventricular complexes (PVCs). Accordingly, we aimed to reveal Holter-guided electrocardiographic criteria to predict the beta-blocker responder ones of PVCs. A total of 89 patients who had pre- and post-treatment Holter electrocardiogram recordings and fulfilled the inclusion criteria were retrospectively included in the study. Holter recordings were screened for heart rate variability, number of PVCs, heart rate, pre- and postcoupling intervals (CIs) in 3 different time intervals (24:00-08:00 am , 08:00 am -16:00 pm and 16:00 pm -24:00). Forty-three patients were defined as beta-blocker responder group with respect to 70% decrease in PVCs burden. Heart rate variability analysis revealed that there were not statistically significant differences between beta-blocker responder and nonresponder groups. CI ratio [(post-PVC CI + pre-PVC CI)/pre-PVC CI] of responder and nonresponder groups in 24.00 to 8.00 am time interval was statistically different (3.19 vs. 2.91, P = 0.006, respectively). Logistic regression analysis revealed that CI ratios of the PVCs during the 24:00-08:00 am intervals have significantly associated with the beta-blocker responsiveness for PVCs (odds ratio, 9.54; 95% confidence interval, 1.89-48.7; P value: 0.006). Nighttime increased CI ratio, that is, shorter CI time has been found to be an independent predictor of beta-blocker response against PVCs. Therefore, beta-blockers may be preferably recommended for PVCs, especially in those with shorter CI or increased CI ratio.