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 (PVC). 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 ECG recordings and fulfilled the inclusion criteria were retrospectively included in the study. Holter recordings were screened for heart rate variability (HRV), numbers of PVC, heart rate, pre and post coupling intervals (CI) in three different time intervals (24:00 to 08:00am, 08:00 am to 16:00 pm and 16:00pm to 24:00) . Forty three patients were defined as beta blocker responder group in respect to 70% decrease in PVCs burden. HRV analysis revealed that there were not statistically significant differences between beta blocker responder and non-responder group. CI ratio ((post-PVC CI+ pre-PVC CI)/Pre-PVC CI) of responder and non-responder 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% CI: 1,89-48.7, P value: 0.006) Night-time increased CI ratio i.e 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.