Holter Parameters Predicting Premature Ventricular Contractions Response to Propranolol

Background: Premature ventricular complexes (PVCs) are common in cardiology and can sometimes lead to symptoms and left ventricular dysfunction. Beta-blockers (BB) are often used for treatment, but the response varies among patients. Holter monitoring offers valuable insights into predicting responsiveness to BB therapy. Objective: To identify Holter parameters that predict the response of PVCs to propranolol in patients with symptomatic PVCs and structurally normal hearts. Methods: This prospective observational study enrolled 60 patients. All patients had symptomatic PVCs, a structurally normal heart, and no contraindications to beta-blockers. Holter monitoring was conducted before and 2-4 weeks after treatment with maximally tolerated propranolol. PVC burden, heart rate prior to PVCs, coupling intervals, QRS duration, and heart rate variability (SDNN) were assessed before and 2-4 weeks after treatment with propranolol. Results: The study included 38 responders and 22 non-responders. Responders predominantly had outflow PVCs (P=0.003) and fixed coupling intervals (P=0.003), while non-responders had non-outflow PVCs and non-fixed intervals. Responders also exhibited higher heart rates (130 bpm vs. 89.7 bpm, P<0.001) and increased SDNN (129.1 bpm vs. 77.27 bpm, P<0.001). However, QRS duration and interpolation were not significant predictors of response. Conclusion: Holter parameters such as PVC localization, coupling interval variability, heart rate, and SDNN can effectively predict the response of PVCs to propranolol, aiding in personalized therapy for patients with symptomatic PVCs.