Objectives: Aim of this study was to find whether ticagrelor increased the frequency of bradyarrhythmic events as compared to clopidogreland also to establish association of these clinical bradyarrhythmias with ventricular pauses within 24-hours of onset of Acute Coronary Syndromes(ACS) in hospitalized patients. Methodology: A cross-sectional study was conducted at Armed Forces Institute of Cardiology and National Institute of Heart Diseases, Rawalpindi, from 1st April 2022 to1st September 2022. A total of 136 patients presenting with ACS were divided in two groups, to compare study drugs ticagrelor and clopidogrel. In-hospital continuous electrocardiographic (cECG)recording was performed for 24 hours. Number of ventricular pauses lasting at least 3 second were recorded. Adverse symptomatic bradycardic events related to these pauses were documented. Results: 24-hours cECG recordings for two study groups ticagrelor and clopidogrel (n=68 each) showed high frequency of ventricular pauses ≥3 sec in ticagrelor group than clopidogrel (7.9% vs 4.6%, p=0.218 ) .While mostof the pauses due to ticagrelor therapy were asymptomatic and sinoatrial (SA) inorigin(6.3% vs.3.03%, p=0.187).While symptomatic bradyarrhythmic events were in excess in ticagrelor group as compared to clopidogrel(syncope: 4.68% vs 1.52%) Conclusion: Ventricular pauses were in excess in ACS- patients who received ticagrelor as compared to clopidogrel. Mostly these were asymptomatic pauses,SA nodal inorigin, andoccurred in excess during the acute phase(within 12-24 hours) of coronary syndromes.

Acute Coronary Syndrome; Ticagrelor, Bradyarrhythmia.