Spectrum, Management, and Prognosis of Cardiac Arrhythmias in Acute Coronary Syndrome: Insights from Northern India

Background: Cardiac arrhythmias are a major contributor to early morbidity and mortality in patients with acute coronary syndrome (ACS). Prompt recognition and appropriate management are essential, particularly in regions with limited access to prehospital cardiac care. Objectives: To evaluate the spectrum of arrhythmias, management strategies, and in-hospital outcomes among patients with ACS admitted to a tertiary care center in Northern India. Methods: This prospective and observational study included 300 consecutive patients admitted with ACS between January 2022 and December 2023. Clinically significant arrhythmias developed in 96 patients (32%). Demographic characteristics, infarct location, electrocardiographic findings, therapeutic interventions, and in-hospital outcomes were systematically recorded and analyzed. Results: Inferior wall myocardial infarction was more frequent among patients with arrhythmias (55.2%) compared with anterior wall infarction (44.8%). Complete heart block (CHB) was the most common arrhythmia (38.5%), followed by ventricular tachycardia (VT) (27.1%), atrial fibrillation (18.7%), high-grade atrioventricular block (9.4%), and ventricular fibrillation or other rhythms (6.3%). Management strategies included temporary pacemaker insertion in 52.1% of patients, percutaneous coronary intervention in 46.9%, thrombolysis in 29.2%, direct current cardioversion in 18.8%, and antiarrhythmic drug therapy in 64.6%. Overall in-hospital mortality was 18.7%, with the highest mortality observed in patients with VT (32.0%) and those with anterior wall myocardial infarction (27.3%). Conclusions: Arrhythmias complicate nearly one-third of ACS admissions and are associated with significant in-hospital mortality. CHB and VT were the most frequent and prognostically adverse arrhythmias. Early rhythm stabilization and timely reperfusion were associated with improved in-hospital outcomes.