Frequency and Pattern of Ventricular Tachyarrhythmias within 48 Hours Following Acute ST-Elevation Myocardial Infarction: A Prospective Observational Study

Abstract

Objectives: To determine the frequency and pattern of ventricular tachyarrhythmias occurring within 48 hours of acute ST-elevation myocardial infarction (STEMI). Methodology: This prospective observational study was conducted in the Department of Cardiology, Shaikh Zayed Hospital, Lahore, from 12 September 2025 to 10 February 2026 after obtaining ethical approval (Ref No: 02-TERC/NHRC-SZH/INT-SC/870). A total of 181 consecutive patients aged 18–80 years presenting with acute STEMI were enrolled after providing informed consent. All participants underwent continuous cardiac telemetry monitoring and serial 12-lead electrocardiography during the first 48 hours following admission. Ventricular tachyarrhythmias, including ventricular tachycardia and ventricular fibrillation, were identified and recorded according to predefined diagnostic criteria. Data were analyzed using SPSS version 26. Quantitative variables were summarized using mean and standard deviation, whereas categorical variables were expressed as frequencies and percentages. A p-value ≤0.05 was considered statistically significant. Results: The mean age of the study population was 53.22 ± 14.85 years, and 119 (65.7%) participants were male. Ventricular tachyarrhythmias occurred in 30 patients, corresponding to an overall frequency of 16.6% (95% CI: 11.2%–22.0%). Among affected patients, ventricular tachycardia was observed in 17 (56.7%) patients and ventricular fibrillation in 13 (43.3%). Patients aged 51–80 years demonstrated a significantly higher frequency of ventricular tachyarrhythmias compared with those aged 18–50 years (21.2% vs. 8.8%, p = 0.030). No significant association was observed between ventricular tachyarrhythmias and gender (p = 0.591). Conclusion: Ventricular tachyarrhythmias occurred in approximately one-sixth of patients during the first 48 hours following acute STEMI, with ventricular tachycardia being more common than ventricular fibrillation. Older age was associated with a significantly higher frequency of arrhythmias. These findings underscore the importance of continuous cardiac monitoring during the early post-infarction period to facilitate timely detection and management of potentially life-threatening ventricular arrhythmias.