Background: Fragmented QRS on the ECG is a straightforward, affordable, and widely accessible indicator of myocardial fibrosis and scarring. This study aimed to assess the predictive value of (fQRS) in diagnosing myocardial ischemia. It evaluated its incremental prognostic significance in patients having single-photon emission computed tomography (SPECT) for exercise-induced myocardial ischemia. Methods: This observational case-control research was executed on 206 patients (52 with myocardial ischemia and 154 controls) who underwent exercise myocardial perfusion SPECT for suspected CAD. All patients were subjected to demographic, clinical, and laboratory data, electrocardiography, echocardiography, and SPECT myocardial perfusion imaging. The existence of fQRS was determined based on electrocardiographic criteria. Multivariate logistic regression analysis was applied to predict myocardial ischemia, and the incremental prognostic value of fQRS was determined utilizing hierarchical regression analysis. Results: The patients had a mean age of 53 ±10 years, and more than one-quarter (28.2%) had fQRS. Patients with myocardial ischemia (Group I) had a greater prevalence of fQRS than the control group fQRS (42.3% vs. 23.4%, P = 0.009). In multivariate analysis, fQRS significantly predicted myocardial ischemia (OR = 2.298, 95% CI = 1.102 – 4.792, P = 0.026). Furthermore, compared to traditional risk factors and a combination of conventional risk factors and STT alterations, the fQRS demonstrated an added predictive value (Global X2 = 34.612). Conclusions: Fragmented QRS complex is a promising ECG marker significantly associated with myocardial ischemia. Its inclusion in risk assessment models enhances predictive accuracy, aiding early CAD diagnosis and risk stratification. |