Fragmented QRS complexes on electrocardiography may reveal subtle myocardial structural and functional abnormalities not captured by conventional metrics such as left ventricular ejection fraction or mass index. Data presented at the European Society of Cardiology Congress 2025 examined 116 patients undergoing cardiovascular magnetic resonance imaging with late gadolinium enhancement, alongside echocardiography and ECG.

Fragmented QRS was present in 40.5% of patients and was linked to higher total scar burden scores (0.44±0.77 vs. 0.15±0.42) and increased mechanical dispersion (79±34 ms vs. 65±23 ms). Global longitudinal strain was also reduced in these patients (14.4±4.9% vs. 16.6±4.5%), whereas left ventricular ejection fraction and mass index were not significantly different. Patients with fragmented QRS in multiple ECG regions had progressively higher scar burden and mechanical dispersion and lower strain values.

These findings suggest that fragmented QRS could serve as a sensitive, non-invasive marker for myocardial scar and dysfunction, providing additional prognostic information beyond standard echocardiographic and magnetic resonance parameters. Incorporating fragmented QRS assessment may enhance early detection of subclinical myocardial alterations and guide risk stratification.