Relationship Between Fragmented QRS and No-Reflow, Infarct Size, and Peri-Infarct Zone Assessed Using Cardiac Magnetic Resonance in Patients With Myocardial Infarction

Background: The relation between fragmented QRS complex (fQRS) and cardiac magnetic resonance parameters is poorly documented in ischemic cardiopathy. Methods: Among 209 consecutive patients, those with fQRS were compared with those without fQRS. Cardiac magnetic resonance studies with late gadolinium-enhanced sequences were done during the week after acute myocardial infarction. Results: fQRS was present in 113 (54%) patients, and associated with a significantly lower left ventricular ejection fraction, increased left ventricular volumes, a larger infarct size (IS), and a larger peri-infarct zone. Microvascular obstruction was more frequent in patients with fQRS (62% vs 45%; P = 0.014) and the extent of the microvascular obstruction was significantly larger (1.6% [range, 0.0-4.4] vs 0.0 [range, 0.0-2.1]; P = 0.004). Finally, the transmurality score in the 2 study populations was identical (48% vs 47%; P = 0.895). In multivariate logistic regression analysis, only IS (odds ratio [OR], 1.06; 95% confidence interval [CI], 1.03-1.09; P < 0.001), systolic blood pressure (OR, 1.02; 95% CI, 1.01-1.04; P < 0.001), and left ventricular endsystolic volume (OR, 1.02; 95% CI, 1.00-1.03; P = 0.013) remained independent predictors of fQRS. Conclusions: This study revealed that fQRS was associated with increased IS, myocardial perfusion abnormalities, decreased left ventricular ejection fraction, and increased left heart volumes. These findings show that fQRS is a reliable marker of infarct size and acute ventricular remodelling.