Prognostic value of the Intermediate QRS prolongation in patients with acute myocardial infarction

Studies have shown different effect of intermediate QRS prolongation on major cardiovascular events in acute myocardial infarction (AMI) patients. The aim of this study was to investigate the predictive and prognostic value of intermediate QRS prolongation on in-hospital complication rate and long term mortality in patients with AMI.

We performed an observational study that enrolled 114 consecutive patients with AMI. Patient's admission electrocardiography (ECG) were enlarged two fold, and QRS duration (QRSd) was measured manually. Patients were divided into two groups according to the admission EKG QRSd. Group A defined as patient with QRSd between 90-120 msn and group B QRSd <90msn. Echocardiographic, angiographic, clinic and laboratory results were recorded for all patients. Patients were followed next twelve months.

In-hospital follow-up period, major adverse cardiac events were higher in group A than group B (0.9 ±0.9 vs. 0.5 ±0.5 p=0.02). There were increased end-diastolic and end-systolic volume in group A (91±15 vs. 82±12 p=0.002; 50±10 vs. 44±9 p=0.002. respectively). Left ventricular ejection fraction (LVEF) was lower in group A. but it did not reach statistical significance (43.5±6.3 vs. 45.5±5.5 p=0.06). Angiographic evaluation was detected severe coronary artery disease (CAD) in group A than group B (1.9±0.8 vs. 1.5±0.7 p=0.013). During 12 months of follow-up period. five patients were died. Although these patients had longer QRSd on admission, it was not statistically significant (96±14 vs. 90±11 p=0.3).

Intermediate QRS prolongation on admission EKG were found to be positively correlated with increased EDV, ESV, major in-hospital cardiovascular events, and multivessel coronary artery disease and inversely correlated with LVEF. Although deceased patients had prolonged QRSd it was not statistically significant.