Background: In prognostic terms, evaluation of an ECG recording in acute myocardial infarction (AMI) appears to be inferior to echocardiographic (ECHO) assessment of left ventricular remodelling and the activities of cardiac enzymes and certain hormones. It was our hypothesis that, in the era of interventional treatment of AMI, some ECG parameters are still valid for the purpose of risk stratification.
Methods: A total of 66 consecutive patients with AMI (43 male and 23 female, with a mean age of 61 ± 11 years) were treated with primary percutaneous coronary intervention (PCI). In each patient ECG and ECHO examinations were performed within 5-7 days of admission for the detection of left ventricular hypertrophy (LVH). In further analysis the following ECG- based LVH parameters were taken into consideration: Sokolov-Lyon voltage duration (SLVd), Cornell voltage duration CVd), 12-lead QRS voltage duration (12QRSVd), their product with QRS duration and an ECG index of left ventricular mass (LVMI_ECG). Patients were followed for 6 months. The combined end-point included death, infarction, a need for prompt coronary intervention and hospitalization for heart failure.
Results: The combined end-point was observed in 16 patients (24.2%). Survival analysis revealed that the most important prognostic factors were associated with a prolongation of the QRS duration. Increased SLVd was found in 43% of the patients with events compared to 14% in those without them (p < 0.01), CVd in 43% vs. 12% (p < 0.05), 12QRSVd in 81% vs. 44% (p < 0.05) and LVMI_ECG in 75% vs. 26%, p < 0.001). There was no evidence for a difference in Cornell voltage. Univariate logistic regression indicated a 4-fold to 8-fold increase in the risk of events associated with abnormal SLV, SLVd or LVMI_ECG. Multivariate Cox analysis showed that the LVH presence in the ECG, defined as an increased SLVd product or increased LVMI_ECG, was an independent predictor of cardiovascular events after AMI.
Conclusions: In the era of interventional treatment of AMI, the ECG features of left ventricular hypertrophy carry independent significant prognostic information. (Cardiol J 2007; 14: 347–354)