Sekwencyjna metoda oceny rokowania u chorych po przebytym zawale serca

Abstract

Introduction: Identification of patients at high risk of malignant ventricular arrhythmias and sudden death still remains an unresolved clinical problem. The aim of this study was to investigate the value of a sequential, 2-step procedure in the prediction of arrhythmic events (sustained ventricular tachycardia, ventricular fibrillation and sudden cardiac death) in patients after myocardial infarction.
Material and methods: In the group of 263 postinfarction patients (mean age 60 ± 9 years, 223 men) the standard ECG variables and left ventricular ejection fraction (LVEF) were used as a screening test for predicting arrhythmic events (first stage of sequential procedure). In patients with two or more risk factors (RR interval < 800 ms, QRS complex > 100 ms, QT dispersion ł 100 ms and LVEF < 40%) the analysis of signal averaged ECG and heart rate variability was performed at second stage of sequential procedure. Ventricular late potentials and standard deviation of RR intervals < 70 ms were considered as predictors of arrhythmic events.
Results: During a follow-up period of 36 ± 19 months, the arrhythmic events were noted in 41 (16%) patients. A two-step risk stratification selected a low-risk group of 211 patients with arrhythmic events incidence of 7.6% and a high-risk group of 52 patients with arrhythmic events incidence of 48.1%. Sensitivity, specificity, positive and negative predictive value of sequential procedure for predicting arrhythmic events were, respectively: 61%, 88%, 48% and 92%.
Conclusions: A two-step risk stratification based on standard ECG variables and determination of LVEF at first stage, and heart rate variability and signal-averaged ECG at second stage may be used for selecting patients with an increased risk for arrhythmic events after myocardial infarction.