Sudden cardiac death (SCD) causes a high burden of premature deaths in the population affecting subjects of all ages. The identification of subjects at high risk for SCD is of great importance as the prevention of many of these events would be possible with the treatment of underlying cardiac diseases and the use of implantable cardioverter-defibrillators (ICD). However, the current selection of patients for ICD therapy is based solely on left ventricular ejection fraction, and thus a substantial portion of patients at high risk does not qualify for the therapy. Role of the standard electrocardiogram (ECG) in SCD risk stratification has been under active research during the last decade and multiple abnormalities of depolarization and repolarization on the ECG associated with an increased risk of SCD have been identified. In this review, we describe the basic pathophysiological principles behind these changes. We also review the current knowledge of the prognostic significance of ECG predictors of SCD in the general population, and in patients with coronary heart disease (CHD), heart failure, cardiomyopathies, and in inheritable arrhythmia syndromes. Also, insights into the novel digital ECG signal processing techniques are provided.
Keywords: Brugada’s syndrome; Death; arrhythmogenic right ventricular dysplasia; cardiac; cardiomyopathy; coronary artery disease; electrocardiography; heart failure; hypertrophic; long QT syndrome; sudden.