Signal-averaged electrocardiogram in patients with arrhythmogenic right ventricular cardiomyopathy and ventricular arrhythmias

Objective The aim of the study was to assess the prevalence, sensitivity, s pecificity and predictive value of the signal-averaged ECG inpatients with arrhythmogenic right ventricular cardiomyopathy and different forms of vent ricular arrhythmias. Methods The signal averaged ECG in 138 patients and 146 healthy subjects (c ontrol group), using a three bandpass filter system (25-250, 40-250, 80-250 Hz), was considered abnormal when at least two parameters were abnormal at each filter setting. Patients were divided into three groups according to the extent of the right ventricular enlargement (mild, moderate, extensive) , and into five groups according to the type of ventricular arrhythmia. Results The signal averaged ECG was abnormal in 57% of the patients and in 4% of the healthy subjects. The sensitivity was 57%, specificity 95% and po sitive predictive value 92%. The signal averaged ECG was abnormal in 94.4%, of patients with the extensive form of the disease, in 77.7% of patients w ith the moderate form and in 31.8% of patients with the minor form, demonst rating good correlation with the extent of the disease. According to the ty pe of ventricular arrhythmia, a higher correlation was found between signal averaged ECG abnormality and sustained ventricular tachycardia with superi or axis (94.4%, P<0.02); the correlation for the other arrhythmias varied f rom 16.6% to 55.8%. Conclusion There is a closer correlation between the signal averaged ECG an d extent of disease than with the presence of ventricular arrhythmias. The signal averaged ECG is not helpful in diagnosing minor forms of the disease , but since it is a non-invasive method, it may be useful in evaluating pro gression of the disease. (Eur Heart J 2000; 21: 58-65) (C) 2000 European So ciety of Cardiology.