Long-term prognostic value of time domain analysis of signal-averaged electrocardiography in idiopathic dilated cardiomyopathy

• Published in: The American journal of cardiology 2000-03, Vol.85 (5), p.618-623
• Main Authors: Fauchier, Laurent, Babuty, Dominique, Cosnay, Pierre, Poret, Philippe, Rouesnel, Philippe, Fauchier, Jean Paul
• Format: Article
• Language: English
• Subjects: Arrhythmias, Cardiac - epidemiology; Biological and medical sciences; Cardiac arrhythmia; Cardiology; Cardiology. Vascular system; Cardiomyopathy, Dilated - diagnosis; Cardiomyopathy, Dilated - mortality; Cardiovascular disease; Death, Sudden, Cardiac - epidemiology; Electrocardiography; Electrocardiography - methods; Electrocardiography, Ambulatory - methods; Evaluation Studies as Topic; Female; Follow-Up Studies; Heart; Humans; Male; Medical sciences; Middle Aged; Myocarditis. Cardiomyopathies; Prognosis; Risk Assessment; Signal Processing, Computer-Assisted; Survival Analysis; Time Factors
• ISSN: 0002-9149; 1879-1913
• DOI: 10.1016/S0002-9149(99)00821-8

The aim of this study was to evaluate the long-term prognostic value of signal-averaged electrocardiography (SAECG) in idiopathic dilated cardiomyopathy (IDC). Time domain analysis of SAECG was assessed in 131 patients with angiographically confirmed IDC (age 52 ± 12 years; 108 men; left ventricular ejection fraction 33 ± 12%) using specific criteria in 44 patients with bundle branch block. Late potentials (LP) on SAECG were present in 27% of the patients. Patients with LP had a similar left ventricular ejection fraction and a similar left ventricular end-diastolic diameter than patients with a normal SAECG. With a follow-up of 54 ± 41 months, 24 patients suffered cardiac death and 19 had major arrhythmic events (sudden death, resuscitated ventricular fibrillation, or sustained ventricular tachycardia). Patients with LP had an increased risk of all-cause cardiac death (RR 3.3, 95% confidence interval 1.5 to 7.5, p = 0.004) and of arrhythmic events (RR 7.2, 95% confidence interval 2.6 to 19.4, p = 0.0001). Using multivariate analysis, only LP on SAECG (p = 0.001), reduced SD of all normal-to-normal intervals (SDNN) (p = 0.002), increased pulmonary capillary wedge pressure (p = 0.005), and history of sustained ventricular tachyarrhythmia (p = 0.02) predicted cardiac death. A history of previous sustained ventricular tachyarrhythmia (p = 0.0001), reduced SDNN (p = 0.003), and LP on SAECG (p = 0.006) were the only independent predictors of major arrhythmic events. Results were not altered when considering separately patients with or without bundle branch block, or after exclusion of patients with a history of sustained ventricular tachyarrhythmia. This study is one of the first to suggest that LP on SAECG is an independent predictor of all-cause cardiac death and is of high interest for arrhythmia risk stratification in IDC.