Risk stratification for arrhythmic events in patients with nonischemic dilated cardiomyopathy and nonsustained ventricular tachycardia: role of programmed ventricular stimulation and the signal-averaged electrocardiogram.
OBJECTIVE
This study investigated prediction of arrhythmic events by the signal-averaged electrocardiogram (ECG) and programmed stimulation in patients with nonischemic dilated cardiomyopathy.


BACKGROUND
Risk stratification in patients with nonischemic dilated cardiomyopathy remains controversial.


METHODS
Eighty patients with nonischemic dilated cardiomyopathy and spontaneous nonsustained ventricular tachycardia underwent signal-averaged electrocardiography (both time-domain and spectral turbulence analysis) and programmed stimulation. All patients were followed up for a mean of 22 +/- 26 months.


RESULTS
Sustained monomorphic ventricular tachycardia was induced in 10 patients (13%), who all received amiodarone. The remaining 70 patients were followed up without antiarrhythmic therapy. Of the 80 patients, 15% had abnormal findings on the time-domain signal-averaged ECG, and 39% had abnormal findings on spectral turbulence analysis. Time-domain signal-averaged electrocardiography had a better predictive accuracy for induced ventricular tachycardia than spectral turbulence analysis (88% vs. 66%, p < 0.01). During follow-up, there were 9 arrhythmic events (5 sudden deaths, 4 spontaneous ventricular tachycardia/fibrillation) and 10 nonsudden cardiac deaths. Cox regression analysis showed that no variables predicted arrhythmic events or total cardiac deaths. The 2-year actuarial survival free of arrhythmic events was similar in patients with or without abnormal findings on the signal-averaged ECG or induced ventricular tachycardia.


CONCLUSIONS
In patients with nonischemic dilated cardiomyopathy, 1) there is a strong correlation between abnormal findings on the time-domain signal-averaged ECG and induced ventricular tachycardia, but both findings are uncommon; and 2) normal findings on the signal-averaged ECG, as well as failure to induce ventricular tachycardia, do not imply a benign outcome.
Turitto
G
G
Department of Medicine, State University of New York Health Science Center at Brooklyn 11203.
Ahuja
R K
RK
Caref
E B
EB
el-Sherif
N
N
D000206:Actuarial Analysis; D000328:Adult; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D002304:Cardiac Pacing, Artificial; D002311:Cardiomyopathy, Dilated / Q000150:complications* / Q000503:physiopathology / Q000628:therapy; D015986:Confounding Factors, Epidemiologic; D016757:Death, Sudden, Cardiac / Q000209:etiology; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D012815:Signal Processing, Computer-Assisted; D016019:Survival Analysis; D017180:Tachycardia, Ventricular / Q000150:complications* / Q000503:physiopathology / Q000628:therapy