Health & Environmental Research Online (HERO)


Print Feedback Export to File
517287 
Journal Article 
Time-domain T-wave alternans measured from Holter electrocardiograms predicts cardiac mortality in patients with left ventricular dysfunction: A prospective study 
Sakaki, K; Ikeda, T; Miwa, Y; Miyakoshi, M; Abe, A; Tsukada, T; Ishiguro, H; Mera, H; Yusu, S; Yoshino, H 
2009 
Yes 
Heart Rhythm
ISSN: 1547-5271
EISSN: 1556-3871 
6 
3 
332-337 
English 
BACKGROUND Time-domain T-wave alternans (TWA) is useful for identifying patients at risk for serious events after myocardial infarction. OBJECTIVE The purpose of this study was to prospectively evaluate the utility of time-domain TWA measured from Hotter ECGs in predicting cardiac mortality in patients with left ventricular (LV) dysfunction. METHODS Two hundred ninety-five consecutive patients with LV dysfunction were enrolled in the study. Patients were divided into two groups: the ischemic group (n = 195) and the nonischemic group (n = 100). Time-domain TWA was assessed using the modified moving average method from routine 24-hour Hotter ECGs recorded during daily activity. The maximal time-domain TWA voltage at heart rate <= 120 bpm in either lead V-5 or V-1 was derived and its value defined as positive when the voltage was >= 65 mu V. The primary end-point was defined as cardiac mortality. RESULTS Mean maximal time-domain TWA voltage was 54 +/- 16 mu V. During follow-up of 390 +/- 212 days, 27 patients (17 in the ischemic group and 10 in the nonischemic group) died of cardiac causes. Fifty-three patients (18%) were time-domain TWA positive and 242 (82%) were time-domain TWA negative. Univariate Cox proportional hazards analyses revealed that older age, New York Heart Association functional class III or IV, diabetes, renal dysfunction, nonsustained ventricular tachycardia, and time-domain TWA were associated with cardiac mortality. In multivariate analysis, time-domain TWA had the most significant value (hazard ratio = 17.1, P <.0001). This index also was significant in both subgroups (ischemic group: hazard ratio 19.0, P <.0001; nonischemic group: hazard ratio = 12.3, P = .002). CONCLUSION Time-domain TWA measured from 24-hour Hotter ECGs predicts cardiac mortality in patients with ischemic and nonischemic LV dysfunction. 
T-wave alternans; Time-domain analysis; Left ventricular dysfunction; Dilated cardiomyopathy; Cardiac mortality; myocardial-infarction; defibrillator implantation; tachyarrhythmic; events; risk stratification; death; cardiomyopathy; benefit