Linkage between mechanical and electrical alternans in patients with chronic heart failure.
BACKGROUND
Progressive heart failure and ventricular fibrillation are major causes of death in patients with chronic heart failure. Mechanical alternans (pulsus alternans) has been observed in patients with severe congestive heart failure. Visible T wave alternans occasionally is a precursor of ventricular fibrillation. We investigated the occurrence of both cardiac alternans in 94 patients with chronic heart failure.


RESULTS
Mean left ventricular ejection fraction (LVEF) of the study population was 35 +/- 10%. Mechanical alternans was detected in left ventricular pressure during diagnostic cardiac catheterization. Only sustained mechanical alternans was included in the study. Visible T wave alternans, not microvolt alternans, was noted on standard surface ECG. Cardiac alternans was examined at rest, during physiologic tachycardia, and during stepwise dobutamine loading (2-4-8 microg/kg/min). Prevalences of mechanical and electrical alternans were 19.1% and 4.4% at rest, 45.5% and 8.0% during physiologic tachycardia, and 62.1% and 9.5% under dobutamine loading. Overall, 70 patients (74.5%) showed mechanical alternans and 10 patients (10.6%) showed T wave alternans. T wave alternans always appeared with large mechanical alternans. Among patients with mechanical alternans, cases with T wave alternans showed lower LVEF than those without (27.5 +/- 4.4 and 35.1 +/- 10.2, P < 0.002).


CONCLUSIONS
Visible T wave alternans was detectable in patients with chronic heart failure, especially under tachycardia or catecholamine exposure. Investigating mechanical and mechanoelectrical alternans may bring new insights into the management of patients with chronic heart failure.
Kodama
Makoto
M
Division of Cardiology, Department of Cardiovascular and Vital Control, Niigata Graduate School of Medical & Dental Sciences, Niigata, Japan. kodamama@med.niigata-u.ac.jp
Kato
Kiminori
K
Hirono
Satoru
S
Okura
Yuji
Y
Hanawa
Haruo
H
Yoshida
Tsuyoshi
T
Hayashi
Manabu
M
Tachikawa
Hitoshi
H
Kashimura
Takeshi
T
Watanabe
Kenichi
K
Aizawa
Yoshifusa
Y
D000293:Adolescent; D000328:Adult; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology; D002908:Chronic Disease; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology; D006333:Heart Failure / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015995:Prevalence; D011379:Prognosis; D013223:Statistics as Topic; D013318:Stroke Volume / Q000502:physiology; D016019:Survival Analysis; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology; D016277:Ventricular Function, Left / Q000502:physiology