EFFECTS OF ANGIOTENSIN-CONVERTING ENZYME-INHIBITOR THERAPY ON PRESENCE OF LATE POTENTIALS DETECTED USING SIGNAL-AVERAGED ELECTROCARDIOGRAPHY IN PATIENTS WITH CONGESTIVE-HEART-FAILURE
Jl. Vacek et al., EFFECTS OF ANGIOTENSIN-CONVERTING ENZYME-INHIBITOR THERAPY ON PRESENCE OF LATE POTENTIALS DETECTED USING SIGNAL-AVERAGED ELECTROCARDIOGRAPHY IN PATIENTS WITH CONGESTIVE-HEART-FAILURE, Coronary artery disease, 4(12), 1993, pp. 1109-1113
Background: Angiotensin-converting enzyme (ACE) inhibitors have been s
hown to improve the mortality rate in patients with congestive heart f
ailure. The exact mechanism of this effect is uncertain. Signal-averag
ed electrocardiography has been used to evaluate the presence of late
potentials as a marker for sudden cardiac death. We examined prospecti
vely the effects of ACE inhibitor therapy on signal-averaged ECGs and
ventricular arrhythmia frequency in 20 patients with moderate to sever
e left ventricular dysfunction and symptomatic congestive heart failur
e. Methods: A signal-averaged ECG and 24 h Holter monitor were perform
ed immediately before and both 1 week and 6 weeks after captopril init
iation. The mean dose of captopril at 6 weeks was 38+/-31 mg. The pati
ents (19 men and one woman, mean age 63+/-12 years) had a baseline eje
ction fraction of 22+/-7% and mean functional class of 2.6+/-0.5. The
cause of congestive heart failure was coronary artery disease in 18 pa
tients, idiopathic cardiomyopathy in one, and valvular disease in one.
Results: All three signal-averaged ECG time-domain parameters tended
to improve over the course of the study (study 1, 2, 3: QRS duration (
ms) = 108+/-11, 106+/-12, 105+/-11; low-amplitude signal duration (ms)
= 30+/-8, 31+/-10, 28+/-10; root mean voltage (muV)=33+/-20, 37+/-24,
40+/-2, respectively). These changes were not statistically significa
nt, although the improvement in QRS duration was nearly so with P=0.06
. The occurrence and complexity of ventricular ectopy did not appear t
o be consistently altered. Conclusion: ACE inhibitor therapy with capt
opril did not appear to alter ventricular ectopy over the course of th
is study. However, the trends toward improvement of signal-averaged EC
G parameters deserve further evaluation in a larger and longer-term st
udy.