Related Experiment Videos
Effects of cilazapril on ventricular arrhythmia in patients with congestive heart failure
Y Hattori1, S Atsushi, F Hiroaki
1Department of Cardiology, Nakatsugawa Municipal Hospital, Gifu, Japan.
Insights
Angiotensin-converting enzyme (ACE) inhibitors like cilazapril may reduce lethal ventricular tachycardia in heart failure patients by lowering sympathetic nerve activity. This study found cilazapril decreased arrhythmias and norepinephrine levels.
Area of Science:
- Cardiology
- Pharmacology
Background:
- Congestive heart failure (CHF) is associated with increased mortality and morbidity.
- Angiotensin-converting enzyme (ACE) inhibitors are known to improve outcomes in CHF patients.
- The antiarrhythmic effects of ACE inhibitors, potentially via sympathetic nerve activity suppression, require further investigation.
Purpose of the Study:
- To investigate the antiarrhythmic effects of the ACE inhibitor cilazapril in patients with CHF.
- To determine if cilazapril reduces ventricular arrhythmia (VA).
- To assess whether any reduction in VA is linked to decreased sympathetic nerve activity.
Main Methods:
- A randomized controlled trial involving 32 CHF patients with ventricular tachycardia (VT).
- Patients received either conventional therapy or conventional therapy plus cilazapril for 2 months.
- Evaluated arrhythmia frequency, plasma norepinephrine levels, and heart rate variability via 24-hour ambulatory ECG monitoring.
Main Results:
- The cilazapril group showed a significant reduction in ventricular couplets and VT runs.
- Plasma norepinephrine levels decreased, and heart rate variability increased in the cilazapril group.
- The control group exhibited no significant changes in arrhythmia frequency.
Conclusions:
- Cilazapril demonstrates antiarrhythmic effects in CHF patients with VT.
- These effects may be attributed to the suppression of elevated sympathetic activity.
- Further research is necessary to confirm these findings and elucidate the precise mechanisms.
Abstract:
Angiotensin-converting enzyme (ACE) inhibitors reduce mortality and morbidity in patients with congestive heart failure. These effects may be mediated, at least in part, by suppression of lethal ventricular tachycardia (VT). The aims of this study were to examine whether the ACE inhibitor cilazapril reduces ventricular arrhythmia in patients with congestive heart failure and, if cilazapril does reduce ventricular arrhythmia, to determine whether this reduction is associated with suppression of sympathetic nerve activity in these patients. Thirty-two congestive heart failure patients (left ventricular ejection fraction, 35 +/- 6%; New York Heart Association class II or III) with VTs (Lown grade IVa or IVb) were randomly assigned to receive either conventional therapy, consisting of diuretics and digitalis (control group), or conventional therapy plus cilazapril (cilazapril group). Twenty-four-hour ambulatory electrocardiographic monitoring was performed at baseline and after 2 months of therapy. Plasma norepinephrine levels and heart rate variability (standard deviation about the mean RR interval) were compared at baseline and after 2 months of treatment. The control group demonstrated no significant change in arrhythmia frequency after 2 months of treatment. In the cilazapril group, however, the number of ventricular couplets and VT runs was significantly decreased. In association with this reduction, plasma norepinephrine levels were decreased, and heart rate variability was increased. These results suggest that cilazapril has antiarrhythmic effects, which may be produced by suppressing high sympathetic activity, in patients with congestive heart failure. It should be noted that the study group was small and that, although ventricular dysrhythmia was reduced with therapy, it remained substantial. Further study is needed to verify these results and to determine the exact causes of the reduction.