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Electrophysiologic Changes in the Human Heart Produced by Enalaprilat (Angiotensin-Converting Enzyme Inhibitor)
Robert A. González-Fernández1, Pablo I. Altieri, Walmor C. De Mello
1Department of Medicine, Pharmacology, Physiology and the Cardiovascular Research Unit, University of Puerto Rico, San Juan, Puerto Rico.
Insights
Enalaprilat, an angiotensin-converting enzyme inhibitor, significantly reduced ventricular activity duration, indicating improved intraventricular conduction velocity. This study evaluated its antiarrhythmic potential in patients with angina.
Area of Science:
- Cardiology
- Pharmacology
Background:
- Angiotensin-converting enzyme (ACE) inhibitors are known to possess antiarrhythmic properties.
- Enalaprilat is an ACE inhibitor with potential therapeutic applications in cardiac electrophysiology.
Purpose of the Study:
- To investigate the electrophysiological effects of Enalaprilat on His bundle recordings.
- To evaluate the impact of Enalaprilat on intraventricular conduction velocity in patients with angina pectoris.
Main Methods:
- A double-blind, crossover study involving patients undergoing coronary angiography for angina.
- His bundle electrograms were recorded at baseline, after saline (placebo), and after intravenous Enalaprilat (2.5 mg).
- Measurements included heart rate, blood pressure, atrioventricular conduction time, and His-Purkinje (HV) conduction time.
Main Results:
- No significant changes were observed in heart rate, mean blood pressure, atrioventricular conduction, or HV conduction.
- Ventricular activity duration significantly decreased from 110 ± 11 ms at baseline to 88 ± 13 ms after Enalaprilat (p < 0.001).
- This reduction in ventricular activity duration suggests an increase in intraventricular conduction velocity.
Conclusions:
- Enalaprilat administration leads to a significant reduction in ventricular activity duration, implying enhanced intraventricular conduction.
- ACE inhibition with Enalaprilat demonstrates a potential antiarrhythmic effect by improving conduction velocity.
Abstract:
Several trials have showed that angiotensin-converting enzyme inhibitors possess some extent of antiarrhythmic properties. To evaluate the effects of Enalaprilat on His bundle recording, patients undergoing diagnostic coronary angiogram due to angina pectoris and a positive thallium exercise test subsequently underwent His bundle electrogram. A double-blind crossover protocol was used with conduction velocity measurements at baseline and after saline (placebo) and Enalaprilat 2.5 mg intravenously. There were no significant changes in heart rate (64 plus minus 9 versus 65 plus minus 11 versus 65 plus minus to beats min(minus sign1)) at baseline, after saline and enalaprilat infusion, respectively, mean blood pressure (97 plus minus 11 versus 94 plus minus 10 versus 94 plus minus 7 mm Hg, respectively), atrioventricular conduction time (100 plus minus 20 versus 100 plus minus versus 100 plus minus 20 versus 100 plus minus ms), and His--Purkinje (HV) conduction time (40 plus minus 12 versus 40 plus minus 13 versus 40 plus minus 12 ms). Ventricular activity duration was 110 plus minus 11 ms at baseline, 110 plus minus 10 ms after saline infusion (p = NS), and 88 plus minus 13 ms after Enalaprilat administration (p < 0.001). Angiotensin-converting enzyme inhibition appears to produce significant reduction in ventricular activity duration (increase in intraventricular conduction velocity).