Open AccessA comparison of the effects of adenosine and verapamil on the conduction and pacemaker system of isolated guinea pig hearts
Author(s) -
Stark Gerhard,
Stark Ulrike,
Bachernegg Maria,
Kasper Karin,
Kickenweiz Elisabeth,
Decrinis Martin
Publication year - 1993
Publication title -
clinical cardiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.263
H-Index - 72
eISSN - 1932-8737
pISSN - 0160-9289
DOI - 10.1002/clc.4960161205
Subject(s) - verapamil , adenosine , medicine , sinus rhythm , atrioventricular node , heart rate , cardiology , rhythm , atrioventricular block , guinea pig , electrocardiography , anesthesia , tachycardia , calcium , blood pressure , atrial fibrillation
Adenosine and verapamil are effective in the treatment of supraventricular arrhythmias. Also, both substances can provoke sinus node arrest or a third‐degree atrioventricular (AV) block with a ventricular escape rhythm. The aim of this study was to compare the effects of adenosine and verapamil on sinus rate and on the rate of the ventricular escape rhythm while a third‐degree AV block was induced by both drugs. Experiments were performed on isolated spontaneously beating guinea pig hearts perfused by the method of Langendorff. A third‐degree AV block was induced by adenosine at a concentration of 30 μm and by verapamil at a concentration of 1 m̈m. Adenosine (30μm) reduced sinus rate only moderately whereas it nearly halved the rate of the ventricular escape rhythm compared with that produced by cutting the AV node. In contrast, verapamil left the rate of the ventricular escape rhythm unchanged but nearly halved the spontaneous sinus rate compared with control conditions. In conclusion, adenosine and verapamil given at dosages with comparable effect on the AV node have markedly different effects on different pacemakers in the same heart. In the treatment of supraventricular arrhythmias, adenosine probably should be used with great caution since it can cause a very slow ventricular escape rhythm.