Verapamil in the treatment of paroxysmal supraventricular tachycardia

Abstract

Summary Verapamil is a novel antiarrhythmic agent which appears to act as a calcium-ion antagonist, blocking calcium transport across the myocardial cell membrane. It was given intravenously, in a dose of 10 mg, to thirty-two patients suffering from paroxysmal supraventricular tachycardia, and sinus rhythm was achieved promptly in all. Identical results were obtained in a further ten patients with supraventricular tachycardias associated with the Wolff-Parkinson-White or other pre-excitation syndromes. In a separate group of eighteen patients in whom A-V junctional tachycardias were induced during intracardiac electrography, conversion to sinus rhythm was achieved in fifteen patients, with prolongation of the cycle length in the others. Circus-movement tachycardias were induced in eight patients with the Wolff-Parkinson-White syndrome, and conversion to sinus rhythm was achieved in seven. The results were less consistent in patients with other supraventricular arrhythmias including ectopic atrial tachycardia and atrial flutter, and, in the single patient with supraventricular and ventricular tachycardia, only the former was controlled. In the single patient with atrial fibrillation complicating the Wolff-Parkinson-White syndrome who received verapamil, sinus rhythm was restored. Side effects were few and mild, with rare exceptions of profound hypotension, bradycardia and asystole; their management is discussed, and reasons are advanced why their occurrence is likely to be related either to the concomitant administration of beta-adrenergic blockers or to the presence of sinoatrial disease. It appears that verapamil is particularly suitable for the treatment of supraventricular tachycardias due to a circus movement as calcium antagonism is likely to be most effective in the N region of the atrioventricular node.

Beneficial effects of high-dose diltiazem in patients with persistent effort angina on beta-blockers and nitrates: a randomized, double-blind, placebo-controlled cross-over study.

“…Diltiazem increased exercise tolerance (submaximal and maximal workload), as well as the time to the onset of electrocardiographic ischemia in all patients. Exercise-induced angina pectoris was totally abolished in eight of 12 patients. Rest and exercise left ventricular ejection fraction was augmented by diltiazem, and there was no evidence of adverse inotropic, chronotropic, or dromotropic effects in the study group.…”

“…These data are similar to those reported by Hung et al,20 who used a dose of diltiazem of 360 mg/day. Since calcium-channel blockers have negative inotropic effects in vitro43 and in vivo, [1][2][3][4][5][6][7][8][9][10][11][12][13] it is clear that their interaction with /3-blockers may be hazardous, particularly in patients with a history of congestive heart failure"- [17][18][19] or with a low (less than 40%) ejection fraction.29…”

The acute hemodynamic effects of intravenous verapamil in coronary artery disease. Assessment by equilibrium-gated radionuclide ventriculography.

“…An indwelling catheter was placed in an arm vein. The patient was then positioned supine on a comfortable table under the collimator and remained in this resting state for 30 minutes, in order to achieve steady state, as judged by a stable heart rate on the ECG and arm-cuff blood pressure. Care was taken that the patient remained quiet and awake during the entire procedure.…”

Calcium-channel blockers and anaesthesia

“…[61][62][63] Whilst DHP do not possess antiarrhythmic properties, verapamil has been used for many years in the management of paroxysmal supraventricular tachycardias. 64 The success rate of conversion to sinus rhythm was more than 80 per cent after 10 mg IV in adults, and approached 100 when combined with carotid sinus massage. 65 Diltiazem 0.15 mg" kg -~ IV or bepridil 2-4 mg.kg-i IV produced similar results.…”