Effect of a long acting beta-adrenoceptor blocker on diurnal variation of cardiac dysrhythmias

Abstract

Summary:To investigate circadian variation of cardiac arrhythmias ambulatory electrocardiogram monitoring was carried out before and after one week's treatment with a long acting beta-adrenoceptor blocker, nadolol, in 26 patients who presented with symptoms attributable to arrhythmias. Analysis of the 24 hour profile of premature ventricular contractions showed a significantly (P <0.05) higher frequency during midday to midnight than between midnight and midday. The frequency of supraventricular tachycardia was significantly (P <0.05) higher during the periods from 12