Does beta-receptor blockade maintain sinus rhythm after electroconversion in patients with chronic atrial fibrillation?
Maintenance treatment with the beta-receptor blocking agent H 56/28 was ineffective at maintaining sinus rhythm after electroconversion in patients with chronic atrial fibrillation.
Abstract. The effectiveness of beta‐receptor blockade as maintenance treatment of sinus rhythm obtained by electroconversion has been evaluated. Out of 98 consecutive patients with chronic atrial fibrillation 74 were converted and controlled at regular intervals. After three months only 27 of the 74 patients remained in sinus rhythm. This gives a maintenance rate of 36%. It is concluded that maintenance treatment with beta‐receptor blockade is ineffective. This conclusion is discussed in the light of pharmacological effects of quinidine and beta‐receptor antagonists and of recent evidence on vagal stimuli as important for occurrence as well as persistence of atrial fibrillation. The new beta‐receptor blocking agent H 56/28 (Aptin® from AB Hässle, Göteborg, Sweden) was employed in the study. Heart failure was provoked in a case of myocarditis. Bradycardia made it necessary to discontinue treatment with the agent in three additional patients. Aside from this no unwanted effects of H 56/28 were observed.
Hillestad et al. (Sun,) studied this question.