Prognosis and Natural History of Drug-Related Bradycardia

• Published in: Korean circulation journal Vol. 39; no. 9; pp. 367 - 371
• Main Authors: Lee, Jang Hoon, Ryu, Hyeon Min, Bae, Myung Hwan, Kwon, Yong Seop, Lee, Ju Hwan, Park, Yongwhi, Heo, Jung-Ho, Lee, Young Soo, Yang, Dong Heon, Park, Hun Sik, Cho, Yongkeun, Chae, Shung Chull, Kim, Yoon-Nyun, Jun, Jae-Eun, Park, Wee-Hyun
• Format: Journal Article
• Language: English
• Published: Korea (South) The Korean Society of Cardiology 01.09.2009; 대한심장학회
• Subjects: Original; 내과학; Drugs; Bradycardia; Arrhythmia; Atrioventricular block
• ISSN: 1738-5520; 1738-5555; 1738-5555
• DOI: 10.4070/kcj.2009.39.9.367

The prognosis and natural history of bradycardia related to drugs such as beta-blockers and non-dihydropyridine calcium channel blockers are not well known. We retrospectively analyzed 38 consecutive patients (age 69+/-11, 21 women) with drug-related bradycardia (DRB) between March 2005 and September 2007. A drug-associated etiology for the bradycardia was established based on the medical history and patient response to drug discontinuation. The mean follow-up duration was 18+/-8 months. The initial electrocardiogram (ECG) showed sinus bradycardia (heart rate </=40/min) in 13 patients, sinus bradycardia with junctional escape beats in 18 patients, and third-degree atrioventricular (AV) block in seven patients. Drug discontinuation was followed by resolution of bradycardia in 60% of patients (n=23). Among them, five (17.8%) patients resumed taking the culprit medication after discharge and none developed bradycardia again. Bradycardia persisted in 10 (26.3%) patients despite drug withdrawal, and a permanent pacemaker was implanted in seven of them. Third-degree AV block, QRS width, and bradycardia requiring temporary transvenous pacing were significantly associated with the bradycardia caused by drugs. Beta-blockers were the most common drugs associated with DRB. However, in one quarter of the cases the DRB was not associated with drugs; in these patients permanent pacemaker implantation should be considered.