title: Prognosis and natural history of drug-related bradycardia.
abstract: OBJECTIVE
  The prognosis and natural history of bradycardia related to drugs such as beta-blockers and non-dihydropyridine calcium channel blockers are not well known.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors: Department of Internal Medicine, Kyungpook National University Hospital, Daegu, Korea.
authors: Jang Hoon
authors: JH
authors: Lee
authors: Hyeon Min
authors: HM
authors: Ryu
authors: Myung Hwan
authors: MH
authors: Bae
authors: Yong Seop
authors: YS
authors: Kwon
authors: Ju Hwan
authors: JH
authors: Lee
authors: Yongwhi
authors: Y
authors: Park
authors: Jung-Ho
authors: JH
authors: Heo
authors: Young Soo
authors: YS
authors: Lee
authors: Dong Heon
authors: DH
authors: Yang
authors: Hun Sik
authors: HS
authors: Park
authors: Yongkeun
authors: Y
authors: Cho
authors: Shung Chull
authors: SC
authors: Chae
authors: Yoon-Nyun
authors: YN
authors: Kim
authors: Jae-Eun
authors: JE
authors: Jun
authors: Wee-Hyun
authors: WH
authors: Park