Life Threatening Iatrogenic Bradycardia Related To The Use of Beta-Blockers Or in Combination With Other Antiarrhythmic Agents In Elderly Patients

Background: Drug-induced bradycardia is common during antiarrhythmic therapy; the major culprits are beta-blockers.However, whether other antiarrhythmic drugs are also a significant cause of this, alone or in combination with beta-blockers, is not well known.Objective: This study examined drugs that cause marked bradycardia in elderly patients in ambulatory settings.Methods: We retrospectively investigated the records of all patients at our Polyclinic for drug-related bradycardia from the years 2017 to 2023.Patients with arterial hypertension, chronic compensated heart failure, coronary artery disease, ischemic cardiomyopathies and other cardiac disease in whom the beta blockers were prescribed with other medications for treatment.Results: Nine patients were identified (mean age, 72±6 years; range, 65-81 years; 5 men).Four patients were taking only beta-blockers, while Five patients were on both beta-blockers and other antiarrhythmic drugs.Heart rates ranged from 23±47 beats/minute.The initial electrocardiogram showed sinus bradycardia (n= 5) or sinus arrest with escape beats (n=4).QRS duration was 80-105ms.The clinical presentation of the patients who taking beta-blockers and other antiarrhythmic drugs was considerably worse than that of the patients with only beta-blockers drugs and included worsening heart failure or presyncope or syncope.Four of the beta/blockers and other antiarrhythmic drugs group patients had been on their medications for over 12 months.In the Beta-blockers group only 3 patients recovered solely with drug discontinuation, while 3 patients in the BB + antiarrhythmic group needed additional treatments, such as intravenous administration of atropine or adrenergic agonist and temporary pacing.Three of all patients were referred to permanent implantation of pacemaker due to persistent life threatening bradycardia.Conclusion: Life-threatening bradycardia may occur in in the elderly with beta-blockers or combination therapy with other antiarrhythmic drugs in the elderly patients, even months after the start of medication, the recovery is challenging and, in some patients, permanent implantation of pacemakers is indicated due to persistent of severe bradycardia and symptoms of presyncope or syncope after discontinuation of medications.