Frederick syndrome associated with beta-blocker overdosage, clinical case

Abstract

Background. Frederick syndrome is a rare entity characterized by atrial fibrillation associated with complete atrioventricular block. Incidence consisting of 1-2 cases per 100,000 people/year, predominantly in patients over 65 years of age with cardiovascular comorbidities and degenerative changes in the conduction system. Objective(s). We present the clinical case of a patient known with chronic coronary syndrome, permanent atrial fibrillation, hypertension and type 2 diabetes mellitus, hospitalized with an overdosage of b-blockers. Materials and methods. Woman, 82 years old, admitted to the MCH "Holy Trinity", cardiology department with altered general condition, palpitations, marked fatigue, severe bradycardia (32 bpm) and hypotension (80/60 mmHg), in the context of an accidental overdosage of beta-blockers (metoprolol), associated with chronic treatment with digoxin. Results. The electrocardiogram revealed atrial fibrillation with a slow, regular ventricular rhythm, suggestive for complete atrioventricular block, characteristic for Frederick syndrome. In the context of severe hemodynamic instability and the impossibility of rapid drug correction, emergency implantation of a permanent pacemaker, a VVIR mono chamber pacemaker, set at the stimulation parameter 70 bpm, implanted through the right sub clavicular vein approach. The post-procedural evolution was favorable with a rapid clinical improvement by normalization of heart rate, stabilization of blood pressure and hemodynamics. Conclusion(s). This case highlights the importance of recognizing Frederick's syndrome in patients with atrial fibrillation with beta-blocker and cardiac glycoside overdose. Pacemaker implantation remains the treatment of choice to restore ventricular rhythm and prevent major complications.