P450 ADVANCED ATRIOVENTRICULAR BLOCK AT LOOP RECORDER MONITORING IN A YOUNG PATIENT WITH BRUGADA SYNDROME AND CONDUCTION ABNORMALITIES: CAUSE OF SYNCOPE OR INCIDENTAL FINDING?

Abstract

Abstract A 32–year–old man healthy man presented to the emergency department because of remittent fever. His past medical history, physical examination and chest X–ray were unremarkable except for a body temperature of 39 Celsius degrees. Laboratory exams showed a marked elevation of transaminases, cholestasis markers and C–reactive protein, while an abdomen ultrasound revealed hepatomegaly and diffuse hyperechogenicity of the liver. He was diagnosed with acute hepatitis and admitted to the Gastroenterology Unit. Due to the persistent hyperpyrexia despite antipyretics and antibiotics, he was successfully treated with intravenous diclofenac, resulting in temporary remission of fever. First electrocardiogram during apyrexia showed sinus rhythm, first–degree atrioventricular block (PR interval 240 milliseconds), and non–specific intraventricular conduction delay. In the following days, liver and cholestasis markers improved, but he underwent two syncopal episodes without prodromes, the former while he was walking and the latter during meal. A new electrocardiogram revealed a type 1 Brugada pattern. At the time of its recording, however, his body temperature was 38.6 Celsius degrees. He was then admitted to the Cardiology Unit for monitoring and further investigations. 2D–echocardiogram and cardiac magnetic resonance imaging were unremarkable. Telemetry monitoring showed nocturnal episodes of marked sinus bradycardia (up to 35 beats per minute), but no ventricular arrhythmias were documented. He also underwent an invasive electrophysiological study with programmed ventricular stimulation, but again no ventricular arrhythmias were induced. Recording of His bundle electrogram, however, revealed the prolongation of both AH and HV interval (190 and 76 milliseconds respectively). Given the syncopal episodes, an implantable cardioverter defibrillator implantation was proposed, but the patient refused, so he underwent an implantable loop recorder implantation. After three months, at remote monitoring, a nocturnal episode of complete atrioventricular block with a pause of 15 seconds was recorded, thus he was again admitted to the Cardiology Unit. This time he was apyretic, but his electrocardiogram showed a spontaneous type 1 Brugada pattern with “high arrhythmic risk” features as first–degree atrioventricular block and a prominent S wave in lead I. He then underwent a successful implantable cardioverter defibrillator implantation with still an uneventful follow up.