Severe Bradycardia Prior to Coronary Artery Bypass Graft Surgery: A Case Report

Amer Harky,Mohamad Bashir,Neil Roberts,Sarah Fendius,Martin Lees,Ciaran Grafton-Clarke

doi:10.18502/jthc.v13i3.134

Abstract

Intraventricular conduction abnormalities following cardiac surgery have been thoroughly described, especially after valvular surgery. It is also widely known that several anesthetic factors can cause autonomic disturbances resulting in the unmasking of sinus node dysfunction, significant bradycardia, and cardiovascular collapse during the intraoperative period. However, little is known about asymptomatic episodes, especially those occurring prior to coronary artery bypass grafting (CABG). We report a rare occurrence of an intraventricular conduction defect that presented in an asymptomatic patient following non-ST-elevation myocardial infarction prior to urgent CABG. Our patient presented with sudden-onset chest pain, and following coronary angiography he was found to have triple-vessel coronary disease. During anesthetic induction for inpatient CABG surgery, he developed episodes of acute sinus tachy-brady episodes, requiring a stat dose of adrenaline to maintain the heart rate prior to the establishment of cardiopulmonary bypass. The arrhythmia persisted postoperatively, necessitating the insertion of a permanent dual-chamber pacemaker for complete heart block. The patient was later discharged without further complications, and upon follow-up 12 months later, he remains in good health.

Highlights

Sick sinus syndrome is a term used to describe the inability of the sinoatrial node to generate a heart rate that meets the physiologic needs of an individual.[1]
The sick sinus spectrum of heart rhythms includes a subgroup of alternating atrial bradycardia with episodes of atrial tachyarrhythmia
Tachycardia-bradycardia is an electrophysiologically and therapeutically interesting clinical entity that can complicate the effective management of acute myocardial infarcts.[2]

Summary

Introduction

Sick sinus syndrome is a term used to describe the inability of the sinoatrial node to generate a heart rate that meets the physiologic needs of an individual.[1]. Due to the presence of diffuse multi-vessel involvement, the patient was deemed suitable for inpatient coronary artery bypass grafting surgery (CABG). He was medically stabilized and optimized for surgery. Three days following the CABG surgery, the patient became hemodynamically unstable with alternate episodes of tachy-brady arrhythmia concomitant with atrial fibrillation. For rate control, he was loaded with intravenous amiodarone. Following the insertion of the PPM, the patient experienced self-limiting episodes of atrial fibrillation associated with a fast-ventricular response rate; he was commenced on beta-blockers. Once the heart rate was controlled, he was discharged from the intensive care unit to a normal ward and made a complete recovery

Discussion

Conclusion