Coronary Artery Bypass Grafting for Refractory Ventricular fibrillation after the Release of the Aortic Cross-Clamp in Patients Undergoing Aortic Valve Replacement: A Case Report

Background: Ventricular fibrillation (VF) is a known complication after the release of the aortic cross-clamp (ACC) during cardiopulmonary bypass (CPB) surgery. Various factors contribute to persistent refractory VF, making its management challenging. This case report describes the successful treatment of postoperative refractory VF by coronary artery bypass grafting (CABG) in a patient undergoing aortic valve replacement (AVR) with ACC release. Case Presentation: A 52-year-old woman with a history of hypertension and ischemic cerebral infarction presented with symptoms of chest tightness, dyspnoea and palpitations. She underwent a modified maze procedure of radiofrequency ablation, mitral repair, left atrial appendage closure and mechanical AVR under a CPB procedure. Following the ACC release, the patient experienced recurrent VF that was unresponsive to standard interventions such as lidocaine, amiodarone and direct current shocks. The suspicion of right coronary artery (RCA) insufficiency led to the decision to perform CABG using the great saphenous vein. After the CABG procedure, the patient's heart rhythm gradually returned to sinus rhythm, and she had an uneventful recovery. Discussion and Conclusions: Refractory VF after the ACC release can pose diagnostic and treatment challenges. In this case, RCA insufficiency was suspected as the cause of refractory VF. The absence of blood flow in the proximal RCA and the presence of distal blood return during cardiac surface exploration supported this suspicion. Coronary artery bypass grafting using the great saphenous vein successfully restored normal sinus rhythm, confirming the diagnosis. This case emphasises the importance of considering coronary artery stenosis or occlusion as a potential cause of refractory VF after the ACC release during CPB, with CABG serving as a viable alternative treatment.