Cardiac arrest due to late-onset coronary artery spasm after radiofrequency catheter ablation in a patient with an implantable cardioverter-defibrillator.

Coronary artery spasm (CAS) associated with catheter ablation is an important perioperative complication. Here we describe a case of late-onset CAS with cardiogenic shock that occurred five hours after ablation.A 55-year-old man diagnosed with CAS previously underwent implantable cardioverter-defibrillator (ICD) implantation due to ventricular fibrillation. Inappropriate defibrillation was repeatedly conducted for frequent episodes of paroxysmal atrial fibrillation. Therefore, pulmonary vein isolation and linear ablation, including cava-tricuspid isthmus line, were performed. Five hours after the procedure, the patient experienced chest discomfort and lost his consciousness. Electrocardiogram monitoring of lead II revealed atrioventricular sequential pacing and ST-elevation. Cardiopulmonary resuscitation and inotropic support were immediately started. Meanwhile, coronary angiography revealed diffuse narrowing in the right coronary artery. Intracoronary infusion of nitroglycerin immediately dilated the narrowed lesion; however, the patient required intensive care with percutaneous cardiac pulmonary support and a left ventricular assist device. Pacing thresholds obtained immediately after cardiogenic shock were stable and almost similar to previous results. This showed that the myocardium was electrically responsive to ICD pacing but was unable to contract effectively due to ischemia. Learning objective: Coronary artery spasm (CAS) associated with catheter ablation commonly occurs during ablation, but rarely as a late-onset complication. CAS may cause cardiogenic shock despite proper pacing of the dual chamber. Continuous monitoring of the electrocardiogram and arterial blood pressure is crucial for the early detection of late-onset CAS. Continuous infusion of nitroglycerin and admission into the intensive care unit after ablation may prevent fatal outcomes.