Atrial fibrillation cryoablation complicated by diffuse coronary artery vasospasm and cardiac arrest: a case report.

Background: Pulmonary vein isolation (PVI) is recommended for rhythm control in selected patients with symptomatic atrial fibrillation (AF). Coronary artery spasm (CAS) is a rare but recognized complication of AF ablation and may result in life-threatening arrhythmias. Case summary: A 47-year-old man underwent cryoballoon PVI for symptomatic paroxysmal AF. Transient inferior ST-segment elevation occurred following left-sided PVI and resolved spontaneously. Shortly after completion of the procedure, recurrent ST-segment elevation developed, progressed to malignant ventricular arrhythmia and cardiac arrest, and emergency angiography demonstrated severe diffuse spasm affecting both coronary systems without obstructive disease. Return of spontaneous circulation occurred following spontaneous resolution of CAS before intracoronary nitrate administration. Ventricular function normalized within 24 h. Recovery was complicated by transient right phrenic nerve palsy and persistent post-traumatic stress disorder. At 2-year follow-up, there was no recurrent AF on implantable loop recorder monitoring. Discussion: This case highlights delayed, recurrent and diffuse CAS as a rare but potentially catastrophic complication of cryoballoon AF ablation. Continuous electrocardiographic monitoring in the peri-procedural period is essential. Although spontaneous resolution occurred in this case, previous reports support rapid access to intravenous or intracoronary nitrates. Emerging data from pulsed field ablation suggests that coronary vasospasm is not restricted to cryothermal energy and that nitroglycerine prophylaxis may reduce, but not abolish, risk.