Thermal Injury Leading to Myocardial Perforation During Cavotricuspid Isthmus Ablation: A Case Report.

BACKGROUND Radiofrequency ablation is an established and safe treatment for atrial arrhythmias, including atrial fibrillation and atrial flutter. However, rare complications related to thermal myocardial injury, such as steam pop, can occur and occasionally result in life-threatening events. This report describes the case of a 70-year-old man who developed myocardial perforation and hemopericardium associated with a steam pop during cavo-tricuspid isthmus (CTI) ablation. CASE REPORT A 70-year-old man with a 6-month history of palpitations and exertional dyspnea underwent catheter ablation for atrial fibrillation and atrial flutter. Pulmonary vein isolation was first performed using a cryo-balloon, followed by cavo-tricuspid isthmus ablation with a non-irrigated IntellaTip MIFI XP™ catheter (Boston Scientific) at 70 W and 65°C under fluoroscopic guidance. During the fourth radiofrequency application, the operator perceived a sudden tactile impulse ("pop") at the catheter tip, without any significant preceding impedance changes. Several minutes later, echocardiography revealed a large pericardial effusion. Immediate pericardial drainage evacuated 1200 mL of blood; however, bleeding persisted, necessitating emergency thoracotomy. A 1-cm myocardial rupture was identified between the inferior vena cava and the tricuspid annulus, consistent with a thermally induced myocardial injury. The patient recovered uneventfully and was discharged on postoperative day 16. CONCLUSIONS This case demonstrates that a steam pop and subsequent cardiac rupture can occur abruptly during cavo-tricuspid isthmus ablation, even in the absence of significant temperature or impedance fluctuations up to onset. Clinicians should be aware that generator parameters do not necessarily exclude the risk of severe complications during radiofrequency ablation.