CE-454610-2 STEREOTACTIC ARRHYTHMIA RADIOABLATION IN VENTRICULAR FIBRILLATION WITH LEFT VENTRICULAR THROMBUS

Abstract

Stereotactic arrhythmia radioablation (STAR) has been studied for management of refractory ventricular tachycardia (VT) that is not amenable to traditional catheter ablation. We present the case of a patient with recurrent ventricular tachycardia (VT) and left ventricular (LV) thrombus successfully treated with STAR therapy. A 48-year-old man with morbid obesity, paroxysmal atrial fibrillation and infarct related cardiomyopathy was admitted with late presentation of new anterolateral ST elevation myocardial infarction complicated by cardiogenic shock, managed with mechanical circulatory support. He was found to have a 3 x 2.7 cm thrombus in the LV apex (Panel A). He underwent successful percutaneous intervention to an acute left anterior descendinig coronary artery occlusion. During hospitalization, despite aggressive measures, he was noted to have polymorphic ventricular tachycardia (VT), triggered by premature ventricular contractions (PVCs) arising from his LV apical infarct (Panel B). He was treated with multiple antiarrhythmic medications (amiodarone, lidocaine) in addition to electrolyte repletion but unfortunately required repeated external defibrillation for PVC induced VF (Panel C). A dual chamber implantable cardioverter-defibrillator was placed and despite overdrive pacing, he suffered from recurrent life-threatening VT and ventricular fibrillation (VF) requiring additional defibrillation (Panel D). Because he was not a candidate for endocardial ablation, orthotopic heart transplantation, and was deemed too unstable for epicardial ablation, the decision was made to pursue STAR. Surface ECG and 4D computed tomography (Panel E) were used to localize the focus of the VT trigger. A single dose of 25 Gray of radiation was delivered to the LV apex. Our patient has been free of ventricular arrhythmias for 14 months. There has been no clinical evidence of early or late toxicity related to radiotherapy thus far. In challenging cases of PVC induced VT and VF not amenable to traditional therapies, such as our patient, STAR may offer a therapeutic option. Further studies are required.