Idiopathic ventricular outflow tract arrhythmias from the great cardiac vein: challenges and risks of catheter ablation

INTRODUCTION: Catheter ablation for idiopathic ventricular arrhythmia is well established but epicardial origin, proximity to coronary arteries, and limited accessibility may complicate ablation from the venous system in particular from the great cardiac vein (GCV).

METHODS: Between April 2009 and October 2010 14 patients (56 ± 15 years; 9 male) out of a total group of 117 patients with idiopathic outflow tract tachycardias were included undergoing ablation for idiopathic VT or premature ventricular contractions (PVC) originating from GCV. All patients in whom the PVC arose from the GCV were subject to the study. In these patients angiography of the left coronary system was performed with the ablation catheter at the site of earliest activation.

RESULTS: Successful ablation was performed in 6/14 (43%) and long-term success was achieved in 5/14 (36%) patients. In 4/14 patients (28.6%) ablation was not performed. In another 4 patients (26.7%), ablation did not abolish the PVC/VT. In the majority, the anatomical proximity to the left coronary system prohibited effective RF application. In 3 patients RF application resulted in a coronary spasm with complete regression as revealed in repeat coronary angiography.

CONCLUSION: A relevant proportion idiopathic VT/PVC can safely be ablated from the GCV without significant permanent coronary artery stenosis after RF application. Our data furthermore demonstrate that damage to the coronary artery system is likely to be transient.