B-po02-202 epicardial ablation of idiopathic ventricular tachycardia (vt) originating from the cardiac crux

Most Idiopathic VT originate from ventricular outflow tracts, the mitral and tricuspid annulus, the papillary muscles, the moderator band and Purkinje-Fascicular network. Idiopathic cardiac crux VT is a rare phenomenon. To recognize and differentiate a rare VT with cardiac crux origin from other idiopathic VT. N/A A 45-year-old man with history of hypertension and frequent palpitations presented with wide complex tachycardia. ECG at baseline was within normal limits. An echocardiogram revealed normal biventricular function. A coronary angiogram was negative for obstruction. On electrophysiology study, clinical ventricular tachycardia was induced with burst pacing from coronary sinus on Isuprel infusion. Twelve lead ECG revealed negative pattern in V1 with abrupt tall R waves in V2 along with pseudo-delta waves, left superior axis, QS in inferior leads and positive R in I and aVL. Mapping during tachycardia revealed early signals in the infero-basal right ventricle and postero-septal left ventricle. We proceeded with mapping in the coronary sinus as the ECG during VT suggested epicardial origin. Earliest signals were noted in the proximal segment of the middle cardiac vein (-33 ms pre QRS) with excellent pace-mapping at this site. Successful radiofrequency ablation at this site rendered the VT non-inducible with aggressive pacing maneuvers. The cardiac crux is a pyramidal space located in the posterior septal region bounded by four cardiac chambers. Unique 12 lead ECG characteristics helped us identify the origin of the VT. Successful ablation can be performed through the proximal segment of the middle cardiac vein.