BACKGROUND: In @entity1 with left @entity1165 ( @entity1165 ) and failed endocardial ablation, a subepicardial substrate may be considered. @entity1 AND METHODS: Seven @entity1 with drug-refractory @entity1165 of @entity714 morphology were investigated to identify the arrhythmogenic substrate using three-dimensional (3-D) electroanatomic endocardial and epicardial mapping. RESULTS: In three @entity1 with repetitive monomorphic @entity1165 during @entity591 showed a focal pattern with an earliest activation preceding the onset of the QRS complex by 20 and 28 ms in the lateral aspect of the epicardial outflow tract in two @entity1 and by 24 ms near the posterolateral mitral annulus in one @entity1 ; in two @entity1 with sustained @entity1165 , endocardial mapping during @entity591 displayed a focal pattern with a wide breakthrough, and epicardial mapping showed a macroreentrant @entity1165 with an isthmus located in the left anterior wall in one @entity1 and in the left inferolateral wall in the other. In the remaining two @entity1 , endocardial and epicardial mapping were performed during sinus rhythm. An area with fragmented and late potentials as well as low amplitude was only identified in the epicardial left inferolateral wall. During @entity591 , a diastolic potential was only recorded on the epicardium and coincided with the late potential during sinus rhythm in the same area. A focal or linear epicardial irrigated lesion terminated the @entity1165 and resulted in noninducibility in all seven @entity1 . During a median follow-up of 16 months, @entity1165 recurred in two patients without antiarrhythmic drugs. The recurrent @entity1165 was successfully reablated in one @entity1 and treated with oral @entity2643 in the other. CONCLUSION: Subepicardial left focal and macroreentrant @entity1165 may present as focal origin on endocardial mapping and can only be abolished by radiofrequency (RF) applications in the epicardial space.

Catheter ablation of subepicardial XXXX using electroanatomic mapping.

@entity1 :: ('9606', 'Species') :: ['patients', 'patient', 'PATIENTS'] @entity2643 :: ('MESH:D000638', 'Chemical') :: ['amiodarone'] @entity1165 :: ('MESH:D017180', 'Disease') :: ['VT', 'ventricular tachycardia', 'VT, endocardial and epicardial mapping'] @entity714 :: ('MESH:D002037', 'Disease') :: ['right bundle branch block'] @entity591 :: ('MESH:D013610', 'Disease') :: ['tachycardia']
@entity1165 :: (MESH:D017180,Disease) :: ['ventricular tachycardia']
