When do you consider epicardial mapping for ventricular tachycardia (VT)?
Indications for epicardial mapping: Mapping and ablation of ventricular tachycardia (VT) is usually done from the endocardial approach except in the following specific situations:
VT in structural heart diseases with a propensity for an epicardial substrate like Chagas disease and arrhythmogenic right ventricular cardiomyopathy (ARVC/ARVD)
Hyperenhancement seen in the epicardial region on contrast enhanced cardiac magnetic resonance (CMR) imaging
Endocardial mapping fails to identify an endocardial scar
Electrocardiographic features of clinical or induced VT indicating an epicardial focus
Failed attempts at ablation by endocardial approach are important indications for epicardial mapping .
Epicardial technique was developed by Sosa E and colleagues in 1996 by modifying the technique for pericardiocentesis for enabling percutaneous access to the pericardial space for mapping and ablation of ventricular tachycardia . The epicardial approach was originally developed to treat patients in whom ablation was unsuccessful by endocardial approach in those patients with Chagas disease and ischemic cardiomyopathy with epicardial scarring. Later the technique was shown to be useful in idiopathic dilated cardiomyopathy, arrhythmogenic right ventricular dysplasia and hypertrophic cardiomyopathy .