Dr. Sauer serves as a consultant for Biosense-Webster, Inc., a manufacturer of ablation and mapping equipment. Dr. Tzou reports a pending research grant from Biosense-Webster. Other authors: No disclosures.
Endocardial Electrogram Characteristics of Epicardial Ventricular Arrhythmias
Article first published online: 11 FEB 2013
© 2013 Wiley Periodicals, Inc.
Journal of Cardiovascular Electrophysiology
Volume 24, Issue 6, pages 649–654, June 2013
How to Cite
TZOU, W. S., NGUYEN, D. T., ALEONG, R. G., VAROSY, P. D., KATZ, D. F., HEATH, R. R., SCHULLER, J. L., LOWERY, C. M., LEWKOWIEZ, L. and SAUER, W. H. (2013), Endocardial Electrogram Characteristics of Epicardial Ventricular Arrhythmias. Journal of Cardiovascular Electrophysiology, 24: 649–654. doi: 10.1111/jce.12096
- Issue published online: 4 JUN 2013
- Article first published online: 11 FEB 2013
- Accepted manuscript online: 14 JAN 2013 02:38PM EST
- Manuscript Accepted: 2 JAN 2013
- Manuscript Revised: 19 DEC 2012
- Manuscript Received: 4 MAY 2012
- catheter ablation;
- electroanatomical mapping;
- ventricular tachycardia;
- ventricular epicardium
Endocardial Electrograms in Epicardial VT/PVCs
While most ventricular arrhythmias (VA) can be ablated successfully using an endocardial (endo) approach, epicardial (epi) mapping and ablation is sometimes required. There may be suggestive clues on the surface electrocardiogram; however, identification of an epi origin of VA with certainty remains problematic.
Methods and Results
All patients referred for ablation of ventricular tachycardia or frequent ventricular ectopy from June 2007 to July 2011 were evaluated. Patients with completed endo and epi electroanatomical activation maps of an epi VA were included (n = 10). Bipolar electrograms (EGMs) in the area of earliest endo activation were analyzed and compared to the area of early epi activation. An EGM component was characterized as far field if it was monophasic and there was inability to capture. We identified 3 characteristics from endo mapping that consistently indicated need for epi ablation: (1) Diffusely early activation (>2 cm2 region of sites with equally earliest activation within 10 milliseconds). (2) Sequence of a far-field EGM followed by a near-field EGM in the region of earliest endo activation. (3) Inability to capture the far-field component of the earliest EGM (stim-QRS < egm-QRS time) or reproduce morphological features of the VA complex with stimulation at the earliest endo site of activation.
The presence of a diffusely early area of activation and inability to capture a far-field endo EGM indicates that epi ablation may be needed to eliminate a VA.