Detection of Epicardial Late Potentials by Endocardial Wide-Bipolar Mapping in a Case of Cardiac Sarcoidosis.

BACKGROUND

Identifying substrates for ventricular tachycardia (VT) from the endocardium is often difficult when the arrhythmia originates from the epicardium.

CASE SUMMARY: A 72-year-old man with sustained VT and a left ventricular aneurysm due to cardiac sarcoidosis underwent left ventricular mapping using a high-density mapping catheter. With conventional omnipolar configuration, no low-voltage area or abnormal potentials were identified. However, reconstruction of the isochronal late activation map with wide-bipolar configuration revealed low-frequency late potentials within the aneurysm. Subsequent epicardial mapping demonstrated extensive late potentials on the contralateral side, and ablation at this site was successful in eliminating VT.

DISCUSSION: Wide-bipolar electrograms include more far-field components than close-bipolar or omnipolar signals, enabling detection of epicardial-originated potentials from the endocardium.

TAKE-HOME MESSAGE: When late potentials are not evident with conventional configurations, wide-bipolar electrograms may uncover epicardial substrates from the endocardial surface.