Effects of pacing sites on decrement-evoked potential mapping for scar-related ventricular tachycardia

Decrement-evoked potential (DEEP) mapping is a useful substrate mapping technique for hemodynamically unstable ventricular tachycardia (VT). This study aimed to elucidate effects of pacing sites on DEEP mapping for scar-related VT in various heart disease.

The patients who underwent substrate mapping and ablation for scar-related VT were consecutively included. DEEP S2 mapping was performed during right ventricular (RV) apex and left ventricular (LV) outflow tract (OT) or RVOT pacing. We analyzed the functional lines of block (LOB) that were additionally discovered from DEEP mapping during OT pacing after DEEP mapping during RV apex pacing according to heart disease.

Total 10 patients (60.3 ± 17.7; 9 males) were consecutively included; 5, ischemic cardiomyopathy (ICM); 3, dilated cardiomyopathy (DCM); and 2, tetralogy of Fallot (TOF). DEEP mapping was performed during RV apex and OT pacing. In ICM, DCM, and TOF, 3.4 ± 1.9, 1.3 ± 1.5, and 0.0 ± 0.0 LOB were discovered during RV apex pacing, respectively. Additional 1.2 ± 0.4, 0.7 ± 0.6, and 1.0 ± 0.0 LOB were discovered during OT pacing in ICM, DCM, and TOF, respectively. Arrangement of 7 of 10 LOBs that were additionally discovered during OT pacing were longitudinal (LV base-to-apex). Noninducibility was achieved at the end of procedure in 60.0% of ICM, 33.3% of DCM, and 100% of TOF.

DEEP mapping during OT pacing is useful for unveiling additional longitudinal LOBs in ICM and TOF.Figure 1