The value of microelectrodes and microbipolar electrograms in premature ventricular complex mapping and ablation: The micro-PVC study

BACKGROUND Catheter ablation is an effective treatment for premature ventricular contractions (PVCs).Mapping typically relies on bipolar (bip-EGMs) and unipolar electrograms (uni-EGMs).Recently, catheters equipped with microbipolar electrodes have become available. OBJECTIVEThis study aimed to investigate the value of microbipolar EGMs (micro-EGMs) in PVCs mapping. METHODSWe performed a multicenter retrospective study including patients who underwent successful outflow tract PVC ablation using QDOT catheters.2 groups were identified based on the superficial or intramural origin of the PVC.EGMs-bip-, uni-, and micro-EGMswere assessed at the successful ablation sites.The primary outcome was the ability of micro-EGM to discriminate between superficial and intramural PVCs.The secondary outcome was signal amplitude.RESULTS Among 81 patients (mean age 54 6 11 years; 59.3% male), 51 had superficial and 30 had intramural PVCs.In superficial PVC, micro-EGM preceded both uni-EGM and bip-EGM in 90% of cases.In particular, when the earliest bip-EGM preceded the earliest micro-EGM by .10ms ( bip-micro .10ms), there was a high probability (sensitivity 0.94; specificity 0.75) of requiring ablation in both the right ventricular outflow tract and left ventricular outflow tract for successful PVC suppression.Micro-EGMs had higher initial deflection amplitude (1.5 vs 2.8 mV; P 5 .025).CONCLUSION Micro-EGMs allow more accurate PVC mapping, improving depth estimation.Micro-EGMs seem to be valuable for local activation time annotation with important implications on automated annotation algorithms within existing electroanatomic mapping systems.