Bipolar electrograms characteristics at the left atrial–pulmonary vein junction: Toward a new algorithm for automated verification of pulmonary vein isolation

Verification of pulmonary vein isolation (PVI) is challenging because of the coexistence of PV and far-field potentials in bipolar electrograms recorded at the left atrial-pulmonary vein (LA-PV) junction.The purpose of this study was to characterize algorithmically LA-PV potentials before and after PVI and to develop an algorithm to differentiate nonisolated from isolated PVs.In 61 patients, we characterized-by type (morphology) and parameters-1440 electrograms recorded during sinus rhythm before and after PVI. Based on vein-dependent prevalence of a given type before and after PVI (first step) and based on vein- and type-dependent cutoff values in parameters specific for recordings before and after PVI (second step), we developed a 2-step algorithm to differentiate nonisolated from isolated PVs. We prospectively validated this algorithm in another dataset of 20 patients.Characteristics before and after PVI were as follows: low voltage (10% ± 7% vs 36% ± 15%), monophasic (13% ± 4% vs 27% ± 9%), biphasic (18% ± 4% vs 21% ± 9%), triphasic (22% ± 5% vs 11% ± 13%), multiphasic (26% ± 7% vs 3% ± 3%), double potentials (11% ± 5% vs 2% ± 1%), peak-to-peak amplitude (0.97 ± 0.21 mV vs 0.35 ± 0.23 mV), maximal slope (0.179 ± 0.033 mV/ms vs 0.071 ± 0.029 mV/ms), minimal slope (0.030 ± 0.003 mV/ms vs 0.024 ± 0.002 mV/ms), and sharpest peak (1.82° ± 0.26° vs 3.45° ± 0.85°, P.01 for all except biphasic). Overall sensitivity and specificity of the 2-step algorithm was 100% and 87%, respectively.We algorithmically characterized LA-PV potentials before and after PVI in a large dataset (library of types and parameters). This library enabled us to develop an accurate 2-step algorithm to automatically differentiate nonisolated from isolated PVs. The 2-step algorithm is objective and reliable for assessing PV isolation without the need for pacing maneuvers.