Abstract Introduction Time to pulmonary vein isolation (PVI) during cryo balloon (CB) PVI is a critical data point in characterizing the pulmonary vein (PV) isolation status as it improves clinical outcomes. PV potentials on the circular mapping catheter may be obscured by power line artifact during the freeze process as ice forms near the electrode. This study assesses the ability of an intelligent digital filter to sample, predict and remove noise from PV electrograms during the freeze cycle to increase the time window available to observe the abolition of PV potentials. Method An intelligent filter that detects and removes power line related signal artifact was developed. The filter algorithm was then retrospectively applied to electrograms collected during delivery of cryo energy in the PVISION trial of the PVI Analyzer study previously described. The PV potential amplitude immediately before the delivery of cryo energy was recorded. During the freeze cycle, artifact amplitude was measured and the time required for the noise to exceed that of the original PV potential recorded. This operation was repeated with the application of the predictive filter. An example of an analysis of a single bipolar trace is shown in Fig 1. Results The PVISION trial included 47 patients who underwent a cryo PVI procedure (42% female, mean age 59 years, +/- 11 years). Of those, 24 cases and 68 vein cryo applications had sufficient information about when the cryo freeze cycle started and ended. Of these 68 veins treated, 33 exhibited power line noise on one or more bipolar traces during the freeze cycle (49%). The mean amplitude of PV potentials before application of energy was 0.49 mV (+/- 0.79 mV) and the mean time to artifact exceeding this level was 69 (+/-50 seconds), across all bipolar traces with freeze noise present. After application of the intelligent filter, the mean time to artifact exceeding the baseline PV amplitude increased to 82 seconds (+/- 57 seconds), across all bipolar traces with freeze noise present. In 44 veins noise amplitude never exceeded PV potential amplitude on any of the bipolar traces during the freeze after application of the intelligent filter. Paired analysis of the average time of noise exceeding the PV potential amplitude during the freeze was 116 s before application of the filter and 26 s with the filter applied. See Fig 2. for a summary of the results. Conclusion An intelligent digital filter designed to remove artifact from electrograms during cryo ablation procedures might increase the time window before noise saturates PV potentials and, in some cases, remove noise such that it never exceeds that of the PV potential.Fig 1 Example of noise and filteringFig 2. Summary of results