Implanted medical device data is received, where the data was sensed by a first lead portion and a sensor over a time period. The number of detected noise events sensed by the first lead portion is counted based on applying first noise detection criteria to the data sensed by the first lead portion. The number of detected noise events over the sensor is counted based on applying second noise detection criteria to the data sensed by the sensor. The mean number of detected noise events is calculated for the first lead portion and sensor based on the number of noise events sensed by the first lead portion and the number of noise events sensed by the sensor. Potential lead failure in the first lead is recorded if the number of detected noise events over the first lead is greater than the mean number of noise events by at least 5%.