An anomalous case of S-ICD malfunctioning: A big trouble or a soap bubble?

Abstract 12 h after the implant of a S-ICD the patient accused an inappropriate shock due to noise oversensing. ICD interrogation showed undersensing of ventricular signals on primary vector and significative noise on alternative vector. Surprisingly, 2 days full recovery of sensing of primary vector was observed. Trapped air was likely to be the cause of malfunctioning.