Several unsuccessful internal and external defibrillations during active can ICD implantation in a patient with pneumothorax.

During implantable cardioverter defibrillator (ICD) implantation of an active can ICD several defibrillations with 20 J and 34 J as well as 360 J externally were ineffective. The implant criteria were finally met with a second defibrillation lead and reversed polarity. A left-sided pneumothorax due to subclavian vein puncture was detected soon after ICD implantation. It is assumed that especially in the active can alignment the developing pneumothorax made defibrillation current flow more difficult. In case of several unsuccessful defibrillations during active can ICD implantation in which the subclavian vein was punctured, the possibility of a pneumothorax should be considered.