Because of multiple ventricular lead fractures with inappropriate shocks, a 31-year-old male received a completely subcutaneous implantable cardioverter defibrillator (ICD) system with the already existing ‘endocardial’ ICD functioning as an atrial pacemaker.
A 31-year-old male received an implantable cardioverter defibrillator (ICD) because of documented polymorphic ventricular tachycardias and collapse during exercise. He was also equipped with an atrial lead because his atrial rate repeatedly dropped below 40 beats per minute due to the use of calcium antagonists and beta blockers to suppress his ventricular arrhythmias.
He experienced three ICD lead fractures in 11 years and underwent 1 year before presentation laser lead extraction and implantation of a new ventricular lead on the left side (Boston Endotak 0181) together with a new ICD (Boston Teligen F 110).
He then presented with two inappropriate ICD shocks as a result of ventricular oversensing.
The impedance of the ventricular pace/sense lead was >2000 ohms and a proximal ventricular lead fracture could be seen on the X-ray. No cause could be found for the multiple lead fractures. Tachycardia therapies were programmed off and the ICD was left programmed AAI (lower rate 55 beats per minute).
Venography showed subclavian vein occlusion and because of multiple lead fractures and young age, we elected to place a completely subcutaneous ICD system (S-ICD, Cameron Health Inc, San Clemente, CA, USA).1
The S-ICD system was programmed normally. No sensing of the atrial pacing spike was seen by the S-ICD during and after implantation, even at an output of 5 V/0.5 ms with atrial pacing at 70 bpm (Figure 1). After induction of ventricular fibrillation by 50 Hz burst the S-ICD successfully defibrillated the heart where after atrial back-up pacing was performed by the ‘endocardial’ ICD.
The patient was then discharged with two ICDs in situ (Figure 2).