Late malfunction of subcutaneous implantable cardioverter-defibrillator in a patient with advanced emphysema

Implantable cardioverter-defibrillators (ICD) are highly effective in treating life-threating ventricular arrhythmias and are commonly implanted in patients at risk of sudden cardiac death. Successful defibrillation by an ICD depends on its ability to deliver shocks that exceed defibrillation thresholds (DT). In a properly implanted and normal functioning ICD system, extracardiac conditions (e.g., pneumothorax, pleural effusion, excessive soft tissue) can increase shock impedances and divert the shock pathway, resulting in defibrillation failure.