An alternative technique of implanting a nontransvenous implantable cardioverter-defibrillator system in adults with no or limited venous access to the heart

BackgroundIn some patients at high risk for sudden cardiac death, a transvenous implantable cardioverter-defibrillator (ICD) cannot be implanted owing to limited vascular access. These patients can benefit from a nontransvenous defibrillation system consisting of a rate-sensing lead attached to the epicardium and a subcutaneous (SQ) array.ObjectiveWe examine the feasibility, safety, and clinical circumstances requiring implant of nontransvenous defibrillation system in adults.MethodsEight patients received an ICD system composed of an SQ array and either a chronic endocardial rate/sense lead (n = 5) or a new epicardial rate/sense lead (n = 3) for primary (n = 2) or secondary (n = 6) prevention. The obstacles to transvenous ICD implantation included recurrent endovascular lead infections (n = 1), congenital heart disease (n = 4), and superior vena cava occlusion (n = 3). The array was tunneled posteriorly, and the epicardial rate-sensing leads were implanted by left lateral minithoractomy. Four patients also required left ventricular pacing.ResultsSuccessful defibrillation was obtained in all patients at 29 ± 2.6 J. There were no major cardiovascular complications. Over a mean follow-up of 545 ± 204 days there was one appropriate and no inappropriate shocks. None of the patients required system revision. There were no significant changes in impedance, pacing threshold, or ventricular sensing observed with the epicardial leads and no change in high-voltage impedance.ConclusionsThe nontransvenous defibrillation system described is an effective technique in an adult population with acceptable pacing and defibrillation threshold.