A Multicenter Experience with Novel Implantable Cardioverter Defibrillator Configurations in the Pediatric and Congenital Heart Disease Population

Abstract

Introduction: In pediatric and congenital heart disease patients, transvenous ICD implantation may be limited secondary to patient size, venous, or cardiac anatomy. Epicardial patches require a thoracotomy, and may lead to a restrictive pericardial process. Because of these issues, we have explored novel ICD configurations. Methods: Retrospective review at 10 centers implanting ICDs without a transvenous shocking coil or epicardial patches. Results: Twenty‐two patients underwent implant at a mean age of 8.9 years (range: 0.3–43.5), with a mean weight of 25.5 kg (range: 5.2–70). Diagnoses included complex CHD, intracardiac tumors, cardiomyopathy, idiopathic VT, LV noncompaction, and long QT syndrome. Three configurations were used: subcutaneous array, a transvenous design ICD lead placed on the epicardium, or a transvenous design ICD lead placed subcutaneously. Difficulties were found at implant in 8 patients: 4 had difficulty inducing VT/VF, and 4 had high DFTs. Over a mean follow‐up of 2.2 years (range: 0.2–10.5), 7 patients had appropriate shocks. Inappropriate shocks occurred in 4 patients. System revisions were required in 7 patients: 2 generator changes (in 1 patient), 3 pace‐sense lead replacement, 1 additional subcutaneous coil placement due to increased DFT, 1 upgrade to a transvenous system, and 1 revision to epicardial patch system. Conclusions: ICD implantation can be performed without epicardial patches or transvenous high‐energy leads in this population, using individualized techniques. This will allow ICD use in patients who have intracardiac shunting or are deemed too small for transvenous ICD leads. The long‐term outcome and possible complications are as yet unknown in this population, and they should be monitored closely with follow‐up DFTs.

Congenital long QT syndrome: Diagnosis and management in pediatric patients

“…The leads are connected to the ICD generator, which is placed in a prepectoral pocket (although a subpectoral pocket is sometimes used for small or thin patients to both protect the device and provide a better cosmetic appearance). In younger and smaller patients ICD placement can be difficult, but a variety of techniques have been proposed to provide adequate defibrillation thresholds [26]. These include placement of a subcutaneous array with one to three electrodes placed around the thorax as well as placement of a transvenous design lead at the epicardial surface.…”

Arrhythmias in Adult Congenital Heart Disease

“…[134][135][136] Numerous configurations of coils and patches have been described for shock delivery when epicardial implantation is the only option. 137,138 However, epicardial implantation has the disadvantage of more invasive procedures, higher lead failure rates, and a possibility of developing restrictive "pericardial" physiology. 134,139 Subcutaneous array and coils originally designed for adjunctive use to lower the defibrillation threshold have been used as the sole defibrillation lead.…”

“…134,139 Subcutaneous array and coils originally designed for adjunctive use to lower the defibrillation threshold have been used as the sole defibrillation lead. 138,140 The novel subcutaneous ICD system also may be useful in those patients who do not require antibradycardia pacing or antitachycardia pacing, as the system is capable of defibrillation only. 2 …”

How the Subcutaneous Implantable Cardioverter Defibrillator Works

“…These systems used a combination of conventional T-ICDs connected to subcutaneous arrays but still required epicardial leads for cardiac sensing and pacing. 25,26 Although these hybrid systems were shown to be effective in small case series, 25,26 they could not deliver the higher energies that would be required in most adult patients and are not suitable for routine implantation. Simultaneously, the concept of a dedicated S-ICD was revisited.…”

“…Therefore, the S-ICD is indicated in any patient at risk for these arrhythmias, including patients resuscitated from ventricular fibrillation or patients with a primary prevention indication for an ICD ( Table 2). The S-ICD is 26 ; however, the defibrillation energy is unlikely to be sufficient for many patients, especially as they become adults, and they still require an epicardial pace-sense lead. These hybrid systems are now redundant because of the availability of purpose-built S-ICDs, which offer greater certainty of defibrillation.…”