Appropriate and Inappropriate ICD Shocks in Children, Adolescents, and Adults with Congenital Heart Disease

In pediatric cardiology and cardiology of adults with congenital heart disease, indication for implantation of an implantable cardioverter-defibrillator (ICD) is often based on underlying diseases like primarily electrical heart disease (channelopathies), cardiomyopathies or congential heart disease. Implantation of a conventional transvenous system may be impossible in small children or patients with complex cardiac anatomy (e. g. after Glenn procedure). In the clinic of pediatric cardiology and intensive care medicine, non-transvenous ICD systems with a tailored follow up program are established as an alternative. Appropriate and inappropriate ICD discharges are negatively correlated with patient’s quality of life. Aim of this single center retrospective study was to report the medical history of a large number of children, adolescents and adults with congenital heart disease after implantation of an ICD. Particular attention was paid to the occurrence of appropriate and inappropriate ICD discharges. Factors associated with appropriate and inappropriate ICD discharges should be identified. Furthermore, the above-mentioned non-transvenous ICD systems were compared with conventional transvenous ICD systems in terms of their safety and effectiveness. Data showed that antitachycardia pacing is effective tool for prevention of appropriate ICD discharge. Patients with primarily electrical heart disease experience appropriate ICD discharge early after implantation, so that special emphasis should be placed on rapid invasive and non-invasive therapy in addition to the implantation of an ICD. Appropriate ICD discharge was rare in patients with congenital heart disease and indication for ICD implantation for primary prevention. Most common cause for inappropriate ICD discharge was supraventricular or atrial tachycardia. Rigorous, possibly invasive treatment therefor is mandatory to prevent inappropriate ICD discharge. Implantation of an atrial lead seems to be of minor importance. Rather, the programming of a low VT detection rate seems to be associated with an increased number of inappropriate shocks due to supraventricular or atrial tachycardia. Regarding inappropriate shocks, non-transvenous ICD systems are not inferior to transvenous systems, though the number of lead dysfunction was higher in non-transvenous systems. In conclusion effectiveness of the used follow-up program with regular defibrillation threshold testing can be assumed. The importance of follow-up care by pediatric cardiologists / electrophysiologists trained in the specific aspects of non-transvenous ICD systems is underlined.2021-02-2