br Associated heart disease in children with
Associated Dinaciclib disease in children with ICD implantations In a multicenter ICD registry of 443 patients , 69% of the patients had CHD and 23% had cardiomyopathy. The most common heart disease was tetralogy of Fallot (19%), followed by hypertrophic cardiomyopathy (14%) (Fig. 3). In structurally normal hearts, long QT syndrome was the most prevalent disease, and it accounted for 31% of the heart disease cases including Brugada syndrome and catecholaminergic polymorphic ventricular tachycardia (Fig. 4).
ICD placement in children Consequently, nonendocardial electrode placement is mandatory for ICD implantations in small infants and patients with certain CHDs. No subcutaneous arrays or patches are available at present, and in most studies [9–12], the ICD shock leads were placed either in the pericardial space or subcutaneously (Fig. 5). The advantages and disadvantages of these lead routes are listed in Table 1. Furthermore, nontransvenous ICD systems reportedly survive for a significantly shorter time than do transvenous ICD systems . Nontransvenous ICD systems are now available [14,15]; however, they are not suitable for small children, because the size of the generator is very large. Table 2 lists the ICD system-related complications . Because of sinus tachycardia or other supraventricular tachycardias, nearly 50% of children with ICD implantations have inappropriate ICD discharges. Depression or anxiety associated with ICD discharges is another problem in children.
Criteria for ICD implantations in children The indications for ICD implantations in children were primary prevention in 52% and secondary prevention in 48% of the patients. Single-chamber ICDs were implanted in 42%, and DDD-ICDs were implanted in 58% of the patients. The suggested retrospective indication criteria for ICD implantations in children  are listed in Tables 3 and 4.
CRT in pediatric and CHD patients In a multicenter retrospective study of CRT in pediatric and CHD patients , the underlying heart diseases were CHD in 71%, cardiomyopathy in 6%, and congenital complete atrioventricular block in 13% of the patients. Cecchin et al.  reported that 77% of patients in their institute underwent CRT, and idiopathic dilated cardiomyopathy was observed in 17%. In a previous study , the mean QRS duration before CRT was 166.1±33.3ms, and it decreased to 37.7±30.7ms (p<0.01) after CRT. In this study, the systemic ventricular ejection fraction before CRT was 26.2±11.6%, and it increased to 39.9±14.8% (p<0.05) after CRT. This improvement did not differ among the types of heart disease (Table 5). Cecchin et al.  reported that of 18 patients listed for heart transplantation, the condition of 3 patients improved sufficiently and they were removed from the heart transplant list, 5 underwent heart transplantation, 2 died, and 8 others are awaiting a heart transplant after CRT. Although data are limited, these studies show that CRT is an effective therapy in CHD patients and children with cardiomyopathy and complete heart block. Another study  showed that the number of nonresponders in the younger patient population was lower than that in the adult patients, and CRT in this younger group may help delay heart transplantation, and systemic right ventricle or single-ventricle patients accounted for approximately 30% of these subjects.
CRT indications The current suggested indications for CRT in pediatric and CHD patients  are listed in Table 6.
Conflict of interest
Introduction Brugada syndrome (BS) is an arrhythmogenic entity characterized by the presence of ST-segment elevation in leads V1–V3 on surface electrocardiogram (ECG), the absence of structural heart disease, and a high risk of ventricular tachycardia/ventricular fibrillation (VT/VF) and sudden cardiac death (SCD) [1–3]. Risk stratification is controversial, especially in asymptomatic individuals [4–6]. Transmural dispersion of repolarization within the ventricular myocardium has been suggested to underlie arrhythmogenesis in BS , and ECG markers of ventricular repolarization have been reported for the identification of high-risk patients with BS . We investigated whether ECG-based spatial and transmural ventricular depolarization and repolarization values are potential risk factors for arrhythmic events in BS patients. In the present study, we used the recently developed signal-averaged vector-projected 187-channel high-resolution ECG (187-channel SAVP-ECG).