The population of patients with congenital heart disease (CHD) is continuously increasing with more and more patients reaching adulthood. A significant portion of these young adults will suffer from arrhythmias due to the underlying congenital heart defect itself or as a sequela of interventional or surgical treatment. The medical community will encounter an increasing challenge as even most of the individuals with complex congenital heart defects nowadays become young adults. Within the past 20 years, management of patients with arrhythmias has gained remarkable progress including pharmacological treatment, catheter ablation, and device therapy. Catheter ablation in patients with CHD has paralleled the advances of this technology in pediatric and adult patients with structurally normal hearts. Growing experience and introduction of new techniques like the 3D mapping systems into clinical practice have been particularly beneficial for this growing population of patients with abnormal cardiac anatomy and physiology. Finally, device therapies allowing maintanence of chronotropic competence and AV conduction, improving haemodynamics by cardiac resynchronization, and preventing sudden death are increasingly used. For pharmacological therapy, ablation procedures, and device therapy decision making requires a deep understanding of the individual pathological anatomy and physiology as well as detailed knowledge on natural history and long-term prognosis of our patients. Composing expert opinions from cardiology and paediatric cardiology as well as from non-invasive and invasive electrophysiology this position paper was designed to state the art in management of young individuals with congenital heart defects and arrhythmias.

Background-Although some patients with adult congenital heart disease (ACHD) report limitations in exercise capacity, we hypothesized that depressed exercise capacity may be more widespread than superficially evident during clinical consultation and could be a means of assessing risk. Methods and Results-Cardiopulmonary exercise testing was performed in 335 consecutive ACHD patients (age, 33Ϯ13 years), 40 non-congenital heart failure patients (age, 58Ϯ15 years), and 11 young (age, 29Ϯ5 years) and 12 older (age, 59Ϯ9 years) healthy subjects. Peak oxygen consumption (peak V O 2 ) was reduced in ACHD patients compared with healthy subjects of similar age (21.7Ϯ8.5 versus 45.1Ϯ8.6; PϽ0.001). No significant difference in peak V O 2 was found between ACHD and heart failure patients of corresponding NYHA class (PϭNS for each NYHA class). Within ACHD subgroups, peak V O 2 gradually declined from aortic coarctation (28.7Ϯ10.4) to Eisenmenger (11.5Ϯ3.6) patients (PϽ0.001). Multivariable correlates of peak V O 2 were peak heart rate (rϭ0.33), forced expiratory volume (rϭ0.33), pulmonary hypertension (rϭϪ0.26), gender (rϭϪ0.23), and body mass index (rϭϪ0.19). After a median follow-up of 10 months, 62 patients (18.5%) were hospitalized or had died. On multivariable Cox analysis, peak V O 2 predicted hospitalization or death (hazard ratio, 0.937; Pϭ0.01) and was related to the frequency and duration of hospitalization (Pϭ0.01 for each). Conclusions-Exercise capacity is depressed in ACHD patients (even in allegedly asymptomatic patients) on a par with chronic heart failure subjects. Lack of heart rate response to exercise, pulmonary arterial hypertension, and impaired pulmonary function are important correlates of exercise capacity, as is underlying cardiac anatomy. Poor exercise capacity identifies ACHD patients at risk for hospitalization or death. (Circulation. 2005;112:828-835.)

Despite good short-term prognosis, life expectancy is markedly reduced in Eisenmenger patients. Markers of heart failure and parameters associated with arrhythmia are of prognostic value in terms of mortality and may guide clinicians caring for Eisenmenger patients.