**2. Diagnosis**

The diagnosis of heart failure in ACHD is often difficult because this population may present with atypical signs and symptoms; however, diagnosis is facilitated by regular follow-up including history and physical exam, laboratory and imaging studies, and functional testing that is part of the management of these patients. Once a hemodynamic lesion is identified on imaging, correction of the lesion is usually required. If no hemodynamic lesion is present, patients are classified into two groups based on whether or not there is impaired ventricular function. Medical management of heart failure is indicated when there is impaired ventricular function without a significant hemodynamic lesion or for patients with normal ventricular function who are clinically symptomatic with either an elevated BNP or evidence of impairment of cardiopulmonary exercise testing. Regular follow-up is indicated if BNP or exercise testing is normal or for clinically, asymptomatic patients with normal ventricular function [1].
