Inclusion criteria:  Patient over 8 years old with univentricular heart disease as defined by the ACC-CHD classification Agreement from adults or parents if minor patients CPET performed within the 6 months before or after performing echocardiography  Exclusion criteria:  Cardiomyopathy unrelated to CHD (eg coronary artery disease, toxic cardiomyopathy) Significant clinical status change between performing CPET and performing echocardiography, according to the investigator's opinion