Cardiac stress testing after surgery for congenital heart disease

Heart failure is an important problem after surgical correction of congenital heart disease. Timely recognition may be difficult. Recent developments in exercise testing and stress-imaging may change the management of patients with congenital heart disease.

Exercise tests are commonly used in the follow-up of patients with congenital heart disease. Maximal exercise studies are not always feasible in this patient population. Variables of submaximal exercise and ventilator efficiency have shown a good correlation with variables of maximal exercise and have been suggested to relate to long-term cardiac function.For evaluation of submaximal exercise, stress imaging may reveal abnormal responses unrecognized at rest. Both physical exercise as well as pharmacological stress may be used in combination with various imaging modalities. For practical reasons, dobutamine is most widely used to generate and mimic stress and is well tolerated in low doses. Particularly in lesions affecting the right ventricle and with single ventricular physiology after the Fontan operation, magnetic resonance stress imaging has provided additional insight into the cardiac function.

The abnormal stress responses can potentially be used for risk assessment in the follow-up of patients with congenital cardiac disease. Further studies are required to provide common protocols for stress imaging.