Exercise cardiac magnetic resonance imaging to assess dynamic right ventricular outflow tract obstruction in congenital heart disease: a case report

BACKGROUND: Right ventricular outflow tract obstruction in patients with congenital heart disease is usually assessed using echocardiographic peak instantaneous gradient at rest. Since right ventricular outflow tract obstruction may change during exercise (dynamic right ventricular outflow tract obstruction), we present a case emphasizing the potential use of exercise cardiac magnetic resonance imaging (CMR). CASE SUMMARY: We discuss a 15-year-old patient with repaired mid-ventricular sub-pulmonary stenosis type double-chambered right ventricle causing right ventricular outflow tract obstruction and symptoms on exertion. In this case, exercise CMR imaging provided additional information, allowing adequate surgical planning. DISCUSSION: The additional value of exercise CMR imaging in a case of right ventricular outflow tract obstruction was described. Although exercise cardiac magnetic resonance imaging did not show a significant increase in peak gradient across the right ventricular outflow tract obstruction, shifting and D-shaping of the interventricular septum with subsequent insufficient left ventricular filling (preload) was observed in the patient with recurrent double-chambered right ventricle. This case demonstrates how exercise CMR imaging can be helpful in the clinical decision beyond standard echocardiographic evaluation by providing additional evidence of adverse haemodynamics during exercise.