Exercise Magnetic Resonance Imaging Is a Gas.

Magnetic resonance imaging (MRI) is particularly valuable in the assessment of diseases that affect the right heart. Concomitant physiological provocation may unmask latent pathology and provide incremental information to inform prognosis and guide therapy. For example, lowdose dobutamine stress MRI has been shown to unmask right ventricular dysfunction in patients with repaired tetralogy of Fallot. Better than pharmacological stress, exercise-induced changes may aid differentiation of WHO group 1 from group 2 pulmonary hypertension, identification of left heart disease not apparent at rest or inducible pulmonary arterial hypertension, and assessment of right ventricular contractile reserve. MRI permits highly reproducible and accurate measurements of right ventricular volumes and function even during exercise.