Lack of increase in stroke volume during exercise in asymptomatic adolescents in sinus rhythm after intraatrial repair for simple transposition of the great arteries

In summary, this study demonstrates that an inappropriate stroke volume response to exercise is observed in a selected group of patients who underwent Mustard or Senning repair for d-transposition of the great arteries and who are asymptomatic, relatively fit, and in sinus rhythm. Therefore, right ventricular dysfunction can exist without chronotropic impairment. Many patients present with both chronotropic impairment attributable to sinus node dysfunction and right ventricular dysfunction. In patients with sinus rhythm, exercise capacity is always limited by right ventricular dysfunction.