The Effect of Exercise on Left to Right Shunt of Blood Through a Ventricular Septal Defect

¹ Bobs Roberts Memorial Hospital for Children, Department of Pediatrics, The University of Chicago.
² Bobs Roberts Memorial Hospital for Children, Department of Pediatrics, The University of Chicago., Benjamin J. Rosenthal Fellow.

The effect of exercise on left to right shunt of blood through a ventricular septal defect has been studied.

Patients with ventricular septal defect and normal right ventricle and pulmonary artery pressures who raised their systemic blood pressure by exercise, showed an increase in the left to right shunt.

It is suggested that this increase in shunt is due to a rise in the interventricular pressure gradient.

In patients with ventricular septal defect and pulmonary hypertension or stenosis, a decrease in left to right shunt occurred with exercise.

This decrease is explained by a fall in systemic resistance with exercise, as compared to pulmonary resistance, while little change or perhaps a diminution in the interventricular pressure gradient occurred.

It is suggested that this technique makes it possible to study the natural history of the left to right shunt in patients with interventricular septal defects and to anticipate the development of frank pulmonary hypertension by repeated tests at necessary or even frequent intervals.