Spontaneous closure of ventricular septal defect in a case of double outlet right ventricle.

A 5 year old child, previously diagnosed as having tetralogy of Fallot, was admitted to hospital in severe congestive heart failure. The electrocardiogram showed left anterior hemiblock and incomplete right bundle-branch block, neither of which was previously present. The child died in intractable congestive heart failure and the necropsy showed a double outlet right ventricle with complete spontaneous closure of the subaortic ventricular septal defect by fibrous tissue. The possible mechanism involved in the production of this unusual complication of double outlet right ventricle is discussed, together with an explanation for the electrocardiographic changes.