EFFECT OF PULMONARY-ARTERY STENOSES ON THE CARDIOPULMONARY RESPONSE TO EXERCISE FOLLOWING REPAIR OF TETRALOGY OF FALLOT

Data from exercise tests, echocardiograms, and lung perfusion scans we re analyzed to determine whether the excessive minute ventilation (V-E ) often encountered among patients with tetralogy of Fallot is due to ventilation-perfusion mismatch secondary to branch pulmonary artery st enoses. Patients with branch PA stenoses had lower peak oxygen consump tions and higher V-E during exercise than did patients without stenose s, and a strong correlation existed between the degree of pulmonary bl ood flow maldistribution on lung perfusion scan and the amount of exce ssive V-E during exercise.