CARDIOPULMONARY PERFORMANCE DURING EXERCISE IN PATIENTS WITH REPAIREDTETRALOGY OF FALLOT WITH ABSENT PULMONARY VALVE

In patients with tetralogy of Fallot and absent pulmonary valve, the d ilated pulmonary arteries sometimes result in bronchial compression an d pulmonary symptoms due to airway obstruction, recurrent pulmonary in fection, and development of bronchiectasis. After complete intracardia c repair, residual pulmonary disease may be expected to result in impa ired cardiopulmonary performance during exercise. To assess this hypot hesis, nine patients with tetralogy of Fallot and absent pulmonary val ve underwent exercise testing and were compared to 38 patients with te tralogy of Fallot repaired using a transannular patch. All patients we re exercised to maximum volition using a I minute incremental treadmil l protocol with monitoring of pulmonary functions and expired gases. M aximal heart rate, maximal oxygen consumption, oxygen consumption at a naerobic threshold, and maximal respiratory exchange ratio were simila r for the two groups. There was no significant difference for ventilat ion and gas exchange parameters at rest or at maximal exercise, and va lues for both groups were below the predicted normal for healthy subje cts. Breathing reserve, however, did tend to be somewhat lower in the group with tetralogy of Fallot with absent pulmonary valve. In summary , despite significant preoperative symptoms, cardiopulmonary performan ce during exercise in patients with tetralogy of Fallot and absent pul monary valve is similar to patients with tetralogy of Fallot repaired with a transannular patch.