TETRALOGY OF FALLOT WITH ABSENT PULMONARY VALVE - ECHOCARDIOGRAPHIC MORPHOMETRIC FEATURES OF THE RIGHT-SIDED STRUCTURES AND THEIR RELATIONSHIP TO PRESENTATION AND OUTCOME

Respiratory symptoms in tetralogy of Fallot with absent pulmonary valv e are believed to be due to bronchial compression secondary to dilated pulmonary arteries; however, not all patients are born compromised. E chocardiographic morphometry of the right-sided structures was investi gated to determine the possible relationship between anatomy and clini cal presentation. Twenty-five patients were identified, and 15 had pre operative echocardiograms. Patients were divided into two groups: thos e with respiratory distress (group I, n = 9) and those without (group II, n = 6). No difference was noted in branch pulmonary artery diamete rs between groups; however, the pulmonary valve/aortic valve ratio, re flecting the dimension of the narrowest pathway from the right ventric le, was larger in group I (0.74 +/- 0.15 versus 0.60 +/- 0.07, p < 0.0 5). Pulmonary, valve diameter correlated with main and right pulmonary artery diameters. We conclude that patients with tetralogy of Fallot with absent pulmonary valve and respiratory compromise have a greater pulmonary valve/aortic valve ratio but do not have greater dilatation of proximal branch pulmonary arteries. This suggests that the pathophy siology is not due solely to compression of the bronchi but is also re lated to the blood flow dynamics in the pulmonary vessels.