SUMMARY In order to determine the presence and extent of obstructive pulmonary vascular disease in patients with congenital heart disease, magnified cineangiograms were obtained with a catheter in the pulmonary artery wedge position in 155 infants and children undergoing cardiac catheterization. The wedge angiograms (WA) were analyzed in groups according to the pulmonary hemodynamics: group A normal pulmonary blood flow (PBF) and pulmonary artery pressure (PAP) (31 patients; 53 WA); group B increased PBF and normal PAP (46 patients; 69 WA); group C: increased PBF and PAP but a pulmonary vascular resistance (PVR) < 6 u/m2 (19 patients; 33 WA); group D increased PAP and PVR > 6 u/M2 (30 patients; 66 WA); group E pulmonary venous hypertension (15 patients; 27 WA); and group F: infants < 3 months old with a variety of congenital heart defects (14 patients; 19 WA).
WA from group A patients defined the microcirculation of the secondary pulmonary lobule with an evenly tapering, orderly arborization of muscular pulmonary arteries and numerous supernumerary vessels as small as 100 μ in diameter with a full, even granular capillary blush surrounding each small, muscular artery. Increased PBF produced dilation of the elastic and muscular vessels with engorgement of the lobule, while increased PAP produced tortuosity of the vessels. An elevated PVR was manifest by dilation and tortuosity of the elastic vessels and a more abrupt tapering of the muscular arteries. Patients with a PVR > 12 u/M2 and those with obstructive vascular disease by histological examination (eight patients) showed marked reduction or absence of supernumerary vessels and decreased arborization of the distal muscular pulmonary arteries as well as the other hypertensive changes, and the capillary blush was incomplete, patchy and reticular. Obstructive signs were distributed randomly within the lobules and the lung lobes.
Pulmonary venous hypertension was associated with dilation of the paralobular veins with a vein:central artery ratio of > 1.3: 1. WA in the infants showed no obstructive pattern, and the microvascular morphology reflected the pulmonary hemodynamics seen in groups A, B and C.
We conclude that the presence of obstructive pulmonary vascular disease can be determined in patients with pulmonary hypertension and elevated PVR by magnification wedge angiography. The degree and extent of obstructive vascular lesions can be assessed more readily by this method than by histologic examination or random lung biopsy specimens.