title: Natural and post-operative history of pulmonary vascular obstruction associated with ventricular septal defect.
abstract: The natural history of pulmonary vascular obstruction in VSD associated with PH was studied by measuring PVR before and after injection of tolazoline 1 mg/kg. Organic pulmonary vascular obstruction (PVO) was minimal in infancy, but increased linearly progressively with advancing age, and average rate of increase in PVR after tolazoline was 1 unit.m2/year. The rate of increase in PVR after tolazoline in Eisenmenger complex was variable and ranged between 0.7 to 4 unit.m2/year in most cases. Analysis of 7 cases of post-operative late death due to PVO revealed that usually these cases were over 5 years of age at operation, and pre-operative PVR was more than 12 unit.m2. Reduction of PVR was confirmed post-operatively in most of these cases whose pre-operative PVR before and after tolazoline were les than 8 unit.m2 and 7 unit.m2 respectively. Early surgical repair is indicated in VSD and PH to prevent progress of PVO.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D003251:Constriction, Pathologic; D006345:Heart Septal Defects, Ventricular / Q000150:complications / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D006976:Hypertension, Pulmonary / Q000503:physiopathology / Q000601:surgery; D007223:Infant; D011183:Postoperative Complications; D011651:Pulmonary Artery / Q000503:physiopathology; D011652:Pulmonary Circulation; D011669:Pulmonary Wedge Pressure / Q000187:drug effects; D014043:Tolazoline
chemical_list: D014043:Tolazoline