[Study of the pulmonary vessel reaction to administration of carbon dioxide and nitroglycerin in congenital heart defects complicated by high pulmonary hypertension].

The results of functional pharmacological tests with nitroglycerine and carbon dioxide gas are presented for patients with congenital heart diseases and pulmonary hypertension, as shown during right heart catheterization. It was established that nitroglycerine, taken sublingually, does not produce any direct effect on the pulmonary artery pressure, and the delayed changes in haemodynamics are a consequence of the altered regimen of pressure in the general circulation. When carbon dioxide gas was administered into the pulmonary artery, it proved to produce a direct effect upon the receptors of the pulmonary arterial bed. However, along with the hypotensive effect, in some cases the carbon dioxide gas increases the pressure in the pulmonary artery due to the embologenic effect of the gas bubbles. Both agents affect the arterial pressure irrespective of the patient's age, the nature of the heart disease, and the degree of pulmonary hypertension.