Effects of theophylline-ethylendiamine on chronic pulmonary arterial hypertension secondary to chronic obstructive pulmonary disease.

The use of theophylline in the treatment of chronic lung disease is wide spread thanks to the positive effects on the bronchial tree, on ventilation and on diaphragmatic contractile activity, which are well documented. On the other hand, the cardiovascular effects of this drug have not been studied much, particularly the effects on the hemodynamics of the pulmonary circulation. The latest studies were carried out by Parker (1966 and 1967) and by Jezek (1970) with heart catheterization and by Matthay (1978) with isotopic angiocardiography, but the problem has not been fully explored from the standpoint of pulmonary arterial hypertension. Therefore we are studying the effects of intravenous infusions of aminophylline in patients with chronic obstructive lung disease, trying to examine the effects of this drug on three different groups of patients: the 1st without pulmonary arterial hypertension; the 2nd with latent pulmonary arterial hypertension; the 3rd with evident pulmonary arterial hypertension. We consider pulmonary arterial hypertension as pulmonary arterial pressure greater than 20 mmHg at rest and pulmonary arterial pressure greater than 35 mmHg at the end of 8 min of exercise in the supine position, with 40 W load cycle ergometer. The experimental protocol includes the clinical and functional identification of subjects with chronic obstructive long disease, the performance of right heart catheterization and the cannulation of a peripheral artery, measuring all pressure levels, cardiac output, hemogasanalytic data and theophylline levels in steady state (20-30 min. after the end of invasive manoeuvres) at the 10th, 20th and 30th min after the end of an infusion of 10 mg/kg of aminophylline.(ABSTRACT TRUNCATED AT 250 WORDS)