Effects of aminophylline upon right and left ventricular performance in chronic obstructive pulmonary disease: Noninvasive assessment by radionuclide angiocardiography

Abstract

Although aminophylline is a widely used bronchodilator in chronic obstructive pulmonary disease (COPD), its effects upon cardiac performance have not been fully established. The effect of aminophylline upon right ventricular and left ventricular ejection fraction and the left ventricular ejection rate was evaluated by first-pass quantitative radionuclide angiocardiography in 15 patients with COPD, including four with cor pulmonale, and in five control subjects without cardiopulmonary disease. Aminophylline infusion (9 mg/kg) significantly increased the right ventricular ejection fraction (45 to 52 per cent), left ventricular ejection fraction (60 to 67 per cent) and left ventricular ejection rate (3.4 to 4.1 sec −1) in patients with COPD (all parameters, p < 0.001). In six of eight patients with depressed control right ventricular performance, right ventricular ejection fraction normalized and in two of five patients with depressed control left ventricular performance, the left ventricular ejection fraction and left ventricular ejection rate normalized. In control subjects, comparable increases were noted in the right ventricular ejection fraction (50 to 56 per cent), left ventricular ejection fraction (62 to 71 per cent) and left ventricular ejection rate (3.2 to 4.6 sec −1) (p < 0.001). One-second forced expiratory volume (FEV 1) and forced vital capacity (FVC) increased significantly in patients with COPD but not in control subjects. Arterial carbon dioxide tension decreased significantly in both groups (p < 0.05), whereas arterial oxygen tension did not change. Theophylline blood levels did not correlate with absolute increases in right ventricular or left ventricular ejection fraction. These data indicate that aminophylline acutely enhances biventricular performance in COPD. Since comparable cardiovascular changes are induced in normal subjects in whom ventilatory function was not altered, the beneficial effects of aminophylline upon global ventricular performance appear to be independent of the degree of pulmonary compromise.