DOSE DEPENDENCY OF AMINOPHYLLINE EFFECTS ON HEMODYNAMIC AND VENTRICULAR-FUNCTION IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY-DISEASE

The effects of aminophylline on pulmonary vascular tone, systemic hemo dynamics, and ventricular ejection fractions reported in the literatur e show some discrepancies. We therefore studied in COPD patients the e ffects of aminophylline on hemodynamics, on ventricular ejection fract ions, and on systolic and diastolic functions of each ventricle, and w e measured simultaneously the blood level of the drug. The analysis of the data revealed a relationship between the blood level of aminophyl line and the variations of right ventricular ejection fraction (RVEF) (r = 0.83, p = 0.005), left ventricular ejection fraction (LVEF) (r = 0.76, p = 0.017), pulmonary vascular resistance index (PVRI) (r = -0.5 8, p = 0.096), systemic vascular resistance index (SVRI) (r = -0.60, p = 0.08), and right ventricular peak systolic pressure/end-systolic vo lume index (RVPSP/ESVI) (r = 0.75, p = 0.02). Modifications of ejectio n fractions and vascular resistance indices were correlated for both v entricles (RVFF vs PVRI, r= -0.77, p = 0.01; LVEF vs SVRI, r = -0.76, p = 0.02). Finally, RVEF modification was also correlated to RVPSP/ESV I variation (r = 0.78, p = 0.01). These results suggest that even with in the therapeutic range (10 to 20 mg/L), the effects of aminophylline seemed to depend on its blood level. This dose dependency could expla in the contradictory data reported in the literature concerning the ef fects of aminophylline on pulmonary and systemic hemodynamics and on v entricular function.