EFFECTS OF PIROXIMONE ON THE RIGHT-VENTRICULAR FUNCTION IN SEVERE HEART-FAILURE PATIENTS

Objectives: To assess the effects of piroximone, a phosphodiesterase i nhibitor, on right ventricular function in patients with heart failure . Design: Randomized study: patients were randomly assigned to the pir oximone infusion rate of 5 or 10 mug/kg/min. Setting: Cardiologic inte nsive care unit. Patients. 12 consecutive patients with severe heart f ailure. Interventions: Right heart catheterization was performed using a Swan-Ganz ejection fraction thermodilution catheter. Measurements a nd results: Measurements of right ventricular ejection fraction (RVEF) , end-diastolic and endsystolic right ventricular volumes were obtaine d using the thermodilution principle. To determine contractility index es, the relationships between end-systolic pulmonary arterial pressure (ESPAP) over right ventricular end-systolic volume (RVESV) and ESPAP over RVEF were calculated during the infusion of prostacyclin at incre mental infusion rates of 2, 4, 6 and 8 ng/kg/min. The slope of the rel ation between ESPAP over RVESV shifted during piroximone therapy from 7.635+/-1.632 to 1.975+/-0.432 (p<0.01) and from 6.092+/-1.99 to 1.028 +/-0.853 (p<0.05) at 5 and 10 mug/kg/min piroximone infusion, respecti vely. The slope of the relation between ESPAP over RVEF decreased from -0.414+/-0.296 to -0.821+/-0.257 (p<0.01) and from -0.127+/-0.048 to -0.533+/-0.135 (p<0.05) at 5 and 10 mug/kg/min piroximone infusion, re spectively. Conclusions. This study suggests a positive action of piro ximone on right ventricular contractility at these 2 dosages. This app roach using this type of catheter allowed us to determine right ventri cular inotropic indexes.