Effects of piroximone on the right ventricular function in severe heart failure patients.

OBJECTIVES

To assess the effects of piroximone, a phosphodiesterase inhibitor, on right ventricular function in patients with heart failure.

DESIGN

Randomized study: patients were randomly assigned to the piroximone infusion rate of 5 or 10 micrograms/kg/min.

SETTING

Cardiologic intensive care unit.

PATIENTS

12 consecutive patients with severe heart failure.

INTERVENTIONS

Right heart catheterization was performed using a Swan-Ganz ejection fraction thermodilution catheter.

MEASUREMENTS AND RESULTS

Measurements of right ventricular ejection fraction (RVEF), end-diastolic and end-systolic right ventricular volumes were obtained using the thermodilution principle. To determine contractility indexes, 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 incremental infusion rates of 2, 4, 6 and 8 ng/kg/min. The slope of the relation 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 micrograms/kg/min piroximone infusion, respectively. 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 micrograms/kg/min piroximone infusion, respectively.

CONCLUSIONS

This study suggests a positive action of piroximone on right ventricular contractility at these 2 dosages. This approach using this type of catheter allowed us to determine right ventricular inotropic indexes.