Acute effects of intravenous UD-CG 115 BS (pimobendan) on the cardiovascular system and left ventricular pump...

Acute hemodynamic effects of 5 and 10 mg i.v. UD-CG 115 BS (pimobendan) were studied by right and left heart catheterization in idiopathic dilated cardiomyopathy (NYHA classes II and III; 5 mg = group I, n = 6; 10 mg = group II, n = 6). Effects on left ventricular function were evaluated by left ventricular angiograms and measurement of left ventricular dp/dtmax before and 2.5 h after administration of UD-CG 115 BS. Right atrial pressure (RAP), pulmonary capillary wedge pressure (PCP), cardiac output (CO), heart rate (HR), and systemic blood pressure (BP) were assessed before and 2.5, 4, and 6 h after administration of UD-CG 115 BS. PCP was maximally reduced by 10 mg of UD-CG 115 BS from 18.3 +/- 6.2 to 6.2 +/- 3.4 mm Hg (p less than 0.005) and by 5 mg from 12.2 +/- 7.5 to 8.3 +/- 7.1 mm Hg (p less than 0.05). Maximum reduction of RAP was significant only in group II (p less than 0.05). CO increased in a similar way after both doses (group I: from 5.5 +/- 1.9 to 7.8 +/- 1.3 L/min, p less than 0.005; group II: from 5.0 +/- 1.3 to 7.5 +/- 1.8 L/min, p less than 0.05). Mean arterial blood pressure was slightly reduced only by 10 mg of UD-CG 115 BS. Heart rate rose from 84 +/- 11 to 100 +/- 14 beats/min in group I (p less than 0.05), whereas after 10 mg no change in heart rate was noted. Left ventricular end-diastolic (EDVI) and end-systolic volume (ESVI) indices were clearly reduced by both 5 and 10 mg of UD-CG 115 BS.(ABSTRACT TRUNCATED AT 250 WORDS)