Hemodynamic Performance During Exercise in Patients with Severe Chronic Congestive Heart Failure Before and After a Single Dose of Pimobendan

Abstract

Duration of symptom-limited exercise on a bicycle ergometer (constant workload of 25 W) was determined in 12 patients with severe chronic congestive heart failure (CHF) due to dilated cardiomyopathy (CMP, 4 patients) or ischemic heart disease (IHD, 8 patients) undergoing hemodynamic monitoring. Mean exercise duration was 214 +/- 124 s and produced severe dyspnea lasting > 5 min in all patients. The next morning, each patient exercised again to the same level; pimobendan (10 mg orally) was then administered, and exercise to the same workload was repeated 4 and 10 h later. Mean +/- SD exercise-induced changes in heart rate (HR, min-1), pulmonary capillary wedge pressure (PCW, mm Hg), cardiac output (CO, L/min-1), and stroke volume index (SVI, ml.min-1) were as follows. At baseline, HR was 85 +/- 17-110 +/- 21 beats/min (p < 0.001), PCW 21 +/- 10-31 +/- 10 mm Hg (p < 0.05), CO 3.7 +/- 1.0-3.9 +/- 1.0 L.min-1 (NS), and SVI, 25 +/- 7-20 +/- 7 ml.m-2 (NS). Four hours after pimobendan administration, HR was 90 +/- 14-113 +/- 21 beats/min (p < 0.001), PCW 11 +/- 7-20 +/- 10 mm Hg (p < 0.05), CO 5.3 +/- 0.7-5.8 +/- 1.0 L.min-1 (NS), and SVI 33 +/- 3-29 +/- 7 ml.m-2 (NS).(ABSTRACT TRUNCATED AT 250 WORDS)