Levosimendan improves cardiac function and myocardial efficiency in rats with right ventricular failure

Figures

• 

  Fig. 1.. (a) Study design. After seven weeks of treatment, cardiac function and energetics were evaluated by echocardiography, 11C-acetate PET, 18F-FDG PET, and invasive pressure measurements. (b) 11C-acetate PET protocol. See text for explanation. (c) 18F-FDG PET protocol. See text for explanation. PTB, PT banding; FDG, fluorodeoxyglucose; PET, positron emission tomography; MRI, magnetic resonance imaging.

• 

  Fig. 2.. Effect of levosimendan on RV energetics. (a) RV external work. Levosimendan increases RV external work mainly by an increase in SV. (b) RV myocardial oxygen consumption (MVO2) estimated from kmono achieved from 11C-acetate PET scans. Levosimendan did not affect RV MVO2. (c) RV myocardial external efficiency (RV MEE), calculated as the ratio of RV external work and total RV MVO2. Levosimendan improved RV MEE. Data are presented as mean ± SEM. Vehicle: n = 7 and Levosimendan: n = 7. *P < 0.01, unpaired t-test.

• 

  Fig. 3.. Representative example of myocardial time activity curve for 11C-acetate PET acquisition. A monoexponential function is fitted to the myocardial clearance starting when most of the blood pool has cleared (around 1 min). This function yields a clearance rate constant kmono which represents the oxidative metabolism and corresponds to myocardial oxygen consumption (MVO2). Note that there is no difference between kmono in the two graphs.

• 

  Fig. 4.. Effect of levosimendan on RV metabolism. (a) Representative data from an 18F-FDG PET scan in a control rat, a vehicle treated rat, and a levosimendan-treated rat. (b) The metabolic rate of glucose uptake was achieved from 18F-FDG PET scans. Note that levosimendan does not affect RV metabolic rate of glucose uptake. Data are presented as mean ± SEM. Controls: n = 5, Vehicle: n = 9, and Levosimendan: n = 6.