Decreased right heart blood volume determined by magnetic resonance imaging: evidence of central underfilling in cirrhosis

Abstract

Whether the central blood volume is reduced or expanded in cirrhosis is still under debate. Accordingly, the current study was undertaken to assess the volume of the heart cavities. Ten cirrhotic patients and matched controls had their right and left ventricular end-diastolic volumes (RVDV and LVDV), and end-systolic volumes (RVSV and LVSV) determined by magnetic resonance imaging (MRI). RVDV (122 vs. control 166 mL, P < .02), RVSV (41 vs. 80 mL, P < .02) and right atrial volume (47 vs. 64 mL, P < .05) were significantly reduced in the patients. In contrast, LVDV (134 vs. 129 mL, NS), LVSV (54 vs. 40 mL, NS), and left atrial volume (70 vs. 57 mL, P = .08) were normal or slightly increased. The right ejection fraction (68% vs. 53%, P < .05) was significantly increased, but the left ejection fraction was slightly reduced (61% vs. 69%, NS). The central and arterial blood volume (CBV), assessed as the cardiac output (CO) multiplied by the central circulation time, was significantly decreased (1.47 vs. 1.81 L, P < .05). The noncentral blood volume (4.43 vs. 3.64 L, P < .02), plasma volume (4.05 vs. 3.27 L, P < .02), and CO (7.11 vs. control 5.22 L/ min, P < .01) were significantly increased in the patients. CCT (13.1 vs. 20.0 sec, P < .005) and the right ventricular transit time (0.79 vs. 1.35 sec, P < .005) were significantly reduced, but the left ventricular transit time was normal (0.91 vs. 0.88 sec, NS). Systemic vascular resistance was reduced (991 vs. 1,490 dyn-sec/cm 5, P < .01). Our results are in keeping with a hyperkinetic circulation in cirrhotic patients with central vascular underfilling with reduced right heart blood volume and central and arterial blood volume. The normal or slightly increased left heart blood volume suggests a complex pattern with a relatively decreased left ventricular function. The results support the concept of an abnormal distribution of the blood volume, with central and arterial underfilling (consequent on the combination of decreased systemic vascular resistance and left ventricular dysfunction) as major elements in the abnormal fluid homeostasis in cirrhosis.