Autonomic dysfunction in extra-hepatic portal vein obstruction: correlation with cardiovascular haemodynamics

Various autonomic dysfunctions (AD) are known to occur in cirrhosis of the liver. The haemodynamic abnormalities of cirrhosis have been correlated with AD and have prognostic implications. The relevance of AD in extrahepatic portal vein obstruction (EHPVO) is not well established. We evaluated AD and cardiac indices in 30 patients, 19 male and 11 female and compared the results with those of 10 controls. The mean age of the patients and controls was 23.77 +/- 1.33 and 20.5 +/- 2.51 years, respectively. Five standard autonomic function tests were done in all the patients. Cardiac output (CO) was measured by echocardiography. Anthropometric measurements were done to determine the cardiac index (CI = Cardiac output/Body surface area) and indicized peripheral vascular resistance (iPVR) was calculated using the formula: mean arterial pressure (MAP) x 80/CI. Each autonomic function test was given a score and the results were interpreted as normal, early or definite, according to the score. AD was recorded as normal in 5, early in 11 and definite in 14 patients. None of the controls had any abnormality in autonomic function. There was a significant difference in the baseline heart rate of controls and patients (76 +/- 2.55 v. 98.9 +/- 2.96 beats/min). There was no difference in the MAP (92.65 +/- 1.71 v. 81.7 +/- 1.99 mmHg), CI (2.99 +/- 0.15 v. 3.23 +/- 0.08), iPVR (2533.59 +/- 124 v. 2176 + 104). CI, iPVR and MAP were also calculated separately in patients in the normal (N), early (E) and definite (D) AD groups. Their respective values were as follows CI: N 3.44 +/- 0.19, E 3.44 +/- 0.19, D 3.23 +/- 0.6; iPVR: N 2150 +/- 75.4, E 2140 +/- 180, D 2372 +/- 142; MAP: N 86 +/- 3.01, E 85.8 +/- 3.59, D 90.79 +/- 3.09. Results are expressed as mean +/- SE. Unlike in cirrhotics, cardiovascular haemodynamics are not altered in patients with EHPVO, even in the presence of AD.