The cardiac response to exercise in cirrhosis

Background - Impaired exercise capacity and oxygen consumption are common i n cirrhosis. Aim - To explore the relationship between possible myocardial dysfunction a nd exercise tolerance in cirrhosis. Methods - Cardiac responses to exercise, using radionuclide angiography and graded upright cycle ergometry with oxygen consumption, were assessed befo re and after exercise in 39 cirrhotics patients and compared with 12 age an d sex matched healthy volunteers. Baseline cardiac chamber dimensions and w all. thickness, ejection fraction, and diastolic function were measured usi ng two dimensional echocardiography is all subjects. Results - Baseline diastolic dysfunction with prolonged isovolumic relaxati on times (p=0.02), left atrial enlargement, and left ventricular wall thick ening were present in all cirrhotics (p=0.02), despite increased mean eject ion fraction. With graded exercise, cirrhotics achieved 71 (4)% (p=0.03) (p re-ascitics) and 46 (3)% (p <0.001) (ascitics) of predicted work loads, res pectively, without significant increases in ejection fraction. The smaller absolute and percentage increases in cardiac output (p=0.003) in the cirrho tics were associated with significantly reduced oxygen consumption (p=0.003 ) and anaerobic threshold (p <0.001), and correlated significantly with wor k and metabolic parameters. Conclusions - Impaired exercise capacity in cirrhosis is associated with my ocardial thickening and ventricular stiffness leading to decreased diastoli c function, inotropic and chronotropic incompetence under conditions of str ess, with metabolic consequences. This picture is compatible with the condi tion now known as cirrhotic cardiomyopathy.