The cardiac response to exercise in cirrhosis
- aDivision of Gastroenterology, Toronto General Hospital, University of Toronto, Ontario, Canada, bDivision of Cardiology, Toronto General Hospital, University of Toronto, Ontario, Canada
- Dr F Wong, Room 220, 9th floor, Eaton Wing, Toronto General Hospital, 200 Elizabeth Street, Toronto M5G 2C4, Ontario, Canada.
- Accepted 12 February 2001
BACKGROUND Impaired exercise capacity and oxygen consumption are common in cirrhosis.
AIM To explore the relationship between possible myocardial dysfunction and exercise tolerance in cirrhosis.
METHODS Cardiac responses to exercise, using radionuclide angiography and graded upright cycle ergometry with oxygen consumption, were assessed before and after exercise in 39 cirrhotics patients and compared with 12 age and sex matched healthy volunteers. Baseline cardiac chamber dimensions and wall thickness, ejection fraction, and diastolic function were measured using two dimensional echocardiography is all subjects.
RESULTS Baseline diastolic dysfunction with prolonged isovolumic relaxation times (p=0.02), left atrial enlargement, and left ventricular wall thickening were present in all cirrhotics (p=0.02), despite increased mean ejection fraction. With graded exercise, cirrhotics achieved 71 (4)% (p=0.03) (pre-ascitics) and 46 (3)% (p<0.001) (ascitics) of predicted work loads, respectively, without significant increases in ejection fraction. The smaller absolute and percentage increases in cardiac output (p=0.003) in the cirrhotics were associated with significantly reduced oxygen consumption (p=0.003) and anaerobic threshold (p<0.001), and correlated significantly with work and metabolic parameters.
CONCLUSIONS Impaired exercise capacity in cirrhosis is associated with myocardial thickening and ventricular stiffness leading to decreased diastolic function, inotropic and chronotropic incompetence under conditions of stress, with metabolic consequences. This picture is compatible with the condition now known as cirrhotic cardiomyopathy.
- Abbreviations used in this paper:
- E/A ratio
- (E velocity=early maximal ventricular filling velocity, A velocity=late diastolic or atrial velocity)
- ejection fraction
- forced expiratory flow from 25–75% of vital capacity
- forced expiratory volume in one second
- forced vital capacity
- oxygen consumption
- oxygen consumption at maximal exertion
- radionuclide angiography
- ventilatory anaebolic threshold