Cardiac output determined by echocardiography in patients with cirrhosis: comparison with the indicator dilution technique Ulrik B. Andersen a , Søren Møller a , Flemming Bendtsen b and Jens H. Henriksen a Background/aims Measurement of cardiac output in hyperkinetic patients with cirrhosis by Doppler echocardiography is increasingly reported, but has not been validated. We have compared simultaneous measurements of cardiac output by Doppler echocardiography (CO d ) and by the indicator dilution technique (CO I ). Methods Twelve patients with cirrhosis were studied. CO d was measured as the spatial mean velocity of the left ventricular outflow tract, multiplied by the cross-sectional area and the heart rate. CO I was determined by the standard indicator dilution technique after injection of 125 I albumin and 99m Tc albumin into the right atrium and subsequent sampling from the femoral artery. Results The mean CO d and CO I were similar (7.20 vs 7.15 l/min, NS). A highly significant correlation was present between CO d and CO I (r 0.86, P < 0.0001; slope 0.91, Y 0 0.78 l/min). However, the mean squared difference between CO d and CO I was 2.3 (l/min) 2 . A Bland–Altman plot revealed no trend with the level of cardiac output. The standard deviation (0.79 vs 0.30 l/min, P < 0.01) and the coefficient of variation (10.5 vs 4.2%, P < 0.01) of duplicate measurements were significantly higher with the Doppler technique. Conclusion Doppler measurements of cardiac output in groups of patients with cirrhosis are accurate with respect to the group mean, but marked disagreements of over- and underestimation were seen in individual patients. The reproducibility of the Doppler technique is acceptable, although not as good as that of the indicator dilution technique. Eur J Gastroenterol Hepatol 15:503–507 & 2003 Lippincott Williams & Wilkins European Journal of Gastroenterology & Hepatology 2003, 15:503–507 Keywords: haemodynamics, liver cirrhosis, Doppler ultrasound, indicator dilution, validation, reproducibility Departments of a Clinical Physiology and b Gastroenterology, Hvidovre Hospital, University of Copenhagen, Denmark. Correspondence to Dr J.H. Henriksen, Department of Clinical Physiology and Nuclear Medicine, 239 Hvidovre Hospital, DK-2650 Hvidovre, Denmark. Tel: +45 3632 2203; fax: +45 3632 3750; e-mail: jens.h.henriksen@hh.hosp.dk Received 25 April 2002 Revised 1 October 2002 Accepted 16 December 2002 Introduction Patients with cirrhosis are often hyperdynamic with increased heart rate and cardiac output [1,2]. The hyperkinetic systemic circulation is related to disease severity and complications, including fluid retention and formation of ascites [2–4]. Moreover, the hyperki- netic systemic circulation bears a close relation to mortality in these patients [5,6]. The last 10 years have seen several reports of the determination of cardiac output by the Doppler echo- cardiographic technique in patients with cirrhosis [2, 7–14]. Although interobserver observations have been reported, the echocardiographic technique for the de- termination of cardiac output has never been evaluated with respect to accuracy and compared to a ‘gold standard’ in these patients. Previous validations on heart patients are not likely to apply to patients with cirrhosis with a very high cardiac output and substan- tially elevated linear velocities at the aortic root. More- over, in patients with cirrhosis arterial compliance is changed, which may also affect measurements by the echocardiography technique. Accordingly, the aim of the present study was to compare cardiac output as determined by the Doppler echocardiographic tech- nique (CO d ) with cardiac output determined by the indicator dilution technique (CO I ) in patients with cirrhosis. Patients and methods Twelve patients with cirrhosis, (six women, six men) with a mean age of 55 years (range 42–76 years) were studied (Table 1). Nine patients had a history of high alcohol intake, i.e., a consumption exceeding 50 g/day for more than 5 years. They had abstained from alcohol for at least 1 week before the study and had no withdrawal symptoms. Two patients had cirrhosis ow- ing to chronic hepatitis C infection. In one patient no specific aetiology could be established. The diagnosis of cirrhosis was verified histologically in all patients. None of the patients had hepatic encephalopathy above grade I or had experienced recent gastrointestinal bleeding. Two patients were in Child–Turcotte class A, six in class B, and four in class C. Four patients had Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. Original article 503 0954-691X & 2003 Lippincott Williams & Wilkins DOI: 10.1097/01.meg.0000059106.41030.8e