Background Anorexia nervosa affects most organ systems, with 80% suffering from cardiovascular complications. Aims To define echocardiographic abnormalities in anorexia nervosa through systematic review and meta-analysis. Method Two reviewers independently assessed eligibility of publications from Medline, EMBASE and Cochrane Database of Systematic Reviews registries. Studies were included if anorexia nervosa was the primary eating disorder and the main clinical association in described cardiac abnormalities. Data was extracted in duplicate and quality-assessed with a modified Newcastle–Ottawa scale. For continuous outcomes we calculated mean and standardised mean difference (SMD), and corresponding 95% confidence interval. For dichotomous outcomes we calculated proportion and corresponding 95% confidence interval. For qualitative data we summarised the studies. Results We identified 23 eligible studies totalling 960 patients, with a mean age of 17 years and mean body mass index of 15.2 kg/m2. Fourteen studies (469 participants) reported data suitable for meta-analysis. Cardiac abnormalities seen in anorexia nervosa compared with healthy controls were reduced left ventricular mass (SMD 1.82, 95% CI 1.32–2.31, P < 0.001), reduced cardiac output (SMD 1.92, 95% CI 1.38–2.45, P < 0.001), increased E/A ratio (SMD −1.10, 95% CI −1.67 to −0.54, P < 0.001), and increased incidence of pericardial effusions (25% of patients, P < 0.01, 95% CI 17–34%, I2 = 80%). Trends toward improvement were seen with weight restoration. Conclusions Patients with anorexia nervosa have structural and functional cardiac changes, identifiable with echocardiography. Further work should determine whether echocardiography can help stratify severity and guide safe patient location, management and effectiveness of nutritional rehabilitation.

Thoracic electrical bioimpedance (TEB) and transthoracic echocardiography (TTE) are non-invasive methods to estimate stroke volume (SV) and cardiac output (CO). Thoracic electrical bioimpedance is not in widespread clinical use with reports of inaccurate cardiac output estimation compared to invasive monitors, particularly in non-healthy populations. We explore its use as a trend monitor by comparing it against thoracic echocardiography in fifteen healthy volunteers undergoing two physical challenges designed to vary cardiac output. Of all paired values, 54.6% showed gross trend agreement and only 1.9% showed direct disagreement between the two monitors. Our results show thoracic bioimpedance may have a role as a non-invasive cardiac output trend monitor in healthy volunteer studies.

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