Portable echocardiography: an innovative tool in screening for cardiac abnormalities in the community.

Abstract

Heart failure is placing an increasing burden on society. This has led to calls for echocardiographic-based programmes to screen for left ventricular systolic dysfunction and other cardiac abnormalities. Echocardiography using new fully portable echocardiography devices would allow community-based cost-effective screening programmes once validated. This study was undertaken to evaluate this further in both high and low-risk subjects. 562 consecutive subjects attending a community-based heart failure screening programme, some at high-risk and some at low-risk of cardiac abnormalities, underwent echocardiography by both portable and traditional echocardiography machines. An 'eyeball' estimate of left ventricular ejection fraction was made on the portable device and compared to a quantitative measure of ejection fraction on the traditional machine. Qualitative measures of valvular regurgitation and quantitative measures of left ventricular hypertrophy were also compared. An estimate of ejection fraction was possible in 97% of cases using portable echocardiography. It gave a sensitivity, specificity and negative predictive value in diagnosing left ventricular systolic dysfunction of 96%, 98% and 99.6%, respectively. Inter-observer variability gave a mean difference in ejection fraction of 2%, and 95% limits of agreement of -8% to +12%. All cases of moderate or severe valvular regurgitation and 29 of 31 cases of significant left ventricular hypertrophy were correctly identified as abnormal on the portable device. Thus, echocardiography performed by experienced sonographers using these new fully portable devices is an accurate and reproducible technique for detecting left ventricular systolic dysfunction, left ventricular hypertrophy and valvular regurgitation in both high-risk and low-risk members of the community. Its very high negative predictive values would allow their use in future community-based screening programmes.