On-Line Assessment of Left Ventricular Volume and Ejection Fraction by the Automated Border Detection Echocardiography

Choi, Hyun Muck; Kim, Young Woo; Lee, Keum Hee; Lee, Sin Hwa; Park, Neung Hwa; Ji, Sang Keun; Cha, Tae Joon; Joo, Seung Jae; Lee, Jae Woo

Abstract

BACKGROUND
The automated border detection(ABD) echocardiography has the ability of recognizing the endocardial-blood interface, and therefore, on-line estimation of the left ventricular(LV) volume every cardiac cycle. Compared with the off-line conventional 2-dimensional echocardiographic method that requires tracing the endocardial border manually, the ABDd system can be a convenient and objective method in the estimation of the LV volume and the ejection fraction(EF). The purpose of this study is to compare the LV volume and EF between the on-line ABD system and the convertional off-line echocardiographic method.
METHODS
In two weeks, 83 adult patients older than 16 years of age were referred to our echocardiographic laboratory. Among these 83 patients, 64 patients who had a normal sinus rhythm were included to our study. Using the Hewlett-Packard SONOS 1500, a 2.5 MHz transducer was placed dat the cardiac apex. Patients with an apical 4 chamber view of the LV in which at least 75% of the endocardium was clearly seen were selected for study. On that view, the ABD system was turned on, and the reansmit power and the time-gain compensation controls were adjusted in order to approximate the automated border to the visually apparent endocardial surface. The LV end-diastolic volume(LVESV) and LV end-systolic volume(LVESV) were calculated by the method of disc. LVEDV, LVESV, and EF were displayed every cardiac cycle. Also the off-line estimation of the LV volume was performed by the method of disc, after manually tracing the endocardial border on the apical 4 chamber view.
RESULTS
44 patients(69%) of 64 patients had > or =75% of the LV endocardium visualized. LVEDV, LVESV, and Ef with the ABD system were highly correlated with those with the off-line, manually traced method(r=0.95, 0.8, respectively), but LVEDV and EF with toe ABD system were significantly less than those with the latter(p<0.01). The limits of agreement between tow methods(off-line, manually traced method-ABD system) were somewhat wide. Those of LVEDV, LVESV and EF were +22~-10ml(mean 6ml), +15~-14ml(mean 0.1ml), and +19~-12%(mean 3.8%), respectively.
CONCLUSION
LVEDV,LVESV, and EF measurements by the ABD system and the off-line manually traced methods thve a strong correlation, The ABD system should habe clinical applications in setting, in which measurements of LV volume and Ef are important, But, the comparison with a more reliable method is necessary.