Quantitative two dimensional echocardiography during bicycle exercise in normal subjects.

A quantitative two dimensional echocardiographic study was conducted in 10 normal subjects performing bicycle exercise in a supine position. Standardized two dimensional echocardiographic short axis and apical views of the left ventricle were analyzed to derive left ventricular sectional areas and length. Over a range of exercise heart rates from 108 to 152 beats/min, satisfactory two dimensional echocardiographic views and measurements were obtained for quantitative assessment of sectional and global left ventricular function. Variability of left ventricular short axis area measurements ranged from 2.9 to 8.3 percent. Left ventricular volume reconstruction employed a simplified formula (volume = 5/6 area X length) with a single papillary muscle level short axis area and left ventricular length. Changes in left ventricular function from rest to exercise quantitated by two dimensional echocardiography indicated a significant reduction in end-systolic volume (from 28.1 +/- 5.6 to 20.8 +/- 4.3 cc/m2, p less than 0.001) and increased left ventricular ejection fraction (from 63.4 +/- 6.3 to 72.1 +/- 5.7 percent, p less than 0.001). The change in end-diastolic volume was not significant. It is concluded that standardized two dimensional echocardiographic study during supine bicycle exercise in normal subjects provides good reproducibility of measurement of sectional and global left ventricular function. Quantitative two dimensional echocardiographic exercise study of global as well as segmental left ventricular performance in patients may be feasible using standardized procedure and analysis.