Left ventricular ejection fraction is increased during transesophageal echocardiography in patients with impaired ventricular function.

Transesophageal echocardiography (TEE) is increasingly being used to assess left ventricular function (LVF). However, little data exist on the quantitative accuracy of this technique and its influence on LVF. Thus 50 ambulatory adult patients (mean age 62 +/- 15 years) were studied with transthoracic echocardiography (TTE) immediately before, before the end, and 10 minutes after TEE. Left ventricular ejection fraction (LVEF) was calculated using the modified Simpson's method. In subjects (n = 24) with impaired LVF (LVEF less than 55% by TTE), TTE-derived LVEF increased from 37 +/- 13% to 45 +/- 15% (p less than 0.001) during TEE. In 13 of 24 subjects with abnormal LVF, LVEF significantly increased during TEE as defined by an increase in LVEF by at least 5 ejection fraction units. In four of these subjects LVF normalized during TEE. LVEF was unchanged during and after TEE in the subjects (n = 26) with normal LVF (LVEF greater than 55%). An excellent correlation was found between LVEF derived by TEE and that derived by TTE performed during TEE (r = 0.93, SEE = 6.6%, p less than 0.001). LVEF determined by TEE compared well with that derived by TTE and should be a useful measure of global left ventricular function. However, an increase in LVEF during TEE occurs in over 50% of patients with impaired LVF and may be important to consider in individual subjects.