Ejection fraction (EF) has become the accepted measurement of global left ventricular systolic function (LVSF). It is a good prognostic indicator and is familiar to most clinicians. Echocardiographic (echo) measurements of EF require apical views which frequently have myocardial dropout or are foreshortened. An alternative "eyeball" EF is totally subjective and qualitative. The goal of this study was to create a global systolic index (GSI) which used common parasternal measurements and was numerically similar to EF. Measurements used were 2D basal fractional shortening (FS), fractional area change (FAC) at the papillary muscle level and the abnormal apical segments when the ASE approved regional score index (RSI) was calculated. The formula used was FAC + FS/3 - the sum of the abnormal apical segments expressed as a percentage. Thus if 2 of the 4 apical segments were akinetic, 6% (2X3 for akinesis) would be subtracted from the combined % of FAC+ FS/3. FAC, FS, and RSI are independent indices of LVSF. FAC, which is the basis for the bullet formula for calculating EF and is commonly used to monitor LVSF, is the dominant value in GSI. FAC is numerically smaller than EF. The addition of FS/3 produces a number in a symmetrically contracting ventricle which approximates EF. FS is also independantly useful in assessing basal LVSF especially with regional disease. Since neither FAC nor FS evaluates the apex, abnormal apical segments from the RSI appropriately reduce the GSI value when apical segmental dysfunction exists. We retrospectively evaluated all patients from January 1992 to September 1996 who had MUGA scans and 2D echoes which were technically acceptable. All in-patient studies were within one week of each other. Outpatient studies were within two weeks. Of the 71 patients who were used in this study, the correlation between the MUGA EF and the echo GSI had an r value of 0.88. Three of the outliers were pretransplant patients with diffuse cardiomyopathy. EF was significantly higher than GSI. Two other outliers were patients with severe right ventricular hypertrophy. EF was significantly lower than GSI. With these few exceptions the correlation between the echo GSI and MUGA EF was excellent giving similar clinically relevant numbers. We conclude that echo GSI derived from 2D parasternal FS and FAC and apical segments from RSI provides a clinically relevant number comparable to MUGA EF.
|Original language||English (US)|
|Number of pages||1|
|Journal||Journal of the American Society of Echocardiography|
|State||Published - Dec 1 1997|
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
- Cardiology and Cardiovascular Medicine