Ejection fraction derived using dye dilution and angiographic methods.

Ventriculographically derived ejection fraction (EF-V) is the most frequently used method to measure left ventricular (LV) function, However, significant error may result in the measurement of end-systolic volume (ESV), which is used to calculate EF-V. This error is ascribed to the variable, irregular, nonellipsoidal geometry of the end-systolic ventricular chamber. Since stroke volume (SV) is determined more accurately by dilution methods than by ventriculography, an improved measure of ESV can be calculated by subtracting green dye determined SV from the ventriculographic determined end-diastolic volume (EDV). The purpose of this study was to measure a correlated ejection fraction (EF-C) using EDV by ventriculography and SV derived using green dye. In eight anesthesized dogs cardiac outputs (COs) were calculated by green dye and left ventriculography. CO determined by ventriculography was greater than that measured by green dye (p less than 0.005). EF-V (55 +/- 15%) was always greater than EF-C (32 +/- 12%) (p less than 0.005). These studies (1) may partially explain the discrepancy in CO calculated from the use of dilution methods and ventriculography and (2) present a method to improve the calculation of LV ejection fraction.