Cross sectional echocardiographic left ventricular ejection fraction: method based variability.

Cross-sectional echocardiographic left ventricular ejection fraction (LVEF) by five different Methods (Teichholz, Area-length, single-plane Simpson, Bullet and Baran Formulae) was determined in 24 normal healthy volunteers (male-17, female-7, age range 16-80 years, mean 37 +/- 13) to assess the method-dependent variability in left ventricular volumes and LVEF. Although the Teichholz and Bullet methods gave somewhat higher values, there was no significant difference between LVEF determined by any of the methods (F = 0.16, p greater than 0.50). There was an a symmetrical distribution of LVEF in this normal group with an absolute mean positive skewness of 6 per cent (range 4-7 percent, coefficient of skewness = +0.43 to +0.87). A cut-off normal lower limit of LVEF at 50 per cent encompassed 88-100 per cent (mean 93.3) of subject population depending upon the method used. Similarly there was no significant difference between left ventricular volumes obtained by various methods. Therefore all the above five methods for quantitation of left ventricular global function are equally useful in clinical studies in patients with normal left ventricular geometry and in absence of segmental asynergy.