Echocardiographic assessment of ejection fraction in left ventricular hypertrophy

Objective-To investigate the value of Simpson's rule, Teichholz's formula, and recording of mitral ring motion in assessing left ventricular ejection fraction (EF) in patients with left ventricular hypertrophy. Design-Left ventricular ejection fraction calculated by Simpson's rule and by Techholt's formula and estimated by mitral ring motion was compared with values obtained by radionuclide angiography. Setting-Secondary referral centre. Patients-16 patients with left ventricular hypertrophy and a clinical diagn osis of hypertrophic cardiomyopathy or hypertension. Results-Calculation by Teichholz's formula overestimated left ventricular e jection fraction by 10% (p=0.002) and estimation based on mitral ring motio n-that is, long axis measurements-underestimated ejection fraction by 19% ( p = 0.002), without significant correlation between ring motion and ejectio n fraction. There was no significant difference between mean values of ejec tion fraction calculated by Simpson's rule and measured by the reference me thod, but a considerable scatter about the regression line with a standard error of the estimate of 9.3 EF%. Conclusions-In patients with left ventricular hypertrophy the ejection frac tion, calculated by Teichholz's formula or Simpson's rule, is a poor measur e of left ventricular function. When mitral ring motion is used for the ass essment in these patients the function should be expressed in ways other th an by the ejection fraction.