A NEW, SIMPLE AND ACCURATE METHOD FOR DETERMINING EJECTION FRACTION BY DOPPLER-ECHOCARDIOGRAPHY

OBJECTIVE: To evaluate the feasibility, accuracy and reproducibility o f a new and simple method for determining ejection fraction by Doppler echocardiography. This method should theoretically be less influenced by the distortions of left ventricular geometry caused by prior myoca rdial infraction, DESIGN: Two groups of patients (total 114) were eval uated independently at the Quebec and Ottawa Heart Institutes (60 and 54 patients, respectively). All were referred for radionuclide angiogr aphy performed within 24 h of the echocardiogram. Regional asynergy wa s present in 59% of Quebec patients and 37% of Ottawa patients. The ne w method for calculating ejection fraction consisted of dividing Doppl er derived stroke volume in the left ventricular outflow tract by left ventricular end-diastolic volume calculated by Teichholz's formula ; for comparison, ejection fraction was also measured by single plane ar ea length or multiple disc planimetry as well as by the Quinones metho d at the Quebec Heart Institute. RESULTS: Feasibility of the new metho d was 97% in Quebec and 100% in Ottawa. Compared with radionuclide ang iography, the correction coefficient for the new method was 0.92 (stan dard error of estimate [SEE] = 7.3) in Quebec compared with 0.88 (SEE = 8.5 and 8.1) for both the Quinones and single plane area length meth ods, and 0.84 (SEE 12.0) in Ottawa compared with 0.77 (SEE = 10.9) for the single plane multiple disc method. Corrections in patients with r egional asynergy were 0.90 in Quebec and 0.75 in Ottawa compared with 0.81 and 0.54 with planimetry. Correction coefficients for interobserv er variability in 12 patients were 0.97 with the new method compared w ith 0.88 with the Quinones method and 0.85 with single plane planimetr y. CONCLUSION: This new and simple method is feasible, accurate and re producible even in patients with regional asynergy. Provided there is no significant mitral regurgitation, it is a time-saving alternative f or the routine evaluation of ejection fraction by Doppler echocardiogr aphy.