Abstract 2211: Left Ventricular Stroke Volume Values Measured by 2- D Echocardiographic Volumetric and Doppler-Based Methods Cannot be Used Interchangeably

Abstract

The values of left ventricular stroke volume (SV) measured by Doppler and 2-D echo are frequently reported as if they were interchangeable. No systematic evaluation of the agreement between these methods has been done. To determine the agreement, correlation and reproducibility of SV values measured by 2-D echo and Doppler methods. 107 healthy subjects (mean age 59 ± 14 yrs, 59 % females), had comprehensive echocardiographic evaluation. 2-D LV volumes (2D) were measured by the biplane Simpson’s method. For Doppler, the product of the area of the LV outflow tract (LVOT) x LVOT time velocity integral (TVI), and the area of aortic annulus (AA), and the product of aortic cusp separation (ACS) x aortic TVI were used. Mixed model analysis of variance was performed and Bland Altman agreement limits, Pearson correlation and within-subject coefficient of variation and intraclass correlation coefficient were determined. The mean SV (ml/beat) measured by 2-D and Doppler methods using LVOT, AA and ACS area were: 64 ± 18, 65 ± 15, 76±14, 70 ± 16, respectively. No differences were found between LVOT and 2-D (p = 0.99), borderline between LVOT and ACS (p = 0.051) and significant differences were found between all the other methods. The within-subject coefficient of variation was 19.3% and the intraclass correlation coefficient =0.71, for all the methods indicating good reproducibility. Bland Altman 95% agreement limits for LVOT vs. 2-D were −38.0 and 38.6 ml/beat. The correlation coefficients for all 4 methods are given below. 1. In healthy subjects, although no significant differences were found between mean SV values measured by 2-D and Doppler LVOT methods, the correlation was weak and the agreement limits were large. 2. There was a modest correlation between the Doppler methods and between AA, ACS and 2-D, but the mean SV values were significantly different. 3. SV values measured by these 4 methods cannot be used interchangeably.