Abstract 13592: M-Mode versus 2D Echocardiography-based Measurements of LV Dimensions: Different Reference Thresholds
LV dimensions and wall thickness by M-Mode echocardiography (echo) appear to be larger than 2D based measurements. This has implications for determining upper limits of normal for measurements acquired by each technique.
Methods: The EchoNoRMAL database is an individual-person meta-analysis of population-based echo data from adults aged 18-80 years free of cardiovascular disease and/or risk factors. M-mode dimensions were available in 9805 individuals (23 studies), and 2D dimensions in 3582 individuals (7 studies). M-mode and 2D measurements were performed by leading-edge to leading-edge method from parasternal long (PSLAX) and short axis (PSSAX) views. Using a centile regression approach, we determined age-appropriate upper reference values for each method (95th centile).
Results: LV end-diastolic dimension (LVEDD, cm) was significantly larger by M-mode than 2D in European men (M-mode 5.2; 2D 5.0) and women (M-mode 4.7; 2D 4.5) in the PSLAX view (p<0.0001). LVEDD by M-mode was smaller than 2D measurement in the PSSAX view in women (M-mode 4.7, 2D 4.8, p=0.014). For both genders, LVEDD by 2D was significantly smaller in the PSLAX than in the PSSAX view (men: PSLAX 5.0, PSSAX 5.2; women: PSLAX 4.5, PSSAX 4.8, p<0.0001). Men had significantly larger LVEDD than women irrespective of the method and the view used (p<0.0001). In linear regression, age, heart rate, systolic blood pressure, gender and year of echo all had a significant association with LVEDD by either method. The 95th centile of LVEDD in men at age 50 was 6.0cm (M-mode) and 5.8cm (2D). For women at age 50, it was 5.5cm (M-mode) and 5.3cm(2D).
Conclusion: There are significant differences in age-adjusted LVEDD values based on gender, echo method (2D vs M-mode) and the view used for image acquisition. LVEDD by M-mode is larger than by 2D, and 2D measurement from the PSSAX (vs PSLAX) view results in larger LVEDD. These important differences have implications for defining the upper limits of normal values for LV dimensions.
- © 2013 by American Heart Association, Inc.