Variability of digitized left ventricular M‐mode echocardiography: a study in healthy subjects and patients with repaired tetralogy of Fallot

Abstract

To assess possible factors affecting the variability of digitized left ventricular M-mode echocardiograms, the influence of respiration and the variability due to different beats and observers were analysed in 11 healthy subjects and 11 patients with repaired tetralogy of Fallot. Left ventricular end-diastolic dimension (LVEDD) decreased from end-expiration to end-inspiration in the healthy subjects, but not in the patients. The maximal rate of dimension change decreased in both healthy subjects and patients from end-expiration to end-inspiration. The beat-to-beat variability assessed by the coefficient of variation (CV,%) between measurements of one cardiac cycle was twice the CV for three cycles, whereas the CV for three and five cardiac cycles was not different. The CV for intraobserver variability was less than 5.0% for dimensions and less than 13.0% for the rates of dimension change, whereas the interobserver variability had CV of 17.1% for rates of dimension changes. The influence of respiration and different observers on the variability of LV end-systolic dimension and shortening fraction was larger in the patients than in the healthy subjects. Thus, to obtain optimal technique for analysis of digitized LV M-mode echocardiograms in serial patient studies, the number of observers should be kept at a minimum and at least 3 beats at end-expiration should be used.

The Ventricular Volume Variability Study of the Pediatric Heart Network: Study Design and Impact of Beat Averaging and Variable Type on the Reproducibility of Echocardiographic Measurements in Children with Chronic Dilated Cardiomyopathy

“…There are few data that examine the impact of beat averaging and variable type on the inter- and intra-observer reproducibility of echocardiographic measurements. (2–5) We elected to perform these analyses before addressing the primary aim of the overall study, so that decisions regarding beat averaging could be applied to all subsequent study analyses.…”

Reproducibility of Left Ventricular Dimension Versus Area Versus Volume Measurements in Pediatric Patients With Dilated Cardiomyopathy

“…5,6 The linear method involves measurement of diameters and wall thickness by 2-dimensional (2D) or M-mode imaging and calculation of shortening fraction (SF) from short-axis images obtained in parasternal or subxiphoid views. The 5/6 area-length volumetric method involves (1) measurement of areas from short-axis LV images; (2) measurement of long-axis lengths from long-axis images obtained in apical 4-chamber or subxiphoid long-axis views; and (3) calculation of volumes, ejection fraction (EF), and mass.…”