Background Two dimensional (2D) measurements of the right ventricle (RV) were first validated by Foale et al in 1986 using a cohort of 41 volunteers. The British Society of Echocardiography (BSE) published the current guidelines for chamber quantification of the RV. These ranges are taken from recommendations made between the American and European Society of echocardiography3, which itself is an adaptation of Foales’ initial findings. BSE guidelines for the assessment of 2D RV are based on absolute dimensions rather than values indexed to body surface area (BSA).
Aim To evaluate RV dimensions in a group of healthy volunteers.
Methods One hundred and fifty three subjects aged between 21 and 71 (mean 44 yrs) were enrolled and following screening (12 lead ECG, health questionnaire and physical examination) underwent a standardised echocardiogram.
Height and weight were measured to estimate BSA. Standard 2D echocardiography assessed the right ventricular outflow tract diameter above the aortic valve (RVOT1), above the pulmonary valve (RVOT2), the RV basal (RVD1) and RV mid (RVD2) diameter, the RV base to apex length (RVD3), RV diastolic (RVDA) and systolic (RVSA) area. Absolute measurements and results corrected for BSA are presented as mean (2SD).
Ten randomly chosen studies were analysed on separate occasions by a second accredited echocardiographer providing an Inter observer agreement index (IOA) and coefficient of variation (CoV). Ethical approval was obtained.
Results The IOA shows high percentage agreement (92.81–97.92%) for 2D caliper measurements. Satisfactory (<15%) CoV results were also obtained within the same measurements. A lower IOA (83.38–91.33%) and higher CoV (20.73–20.83%) were calculated for RVDA and RVSA. All measurements were normally distributed.
When compared to current guidelines up to 52% of all absolute RV dimensions measured were outside the reference range. However, when indexed to BSA this fell to a maximum of 13% using the indexed range initially proposed by Foale et al. Due to image quality not every measurement was available on all volunteers.
Conclusion Indexing echocardiographic measurements to BSA is standard practice with indices of normality already established for the left ventricle. We have shown that a substantial degree of individual variability of absolute RV dimensions exists within this clinically normal population. These data suggest that indexing absolute RV dimensions according to BSA would be clinically more valuable and accurate than using absolute RV dimensions alone. Absolute and indexed ranges from our data are shown in abstract 085 table 1.
- Right ventricle
- normal BSA