Current status and issues regarding reference values for echocardiography: a short review.

In general, the reference values of diagnostic test parameters are specified based on the values of 95% confidence intervals of those parameters measured in healthy subjects. As heart size varies according to sex, there are sex-related differences in the reference values of echocardiographic parameters. There have been attempts to minimize the variability in the reference values of echocardiographic parameters worldwide by correcting for age-related, sex-related, and body size-related differences. This short review describes the current status and issues regarding the reference values of echocardiographic parameters and discusses the findings of research aimed at resolving these issues.