Interpretation of echocardiographic measurements: A call for standardization

Background Although echocardiography is used extensively in clinical medicine, guidelines for quantitative interpretation of echocardiographic measurements are unavailable. The goals of this investigation were to provide an overview of scientific standards for formulating reference values, with clinical chemistry used as a model, to evaluate published echocardiographic reference limits, to survey clinical echocardiography laboratories regarding their interpretation of echocardiographic measurements, and to provide recommendations for improving the interpretation and reporting of echocardiographic measurements. Methods and Results We reviewed the original reports of the International Federation of Clinical Chemistry on guidelines for formulating reference values. We obtained published reports on echocardiographic reference limits through searches of electronic databases supplemented by a manual search of relevant bibliographies. We also surveyed echocardiographic laboratories in 35 adult acute-care hospitals in Eastern Massachusetts. Studies on echocardiographic reference values were evaluated with the use of guidelines from clinical chemistry. Responses from the 29 participating echocardiographic laboratories were evaluated for their practice of quantitative echocardiographic interpretation. There is considerable heterogeneity in the echocardiographic reference values available in the literature. There is also a lack of agreement in the literature and among echocardiographers regarding the partitioning of reference values (by sex, ethnicity, or age), the anthropometric measure to be used for indexation, and the choice of cut points for categorizing values within the abnormal range. Conclusions We advocate that echocardiographic reference limits be standardized and a consensus generated regarding the partitioning of reference limits and the indexation of echocardiographic measurements. Such measures can aid in quantitative echocardiographic interpretation and render the results more scientific and consistent.