Echocardiographic assessment of right ventricular systolic function in a population of unselected patients before cardiac surgery: a multiparametric approach is necessary

Background: According to recent USA guidelines, right ventricular (RV) dysfunction can be diagnosed on the basis of a single parameter, such as tricuspid lateral annular systolic velocity (S')<10 cm/s or RV fractional area change (RVFAC)<35%.

Aims: To assess these recommendations in a large unselected cohort of patients awaiting cardiac surgery and evaluate less validated RV function criteria.

Methods: Among the consecutive patients, 413 were prospectively enrolled and underwent comprehensive echocardiography, including S', RVFAC and other RV parameters (right myocardial performance index; acceleration time, isovolumic velocity and isovolumic acceleration [IVA]; RV dP/dt; isovolumic relaxation time; two-dimensional [2D] strain). We defined subgroups of highly probable RV dysfunction (S'<10 cm/s and RVFAC<35%) and highly probable normal RV function (S'≥10 cm/s and RVFAC≥35%) as reference groups. Indices of preload and afterload were also recorded.

Results: Of 413 patients, 320 (77.5%) had normal RV function. In 93 patients, S' and/or RVFAC were abnormal; both were abnormal in 39 (42%) patients. Using our reference groups, IVA≤1.8 m/s2 and basal 2D strain≥-17% were of most value in diagnosing RV dysfunction. IVA was least load dependent while basal 2D strain appeared to be afterload and preload dependent.

Conclusion: In this large population, S' and RVFAC were sometimes discrepant, supporting the need for a multiparametric approach when evaluating RV function. Among seven less validated criteria, IVA and 2D strain had the best diagnostic value. Unlike 2D strain, IVA was not influenced by loading conditions.