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.