Echocardiographic linear fractional shortening for quantification of right ventricular systolic function-A cardiac magnetic resonance validation study.

BACKGROUND

Echocardiography (echo)-based linear fractional shortening (FS) is widely used to assess left ventricular dysfunction (LV ), but has not been systematically tested for right ventricular dysfunction (RV ).

METHODS

The population comprised LV patients with and without RV (EF<50%) on cardiac MRI (CMR): Echo included standard RV indices (fractional area change [FAC], TAPSE, S', and FS in parasternal long-axis (RV outflow tract [RV ]) and apical four-chamber views (width [RV ], length [RV ]).

RESULTS

A total of 168 patients underwent echo and CMR (3±3 days); FAC (46±9 vs 28±11), TAPSE (1.9±0.4 vs 1.5±0.3), and S' (11.4±2.3 vs 10.0±2.6, all P≤.001) were lower among RV patients, as were FS indices (RV 32±8 vs 17±10 | RV 40±11 vs 22±12 | RV 16±5 vs 9±4%; all P<.001). FS indices yielded similar magnitude of correlation with CMR RVEF (r=.73-.56) as did FAC (r=.70), which was slightly higher than TAPSE (r=.47) and S' (r=.31; all P<.001). FS indices decreased stepwise vs CMR RVEF tertiles, as did FAC (all P<.001). In multivariate analysis, FS in RV (regression coefficient .51 [CI 0.37-0.65]), RV (0.30 [0.19-0.41]), and RV (0.45 [0.20-0.71]; all P≤.001) was independently associated with CMR RVEF. FS indices yielded good overall diagnostic performance (AUC: RV 0.89 [CI 0.82-0.97] | RV 0.87 [0.78-0.96] | RV 0.80 [0.70-0.90]; all P<.001) for CMR-defined RV (RVEF<50%).

CONCLUSIONS

RV linear FS provides RV functional indices that parallel CMR RVEF. Parasternal long-axis RV width, four-chamber RV width, and length are independently associated with RVEF, supporting use of multiple FS indices for RV functional assessment.