Exploring Noninvasive Tricuspid dP/dt as a Marker of Right Ventricular Function

Background: Right ventricular (RV) function assumes prognostic significance in various disease states, but RV geometry is not amenable to volumetric assessment by two-dimensional echocardiography. Intra-ventricular pressure rate of rise (dP/dt) predicts myocardial contractility and adjusting for the maximal regurgitant velocity (Vmax) corrects for preload. We examined the relationship of noninvasive tricuspid dP/dt and dP/dt/Vmax with RV ejection fraction (RVEF) by cardiac magnetic resonance imaging (CMR) as a measure of RV function.

Methods: Fifty CMRs and echocardiograms performed within 30 days were included. Tricuspid regurgitation (TR) spectral Doppler trace was analyzed offline. TR dP/dt was calculated using simplified Bernoulli equation (dP/dt between 1 and 2 m/sec). dP/dt/Vmax was calculated as a ratio of dP/dt and TR Vmax . RV end-diastolic (EDV) and end-systolic volumes (ESV) were obtained from contouring of steady-state-free precession axial stack CMR images; RVEF was calculated as [(RVEDV - RVESV)/RVEDV] × 100. RVEF >42% was considered normal.

Results: Majority of studies were suitable for analysis. Median age was 48 years (IQR = 36-63); 56.4% were female (n = 22/39). There was correlation between dP/dt and RVEF (r(2) = 0.51, P < 0.01) which improved with dP/dt/Vmax (r(2) = 0.59, P < 0.01). dP/dt >400 mmHg/sec had a positive predictive value of 91%, sensitivity and specificity of 74% and 84% respectively for normal RVEF. Inter-observer agreement and repeatability analysis showed no significant difference.

Conclusion: Tricuspid dP/dt correlates well with CMR RVEF. A dP/dt of more than 400 mmHg/sec strongly predicts normal RVEF. Adjusting for preload (dP/dt/Vmax) further improves this correlation.