Value of Conventional and Tissue Doppler Echocardiography in the Noninvasive Measurement of Right Atrial Pressure

BACKGROUND: Evaluation of right atrial pressure (RAP) provides useful diagnostic, therapeutic, and prognostic information. AIM: To assess the utility of several conventional and tissue Doppler parameters in the estimation of RAP. METHODS: Among 50 consecutive patients (median age: 50 years; all in sinus rhythm), invasively measured RAP was simultaneously correlated with pulsed Doppler of tricuspid inflow (peak E and A velocities, E-wave deceleration time) and pulsed tissue Doppler of lateral tricuspid annulus (peak E' and A' velocities, isovolumic relaxation time [IVRT], acceleration time and rate of E'-wave, deceleration time and rate of E'-wave). These ratios were calculated: E/A, E'/A', E/E', and E/IVRT. RESULTS: The median RAP was 14 mmHg (range 1-27 mmHg) with 29 patients (58%) having an elevated RAP (>10 mmHg). Among all studied Doppler variables, E/E' ratio showed the strongest correlation with RAP (r = 0.84, P < 0.001) with the following regression equations: RAP = 1.24 + (1.69 × E/E'). The mean difference between Doppler and invasively measured RAP was 0.21 ± 2.6 mmHg. E/ E' ratio ≥ 4.5 provides 89% sensitivity and 100% specificity for detection of elevated RAP (receiver operating characteristic area 0.95; P < 0.001). CONCLUSION: Of all echocardiographic variables investigated, tricuspid annular E/E' ratio is identified as the best index for noninvasive determination of RAP.