The feasibility and clinical implication of tricuspid regurgitant velocity and pulmonary flow acceleration time evaluation for pulmonary pressure assessment during exercise stress echocardiography.

Abstract

Echocardiography can estimate pulmonary arterial pressure (PAP) from tricuspid regurgitation velocity (TRV) or acceleration time (ACT) of pulmonary flow. We assessed the feasibility of TRV and ACT measurements during exercise stress echocardiography (ESE) and their correlation in all stages of ESE. We performed ESE in 102 subjects [mean age 49 ± 17 years, 50 females, 39 healthy, 30 with cardiovascular risk factors, and 33 with pulmonary hypertension (PH)] referred for the assessment of exercise tolerance and ischaemia exclusion. ESE was performed on cycloergometer with the load increasing by 25 W for each 2 min. Assessment of TRV with continuous wave and ACT with pulsed Doppler were attempted in 306 time points: at rest, peak exercise, and recovery. In 20 PH patients we evaluated the correlations of TRV and ACT with invasively measured PAP. The success rate was 183/306 for TRV and 304/306 for ACT (feasibility: 60 vs. 99%, P < 0.0001). There was a close correlation between TRV and ACT: r = 0.787, P < 0.001 and ACT at peak ≤67 ms showed 94% specificity for elevated systolic PAP detection. Moreover, TRV and ACT at peak exercise reflected better that resting data the invasive systolic PAP and mean PAP with r = 0.76, P = 0.0004 and r = -0.67, P = 0.0018, respectively. ACT is closely correlated with and substantially more feasible than TRV during ESE and inclusion of both parameters (TRACT approach) expands the possibility of PAP assessment, especially at exercise when TRV feasibility is the lowest but correlation with invasive PAP seems to increase.