Improving the echocardiographic assessment of pulmonary pressure using the tricuspid regurgitant signal: the “chin” vs the “beard”

Aim: Transthoracic echocardiography (TTE) is a fundamental investigation for the noninvasive assessment of pulmonary hemodynamics and right heart function. The aim of this study was to assess the correlation and agreement of Doppler calculation of right ventricular systolic pressure (RVSP) and pulmonary vascular resistance (PVR) using “chin” and “beard” measurements of tricuspid regurgitant velocity (TRV _max), with invasive pulmonary artery systolic pressure (PASP) and PVR. Methods: One hundred patients undergoing right heart catheterisation (RHC) and near simultaneous transthoracic echocardiography were studied. TRV _max was recorded for “chin” measurement (distinct peak TRV _max signal) and where available (63 patients), “beard” measurement (higher indistinct peak TRV _max signal). Results: Measurable TRV signal was obtained in 96 patients. Mean RVSP _chin 54.7 ± 22.7 mm Hg and RVSP _beard 68.6 = 23 ± 26.3 mm Hg (P <.001). There was strong correlation between both RVSP _chin and RVSP _beard with invasive PASP (Pearson’s r =.9, R ² = 0.82, P <.001-r =.88, R =.78, P <.001, respectively.). Bland-Altman analysis for RVSP _chin and RVSP _beard showed a mean bias of −0.5 mm Hg (95% limits of agreement −21.4 to 20.5 mm Hg) and −10.7 (95% LOA −35.5 to 14.2 mm Hg), respectively. Receiver operator characteristics of TRV _max “chin” and “beard” for diagnosis of pulmonary hypertension was assessed with optimal cut-offs being 2.8 m/s (sensitivity 93%, specificity 87%) and 3.2 m/s (sensitivity 91%, specificity 82%), respectively. There was similar correlation between PVR _chin and PVR _beard (r =.87, R ² = 0.75, P <.001 and r =.86, R ² = 0.74, P <.001, respectively). At higher PVR, there was overestimation of calculated PVR using PVR _beard. Conclusion: The accuracy of noninvasive measurement of right heart pressures is increased using the “chin” in estimation of both RVSP and PVR.