Obokata Masaru, Kane Garvan C, Sorimachi Hidemi, Reddy Yogesh N V, Olson Thomas P, Egbe Alexander C, Melenovsky Vojtech, Borlaug Barry A
Dept of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA.
Institute for Clinical and Experimental Medicine - IKEM, Prague, Czech Republic.
Eur Respir J. 2020 Feb 12;55(2). doi: 10.1183/13993003.01617-2019. Print 2020 Feb.
Identification of elevated pulmonary artery pressures during exercise has important diagnostic, prognostic and therapeutic implications. Stress echocardiography is frequently used to estimate pulmonary artery pressures during exercise testing, but data supporting this practice are limited. This study examined the accuracy of Doppler echocardiography for the estimation of pulmonary artery pressures at rest and during exercise.
Simultaneous cardiac catheterisation-echocardiographic studies were performed at rest and during exercise in 97 subjects with dyspnoea. Echocardiography-estimated pulmonary artery systolic pressure (ePASP) was calculated from the right ventricular (RV) to right atrial (RA) pressure gradient and estimated RA pressure (eRAP), and then compared with directly measured PASP and RAP.
Estimated PASP was obtainable in 57% of subjects at rest, but feasibility decreased to 15-16% during exercise, due mainly to an inability to obtain eRAP during stress. Estimated PASP correlated well with direct PASP at rest (r=0.76, p<0.0001; bias -1 mmHg) and during exercise (r=0.76, p=0.001; bias +3 mmHg). When assuming eRAP of 10 mmHg, ePASP correlated with direct PASP (r=0.70, p<0.0001), but substantially underestimated true values (bias +9 mmHg), with the greatest underestimation among patients with severe exercise-induced pulmonary hypertension (EIPH). Estimation of eRAP during exercise from resting eRAP improved discrimination of patients with or without EIPH (area under the curve 0.81), with minimal bias (5 mmHg), but wide limits of agreement (-14-25 mmHg).
The RV-RA pressure gradient can be estimated with reasonable accuracy during exercise when measurable. However, RA hypertension frequently develops in patients with EIPH, and the inability to noninvasively account for this leads to substantial underestimation of exercise pulmonary artery pressures.
运动期间肺动脉压力升高的识别具有重要的诊断、预后和治疗意义。负荷超声心动图常用于运动试验期间评估肺动脉压力，但支持这种做法的数据有限。本研究探讨了多普勒超声心动图在静息和运动时评估肺动脉压力的准确性。
对97例呼吸困难患者在静息和运动时进行同步心导管检查-超声心动图研究。根据右心室（RV）至右心房（RA）压力梯度和估计的RA压力（eRAP）计算超声心动图估计的肺动脉收缩压（ePASP），然后与直接测量的PASP和RAP进行比较。
静息时57%的受试者可获得估计的PASP，但运动期间可行性降至15%-16%，主要原因是负荷时无法获得eRAP。估计的PASP与静息时直接PASP相关性良好（r=0.76，p<0.0001；偏差-1 mmHg），运动时也如此（r=0.76，p=0.001；偏差+3 mmHg）。假设eRAP为10 mmHg时，ePASP与直接PASP相关（r=0.70，p<0.0001），但显著低估真实值（偏差+9 mmHg），在重度运动性肺动脉高压（EIPH）患者中低估最严重。根据静息eRAP估计运动时的eRAP可改善对有无EIPH患者的鉴别（曲线下面积0.81），偏差最小（5 mmHg），但一致性界限较宽（-14-25 mmHg）。
运动期间可测量时，RV-RA压力梯度可得到合理准确的估计。然而，EIPH患者常出现RA高压，无法无创考虑这一点会导致运动肺动脉压力被严重低估。
