Cardiology University Department, IRCCS Policlinico San Donato, Milan, Italy.
Department for Biomedical Sciences for Health, University of Milano, Milan, Italy.
Am J Physiol Heart Circ Physiol. 2021 Feb 1;320(2):H642-H653. doi: 10.1152/ajpheart.00507.2020. Epub 2020 Dec 11.
Exercise-induced mitral regurgitation (Ex-MR) is one of the mechanisms that contribute to reduced functional capacity in heart failure (HF). Its prevalence is not well defined across different HF subtypes. The aim of the present study was to describe functional phenotypes and cardiac response to exercise in HFrEF, HFmrEF, and HFpEF, according to Ex-MR prevalence. A total of 218 patients with HF [146 men, 68 (59-78) yr], 137 HFrEF, 41 HFmrEF, 40 HFpEF, and 23 controls were tested with cardiopulmonary exercise test combined with exercise echocardiography. Ex-MR was defined as development of at least moderate (≥2+/4+) regurgitation during exercise. Ex-MR was highly prevalent in the overall population (52%) although differed in the subgroups as follows: 82/137 (60%) in HFrEF, 17/41 (41%) in HFmrEF, and 14/40 (35%) in HFpEF ( < 0.05). Ex-MR was associated with a high rate of ventilation (VE) to carbon dioxide production (VCO) in all HF subtypes [31.2 (26.6-35.6) vs. 33.4 (29.6-40.5), = 0.004; 28.1 (24.5-31.9) vs. 34.4 (28.2-36.7), = 0.01; 28.8 (26.6-32.4) vs. 32.2 (29.2-36.7), = 0.01] and with lower peak VO in HFrEF and HFmrEF. Exercise right ventricle to pulmonary circulation (RV-PC) uncoupling was observed in HFrEF and HFpEF patients with Ex-MR [peak TAPSE/SPAP: HFrEF 0.40 (0.30-0.57) vs. 0.29 (0.23-0.39), = 0.006; HFpEF 0.44 (0.28-0.62) vs. 0.31 (0.27-0.33), = 0.05]. HFpEF with Ex-MR showed a distinct phenotype characterized by better chronotropic reserve and peripheral O extraction. Ex-MR is a common mechanism across the spectrum of HF subtypes and combines with ventilatory inefficiency and RV-PC uncoupling. Interestingly, in HFpEF, Ex-MR emerged as unexpectedly prevalent and peculiarly associated with increased chronotropic response and peripheral O extraction as potential adaptive mechanisms to backward flow redistribution.
运动诱发的二尖瓣反流（Ex-MR）是导致心力衰竭（HF）患者功能能力下降的机制之一。其在不同 HF 亚型中的患病率尚不清楚。本研究旨在根据 Ex-MR 的患病率，描述 HFrEF、HFmrEF 和 HFpEF 患者的功能表型和对运动的心脏反应。共 218 例 HF 患者[男性 146 例，68（59-78）岁]，137 例 HFrEF、41 例 HFmrEF、40 例 HFpEF 和 23 例对照接受心肺运动试验联合运动超声心动图检查。Ex-MR 定义为运动时至少出现中度（≥2+/4+）反流。尽管 Ex-MR 在各组之间存在差异（如下所示），但在整个人群中患病率很高（52%）：82/137（60%）在 HFrEF 中，17/41（41%）在 HFmrEF 中，14/40（35%）在 HFpEF 中（<0.05）。在所有 HF 亚型中，Ex-MR 与高 VE 至 VCO 相关[31.2（26.6-35.6）与 33.4（29.6-40.5），=0.004；28.1（24.5-31.9）与 34.4（28.2-36.7），=0.01；28.8（26.6-32.4）与 32.2（29.2-36.7），=0.01]，并且在 HFrEF 和 HFmrEF 中峰值 VO 较低。在 HFrEF 和 HFpEF 患者中观察到运动右心室至肺循环（RV-PC）解耦[峰值 TAPSE/SPAP：HFrEF 0.40（0.30-0.57）与 0.29（0.23-0.39），=0.006；HFpEF 0.44（0.28-0.62）与 0.31（0.27-0.33），=0.05]。HFpEF 合并 Ex-MR 表现出独特的表型，特征为变时性储备更好和外周 O 提取增加。Ex-MR 是 HF 亚型谱中常见的机制，与通气效率降低和 RV-PC 解耦相结合。有趣的是，在 HFpEF 中，Ex-MR 出乎意料地普遍存在，并且与向后血流重新分布的潜在适应性机制相关的变时性反应和外周 O 提取增加特别相关。
