Kato Takao, Kasai Takatoshi, Yatsu Shoichiro, Murata Azusa, Matsumoto Hiroki, Suda Shoko, Hiki Masaru, Shiroshita Nanako, Kato Mitsue, Kawana Fusae, Miyazaki Sakiko, Daida Hiroyuki
Department of Cardiovascular Medicine, Juntendo University School of Medicine, Tokyo, Japan.
Cardiovascular Respiratory Sleep Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan.
Front Physiol. 2017 Nov 23;8:921. doi: 10.3389/fphys.2017.00921. eCollection 2017.
Acute effects of positive airway pressure (PAP) [including continuous PAP (CPAP) and adaptive servo-ventilation, an advanced form of bi-level PAP] on functional mitral regurgitation (fMR) in patients with heart failure (HF) with left ventricular (LV) systolic dysfunction remain unclear. Thus, whether PAP therapy reduces fMR in such patients with HF was investigated. Twenty patients with HF and LV systolic dysfunction defined as LV ejection fraction (LVEF) <50% (14 men; mean LVEF, 35.0 ± 11.5%) with fMR underwent echocardiography during 10-min CPAP (4 and 8 cm HO) and adaptive servo-ventilation. For fMR assessment, MR jet area fraction, defined as the ratio of MR jet on color Doppler to the left atrial area, was measured. The forward stroke volume (SV) index (fSVI) was calculated from the time-velocity integral, cross-sectional area of the aortic annulus, and body surface area. fMR significantly reduced on CPAP at 8 cm HO (0.30 ± 0.12) and adaptive servo-ventilation (0.29 ± 0.12), compared with the baseline phase (0.37 ± 0.12) and CPAP at 4 cm HO (0.34 ± 0.12) ( < 0.001). The fSVI did not change in any of the PAP sessions ( = 0.888). However, significant differences in fSVI responses to PAP were found between sexes (P for interaction, 0.006), with a significant reduction in fSVI in women ( = 0.041) and between patients with baseline fSVI ≥ and < the median value (27.8 ml/m, P for interaction, 0.018), with a significant fSVI reduction in patients with high baseline fSVI ( = 0.028). In addition, significant differences were found in fSVI responses to PAP between patients with LV end-systolic volume (LVESV) index ≥ and < the median value (62.0 ml/m, P for interaction, 0.034), with a significant fSVI increase in patients with a high LVESV index ( = 0.023). In patients with HF, LV systolic dysfunction, and fMR, PAP can alleviate fMR without any overall changes in forward SV. However, MR alleviation due to PAP might be associated with a decrease in forward SV in women with high baseline SV, whereas MR alleviation due to PAP might be accompanied by increased forward SV in patients with a dilated LV.
对于左心室（LV）收缩功能障碍的心力衰竭（HF）患者，气道正压通气（PAP）[包括持续气道正压通气（CPAP）和双水平气道正压通气的一种先进形式——适应性伺服通气]对功能性二尖瓣反流（fMR）的急性影响仍不清楚。因此，本研究调查了PAP治疗是否能降低此类HF患者的fMR。20例HF且LV收缩功能障碍（定义为LV射血分数[LVEF]<50%，14例男性；平均LVEF为35.0±11.5%）并伴有fMR的患者在10分钟的CPAP（4和8 cm H₂O）及适应性伺服通气期间接受了超声心动图检查。对于fMR评估，测量了二尖瓣反流射流面积分数，其定义为彩色多普勒上二尖瓣反流射流与左心房面积之比。根据时间-速度积分、主动脉瓣环横截面积和体表面积计算每搏输出量（SV）指数（fSVI）。与基线期（0.37±0.12）和4 cm H₂O的CPAP（0.34±0.12）相比，8 cm H₂O的CPAP（0.30±0.12）和适应性伺服通气（0.29±0.12）时fMR显著降低（P<0.001）。在任何PAP阶段，fSVI均未改变（P = 0.888）。然而，发现PAP对fSVI的反应在性别之间存在显著差异（交互作用P值为0.006），女性的fSVI显著降低（P = 0.041）；在基线fSVI≥和<中位数（27.8 ml/m²）的患者之间也存在显著差异（交互作用P值为0.018），基线fSVI高的患者fSVI显著降低（P = 0.028）。此外，在LV收缩末期容积（LVESV）指数≥和<中位数（62.0 ml/m²）的患者之间，PAP对fSVI的反应也存在显著差异（交互作用P值为0.034），LVESV指数高的患者fSVI显著增加（P = 0.023）。在HF、LV收缩功能障碍和fMR患者中，PAP可减轻fMR，而心输出量总体无变化。然而，PAP导致的二尖瓣反流减轻可能与基线心输出量高的女性的心输出量降低有关，而PAP导致的二尖瓣反流减轻可能与LV扩张患者的心输出量增加有关。
