First Department of Medicine, Hokkaido University Hospital, Japan.
Int J Cardiol. 2013 Sep 20;168(1):420-6. doi: 10.1016/j.ijcard.2012.09.133. Epub 2012 Oct 8.
Few studies have focused on right atrial (RA) structure and function in pulmonary hypertension (PH). We sought to evaluate RA volume and phasic function using cardiac magnetic resonance (CMR), and to examine their clinical relevance in PH.
We prospectively studied 50 PH patients and 21 control subjects. RA volume and indices of phasic function (reservoir volume, ejection fraction [EF], and conduit volume) were evaluated by CMR.
Maximum RA volume index was significantly higher in PH patients (56 [44-70] ml/m(2)) than in controls (40 [30-48] ml/m(2)) (p<0.001). Reservoir volume index was significantly lower in PH than in controls (p<0.001), but conduit volume index was higher in PH than in controls (p=0.008). RA EF was similar when comparing the two groups (p=0.925). Interestingly, RA EF was increased in PH patients with WHO functional class III patients as compared with controls (p<0.001) but was reduced in advanced PH patients with WHO functional class IV (p<0.01). Maximum RA volume and RA EF significantly correlated with pulmonary hemodynamic indices, atrial and brain natriuretic hormone levels, and CMR-derived right ventricular indices. By contrast, RA reservoir volume correlated with cardiac index and 6-minute walk distance.
PH is associated with increased size, decreased reservoir function, and increased conduit function of the right atrium. RA systolic function indicated by RA EF increases in patients with mild to moderate PH but decreases in patients with advanced PH. Varying associations between RA indices and conventional PH indices suggest their unique role in the management of PH.
很少有研究关注肺动脉高压（PH）患者的右心房（RA）结构和功能。我们试图通过心脏磁共振（CMR）评估 RA 容积和时相功能，并探讨其在 PH 中的临床相关性。
我们前瞻性研究了 50 例 PH 患者和 21 例对照者。通过 CMR 评估 RA 容积和时相功能指标（储备容积、射血分数[EF]和输送容积）。
PH 患者的最大 RA 容积指数显著高于对照组（56[44-70]ml/m2）（p<0.001）。PH 患者的储备容积指数明显低于对照组（p<0.001），但输送容积指数高于对照组（p=0.008）。两组 RA EF 相似（p=0.925）。有趣的是，与对照组相比，WHO 功能分级 III 级的 PH 患者的 RA EF 增加（p<0.001），但 WHO 功能分级 IV 级的晚期 PH 患者的 RA EF 降低（p<0.01）。最大 RA 容积和 RA EF 与肺血流动力学指标、心房和脑利钠肽水平以及 CMR 衍生的右心室指数显著相关。相比之下，RA 储备容积与心指数和 6 分钟步行距离相关。
PH 与右心房增大、储备功能降低和输送功能增加有关。由 RA EF 表示的 RA 收缩功能在轻度至中度 PH 患者中增加，但在晚期 PH 患者中降低。RA 指数与传统 PH 指数之间的不同关联表明它们在 PH 管理中的独特作用。
