Hongning Yin, Stewart Ralph A, Whalley Gillian A
The 2nd Hospital of Hebei Medical University, Shijiazhuang, China.
Auckland City Hospital, Auckland, New Zealand.
Heart Lung Circ. 2014 Apr;23(4):378-80. doi: 10.1016/j.hlc.2013.10.090. Epub 2013 Nov 1.
Although mitral regurgitation (MR) results in left ventricular (LV) volume overload, right ventricular (RV) function may also be impaired. We investigated the influence of short-term beta-blockade on RV function in patients with moderate-severe MR.
Twenty-six patients were randomised in a cross-over design to receive two weeks of beta-blockade or placebo. Echocardiography was performed at baseline and at the end of the treatment periods. Measurements included: RV ejection fraction (RVEF) tricuspid annular motion and Tei index.
No differences in mean RVEF (64.0 ± 6.0 v 67.0 ± 8.0%, p=0.3), tricuspid annular motion (13.5 ± 3.0 v 14.7 ± 2.9 cm/s, p=0.5), or median Tei index (0.61 (0.54, 0.88) v 0.59 (0.54, 0.74), p=0.8) were observed between placebo and metoprolol, despite significantly longer cardiac time intervals. Tei index under both conditions was significantly reduced.
Short-term treatment with a beta-blocker did not influence RV function in these patients. Interestingly, the RV Tei index was high suggesting significant RV dysfunction despite normal RVEF.
尽管二尖瓣反流（MR）会导致左心室（LV）容量超负荷，但右心室（RV）功能也可能受损。我们研究了短期β受体阻滞剂对中重度MR患者右心室功能的影响。
26例患者采用交叉设计随机分组，分别接受为期两周的β受体阻滞剂治疗或安慰剂治疗。在基线期和治疗期末进行超声心动图检查。测量指标包括：右心室射血分数（RVEF）、三尖瓣环运动和Tei指数。
尽管心脏时间间期显著延长，但安慰剂组和美托洛尔组之间在平均RVEF（64.0±6.0对67.0±8.0%，p=0.3）、三尖瓣环运动（13.5±3.0对14.7±2.9 cm/s，p=0.5）或中位数Tei指数（0.61（0.54，0.88）对0.59（0.54，0.74），p=0.8）方面均未观察到差异。两种情况下Tei指数均显著降低。
β受体阻滞剂短期治疗对这些患者的右心室功能没有影响。有趣的是，尽管RVEF正常，但右心室Tei指数较高，提示存在明显的右心室功能障碍。
