Mehta Rajendra H, Supiano Mark A, Grossman P Michael, Oral Hakan, Montgomery Daniel G, Briesmiester Kerri A, Smith Marla J, Starling Mark R
University of Michigan and Veterans Affairs, Healthcare Systems, Ann Arbor, MI, USA.
Am Heart J. 2004 Apr;147(4):729-35. doi: 10.1016/j.ahj.2003.10.020.
We have shown that the systemic sympathetic nervous system (SNS) is activated in patients with chronic mitral regurgitation (MR). However, the fate of systemic SNS activity after surgical correction of MR is currently unknown.
We examined 14 patients with MR who had normal sinus rhythm with an investigational, preoperative cardiac catheterization, including arterial norepinephrine (NE) sampling and [(3)H]-NE infusions and arterial blood sampling to determine NE kinetic parameters using a 2-compartment modeling analysis. The arterial NE and NE kinetic parameters were determined in all patients after mitral valve surgery (MVS) at a mean of 12 months. A 2-dimensional echocardiographic examination was also performed before and after MVS.
The average extravascular NE release rates (NE(2)) before and after MVS were 1.89 +/- 0.66 and 2.26 +/- 0.82 microg/min/m(2) (P =.24), respectively. The average left ventricular (LV) end-diastolic dimension, fractional shortening, and ejection fraction decreased, whereas the mean LV end-systolic dimension did not change between the pre- and post-MVS echocardiographic studies. However, these group averages were comprised of patients with MR in whom the NE(2) and echocardiographic values both increased and decreased. This lack of homogeneity was a reflection of our new observation that the pre- to post-MVS changes in NE(2) were directly proportional to the changes in LV end-systolic dimension (r = 0.91, P <.001) and inversely related to the changes in LV fractional shortening (r = -0.82, P <.001) and ejection fraction (r = -0.78, P <.001).
The response in systemic SNS activity in patients with MR after MVS is not homogeneous, and these changes are concordant with the post-MVS changes in LV size and systolic performance. These data further support our earlier observations and extend them to suggest that systemic SNS activation in patients with chronic MR is related to LV remodeling and impaired systolic performance.
我们已经表明，慢性二尖瓣反流（MR）患者的全身交感神经系统（SNS）被激活。然而，MR手术矫正后全身SNS活动的转归目前尚不清楚。
我们检查了14例窦性心律正常的MR患者，进行了一项术前心脏导管检查研究，包括动脉去甲肾上腺素（NE）采样、[³H]-NE输注以及动脉血采样，以使用两室模型分析确定NE动力学参数。在二尖瓣手术（MVS）后平均12个月时，测定所有患者的动脉NE和NE动力学参数。MVS前后还进行了二维超声心动图检查。
MVS前后的平均血管外NE释放率（NE₂）分别为1.89±0.66和2.26±0.82μg/min/m²（P = 0.24）。在MVS前后的超声心动图研究之间，平均左心室（LV）舒张末期内径减小、缩短分数和射血分数降低，而平均LV收缩末期内径未改变。然而，这些组平均值包括NE₂和超声心动图值均升高和降低的MR患者。这种缺乏同质性反映了我们的新观察结果，即MVS前后NE₂的变化与LV收缩末期内径的变化成正比（r = 0.91，P < 0.001），与LV缩短分数的变化成反比（r = -0.82，P < 0.001）以及与射血分数的变化成反比（r = -0.78，P < 0.001）。
MR患者MVS后全身SNS活动的反应并不均匀，并且这些变化与MVS后LV大小和收缩功能的变化一致。这些数据进一步支持了我们早期的观察结果，并扩展表明慢性MR患者的全身SNS激活与LV重塑和收缩功能受损有关。
