Power J M, Raman J, Dornom A, Farish S J, Burrell L M, Tonkin A M, Buxton B, Alferness C A
Department of Medicine, University of Melbourne, Australia.
Cardiovasc Res. 1999 Dec;44(3):549-55. doi: 10.1016/s0008-6363(99)00255-2.
Dilated cardiomyopathy (DCM) is associated with a progressive deterioration in cardiac function. We hypothesised that some of the deleterious effects of DCM could be reduced by mechanically limiting the degree of cardiac dilatation.
A Transonic 20A cardiac output (CO) flow-probe was implanted in the pulmonary artery of 12 adult (52 +/- 4 kg) sheep. Early heart failure was created by rapid right ventricular (RV) pacing for 21 days at a rate which resulted in an initial 10% decrease in CO (to a maximum of 190 bpm). A custom polyester jacket (Acorn Cardiovascular, St Paul, MN) was then placed, via a partial lower sternotomy, on the ventricular epicardium of all sheep. Animals were randomised either to jacket retention (wrap) or removal (sham). Pacing was recommenced at a higher rate (that initiated a further 10% decrease in CO) for 28 days. Haemodynamic and echocardiographic parameters were determined at baseline, implant and at termination.
At termination, the left ventricular fractional shortening was significantly higher (p = 0.03), the degree of mitral valve regurgitation lower (scaled 0-3) (p = 0.03) and the left ventricular long axis area smaller (p = 0.02) in the wrap animals compared with sham.
In this model of heart failure, ventricular constraint with a polyester jacket diminished the deterioration in cardiac function associated with progressive dilated cardiomyopathy. These results suggest that maintainance of a more normal cardiac size and shape may be beneficial in patients with dilated cardiomyopathy.
扩张型心肌病（DCM）与心功能的进行性恶化相关。我们假设，通过机械限制心脏扩张程度，可以减轻DCM的一些有害影响。
将一个Transonic 20A心输出量（CO）流量探头植入12只成年（52±4千克）绵羊的肺动脉中。通过快速右心室（RV）起搏21天来诱发早期心力衰竭，起搏速率导致初始CO下降10%（最高达190次/分钟）。然后通过部分低位胸骨切开术，将定制的聚酯外套（Acorn Cardiovascular，明尼苏达州圣保罗）放置在所有绵羊的心外膜上。动物被随机分为外套保留组（包裹组）或移除组（假手术组）。以更高的速率重新开始起搏（使CO进一步下降10%）持续28天。在基线、植入时和实验结束时测定血流动力学和超声心动图参数。
实验结束时，与假手术组相比，包裹组动物的左心室缩短分数显著更高（p = 0.03），二尖瓣反流程度更低（分级为0 - 3）（p = 0.03），左心室长轴面积更小（p = 0.02）。
在这个心力衰竭模型中，用聚酯外套对心室进行约束可减轻与进行性扩张型心肌病相关的心功能恶化。这些结果表明，对于扩张型心肌病患者，维持更正常的心脏大小和形状可能有益。
