Analysis of patient-specific surgical ventricular restoration: importance of an ellipsoidal left ventricular geometry for diastolic and systolic function
Analysis of patient-specific surgical ventricular restoration: importance of an ellipsoidal left ventricular geometry for diastolic and systolic function
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DOI：
10.1152/japplphysiol.00662.2012
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发表时间：
2013-07-01
影响因子：
3.3
通讯作者：
Guccione, Julius M.
中科院分区：
文献类型：
--
作者：
Lee, Lik Chuan;Wenk, Jonathan F.;Guccione, Julius M.
心室修复手术（SVR）是一种通过手术从扩张的衰竭左心室中排除梗塞组织来治疗心力衰竭的手术。为了阐明和预测 SVR 几何变化对心脏功能的影响，我们使用未标记的磁共振图像在手术前后创建了患者特定的数学（有限元）左心室模型。我们的结果预测，术后收缩功能的改善会因患者舒张期扩张性的下降而受到损害。这两种相互矛盾的影响通常表现为手术后 Starling 关系（每搏输出量与舒张末期压力）更加沮丧。通过模拟左心室恢复到其测量的基线球形度，我们表明舒张功能和收缩功能均得到改善。这一结果证实了 SVR（心室内圆形补片成形术）后常见的左心室球形度增加具有负面影响，并在一定程度上导致了 Starling 关系的降低。另一方面，SVR 后肌纤维应力峰值显着降低（50%），并且左心室肌纤维应力分布变得更加均匀。 SVR 后肌纤维应力的显着降低可能有助于减少左心室的不良重塑。这些结果与缺血性心力衰竭手术治疗试验 (20) 中针对中性结果提出的推测一致，即“手术心室重建缺乏益处是手术减少左心室体积（减少壁应力和改善收缩功能）带来的预期益处被舒张期扩张性的降低所抵消。”
Surgical ventricular restoration (SVR) is a procedure designed to treat heart failure by surgically excluding infarcted tissues from the dilated failing left ventricle. To elucidate and predict the effects of geometrical changes from SVR on cardiac function, we created patient-specific mathematical (finite-element) left ventricular models before and after surgery using untagged magnetic resonance images. Our results predict that the postsurgical improvement in systolic function was compromised by a decrease in diastolic distensibility in patients. These two conflicting effects typically manifested as a more depressed Starling relationship (stroke volume vs. end-diastolic pressure) after surgery. By simulating a restoration of the left ventricle back to its measured baseline sphericity, we show that both diastolic and systolic function improved. This result confirms that the increase in left ventricular sphericity commonly observed after SVR (endoventricular circular patch plasty) has a negative impact and contributes partly to the depressed Starling relationship. On the other hand, peak myofiber stress was reduced substantially (by 50%) after SVR, and the resultant left ventricular myofiber stress distribution became more uniform. This significant reduction in myofiber stress after SVR may help reduce adverse remodeling of the left ventricle. These results are consistent with the speculation proposed in the Surgical Treatment for Ischemic Heart Failure trial (20) for the neutral outcome, that "the lack of benefit seen with surgical ventricular reconstruction is that benefits anticipated from surgical reduction of left ventricular volume (reduced wall stress and improvement in systolic function) are counter-balanced by a reduction in diastolic distensibility."