Distinct loading conditions reveal various patterns of right ventricular adaptation
Distinct loading conditions reveal various patterns of right ventricular adaptation
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DOI：
10.1152/ajpheart.00180.2013
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发表时间：
2013-08-01
影响因子：
4.8
通讯作者：
Berger, Rolf M. F.
中科院分区：
文献类型：
--
作者：
Borgdorff, Marinus A. J.;Bartelds, Beatrijs;Berger, Rolf M. F.
慢性负荷异常引起的右心室（RV）衰竭是肺动脉高压（PH）和先天性心脏病结局的主要决定因素。然而，不同类型的RV负荷与不同的结局相关。为了确定适应性RV反应是否取决于负荷类型，我们比较了肺动脉束带（PAB）导致的压力超负荷、PH导致的压力超负荷、压力和容量联合超负荷以及单独容量负荷模型中的血流动力学、运动和肥大。对94只大鼠进行PAB、野百合碱诱导的PH（PH）、下腔静脉分流（分流）或野百合碱和下腔静脉联合分流（PH +分流）。我们在第4周进行了压力-容量分析和自愿运动测量。我们比较了PAB与PH（第一部分）和PH +分流与孤立PH或分流（第二部分）。在第I部分，PH和PAB中存在增强的收缩力（收缩末期弹性和前负荷可复搏功），但PAB中最强。在PAB和PH中，Frank-Starling机制都是活跃的。在PAB中，这伴随着舒张功能障碍（舒张末期弹性增加，舒张常数），RV衰竭的临床体征和运动减少。这些不同的反应并不归因于肥大的差异。在第二部分中，在PH +分流中，收缩反应与PH相比变钝，这导致参数的非正化。额外的容量超负荷强烈增强肥厚的PH。我们得出结论，不同类型的负荷导致不同的RV适应模式。这对于治疗慢性RV负荷增加的患者和各种类型RV衰竭的实验研究具有重要意义。
Right ventricular (RV) failure due to chronically abnormal loading is a main determinant of outcome in pulmonary hypertension (PH) and congenital heart disease. However, distinct types of RV loading have been associated with different outcomes. To determine whether the adaptive RV response depends on loading type, we compared hemodynamics, exercise, and hypertrophy in models of pressure overload due to pulmonary artery banding (PAB), pressure overload due to PH, combined pressure and volume overload, and isolated volume load. Ninety-four rats were subjected to either PAB, monocrotaline-induced PH (PH), aortocaval shunt (shunt), or combined monocrotaline and aortocaval shunt (PH + shunt). We performed pressure-volume analysis and voluntary exercise measurements at 4 wk. We compared PAB to PH (part I) and PH + shunt to either isolated PH or shunt (part II). In part I, enhanced contractility (end-systolic elastance and preload recruitable stroke work) was present in PH and PAB, but strongest in PAB. Frank-Starling mechanism was active in both PAB and PH. In PAB this was accompanied by diastolic dysfunction (increased end-diastolic elastance, relaxation constant), clinical signs of RV failure, and reduced exercise. These distinct responses were not attributable to differences in hypertrophy. In part II, in PH + shunt the contractility response was blunted compared with PH, which caused pseudonormalization of parameters. Additional volume overload strongly enhanced hypertrophy in PH. We conclude that different types of loading result in distinct patterns of RV adaptation. This is of importance for the approach to patients with chronically increased RV load and for experimental studies in various types of RV failure.