Department of Cardiovascular Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences and Okayama University Hospital, 2-5-1 Shikatacho, Kitaku, Okayama, 700-8558, Japan.
Department of Research Promotion and Management, National Cerebral and Cardiovascular Center, 6-1 Kishibe-Shimmachi, Suita, Osaka, 564-8565, Japan.
J Physiol Sci. 2024 Nov 2;74(1):53. doi: 10.1186/s12576-024-00946-z.
Mechanical circulatory support is a potential treatment for failing Fontan patients. In this study, we performed a theoretical analysis using a computational model to clarify the effects of systemic ventricular assist device (VAD) in failing Fontan patients. Cardiac chambers and vascular systems were described using the time-varying elastance model and modified Windkessel model, respectively. A VAD was simulated as a nonlinear function. In systolic and diastolic ventricular dysfunction and atrioventricular valve regurgitation models, systemic VAD increased the cardiac index and decreased the central venous pressure (CVP). However, in the high pulmonary vascular resistance model, CVP became extremely high above 15 mmHg to maintain the cardiac index when the pulmonary vascular resistance index (PVRI) was above 5 Wood units m. In Fontan patients with ventricular dysfunction or atrioventricular valve regurgitation, systemic VAD efficiently improves the hemodynamics. In Fontan patients with PVRI of > 5 Wood units m, systemic VAD seems ineffective.
机械循环支持是治疗 Fontan 衰竭患者的一种潜在方法。在这项研究中，我们使用计算模型进行了理论分析，以阐明在 Fontan 衰竭患者中使用全身心室辅助装置（VAD）的效果。心脏腔室和血管系统分别使用时变顺应性模型和改良的 Windkessel 模型进行描述。VAD 被模拟为一个非线性函数。在收缩和舒张心室功能障碍以及房室瓣反流模型中，全身 VAD 增加了心指数并降低了中心静脉压（CVP）。然而，在肺动脉阻力指数（PVRI）高于 5 Wood 单位 m 的情况下，当肺动脉阻力指数高于 5 Wood 单位 m 时，CVP 会变得非常高，以维持心指数。在存在心室功能障碍或房室瓣反流的 Fontan 患者中，全身 VAD 可有效地改善血液动力学。在 PVRI 高于 5 Wood 单位 m 的 Fontan 患者中，全身 VAD 似乎无效。
