PDF(Pubmed)
Abstract：
BACKGROUND: Left ventricular assist device (LVAD) is associated with a high incidence of right ventricular (RV) failure, which is hypothesized to be caused by the occurring inter-ventricular interactions when the LV is unloaded. Factors contributing to these interactions are unknown.
METHODS: We used computer modeling to investigate the impact of the HeartMate 3 LVAD on RV functions. The model was first calibrated against pressure-volume (PV) loops associated with a heart failure (HF) patient and validated against measurements of inter-ventricular interactions in animal experiments. The model was then applied to investigate the effects of LVAD on (1) RV chamber contractility indexed by V 60 derived from its end-systolic PV relationship, and (2) RV diastolic function indexed by V 20 derived from its end-diastolic PV relationship. We also investigated how septal wall thickness and regional contractility affect the impact of LVAD on RV function.
RESULTS: The impact of LVAD on RV chamber contractility is small at a pump speed lower than 4k rpm. At a higher pump speed between 4k and 9k rpm, however, RV chamber contractility is reduced (by ~3% at 6k rpm and ~10% at 9k rpm). The reduction of RV chamber contractility is greater with a thinner septal wall or with a lower myocardial contractility at the LV free wall, septum, or RV free wall.
CONCLUSIONS: RV chamber contractility is reduced at a pump speed higher than 4k rpm, and this reduction is greater with a thinner septal wall or lower regional myocardial contractility. Findings here may have clinical implications in identifying LVAD patients who may suffer from RV failure.
METHODS: We used computer modeling to investigate the impact of the HeartMate 3 LVAD on RV functions. The model was first calibrated against pressure-volume (PV) loops associated with a heart failure (HF) patient and validated against measurements of inter-ventricular interactions in animal experiments. The model was then applied to investigate the effects of LVAD on (1) RV chamber contractility indexed by V 60 derived from its end-systolic PV relationship, and (2) RV diastolic function indexed by V 20 derived from its end-diastolic PV relationship. We also investigated how septal wall thickness and regional contractility affect the impact of LVAD on RV function.
RESULTS: The impact of LVAD on RV chamber contractility is small at a pump speed lower than 4k rpm. At a higher pump speed between 4k and 9k rpm, however, RV chamber contractility is reduced (by ~3% at 6k rpm and ~10% at 9k rpm). The reduction of RV chamber contractility is greater with a thinner septal wall or with a lower myocardial contractility at the LV free wall, septum, or RV free wall.
CONCLUSIONS: RV chamber contractility is reduced at a pump speed higher than 4k rpm, and this reduction is greater with a thinner septal wall or lower regional myocardial contractility. Findings here may have clinical implications in identifying LVAD patients who may suffer from RV failure.
摘要：
背景：左心室辅助装置（LVAD）与右心室（RV）衰竭的高发生率有关，这被认为是由左心室卸载时发生的心室间相互作用引起的。导致这些相互作用的因素是未知的。
方法：我们使用计算机建模来研究HeartMate3LVAD对RV功能的影响。该模型首先针对与心力衰竭（HF）患者相关的压力-容积（PV）回路进行校准，并在动物实验中针对心室间相互作用的测量结果进行验证。然后将该模型用于研究LVAD对（1）RV室收缩性的影响，该收缩性由V60$${V}_{60}$$$得出，（2）RV舒张功能由V20$${V}_{20}$$从其舒张末期PV关系得出。我们还研究了间隔壁厚度和区域收缩性如何影响LVAD对RV功能的影响。
结果：在低于4krpm的泵速下，LVAD对RV腔室收缩性的影响很小。在4k和9krpm之间的较高泵速下，然而,RV室收缩性降低(在6krpm下降低~3%,在9krpm下降低~10%)。室间隔壁较薄或左心室游离壁心肌收缩力较低时，右心室室收缩力降低更大。隔膜,或RV自由墙。
结论：泵速高于4krpm时，RV腔室收缩力降低，中隔壁较薄或局部心肌收缩力较低，这种降低更大。本文的研究结果可能对识别可能患有RV衰竭的LVAD患者具有临床意义。
方法：我们使用计算机建模来研究HeartMate3LVAD对RV功能的影响。该模型首先针对与心力衰竭（HF）患者相关的压力-容积（PV）回路进行校准，并在动物实验中针对心室间相互作用的测量结果进行验证。然后将该模型用于研究LVAD对（1）RV室收缩性的影响，该收缩性由V60$${V}_{60}$$$得出，（2）RV舒张功能由V20$${V}_{20}$$从其舒张末期PV关系得出。我们还研究了间隔壁厚度和区域收缩性如何影响LVAD对RV功能的影响。
结果：在低于4krpm的泵速下，LVAD对RV腔室收缩性的影响很小。在4k和9krpm之间的较高泵速下，然而,RV室收缩性降低(在6krpm下降低~3%,在9krpm下降低~10%)。室间隔壁较薄或左心室游离壁心肌收缩力较低时，右心室室收缩力降低更大。隔膜,或RV自由墙。
结论：泵速高于4krpm时，RV腔室收缩力降低，中隔壁较薄或局部心肌收缩力较低，这种降低更大。本文的研究结果可能对识别可能患有RV衰竭的LVAD患者具有临床意义。
