Department of Medicine, Section of Cardiology, University of Chicago, Chicago, Illinois.
Columbia University Medical Center, New York, New York; Cardiovascular Research Foundation, New York, New York.
JACC Cardiovasc Imaging. 2018 Feb;11(2 Pt 1):159-169. doi: 10.1016/j.jcmg.2016.12.019. Epub 2017 Apr 12.
The purpose of this study was to investigate the differential impact of the 2 most commonly available left ventricular assist device (LVAD) types on the right ventricle (RV) and left ventricle (LV) using 3-dimensional (3D) echocardiography-based analysis of ventricular morphology.
LVADs have emerged as common therapy for advanced heart failure. Recent data suggest that the heart responds differently to speed settings in the 2 main devices available (HeartMate II [HMII], St Jude Medical, Pleasanton, California, and HVAD, HeartWare International, Framingham, Massachusetts). The authors hypothesized that 3D echocardiographic assessment of LV and RV volumes and shape would help describe the differential impact of the 2 LVAD types on the heart.
Simultaneous 3D echocardiography, ramp test, and right heart catheterization were performed in 31 patients with LVADs (19 with HMII and 12 with HVAD). Device speed was increased stepwise (8,000 to 12,000 for HMII and 2,300 to 3,200 revolutions per minute for HVAD). 3D echocardiographic full-volume LV and RV datasets were acquired, and endocardial surfaces were analyzed using custom software to calculate LV sphericity, conicity (perfect sphere/cone = 1) and RV septal and free-wall curvature (0 = flat; <0 = concave; >0 = convex).
For both devices, cardiac output increased and wedge pressure decreased with increasing speed. In HMII, LV volumes progressively decreased (meanΔ = 127 ml) as the LV became less spherical and more conical, whereas the RV volume initially remained stable, but subsequently increased at higher speeds (meanΔ = 60 ml). Findings for the HVAD were similar, but less pronounced (LV:meanΔ = 51 ml, RV:meanΔ = 22 ml), and the LV remained significantly more spherical even at high speeds. On average, in HMII patients, the RV septum became more convex (bulging into the LV) at the highest speeds whereas in HVAD patients, there was no discernable change in the RV septum.
The heart responds differently to pump speed changes with the 2 types of LVAD, as reflected by the volume and shape changes of both the LV and RV. Our study suggests that adding RV assessment to the clinical echo-ramp study may better optimize LVAD speed. Further study is needed to determine whether this would have an impact on patient outcomes.
本研究旨在通过基于 3 维（3D）超声心动图的心室形态分析，研究 2 种最常用的左心室辅助装置（LVAD）对右心室（RV）和左心室（LV）的不同影响。
LVAD 已成为晚期心力衰竭的常见治疗方法。最近的数据表明，这两种主要设备（HeartMate II [HMII]，St Jude Medical，加利福尼亚州普莱森顿和 HVAD，HeartWare International，马萨诸塞州弗雷明汉）的速度设置对心脏的反应不同。作者假设 3D 超声心动图评估 LV 和 RV 容积和形状将有助于描述这 2 种 LVAD 类型对心脏的不同影响。
对 31 例 LVAD 患者（19 例使用 HMII，12 例使用 HVAD）进行同步 3D 超声心动图、斜坡试验和右心导管检查。设备速度逐步增加（HMII 为 8000 至 12000 转/分，HVAD 为 2300 至 3200 转/分）。采集 3D 超声心动图全容积 LV 和 RV 数据集，并使用定制软件分析心内膜表面，以计算 LV 球形度、圆锥度（完美球体/圆锥=1）和 RV 间隔和游离壁曲率（0=平坦；<0=凹；>0=凸）。
对于这两种设备，心输出量随着速度的增加而增加，楔压随着速度的增加而降低。在 HMII 中，随着 LV 变得越来越不球形和越来越圆锥形，LV 容积逐渐减小（平均Δ=127ml），而 RV 容积最初保持稳定，但随后在较高速度时增加（平均Δ=60ml）。HVAD 的结果相似，但不那么明显（LV：平均Δ=51ml，RV：平均Δ=22ml），即使在高速时，LV 仍然明显更球形。平均而言，在 HMII 患者中，RV 间隔在最高速度时变得更加凸（向 LV 膨出），而在 HVAD 患者中，RV 间隔没有明显变化。
这两种类型的 LVAD 对泵速变化的反应不同，这反映在 LV 和 RV 的容积和形状变化上。我们的研究表明，在临床超声心动图斜坡研究中增加 RV 评估可能会更好地优化 LVAD 速度。需要进一步研究以确定这是否会对患者预后产生影响。
