Martinez Sara C, Bradley Elisa A, Novak Eric L, Rasalingam Ravi, Cedars Ari M, Ewald Gregory A, Silvestry Scott C, Joseph Susan M
Department of Internal Medicine, Cardiovascular Division (Drs. Bradley, Cedars, Ewald, Joseph, Martinez, and Rasalingam; and Mr. Novak), and Department of Surgery, Division of Cardiothoracic Surgery (Dr. Silvestry), Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110.
Tex Heart Inst J. 2014 Jun 1;41(3):262-72. doi: 10.14503/THIJ-13-3604. eCollection 2014 Jun.
Left ventricular assist device (LVAD)-supported patients are evaluated routinely with use of transthoracic echocardiography. Values of left ventricular unloading in this unique patient population are needed to evaluate LVAD function and assist in patient follow-up. We introduce a new M-mode measurement, the slope of the anterior mitral valve leaflet (SLAM), and compare its efficacy with that of other standard echocardiographically evaluated values for left ventricular loading, including E/e' and pulmonary artery systolic pressures. Average SLAM values were determined retrospectively for cohorts of random, non-LVAD patients with moderately to severely impaired left ventricular ejection fraction (LVEF) (<0.35, n=60). In addition, pre- and post-LVAD implantation echocardiographic images of 81 patients were reviewed. The average SLAM in patients with an LVEF <0.35 was 11.6 cm/s (95% confidence interval, 10.4-12.8); SLAM had a moderately strong correlation with E/e' in these patients. Implantation of LVADs significantly increased the SLAM from 7.3 ± 2.44 to 14.7 ± 5.01 cm/s (n=42, P <0.0001). The LVAD-supported patients readmitted for exacerbation of congestive heart failure exhibited decreased SLAM from 12 ± 3.93 to 7.3 ± 3.5 cm/s (n=6, P=0.041). In addition, a cutpoint of 10 cm/s distinguished random patients with LVEF <0.35 from those in end-stage congestive heart failure (pre-LVAD) with an 88% sensitivity and a 55% specificity. Evaluating ventricular unloading in LVAD patients remains challenging. Our novel M-mode value correlates with echocardiographic values of left ventricular filling in patients with moderate-to-severe systolic function and dynamically improves with the ventricular unloading of an LVAD.
左心室辅助装置（LVAD）支持的患者通常采用经胸超声心动图进行评估。需要了解这一独特患者群体的左心室卸载值，以评估LVAD功能并辅助患者随访。我们引入了一种新的M型测量方法，即二尖瓣前叶斜率（SLAM），并将其与其他用于评估左心室负荷的标准超声心动图测量值（包括E/e'和肺动脉收缩压）的效能进行比较。回顾性确定了左心室射血分数（LVEF）中度至重度受损（<0.35，n=60）的随机非LVAD患者队列的平均SLAM值。此外，还回顾了81例患者LVAD植入前后的超声心动图图像。LVEF<0.35的患者平均SLAM为11.6 cm/s（95%置信区间，10.4-12.8）；在这些患者中，SLAM与E/e'具有中度强相关性。LVAD植入显著增加了SLAM，从7.3±2.44增加到14.7±5.01 cm/s（n=42，P<0.0001）。因充血性心力衰竭加重而再次入院的LVAD支持患者的SLAM从12±3.93降至7.3±3.5 cm/s（n=6，P=0.041）。此外，10 cm/s的切点可将LVEF<0.35的随机患者与终末期充血性心力衰竭（LVAD植入前）患者区分开来，敏感性为88%，特异性为55%。评估LVAD患者的心室卸载仍然具有挑战性。我们新的M型测量值与中度至重度收缩功能患者的左心室充盈超声心动图值相关，并随着LVAD的心室卸载而动态改善。
