Pollick Charles, Shmueli Hezzy, Maalouf Nicolas, Zadikany Ronit H
Smidt Heart Institute, Cedars Sinai Medical Center, Los Angeles, California, USA.
Echocardiography. 2020 Jun;37(6):822-831. doi: 10.1111/echo.14710. Epub 2020 May 22.
Controversy surrounds the cause of the pressure gradient in patients with hypertrophic obstructive cardiomyopathy (HOCM). Left ventricular cavity obliteration (LVCO) was first described as the cause of the gradient but subsequently systolic anterior motion (SAM) of the mitral valve has been established as the cause. Nevertheless, the two gradients, though different in origin and significance, share similar characteristics. They both have a similar "dagger" profile, are obtained from the cardiac apex, are associated with a hyperdynamic left ventricle, and the gradients are worsened by Valsalva. The distinction has clinical relevance, because treating the intracavitary gradient (ICG) of LVCO as if it were a SAM-associated gradient associated with HOCM would be inappropriate and possibly harmful.
To clarify the cause and characteristics of the ICG in patients with LVCO in patients without HOCM, we assessed the extent and duration of cavity obliteration, and for differentiation, we compared the spectral profiles with patients with HOCM and severe aortic stenosis (AS).
Higher ICG is associated with a greater extent and more prolonged apposition of LV walls, and smaller left ventricular cavity size. The spectral profile of patients with AS, HOCM, and LVCO is differentiated by the peak/mean gradient ratios of 2 or less, 2-3, and 3 or greater, respectively, in >90% of patients. Most patients with LVCO without HOCM or severe LVH have an ICG < 36 mm Hg.
The magnitude of ICG is quantitatively associated with the extent and duration of LVCO. Spectral profiles of severe AS, HOCM, and LVCO can be differentiated by the peak/mean gradient ratio.
肥厚性梗阻性心肌病（HOCM）患者压力阶差的病因存在争议。左心室腔闭塞（LVCO）最初被描述为压力阶差的病因，但随后二尖瓣收缩期前向运动（SAM）已被确认为病因。然而，这两种压力阶差虽然起源和意义不同，但具有相似的特征。它们都具有相似的“匕首”形态，从心尖获取，与高动力性左心室相关，并且瓦尔萨尔瓦动作会使压力阶差恶化。这种区分具有临床相关性，因为将LVCO的腔内压力阶差（ICG）当作与HOCM相关的SAM压力阶差来治疗是不合适的，甚至可能有害。
为了阐明无HOCM的LVCO患者ICG的病因和特征，我们评估了腔闭塞的程度和持续时间，并且为了进行区分，我们将频谱形态与HOCM和严重主动脉瓣狭窄（AS）患者进行了比较。
较高的ICG与左心室壁更大程度、更长时间的贴合以及更小的左心室腔大小相关。在超过90%的患者中，AS、HOCM和LVCO患者的频谱形态分别通过峰值/平均压力阶差比值小于等于2、2至3和大于等于3来区分。大多数无HOCM或严重左心室肥厚的LVCO患者的ICG<36mmHg。
ICG的大小与LVCO的程度和持续时间在数量上相关。严重AS、HOCM和LVCO的频谱形态可以通过峰值/平均压力阶差比值来区分。
