Herrmann S, Niemann M, Störk S, Hu K, Voelker W, Ertl G, Weidemann F
Medizinische Klinik I - Kardiologie, Deutsches Zentrum für Herzinsuffizienz, Universitätsklinik, Oberdürrbacherstr. 6, 97080, Würzburg, Deutschland.
Herz. 2013 May;38(3):261-8. doi: 10.1007/s00059-012-3640-y. Epub 2012 Jun 28.
Low gradient aortic stenoses (AS) represent a special challenge for physicians with respect to an exact diagnosis and optimal therapy. The difficulty lies in the estimation of the severity of AS which is decisive for subsequent treatment and the prognosis. Low flow and low gradient can be due to systolic or diastolic dysfunction by high-grade as well as by medium-grade AS and be of non-valvular origin. The latter group is to be interpreted as pseudoaortic stenosis as long as the low flow can successfully be raised by interventional means. However, only patients in the first group can be expected to profit from valve replacement and for patients in the second group the accompanying diseases must be the focus of therapeutic treatment. Therefore, according to recent European surveys up to 30% of patients with severe AS are undertreated due to false estimation of the severity of stenosis and perioperative risk stratification. Furthermore, follow-up investigations have shown that patients with low flow/low gradient stenosis and borderline-normal ejection fraction (EF) are in an advanced stage of the disease because they have often developed a severe reduction in longitudinal myocardial function and in addition have pronounced myocardial replacement fibrosis due to cardiac remodelling despite a preserved EF. Therefore, aortic valve area, mean pressure gradient and EF alone cannot be taken into consideration for the management of patients with severe AS but a comprehensive assessment of the hemodynamics, such as stroke volume, special functional parameters as well as individual clinical appearance is essential for precise diagnostic and therapeutic decision making.
低梯度主动脉瓣狭窄（AS）在准确诊断和优化治疗方面给医生带来了特殊挑战。困难在于对AS严重程度的评估，这对后续治疗和预后起着决定性作用。低流量和低梯度可能是由于重度以及中度AS导致的收缩期或舒张期功能障碍，也可能是非瓣膜性起源。只要通过介入手段能够成功提高低流量，后一组就应被解释为假性主动脉瓣狭窄。然而，只有第一组患者有望从瓣膜置换中获益，而对于第二组患者，伴随疾病必须成为治疗的重点。因此，根据最近的欧洲调查，由于对狭窄严重程度和围手术期风险分层的错误估计，高达30%的重度AS患者治疗不足。此外，随访研究表明，低流量/低梯度狭窄且射血分数（EF）临界正常的患者处于疾病晚期，因为他们通常已经出现纵向心肌功能严重下降，并且尽管EF保留，但由于心脏重塑，还存在明显的心肌替代性纤维化。因此，对于重度AS患者的管理，不能仅考虑主动脉瓣面积、平均压力梯度和EF，而对血流动力学进行全面评估，如每搏输出量、特殊功能参数以及个体临床表现，对于精确的诊断和治疗决策至关重要。
