Delgado Victoria, Tops Laurens F, Schuijf Joanne D, de Roos Albert, Brugada Josep, Schalij Martin J, Thomas James D, Bax Jeroen J
Department of Cardiology, Leiden University Medical Center, Leiden, the Netherlands.
JACC Cardiovasc Imaging. 2009 May;2(5):556-65. doi: 10.1016/j.jcmg.2008.12.025.
The purpose of the present study was to assess the anatomy and geometry of the mitral valve by using 64-slice multislice computed tomography (MSCT).
Because it yields detailed anatomic information, MSCT may provide more insight into the underlying mechanisms of functional mitral regurgitation (FMR).
In 151 patients, including 67 patients with heart failure (HF) and 29 patients with moderate to severe FMR, 64-slice MSCT coronary angiography was performed. The anatomy of the subvalvular apparatus of the mitral valve was assessed; mitral valve geometry, comprising the mitral valve tenting height and leaflet tethering, was evaluated at the anterolateral, central, and posteromedial levels.
In the majority of patients, the anatomy of the subvalvular apparatus was highly variable because of multiple anatomic variations in the posterior papillary muscle (PM): the anterior PM had a single insertion, whereas the posterior PM showed multiple heads and insertions (n = 114; 83%). The assessment of mitral valve geometry demonstrated that patients with HF with moderate to severe FMR had significantly increased posterior leaflet angles and mitral valve tenting heights at the central (44.4 degrees +/- 11.9 degrees vs. 37.1 degrees +/- 9.0 degrees, p = 0.008; 6.6 +/- 1.4 mm/m(2) vs. 5.3 +/- 1.3 mm/m(2), p < 0.0001, respectively) and posteromedial levels (35.9 degrees +/- 10.6 degrees vs. 26.8 degrees +/- 10.1 degrees, p = 0.04; 5.4 +/- 1.6 mm/m(2) vs. 4.1 +/- 1.2 mm/m(2), p < 0.0001, respectively), as compared with patients with HF without FMR. In addition, a more outward displacement of the PMs, reflected by a higher mitral valve sphericity index, was observed in patients with HF with FMR (1.4 +/- 0.3 vs. 1.2 +/- 0.3, p = 0.004). Mitral valve tenting height at the central level and mitral valve sphericity index were the strongest determinants of FMR severity.
MSCT provides anatomic and geometric information on the mitral valve apparatus. In patients with HF with moderate to severe FMR, a more pronounced tethering of the mitral leaflets at the central and posteromedial levels was demonstrated using MSCT.
本研究旨在通过使用64层多层螺旋CT（MSCT）评估二尖瓣的解剖结构和几何学特征。
由于MSCT能产生详细的解剖学信息，它可能会为功能性二尖瓣反流（FMR）的潜在机制提供更多见解。
对151例患者进行了64层MSCT冠状动脉造影，其中包括67例心力衰竭（HF）患者和29例中重度FMR患者。评估二尖瓣瓣下结构的解剖情况；在二尖瓣前外侧、中央和后内侧层面评估二尖瓣几何学特征，包括二尖瓣帐篷高度和瓣叶牵拉情况。
在大多数患者中，由于后乳头肌（PM）存在多种解剖变异，瓣下结构的解剖情况高度可变：前PM有单一附着点，而后PM有多个头和附着点（n = 114；83%）。二尖瓣几何学特征评估显示，与无FMR的HF患者相比，中重度FMR的HF患者在中央层面（44.4°±11.9°对37.1°±9.0°，p = 0.008；6.6±1.4 mm/m²对5.3±1.3 mm/m²，p < 0.0001）和后内侧层面（35.9°±10.6°对26.8°±10.1°，p = 0.04；5.4±1.6 mm/m²对4.1±1.2 mm/m²，p < 0.0001）的后叶角度和二尖瓣帐篷高度显著增加。此外，FMR的HF患者中观察到PM更向外移位，这由更高的二尖瓣球形指数反映（1.4±0.3对1.2±0.3，p = 0.004）。中央层面的二尖瓣帐篷高度和二尖瓣球形指数是FMR严重程度的最强决定因素。
MSCT提供了二尖瓣装置的解剖学和几何学信息。在中重度FMR的HF患者中，使用MSCT显示二尖瓣叶在中央和后内侧层面有更明显的牵拉。
