Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
Am J Cardiol. 2010 Jul 15;106(2):243-8. doi: 10.1016/j.amjcard.2010.02.035.
Abnormal traction and excursion of the papillary muscle (PM) can be observed in patients with mitral valve prolapse (MVP) and can adversely affect the electrophysiologic stability of the underlying myocardium. Cardiovascular magnetic resonance (CMR) techniques can directly measure the excursion and velocity of PM tips during ventricular systole. In addition, high-resolution late gadolinium enhancement (LGE) CMR imaging allows for visualization of the underlying potentially arrhythmogenic PM fibrosis substrate. We prospectively studied 16 patients with MVP and 9 healthy adult subjects using phase-contrast CMR and cine CMR to assess the PM velocity and excursion. LGE CMR was performed in 13 patients with MVP (81%). The peak PM systolic velocity and maximum PM excursion were significantly increased in those with MVP (12 +/- 5 vs 5 +/- 2 cm/s and 15 +/- 5 vs 2 +/- 3 mm, both p <0.001). Definite PM LGE was found in 6 patients (46%) but the finding did not correlate with PM velocity or excursion. In conclusion, functional CMR imaging demonstrated increased peak PM systolic velocity and excursion distance in patients with MVP. These parameters, however, did not relate to underlying PM fibrosis.
乳头肌（PM）的异常牵引和移位可在二尖瓣脱垂（MVP）患者中观察到，并可能对潜在心肌的电生理稳定性产生不利影响。心血管磁共振（CMR）技术可直接测量心室收缩期间 PM 尖端的移位和速度。此外，高分辨率晚期钆增强（LGE）CMR 成像可显示潜在的致心律失常性 PM 纤维化基质。我们前瞻性研究了 16 名 MVP 患者和 9 名健康成年受试者，使用相位对比 CMR 和电影 CMR 评估 PM 速度和位移。在 13 名 MVP 患者（81%）中进行了 LGE CMR。MVP 患者的 PM 收缩期峰值速度和最大 PM 位移明显增加（12±5 与 5±2cm/s 和 15±5 与 2±3mm，均 p<0.001）。在 6 名患者（46%）中发现了明确的 PM LGE，但该发现与 PM 速度或位移无关。总之，功能 CMR 成像显示 MVP 患者的 PM 收缩期峰值速度和位移距离增加。然而，这些参数与潜在的 PM 纤维化无关。
