Department of Cardiac, Thoracic and Vascular Sciences, University of Padova, Padova, Italy.
JACC Cardiovasc Imaging. 2013 Jan;6(1):32-41. doi: 10.1016/j.jcmg.2012.08.013.
This study sought to evaluate the prevalence and potential role of myocardial bridging in the pathogenesis of apical ballooning syndrome (ABS).
ABS is characterized by reversible left ventricular dysfunction, frequently precipitated by a stressful event, but the pathogenesis remains still unclear.
Forty-two consecutive patients (40 female, mean age 66 ± 7 years) with ABS underwent echocardiography, cardiac magnetic resonance, coronary angiography (CA) with intravascular ultrasound, and computed tomography angiography (CTA). Myocardial bridging was diagnosed by CA when a dynamic compression phenomenon was observed in the coronary artery and by CTA when a segment of coronary artery was completely (full encasement) or incompletely (partial encasement) surrounded by the myocardium. The prevalence of myocardial bridging detected by CTA and CA in ABS patients was compared with 401 controls without ABS who underwent both CTA and CA.
Myocardial bridging by CTA was observed in 32 ABS patients (76%): 23 with partial encasement and 9 with full encasement. All myocardial bridging was located in the mid segment of the left anterior descending coronary artery (LAD) with a mean length of 17 ± 9 mm. CA revealed myocardial bridging in 17 subjects (40%) (9 with partial encasement and 8 with full encasement by CTA). All subjects in which dynamic compression was observed by CA showed myocardial bridging by CTA, while none of the subjects with negative findings for myocardial bridging by CTA revealed dynamic compression by CA. Compared with controls, ABS patients showed a significant higher prevalence of myocardial bridging in the LAD either by CA (40% vs. 8%; p < 0.001) or by CTA (76% vs. 31%; p < 0.001).
Our study showed that myocardial bridging of the LAD is a frequent finding in ABS patients as revealed both by CA and, mostly, by CTA, suggesting a role of myocardial bridging as potential substrate in the pathogenesis of ABS.
本研究旨在评估心肌桥在 apical ballooning syndrome（ABS）发病机制中的普遍性及其潜在作用。
ABS 的特征是左心室功能可逆性障碍，常由应激事件引发，但发病机制仍不清楚。
42 例连续 ABS 患者（40 名女性，平均年龄 66 ± 7 岁）接受了超声心动图、心脏磁共振、冠状动脉造影（CA）伴血管内超声和计算机断层血管造影（CTA）检查。通过 CA 观察到冠状动脉的动态压迫现象，或通过 CTA 观察到冠状动脉的某一段完全（完全包裹）或不完全（部分包裹）被心肌包围时，诊断为心肌桥。比较 ABS 患者中 CTA 和 CA 检测到的心肌桥的发生率，与同时接受 CTA 和 CA 检查的 401 名无 ABS 的对照组进行比较。
32 例 ABS 患者（76%）通过 CTA 观察到心肌桥：23 例部分包裹，9 例完全包裹。所有心肌桥均位于左前降支（LAD）中段，平均长度为 17 ± 9mm。CA 显示 17 例（40%）患者存在心肌桥（9 例通过 CTA 显示部分包裹，8 例通过 CTA 显示完全包裹）。CA 观察到动态压迫的所有患者均通过 CTA 显示心肌桥，而 CTA 观察到无动态压迫的患者中无一例显示 CA 观察到动态压迫。与对照组相比，通过 CA（40%比 8%；p < 0.001）或 CTA（76%比 31%；p < 0.001），ABS 患者 LAD 中的心肌桥发生率显著更高。
本研究表明，LAD 的心肌桥在 ABS 患者中是一种常见发现，通过 CA 和 CTA 都能发现，这表明心肌桥作为 ABS 发病机制的潜在底物的作用。
