CT-based Assessment of Myocardial Bridging in Patients with Acute Chest Pain and No Atherosclerotic Etiology

Abstract

Abstract Introduction: The term “myocardial bridging” is used to describe an anatomic variant where a band of cardiac muscle overlies a segment of an epicardial coronary artery. It is a highly debated topic, because it can cause conditions such as acute coronary syndrome. Myocardial bridging (MB) can be diagnosed using invasive procedures, but also non-invasive ones, such as Multislice Computed Tomography Angiography (MSCTA). Objectives: A comparative analysis was performed on the patients who were admitted to the clinic with typical angina, ischemic ECG changes and muscular bridging shown on MSCTA, and patients with the same symptoms, but without MB. A sub-study was also undertaken in which the MB site and ischemia revealed by thickening of the myocardial muscle, using 3D Polar Mapping, were compared. Materials and methods: A retrospective study assessed 59 patients with typical angina pectoris, shortness of breath and clinical appearance of an acute coronary syndrome, and for whom MSCTA was carried out. Patients were divided into two groups: Group 1 — patients with MB, and Group 2 — patients without MB. Thirty patients in Group 1 had 3D polar mapping to evaluate the thickness of the myocardial muscle. Results: The mean age of our patients with muscular bridging was 55.51 ± 11.4 years, CI 51.57–59.45 years. Patients without MB had a mean age of 59.17 ± 9.6 years, CI 54.98–63.6 years, p = 0.211. 24.32% of the patients with MB were females and 60.86% from the patients without MB were males, p = 0.040. 40.54% of patients presented with MB in the first segment of the LAD and 15.62% had an MB in the second segment of LAD. In patients with an ischemic site smaller than 2 cm of the MB, the ischemic myocardial area was more pronounced compared to the patients with higher length MB (21.85 ± 6.123% vs. 17.62 ± 5.856%). Conclusions: MSCTA is an important procedure that contributes to the clinical investigations of patients with typical angina and suspected acute coronary syndrome. There is a good positive correlation between the location of the MB and the ischemic segments as shown on 3D CT-based polar maps.