Myocardial Bridging

Abstract

According to postmortem studies, coronary atherosclerosis can be substantial and reach a high prevalence of advanced lesions, including atheroma and fibroatheroma in young adults.1,2 Risk factors associated with coronary atherosclerosis such as dyslipidemia, smoking, diabetes mellitus, and hypertension have been identified. The development of atherosclerosis seems to be related to the magnitude and duration of exposure.3 Although research concentrates on identifying genetic markers in genome-wide association studies, there is still a lack of knowledge about the individual risk of developing coronary atherosclerosis.4 When atherosclerosis presents as acute coronary syndromes, mortality may be high.5 Plaque rupture and erosion have been identified as major underlying pathological-anatomic characteristics,6 but some suspect other mechanisms.7 In this issue of Circulation , Ishikawa et al8 present evidence that myocardial bridging may play a role as a congenital anatomic risk factor for coronary atherosclerosis and myocardial infarction. Article see p 376 Myocardial bridging results when myocardial tissue covers part of the left anterior descending coronary artery, resulting in a tunneled arterial segment, which can be regarded as a congenital variant.9–11 The prevalence is reported to be >50% at autopsy.12 Clinically, the diagnosis of myocardial bridging is established by coronary angiography demonstrating a systolic compression, described as a “milking effect,”13 but it was present in only <5% of cases recently in a large number of Chinese patients.14 When nitroglycerin was used as …