Prevalence of Myocardial Bridges
Myocardial bridges are remarkably common, occurring in 15-85% of the population at autopsy, though they are detected in only 0.5-4.5% of patients undergoing coronary angiography. 1
Understanding the Discrepancy Between Pathological and Angiographic Detection
The dramatic difference between autopsy findings and angiographic detection reflects the limitations of coronary angiography in identifying this anatomic variant:
Pathological studies consistently demonstrate myocardial bridges in 15-85% of examined hearts, representing the true anatomical prevalence in the general population 1, 2
Angiographic detection rates are substantially lower at 0.5-4.5% because angiography only visualizes bridges that cause sufficient systolic compression to be visible during the cardiac cycle 1, 2
In a prospective study of 2,547 patients undergoing coronary angiography for chest pain, myocardial bridges were identified in only 5% of the 511 patients without fixed coronary obstruction 3
Anatomical Distribution
The left anterior descending artery is affected in almost all cases of myocardial bridging 1, 2
The middle segment of the left anterior descending coronary artery is the most common location 4
Special Population Considerations
Myocardial bridges occur in 30-50% of patients with hypertrophic cardiomyopathy, representing a significantly higher prevalence than in the general population and potentially contributing to sudden cardiac death risk in this subset 1, 5, 2
Clinical Significance of the High Prevalence
Despite the high anatomical prevalence, the clinical significance remains limited:
The general population prevalence of approximately 25% is considered a benign variation of normal coronary development 6
Among patients with angiographically detected bridges, only a small minority demonstrate functional ischemia—in one prospective study, only 1 of 26 patients (4%) with identified bridges showed ischemia on stress testing 3
The long-term prognosis of isolated myocardial bridges appears to be excellent in most cases, though rare cases may cause ventricular tachyarrhythmias and sudden cardiac death 1