[Myocardial bridging. The role of microcirculation, coronary reserve and systolic endothelial injury].

BACKGROUND

The relationship between myocardial bridging (MB) and ischemic heart disease is still controversial. However, a recent new evidence suggests that this relation is not by chance.

PURPOSE: The purpose of our study was to review in a critical manner, the evidence for the relationship between MB and myocardial ischemia and its possible consequences.

METHODS

We present 2 cases of our series and review the medical literature from January 1966 to January 1998 published and included in Medline and Current Contents.

RESULTS AND

CONCLUSIONS

The principal findings after this review were: 1) MB is not a normal variant; 2) The clinical impact of MB depends on its anatomical extension and degree of compressive effect; 3) The MB muscle is not similar to myocytes from other cardiac areas; 4) The environment surrounding coronary artery may be a crucial factor in determining whether the MB influences the induction of heart disorders or not; 5) The overshoot due to compressive effect on coronary artery might determine endothelial injury in the microcirculation post-MB; 6) In some cases, the systolic endothelial injury may contribute to release factors that are able to reduce the coronary reserve, resulting in myocardial ischemia; 7) The possible role of PTCA in this disorder still has to be proven. Surgical treatment should be considered when important myocardial ischemia had been demonstrated, even in those asymptomatic cases.