Myocardial bridging of the left anterior descending coronary artery in acute inferior wall myocardial

Background: We observed marked myocardial bridging of the left anterior des cending coronary artery (LAD) in the acute stages of inferior wall myocardi al infarction (MI) in a group of patients who developed shock despite succe ssful reperfusion of the infarct-related lesion (IRL). Hypothesis: The purpose of this study was to elucidate the clinical signifi cance of myocardial bridging in patients with inferior wall MI and shock. Methods: The study group consisted of 53 patients with single-vessel diseas e of the right coronary artery, who underwent coronary angiography for acut e inferior wall MI. Clinical characteristics, coronary angiographic finding s, and left ventricular function during the chronic phase were compared bet ween the patients who developed shock (the shock group) and those who did n ot (the non-shock group). In addition, a multiple logistic analysis was per formed to identify independent predictors of shock in patients with acute i nferior wall MI. Results: Reperfusion of the IRL was obtained in all 53 patients. The incide nce of myocardial bridging of the LAD, the incidence of right ventricular M l, the peak creatine phosphokinase (CPK-MB), the pulmonary capillary wedge pressure, and the prevalence of pulmonary congestion seen on chest roentgen ogram were significantly higher in the shock group than in the non-shock gr oup. Myocardial bridging (p = 0.0018), right ventricular MI (p = 0.0374), a nd peak CPK-MB (p = 0.0189) were identified as independent predictors of sh ock in acute inferior wall MI. Conclusion: This study suggests that myocardial bridging plays a role in le ft ventricular function in the acute stage of inferior wall MI.