Clinical Study of Myocardial Bridge

ABSTRACT

BACKGROUND AND OBJECTIVES: Myocardial bridge is congenital coronary anomaly and cause myocardial ischemia by milking effect. The general study of myocardial bridge is to be weak, so we examined a clinical study of myocardial bridge. MATERIALS AND METHOD: This study included 36 bridge cases out of 1048 patients who underwent coronary angiography due to chest pain from Jan. 1993 to Jul. 1998. Angiographic film, medical records and interview by telephone were reviewed retrospectively. Total follow-up duration was mean 27 months (1 month to 62 months). RESULTS: Incidence of myocardial bridges diagnosed by angiography was 3.4%. Angiography showed normal in 32, 1 vessel disease in 3 and 2 vessel disease in one patient. Mean reference diameter was 2.97+/-0.36mm, bridge diameter was 2.75+/-0.33mm in diastole, 1.12+/-0.47mm in systole. Myocardial bridge length was 12.50+/-7.44mm, mean % diameter stenosis was 59.26+/-17.7%. Myocardial bridge location was 80.6% in mid LAD and 13.9% in mid & distal LAD and 5.5% in distal LAD. There was no statistically significant correlation with sex, risk factor of coronary heart disease, resting electrocardigraphy, treadmill test, diameter and angulation of coronary artery, clinical symptom in the severity of myocardial bridge. But the severity of myocardial bridge correlated with bridge length(r=.5033). CONCLUSION: Clinical outcomes of bridge patients were relatively good during the mean follow up periods of 27 months. Myocardial bridge was more severe in younger age and longer bridge length.