Electrocardiography ; Humans ; Male ; Middle Aged ; Myocardial Bridging ; complications ; Myocardial Infarction ; etiology ; Myocardium ; pathology

Atherosclerosis ; etiology ; pathology ; Coronary Angiography ; Humans ; Myocardial Bridging ; diagnosis ; epidemiology ; physiopathology

BACKGROUNDLarge discrepancy of the incidence of myocardial bridging (MB) has been reported either among the postmortem studies or among the studies with coronary angiogram. This study was to investigate the prevalence of MB in large number of coronary angiograms and the angiographic characteristics of MB.

METHODSA total of 5525 consecutive patients who underwent first diagnostic coronary angiography from January 2003 to March 2006 in Zhongshan Hospital were enrolled in this study. MB was diagnosed when the angiographical "milking effect", defined as the systolic compression and complete or partly release of the compression in diastole, was seen in the epicardial coronary arteries. Angiography was routinely repeated after intracoronary injection of 200 microg nitroglycerin. The systolic compression and length of MB were compared before and after the administration of nitroglycerin and also before and after stent implantation in patients with significant stenosis in segment proximal to the MB.

RESULTSAmong 5525 patients, MBs were found in a total of 888 patients angiographically with the prevalence of 16.1%. Atherosclerotic lesions were found more often in the segment proximal to the MB with 344/854 (40.3%) patients than in the segment distal to the MB with 47/854 (5.5%) (P < 0.01). The systolic compression ((43.3 +/- 13.7)% at baseline vs (54.2 +/- 14.0)% after nitroglycerine) and the average length ((20.9 +/- 7.5) mm at baseline vs (22.7 +/- 8.0) mm after nitroglycerine) of the MB segment were increased after intracoronary injection of nitroglycerin (both P < 0.01). Stent implantation was performed in 88 patients with significant stenosis in the segment proximal to the MB. The systolic compression and the length of the MB segment were increased after stenting compared with those before stenting (systolic compression, (49.4 +/- 14.6)% at baseline vs (57.3 +/- 12.3)% after stenting, and length of MB, (19.5 +/- 6.1) mm at baseline vs (21.8 +/- 6.3) mm after stenting, P < 0.01).

CONCLUSIONSMB was a frequent finding in coronary angiogram with an incidence of 16.1%. Intracoronary administration of nitroglycerin and stent implantation in the segment proximal to the MB could enhance the systolic compression and the length of the MB angiographically.

Aged ; Coronary Angiography ; methods ; Female ; Humans ; Male ; Middle Aged ; Myocardial Bridging ; diagnosis ; pathology ; Retrospective Studies

OBJECTIVETo investigate whether myocardial bridging (MB) is an independent risk factor for coronary atherosclerosis proximal to the bridge site in the left anterior descending coronary artery (LAD) in diabetic patients.

METHODSFrom March 2011 to December 2012, 9862 patients with suspected coronary disease underwent coronary computed tomography angiography (CCTA) using a dual-source CT scanner. The baseline clinical characteristics (age, gender, smoking history, presence of hypertension, dyslipidemia, diabetes mellitus, family history of heart attack and body mass index) and the results of CCTA were reviewed. Two radiologists evaluated the MB and coronary atherosclerosis stenosis (CAS) over 50% in the LAD and made a diagnosis by consensus. Significant independent risk factors for CAS were investigated by logistic regression analysis.

RESULTSOf the 2345 patients identified to have diabetes mellitus, 1373 had MB, among whom 827 had coronary atherosclerosis proximal to the bridge site; 972 of the diabetic patients were free of MB, among whom 254 had coronary atherosclerosis at the equivalent site. None of the patients had CAS in the tunneled segment. After adjusted for clinical data, logistic regression analysis showed that MB in the LAD was significantly correlated with coronary atherosclerosis in the proximal LAD in diabetic patient (OR=3.91) and non-diabetic patients (OR=2.69) (P<0.05).

CONCLUSIONIn diabetic patients, atherosclerosis occurred frequently in the segment proximal to MB in the LAD, and MB in the mid-LAD is an independent risk factor for CAS in the proximal LAD.

Angiography ; Atherosclerosis ; Coronary Artery Disease ; Coronary Stenosis ; Diabetes Mellitus ; Humans ; Myocardial Bridging ; Myocardium ; pathology ; Risk Factors

OBJECTIVETo explore the imaging and clinical characteristics and related risk factors of patients with coronary artery stenosis located proximally to myocardial bridging.

METHODSThis study enrolled 603 patients with angiography evidenced myocardial bridging-mural coronary artery between May 2004 to May 2009. Angiographic and clinic data were collected according to uniform protocol and standard questionnaires were used to obtain patients' demographic and clinical information. Univariate and multivariate analysis were performed to explore related risk factors.

RESULTSChest pain was present in 247 cases (41.0%). Dynamic ST-T changes were found in 229 cases (38%). A total of 644 myocardial bridging-mural coronary arteries were detected including 382 (62.4%) segments located proximally to myocardial bridging. Diastolic vessel diameters in the myocardial bridging segment were significantly smaller than reference segments (all P < 0.01). Stepwise multiple regression analysis suggested that vascular bifurcation lesions, the degree of narrowing and the number of diseased coronary vessels of non- myocardial bridging-mural coronary arteries, age, LDL-C/HDL-C, male gender, diabetes, and systolic narrow rate of myocardial bridging-mural coronary arteries were positively related with the narrowing degree of the first coronary artery stenosis located proximally to myocardial bridging (P < 0.05 or P < 0.01). Vascular bifurcation lesions, the degree of narrowing and the number of diseased coronary vessels of non- myocardial bridging-mural coronary arteries, age, LDL-C/HDL-C, male, diabetes and dyslipidemia were positively related with the narrowing degree of the most severe coronary artery stenosis located proximally to myocardial bridging (P < 0.05 or P < 0.01).

CONCLUSIONSMyocardial ischemia is common in patients with myocardial bridging and the artery segments located proximally to myocardial bridging are prone to stenosis. Systolic narrow rate of myocardial bridging-mural coronary arteries is one of major determinants of coronary artery stenosis located proximally to myocardial bridging. Whereas the other coronary heart disease risk factors are likely to play more important roles.

Aged ; Coronary Angiography ; Coronary Stenosis ; diagnostic imaging ; pathology ; Female ; Humans ; Male ; Middle Aged ; Myocardial Bridging ; diagnostic imaging ; pathology ; Risk Factors

Objective To analyze the correlation between tortuosity and stenosis in patients with myocardial bridge(MB)on the left anterior descending artery(LAD). Methods Data of patients with MB on the LAD,which was discovered by coronary computed tomography angiography(CCTA),in the Affiliated Hospital of North China University of Science and Technology from October 2015 to December 2018 were retrospectively analyzed.Among them 278 patients with tortuosity on LAD and 278 patients without tortuosity were selected.The clinical charateristics(age,gender,hypertension,hyperlipidemia,diabetes,smoking history,and family history)as well as the incidence and severity of stenosis of LAD were recorded and compared. Results The incidence of coronary artery stenosis in the non-tortuosity group(57.6%)was significantly lower than that in the tortuosity group(71.9%)($\bar{χ}$=12.608,
China ; Constriction, Pathologic ; Coronary Angiography ; Coronary Stenosis/epidemiology* ; Coronary Vessels/diagnostic imaging* ; Humans ; Myocardial Bridging/pathology* ; Retrospective Studies