Prevalence and characteristics of myocardial bridge in patients undergoing percutaneous coronary angiography - Nguyễn Văn Tuấn

Prevalence and characteristics of myocardial 
bridge in patients undergoing percutaneous 
coronary angiography 
BS Nguyễn Văn Tuấn - BVQY 103 
INTRODUCTION 
Myocardial bridge (MB): a muscle bridge over a segment of 
the coronary arteries that leads to narrowing of coronary artery 
Systolic Diastolic 
INTRODUCTION 
 Prevalence: 
• Autopsy: 5,4% ~ 85,7%* 
• Angiography: 0,5% ~ 16% 
 Clinical significance: 
* Jorge R. Alegria (2005): Myocardial bridging, European Heart Journal 26, 1159-1168. 
INTRODUCTION 
INTRODUCTION 
INTRODUCTION 
 Treatment of symptomatic patients: 
• Negative inotropic and/or negative chronotropic agents: Beta-
blocker, calcium antagonists. 
OBJECTIVE 
To investigate the prevalence, clinical and 
paraclinical characteristics of myocardial bridge 
in patients undergoing PCA 
SUBJECTS AND METHODS 
 SUBJECTS 
 1386 patients underwent PCA in Department of 
Cardiology, Military Hospital 103 from 1/2013 to 3/2016 
 METHODS 
• Descriptive, cross – sectional. 
• Clinical and paraclinical examination 
• Percutaneous coronary angiography (PCA) 
SUBJECTS AND METHODS 
• Diagnosis of MB: Systolic compression of the artery 
with narrowing of the lumen and diastolic relaxation. 
• Grading of angina pectoris: Canadian Cardiovascular 
Society (CCS) (1976) 
• Assessment of coronary artery stenosis * 
 Mild: < 50% 
 Moderate: 50 – 74% 
 Severe: ≥ 75% 
 *Kern MJ (2013), “The interventional cardiac catheterization handbook third edition”. 
RESULTS 
1291 pts 
(93.2%) 
95 pts (6.8%) 
Chart 1. Myocardial bridge prevalence 
no MB
MB
. John R. Kramer (1982): 12% (PCA) 
. Atar E (2007): 17% (MSCT) 
. Lazoura O (2010): 21% (MSCT) 
RESULTS 
Table 1. General characteristic of participants (n = 95) 
Variable X ± SD or n (%) 
Age (year) 61.85 ± 12.45 
Male 77 (81.1%) 
Concomitant 
diseases 
Hypertension 55 (57.9%) 
Type 2 Diabetes 
Mellitus 
13 (13.7%) 
Stable ischemic 
heart disease 
 14 (14.73%) 
RESULTS 
Table 2. Grading of angina pectoris according to CCS (n = 81) 
CCS n (%) 
1 35 (43.2%) 
2 30 (37%) 
3 15 (18.6%) 
4 1 (1.2%) 
Total 81 (100%) 
RESULTS 
Table 3. ECG characteristic (n = 81) 
Variable X ± SD or n (%) 
ECG 
Normal 61 (75.3%) 
ST depression, T (-) 12 (14.8%) 
ST elevation 8 (9.9%) 
Li Wan (2005): Abnormal ECG occurred in 10% patients. 
RESULTS 
Table 4. Echocardiography characteristic (n = 81) 
Variable X ± SD or n (%) 
Echocardiography 
LVDd (mm) 46.74 ± 5.98 
LVDs (mm) 29.95 ± 6.38 
EF (%) 63.76 ± 10.50 
Regional wall dyskinesia 6 (7.4%) 
LV dilatation 17 (20.9%) 
RESULTS 
Chart 2. MB locations (n = 81) 
3.60% 
60.30% 
30.10% 
2.40% 
1.20% 
2.40% 
LAD1
LAD2
LAD3
LCX
RCA
OTHERS
Atar E (2007): 60% MB in LAD 
Lazoura O (2010): 100% MB in LAD, 68% in LAD2 
RESULTS 
 Table 5. The degree of systolic coronary stenosis caused by MB (n = 81) 
Degree n (%) 
Mild (< 50%) 52 (64.19%) 
Moderate (50-74%) 20 (24.69%) 
Severe 
75-89% 4 (4.95%) 
≥ 90% 5 (6.17%) 
Total 81 (100%) 
RESULTS 
Table 6. The relation between angina and coronary artery stenosis degree 
(n = 81) 
Mild and 
Moderate 
stenosis (n(%)) 
Severe stenosis 
(n(%)) 
p 
CCS 1-2 58 (71.6%) 7 (8.6%) 
> 0.05 
CCS 3-4 14 (17.3%) 2 (2.5%) 
CONCLUSION 
 The prevalence of MB is 6.8% of patients 
undergoing percutaneous coronary angiography. 
 Most of MB was found in LAD 
 There was no relation between angina and 
coronary artery stenosis degree