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Objective To design and develop an in vitro simulation device for circumferential stress of mural coronary artery, so as to achieve the in vitro loading of mural circumferential stress under coronary myocardial bridge oppression with different degrees. MethodsUsing the in vitro simulation device for myocardial bridge coronary artery hemodynamics, the in vitro measurement of mural circumferential stress was achieved. Based on the experimental data, the in vitro loading of mural circumferential stress under coronary myocardial bridge oppression with different degrees was achieved. Results The in vitro measurement experiment showed that the maximum, average and fluctuation of circumferential stress at proximal end of mural coronary artery would increase significantly with the increase in the degree of myocardial bridge oppression. The in vitro loading experiment of mural circumferential stress verified that the loading waveform coincided basically with the experimental waveform from in vitro measurement. Conclusions The device could realize the in vitro loading of mural circumferential stress, which provided an in vitro simulation platform which was as close as possible to the in vivo environment, so as to explore the influence from hemodynamic abnormality of proximal mural coronary artery on the occurrence of atherosclerosis and plaque rupture.
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Objective To analyze the pathological and anatomic features of myocardial bridge (MB) using coronary computed tomography angiography (CTA), so as to deepen the understanding of MB. Methods The data of 1 658 patients with MB diagnosed by coronary CTA were retrospectively analyzed. The distribution of MB in the coronary system were analyzed, the length of mural coronary artery (MCA) and average systolic stenosis rate of different types of MB were measured, and the anatomic morphological differences of different types of MB were statistically analyzed. Results Among the 1 658 patients, 1 606 (98.86%) were single MB in single coronary artery, 9 (0.54%) were multiple MB in single coronary artery, and 43 (2.60%) were single MB in different coronary arteries. A total of 1 606 MB lesions in 1 559 cases (94.03%) were located at the left anterior descending (LAD) coronary artery, 87 MB lesions in 81 cases (4.88%) at the left circumflex (LCX) coronary artery, and 19 MB lesions in 18 cases (1.09%) at the right coronary artery (RCA). There were 1 244 cases (75.03%) of incomplete MB, 362 cases (21.83%) of complete MB, and 52 cases (3.14%) of complex MB with the features of both types. The length of MCA in the complex MB was significantly longer than that of the complete MB ([24.32±4.02] mm vs [16.13±1.27] mm, P50% (31.19% [388/1 244] vs 41.16% [149/362]), incidence of proximal coronary artery disease (9.41% [117/1 244] vs 35.08% [127/362]), positive rate of ischemic symptom (32.88% [409/1 244] vs 58.29% [211/362]), and positive rate of ischemic electrocardiogram (37.78% [470/1 244] vs 65.75% [238/362]) of the incomplete MB were significantly lower than those of the complete MB (all P<0.05). Conclusion MB lesions mainly locate at LAD coronary artery and are single MB in single coronary artery. MB-MCA morphology can be divided into complete, incomplete and complex types by coronary CTA, with incomplete type being the main type, and each type of MB has different clinical and morphological features.
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Objective To analyze the CTA features of asymptomatic myocardial bridge.Methods The CTA images of 69 cases with asymptomatic solitary myocardial bridge were studied retrospectively, and CTA images of 60 cases with symptoms as the contrast group.The type, age, thickness of myocardial bridge, mural coronary artery length and diameter changes of each cases of two groups were analyzed.Results In the study group, 51 cases of 69 (74%) were superficial style, while 18 cases were deep type (26%).In the contrast group, the superficial and deep style were 13 (22%) and 47 (78%) respectively.The mean age,thickness of myocardial bridge,mural coronary artery length and the diameter of mural coronary artery were (53.01±11.17) years old,(1.25±1.16) mm,(21.33±7.32) mm,(2.86±0.45) mm and (51.36±9.31) years old,(1.45±1.87) mm,(20.07±6.60) mm and (1.37±0.41) mm.The rate of type and diameter of mural coronary artery had significant differences between two groups (P0.05).Conclusion The CTA features of asymptomatic myocardial bridge are mostly superficial type.The diameter of mural coronary artery on the end systolic is a factor to judge the rate on the occurrence of clinical symptom.
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Objective To study the imaging findings of myocardial bridge-mural coronary artery (MBMCA)using 256-slice coronary CT angiography (CTA).Methods 335 patients with MBMCA were diagnosed in our hospital,189 of whom with complete data were collected.The image findings of the MBMCA on 256-slice coronary CTA were reviewed,and the related measurements were done by two independent radiologists.A statistical software (SPSS13.0)was used and P <0.05 was regarded as significant difference.Results The incidence of MBMCA was 8.1 1% on 256-slice coronary CTA.Most MBMCAs were seen in the left anterior descending artery (LAD)(79.59%)with mean length of (23.24±10.32)mm.The mean diameter of MBMCA was (2.21±0.73)mm on later systol phase and (2.35±0.76)mm on later distol phase (t=3.140,P =0.005).The thickness of myocardial bridge was (1.44 ±1.31)mm.The average area change from systol phase to distole phase was decreased by 24.62% on retrospective electrocardiogating coronary CTA. Among the 189 patients,only MBMCA was diagnosed in 100,and MBMCA in combination with coronary atherosclerosis was in 89. The MBMCA and coronary atherosclerosis were found in the same artery in 74.Conclusion Myocardial bridge-mural coronary artery is a poten-tial heart disease because of artery abnormality.Coronary CT angiography palys an important role in diagnosis of this disease.
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Objective:To comparative Research with MSCT and CAG in the myocardial bridge-wall diagnostic coronary. Methods: Selected 93 patients for the study in January 2011 to the end of December 2013,MB-MCA patients diagnosed in Beijing North Hospital, all patients underwent catheter coronary angiography (CAG) and 64-slice spiral CT (MSCT), comparison of the diagnostic accuracy of the two inspection methods, and the results of the correlation analysis, results processing and analysis using statistical software SPSS17.0. Results:MSCT and CAG were two examination methods in the diagnosis of superficial and deep type MB-MCA, with a high degree of consistency in the diagnosis of MB-MCA average length, average depth comparison with statistical significance(t=3.021, t=3.758;P<0.05), there was not statistically significant comparison in the narrow detection rate. Conclusion:MSCT as a novel, non-invasive means of MB-MCA examination, the diagnosis results are reliable, accurate and capable of providing a richer diagnostic information for clinicians, clinician and patient can be widely applied.
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Objective To evaluate the application value of 64-row spiral CT coronary angiography(CAG)in myocardial bridge (MB)and mural coronary artery(MCA) .Methods Imaging data of 436 consecutive subjects underwent coronary CT angiography in Hospital of Beijing Puren were enrolled in this study .The prevalence ,clinical effects of patients ,precise location and incidence of each branch were evaluated .In addition ,the length and depth of MB ,as well as their relationship with MCA in stenosis were evalua-ted .Moreover ,the group of subjects with MB was compared with the control group(subjects without MB)in the probability of ath-erosclerosis .Results Among the total of 436 subjects ,76 subjects(17 .4% ,76/436)were found to have MB .The left anterior de-scending artery(LAD)was the most common coronary artery involved(68 .4% ,52/76) .The pressure level of MCA associated with the length and depth of MB .A significant difference was found between the LAD-MB-MCA group and the control group in the presence of coronary artery plaques(P<0 .05) .Conclusion The anatomic relation between MB and MCA can be precisely displayed on 64-row spiral CT coronary angiography ,which is considered to be an excellent diagnostic method to screen MB-MCA initially . There is a relationship between stenosis of MCA and the length and depth of MB .The present and stenosis of MB-MCA are meant to form coronary artery plaques in LAD segment more easily .
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Objective To study the effect of myocardial bridge oppression on blood flow, positive pressure, circumferential stress and shear stress of the coronary artery. Methods The original myocardial bridge simulative device was greatly improved to be able to measure multi-hemodynamic parameters, such as normal stress, circumferential stress and shear stress, so as to exactly simulate real blood dynamics environment with the common effect of several stresses, and comprehensively investigate the relationship between hemodynamics and atherosclerosis of mural coronary artery under the combined effects of several stresses. Results The results from the myocardial bridge simulative device indicated that the hemodynamic abnormalities were mainly located in the proximal end of mural coronary artery, and the mean and oscillation values of normal stress at the proximal end were increased by 27.8% and 139%, respectively, showing a significant increase with the intensification of myocardial bridge oppression. Conclusions It is myocardial oppression that causes the hemodynamic abnormity of proximal coronary artery, which is quite important for understanding the hemodynamic mechanism of coronary atherosclerotic diseases and valuable for studying pathological effects and treatments of the myocardial bridge in clinic.