The relationship between CTA performances and cardiac function indicators in myocardial bridge and mural coronary artery.

OBJECTIVE: To investigate the relationship between computed tomography angiography (CTA) performances and cardiac function indicators in patients with myocardial bridge and mural coronary artery (MB-MCA). METHODS: The clinical data of 60 patients with MB-MCA receiving CTA in the First Hospital of Zhangjiakou from January 2021 to February 2022 were analyzed retrospectively. The patients were divided into different groups based on CTA performances, including the degree of stenosis of the left anterior descending (LAD) MCA, whether there was atherosclerosis in the anterior segment of MB of LAD branch, the MB thickness, and the degree of stenosis of the LAD branch. The correlation between these TCA performances and cardiac function indicators including end-systolic volume (ESV), end-diastolic volume (EDV), stroke volume (SV), cardiac output (CO), and left ventricular ejection fraction (LVEF) was analyzed. Besides, the receiver operating characteristic (ROC) curve was used to analyze the predictive performance of cardiac function indicators for the severity of MB-MCA. RESULTS: ESV, EDV, SV, CO and LVEF were statistically different between the moderate stenosis group and mild stenosis group (all P < 0.05). EDV, SV, CO, and LVEF were statistically different between the atherosclerosis group and non-atherosclerosis group (all P < 0.05). SV, CO, LVEF in the deep group were lower than that in the superficial group (all P < 0.05). EDV, CO, LVEF were different between the LAD moderate stenosis group and LAD mild stenosis group (all P < 0.05). The AUC (areas under the curve) of combined detection of ESV, EDV, SV, CO, and LVEF in predicting the severity of MB-MCA was 0.907, which was higher than the single indicator predictive effect. CONCLUSIONS: Cardiac function indicators, mainly CO and LVEF are correlated with the CTA performance of MB-MCA patients. The combination of cardiac function indicators has a good effect in predicting the severity of MB-MCA.

Diagnostic value of myocardial bridge-mural coronary artery vascular morphology based on CTA technique.

OBJECTIVE: To investigate the diagnostic value of coronary CT angiography (CTA) technique on the vascular morphology of the myocardial bridge-mural coronary artery (MB-MCA). METHODS: In this retrospective study, 180 patients with suspected MB-MCA attending Hebei Huaao Hospital from February 2019 to February 2020 were analyzed. The image quality, myocardial bridge distribution, type, length, and degree of stenosis of wall coronary vessels were compared between CTA and Coronary angiography (CAG). The area under the curve (AUC) was used to analyze the diagnostic efficiency of CTA. RESULTS: There was no difference in the excellent CTA image quality rate between the two methods (P > 0.05). The mean length of myocardial bridges measured by CTA was greater than that measured by CAG (P < 0.05), while the mean degree of stenosis measured by CTA was lower than that measured by CAG (P < 0.05). The Kappa value of CTA for determining MB-MCA stenosis versus CAG results was 0.831 (P < 0.05); The Kappa value of CTA for determining MB-MCA versus CAG results was 0.895 (P < 0.05). The receiver operating characteristic (ROC) curve analysis showed that the AUC was 92.41, sensitivity was 98.73%, and specificity was 92.47% (P < 0.05). CONCLUSIONS: CTA showed good distribution and length of myocardial bridges, high accuracy for MB-MCA assessment and diagnosis, and good agreement with the gold standard CAG diagnosis.

Development of an in vitro Loading Device for Circumferential Stress of Mural Coronary Arteries / 医用生物力学

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.

Myocardial bridge-related coronary heart disease: Independent influencing factors and their predicting value.

BACKGROUND: Myocardial bridge (MB) will compress the mural coronary artery (MCA) during the systole and cause myocardial ischemia. In the diagnosis of coronary heart disease (CHD), because the structure of MB is difficult to be observed by coronary angiography (CAG), the clinical study of the influence of MB on CHD is lacking. With the advancement of computed tomography coronary angiography technology, detailed observations of the MB anatomy have realized. AIM: To explore the main influencing factors of MB-related CHD and to find potential indicators for predicting MB-related CHD. METHODS: A total of 1718 patients with suspected CHD due to the symptoms of myocardial ischemia were enrolled as subjects. Patients diagnosed with CHD were included in a CHD group, and patients with no significant abnormalities were included in a control group. In the CHD group, patients were divided into an MB-CHD subgroup if MB-related CHD was found. In the control group, patients were divided into a simple MB subgroup if MB was found. The patient's clinical data and MB-related indicators, including the branch of MB, MB type (superficial/deep type), MB length, MB thickness, systolic and diastolic compression of the MCA, and MCA systolic stenosis rate were recorded and compared. Logistic regression analysis was used to explore the independent influencing factors of MD-related CHD. ROC curve was used to analyze the diagnostic efficacy of potential indicators for MB-related CHD. RESULTS: There were 1060 cases in the CHD group and 658 cases in the control group, and there were 236 cases in the MB-CHD subgroup and 52 cases in the simple MB subgroup. Multivariate logistic regression analysis showed that the combined MB had a significant effect on the occurrence of CHD (P < 0.05). MB thickness, systolic compression, diastolic compression, and MCA systolic stenosis rate had significant effects on the occurrence of MB-related CHD (P < 0.05). The area under the curve (AUC) of the combination of these influencing factors for the diagnosis of MB-related CHD was 0.959, which was significantly higher than the AUCs of the four indicators separately (P < 0.05). The sensitivity was 97.06% and the specificity was 87.63%. CONCLUSION: MB thickness, systolic compression, diastolic compression, and MCA systolic stenosis are independent influencing factors for MB-related CHD. The combination of these factors has potential diagnostic value for MB-related CHD.

Features of myocardial bridge based on computed tomography angiography / 第二军医大学学报

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.

Estimation of shear stress by using a myocardial bridge-mural coronary artery simulating device.

BACKGROUND: This study was aimed at developing a myocardial bridge-mural coronary artery simulative device and analyzing the relationship between shear stress on the mural coronary artery and atherosclerosis. METHODS: A myocardial bridge-mural coronary artery simulative device was used to simulate experiments in vitro. In the condition of maintaining any related parameters such as system temperature, average flow rate, and heart rate, we calculated and observed changes in proximal and distal mean values, and oscillatory value of shear stress on the mural coronary artery by regulating the compression level of the myocardial bridge to the mural coronary artery. RESULTS: Under 0% compression, no significant differences were observed in distal and proximal mean values and oscillatory value of the shear stress on the mural coronary artery. With the increase in the degree of compression, the mean shear stress at the distal end was greater than that at the proximal end, but the oscillatory value of the shear stress at the proximal end was greater than that at the distal end. CONCLUSIONS: The experimental results of this study indicate that myocardial bridge compression leads to abnormal hemodynamics at the proximal end of the mural coronary artery. This abnormal phenomenon is of great significance in the study of atherosclerosis hemodynamic pathogenesis, which has potential clinical value for pathological effects and treatments of myocardial bridge.

CTA features of pure myocardial bridge on the patients without symptom / 实用放射学杂志

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.

Imaging findings of the myocardial bridge-mural coronary artery with 256-slice coronary CT angiography / 实用放射学杂志

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.

In vitro simulation on haemodynamics of mural coronary artery / 医用生物力学

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.

The diagnostic value of 64-row spiral CT coronary angiography on myocardial bridge and mural coronary artery / 重庆医学

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 .

Comparative research with MSCT and CAG in the myocardial bridge-wall diagnostic coronary angiography / 中国医学装备

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.

Clinical value of the correlations of mural coronary artery compression extent with myocardial bridge length and thickness evaluated by 128-slice CT.

This study aimed to investigate the correlations between the detection rate of mural coronary artery (MCA) by 128-slice CT and the MCA compression extent in systole with myocardial bridge (MB) length and thickness. A retrospective analysis was conducted for 580 patients receiving multislicespiral CT coronary angiography (MSCTCA). In addition, the MCA incidence rate and position were detected, and the MB length and thickness in the left anterior descending branch (LAD) and MCA compression extent in systole were measured to compare the differences between MB-MCA length and thickness among the mild, moderate and severe groups. A total of 140 cases of MB-MCA (24.14%) were involved in the study. Among them, 104 cases occurred in the middle segment of the LAD (74.3%), 16 cases (11.4%) occurred in the distal segment of the LAD, 8 cases (5.7%) occurred in the left circumflex-obtuse marginal branch (LCX-OM), 7 cases (5.0%) occurred in the first diagonal branch (1st D), 3 cases (2.1%) in the intermediate branch (M) and 2 cases (1.5%) occurred in the posterior descending branch of the right coronary artery (RCA-PD). The mean length of the MB in the LAD was 21.80±5.98 mm, the mean thickness was 2.15±0.74 mm and the mean compression extent was 38.5±19.6%. Among the different groups, there were no significant difference in MB length (P>0.05) but there were significant differences in MB thickness (P<0.05). In addition, the extent of MCA compression in systole was linearly and positively correlated with MB thickness (r=0.408, P<0.05) but was not correlated with MB length (r=0.076, P>0.05). 128-slice CT coronary angiography (SCTCA) is able to accurately detect MB-MCA and evaluate the correlations of MCA compression extent in systole with MB length and thickness which provides a basis for its clinical use.