ABSTRACT
SUMMARY: Myocardial bridges are inborn anomalies frequently found in authopsies. Although tipically clinically silent, they are occasionally associated with severe clinical manifestations, e.g. myocardial ischemia or even sudden death. The pathophysiology and risk factors for these manifestations have not yet been completely elucidated. The connective tissue underneath the bridge has been considered as one of the factors the symptoms depend on. Thus, the aim of this research was to determine the histological characteristics of the connective tissue lying underneath the myocardial bridge and to contribute to a better understanding of the protective effects this passive compartment might have in prevention of severe clinical manifestations of myocardial bridging. The study was carried out on twenty hearts with myocardial bridges. Length of the bridge was determined using a precise electronic caliper. Sections of the myocardial bridges with the underlying connective tissue were obtained and prepared for qualitative and quantitative analysis. The connective tissue underneath the bridges was composed of adipose tissue and loose connective tissue in different ratios. The tissue underneath thin bridges was predominantly composed of adipose tissue, while loose connective tissue was the dominant component under thick bridges. The myocardial bridges had an average thickness of 0,98 ± 0.44 mm and an average length of 15,25±5,65 mm. We found a strong positive correlation between the myocardial bridge thickness and length (r = 0,860, p = 0,0001). The thickness of the passive connective tissue compartment under the myocardial bridges was 0,58±0,22 mm, and there was no correlation between this parameter and the myocardial bridge thickness (r = -0,011; p = 0,963). In the clinical evaluation of patients with these anomalies it is necessary to take into account independently the myocardial bridge thickness and length on one side and the thickness of the connective tissue lying underneath it on the other.
Los puentes miocárdicos son anomalías congénitas que se encuentran con frecuencia en las autopsias. Aunque típicamente éstos son clínicamente silenciosos, ocasionalmente se asocian con manifestaciones clínicas graves, como isquemia miocárdica o incluso muerte súbita. La fisiopatología y los factores de riesgo de estas manifestaciones aún no se han dilucidado por completo. El tejido conectivo debajo del puente se ha considerado como uno de los factores de los que dependen los síntomas. Por lo tanto, el objetivo de esta investigación fue determinar las características histológicas del tejido conectivo que se encuentra debajo del puente miocárdico y contribuir a una mejor comprensión de los efectos protectores que este compartimento pasivo podría tener en la prevención de manifestaciones clínicas graves de puente miocárdico. El estudio se llevó a cabo en veinte corazones con puentes miocárdicos. La longitud del puente se determinó utilizando un calibrador electrónico preciso. Se obtuvieron secciones de los puentes miocárdicos con el tejido conjuntivo subyacente y se prepararon para análisis cualitativo y cuantitativo. El tejido conectivo debajo de los puentes estaba compuesto de tejido adiposo y tejido conectivo laxo en diferentes proporciones. El tejido debajo de los puentes delgados estaba predominantemente compuesto de tejido adiposo, mientras que el tejido conectivo laxo era el componente dominante debajo de los puentes gruesos. Los puentes de miocardio tenían un espesor promedio de 0,98 ± 0,44 mm y una longitud promedio de 15,25 ± 5,65 mm. Encontramos una fuerte correlación positiva entre el grosor y la longitud del puente miocárdico (r = 0,860, p = 0,0001). El grosor del compartimiento de tejido conectivo pasivo debajo de los puentes miocárdicos era de 0,58±0,22 mm, y no hubo correlación entre este parámetro y el grosor del puente miocárdico (r = -0,011; p = 0,963). En la evaluación clínica de pacientes con estas anomalías es necesario tener en consideración de forma independiente el grosor y la longitud del puente de miocardio por un lado y el grosor del tejido conectivo que se encuentra debajo del mismo por el otro.
Subject(s)
Humans , Connective Tissue/anatomy & histology , Myocardial Bridging/pathology , Adipose Tissue/anatomy & histology , Adventitia/anatomy & histologyABSTRACT
SUMMARY: Most histopathological studies have reported that the segment of the coronary artery below the myocardial bridge does not present atheromatous plaque, while the segment proximal to the myocardial bridge may have it. The aim of this study was to evaluate the microscopic environment of myocardial bridges. This descriptive study was carried out with 60 hearts of individuals who underwent autopsy at the National Institute of Legal Medicine and Forensic Sciences in Bucaramanga-Colombia. For each specimen, the coronary arteries and their branches were dissected, removing the subepicardial adipose tissue to identify the myocardial bridges and obtain histological sections of the compromised arterial branches. The presence of myocardial bridges was observed in 22 hearts (36.7%) with a length of 17.31 + 4.41 mm and a thickness of 904.57 + 312.27 mm. The coronary vessel caliber at the prepontine level was 246.57 + 49.33 mm and was significantly higher than in the pontine (188.92 + 60.55 mm) and postpontin (190.40 + 47 mm) segments (p=0.001 for both values). Atheromatous plaque was observed in the prepontine segment in 12 cases (46.15 %) and in 8 samples (30.76%) at the pontine level, but in this segment, there was slight damage to the vascular endothelium, or phase I level. The thickness of the tunica intima in the cases with atheromatous plaque was 15.68 + 13.39 mm and that of the plaque-free segments was 5.10 + 4.40 mm (p=0.005), and in the pontine segment the overlying periarterial adipose tissue had a thickness of 72.01 + 69.44 mm, which was higher than the other three locations (p=0.005). The morphometry of the perivascular fat pad and the presence of phase I atheromatous plaque are the main contributions of this study to the histology of myocardial bridges.
RESUMEN: La mayoría de los estudios histopatológicos han reportado que el segmento de la arteria coronaria debajo del puente miocárdico no presenta placa ateromatosa, mientras que el segmento proximal al puente miocárdico puede tenerla. El objetivo de este estudio fue evaluar el entorno microscópico de los puentes miocárdico. Este estudio descriptivo se realizó con 60 corazones de individuos a quienes se les práctico autopsia en el Instituto Nacional de Medicina Legal y Ciencias Forenses de Bucaramanga-Colombia. Para cada espécimen se realizó disección de las arterias coronarias y sus ramas, eliminando el tejido adiposo subepicárdico para identificar los puentes miocárdicos y obtener secciones histológicas de las ramas arteriales comprometidas. Se observó presencia de puentes miocárdicos en 22 corazones (36,7 %) con una longitud de 17.31 + 4.41 mm y un espesor de 904.57 + 312.27 mm. El calibre del vaso coronario a nivel prepontino fue 246.57 + 49.33 mm y fue significativamente mayor que en el segmento pontino (188.92 + 60.55 mm) y pospontino (190.40 + 47 mm) (p=0.001 para ambos valores). Se observó placa ateromatosa en el segmento prepontino en 12 casos (46.15 %) y en 8 muestras (30.76%) al nivel pontino, pero en este segmento, correspondieron a fase I, con ligero daño en el endotelio vascular. El espesor de la túnica íntima en los casos con placa ateromatosa fue de 15.68 + 13.39 mm y de los segmentos libres de placa fue 5.10 + 4.40 mm (p=0.005) y en el segmento pontino el tejido adiposo periarterial suprayacente presento un espesor de 72.01 + 69.44 mm, el cual fue mayor a las otras tres ubicaciones (p=0.005). La morfometría de la almohadilla adiposa perivascular y la presencia de placa ateromatosa en fase I son los principales aportes de este estudio a la histología de los puentes miocárdicos.
Subject(s)
Humans , Adipose Tissue/ultrastructure , Myocardial Bridging/pathology , Plaque, Atherosclerotic/ultrastructure , Cross-Sectional Studies , Tunica Intima , MicroscopyABSTRACT
Objective: To explore the relationship of epicardial adipose tissue (EAT) volume with coronary atherosclerosis and myocardial bridge (MB). Methods: Imaging data of 375 patients who underwent coronary CTA were analyzed retrospectively, including 116 cases of atherosclerosis (plaque group), 78 cases of MB (MB group), 35 cases of MB with atherosclerosis (MB+plaque group) and 146 normal ones (normal group). The volume of EAT was measured manually and compared among 4 groups. Results: EAT volume of plaque group, MB group, MB+plaque group and normal group were (110.76+37.17)cm3, (104.97+36.72)cm3, (112.02+45.32)cm3 and (91.06±34.27)cm3, respectively. EAT volume of plaque group, MB group, MB+plaque group were significantly higher than that of normal group (P=0.001, 0.031, 0.043. There was no difference among plaque group, MB group and MB+plaque group (all P>0.05). Conclusion: Patients with MB have higher EAT volume than those with normal coronary artery, presenting higher potential risk of developing coronary atherosclerosis.
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To explore the correlation between the transluminal attenuation gradient with corrected contrast opacification(TAG-CCO)and the severity of atherosclerotic stenosis in the anterior segment of myocrardial bridge(MB). The imaging data of 200 patients diagnosed with left anterior descending branch(LAD)single MB and coronary atherosclerosis in the anterior segment of MB were retrospectively analyzed.According to MB types,the patients were divided into two groups:incomplete and complete.There were some significant differences in TAG-CCO between patients with the same degree of coronary atherosclerosis(mild,moderate,and severe stenosis)in two groups.The relationships among groups with different degrees(mild,moderate,and severe stenosis)of the same type of MB were further compared. Among 84 patients with complete MB,36,30,and 18 patients had mild,moderate,or severe coronary atherosclerosis in the anterior segment of MB;among 116 patients with incomplete MB,45,42,and 29 patients had mild,moderate,or severe coronary atherosclerosis in the anterior segment of MB.In the complete MB group,the TAG-CCO in the anterior segment of MB subgroups were(-0.0086±0.0014)/10 mm,(-0.0170±0.0180)/10 mm,and(-0.0230±0.0026)/10 mm,respectively,in mild,moderate,and severe subgroups( = 404.728, <0.001).In the incomplete MB group,the TAG-CCO of patients with mild,moderate and severe coronary stenosis in the anterior segment of MB were(-0.0039±0.0011)/10 mm,(-0.0100±0.0140)/10 mm,and(-0.0160±0.0020)/10 mm,respectively,and the difference among the different stenosis groups was statistically significant( = 17.756, < 0.001);the TAG-CCO of patients with mild( = 16.519, < 0.001),moderate( = 2.570, = 0.012)and severe anterior segment coronary stenosis( = 10.714, < 0.001)were significantly lower in the complete MB group than in the incomplete MB group. TAG-CCO is correlated with the MB type and the degree of anterior coronary artery stenosis.Thus,TAG-CCO can be used as a predictive indicator for the degree of atheroscleratic stenosis in the anterior segment of MB.
Subject(s)
Humans , Atherosclerosis , Coronary Angiography , Coronary Artery Disease , Coronary Stenosis , Coronary Vessels , Retrospective StudiesABSTRACT
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,
Subject(s)
Humans , China , Constriction, Pathologic , Coronary Angiography , Coronary Stenosis/epidemiology , Coronary Vessels/diagnostic imaging , Myocardial Bridging/pathology , Retrospective StudiesABSTRACT
RESUMEN Se presenta el caso de un paciente, sin comorbilidades, que se interna por cuadro de infarto agudo de miocardio a repetición. En todas las ocasiones presentó dolor precordial típico y elevación de troponinas. En su primera cinecoronariografía no se encontraron lesiones angiográficas. Meses después vuelve a internarse por cuadro similar, se repite cinecoronariografía que informa nuevamente vasos coronarios sin lesiones angiográficas pero como hallazgo describe una imagen compatible con un puente muscular a nivel del tercio medio de la arteria descendente anterior, con efecto compresivo durante las sístoles y como responsable de las isquemias del miocardio. Finalmente se concluye como un infarto agudo de miocardio tipo 2 y se instaura tratamiento médico específico, respondiendo favorablemente.
ABSTRACT We present the case of a patient, without comorbidities, who is hospitalized due to recurrent acute myocardial infarction. On all occasions he presented typical precordial pain and elevated troponins. In his first cinecoronariography no angiographic lesions were found. Months later, he returned to hospital for a similar case, cinecoronariography is repeated that again reports coronary vessels without angiographic lesions but as a finding describes an image compatible with a muscular bridge at the level of the middle third of the anterior descending artery, with compressive effect during systoles and responsible for the myocardial ischemia. Finally, it is concluded as an acute type 2 myocardial infarction and specific medical treatment is established, responding favorably.
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Objective To evaluate the relationship between concurrent myocardial bridge at anterior descending branch and the formation of coronary atherosclerosis plaques by using transluminal attenuation gradient (TAG). Methods A total of 198 patients underwent coronary CTA in Renji Hospital of Shanghai Jiaotong University School of Medcine from June 2017 to March 2018 and the results showed the anterior descending myocardial bridge. The data were retrospectively analyzed. All patients completed the coronary CTA with 320?row detector CT. According to the manifestations of myocardial bridge on CTA,the patients were divided into deep and superficial myocardial bridge groups. According to whether the patients were complicated with coronary atherosclerotic plaques, they were divided into isolated myocardial bridge group and myocardial bridge with coronary atherosclerotic plaque group. The thickness and length of myocardial bridge, the volume of coronary atherosclerotic plaques at the site of myocardial bridge, the pre?bridge and post?bridge TAG values, and the K ratio were recorded. Independent sample t test (normal distribution) or Mann?Whitney U test (skewed distribution) was used to compare the difference of measurement data among different groups. χ2 test was used to compare the difference of enumeration data among different groups. Pearson correlation test was used to analyze the correlation among pre?bridge and post?bridge TAG values,K ratio,thickness and length of myocardial bridge and plaque volume. The influence of above indexes on plaque occurrence was analyzed by binary logistic regression analysis. The relationship between main influence indexes and plaque formation was analyzed by receiver operating characteristic curve (ROC). Results Ninety nine patients had isolated myocardial bridge,99 with myocardial bridge and coronary atherosclerotic plaques,27 with superficial myocardial bridge and 171 with deep myocardial bridge. All atherosclerotic plaques occurred in pre?bridge and the mean volume of plaques was (91.6±83.0)mm3. The differences in sex, age, height, body weight and body mass index werenot statistically significant between isolated myocardial bridge group and myocardial bridge with coronary atherosclerotic plaque group (all P>0.05). The difference in pre?bridge TAG value was statistically significant between the isolated myocardial bridge group and myocardial bridge with coronary atherosclerotic plaque group (all P<0.05), but not statistically significant in post?bridge TAG value and K ratio (all P>0.05). The difference in pre?bridge and post?bridge TAG values and K value was not statistically significant between the superficial group and the deep group (all P>0.05). There was a weak negative correlation (r=-0.205,-0.316,-0.339,respectively,P<0.05) between the plaque volume and pre?bridge&post?bridge TAG values and K ratio. The pre?bridge TAG value significantly affected the plaque formation (P=0.014) and the odds ratio was 0.884 (95% CI 0.801 to 0.976). While other factors had no significant effects on plaque formation (all P>0.05). The area under curveof plaque formation promoted by pre?bridge TAG value was 0.582. When the diagnostic critical value was －37.26 HU/mm, the sensitivity and specificity of pre?bridge TAG value in plaque formation were 31.31% and 81.82%, respectively. Conclusion The TAG value of anterior descending bridge is an independent risk factor for plaque occurrence. The abnormal TAG value of anterior descending myocardial bridge can be detected early by CTA.
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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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Resumen Los puentes miocárdicos están constituidos por haces de fibras musculares que recubren un trayecto variable de una arteria coronaria; son un hallazgo relativamente frecuente, con incidencia que varía en función del método de estudio usado (angiográfico). Aunque por lo general tienen pronóstico benigno, pues en muchos casos cursan de manera asintomática y su hallazgo es casual, su existencia se considera causa de angina, arritmias malignas, infarto de miocardio y muerte súbita. Su diagnóstico se realiza in vivo por estudio angiográfico al comprobar una compresión sistólica (contracción muscular) de una arteria coronaria que desaparece durante la diástole (relajación muscular). Comunicamos el caso de una paciente de 46 años de edad, sin factores de riesgo cardiovascular, que ingresó al servicio de Urgencias por cuadro de dolor precordial típico y síntomas de descarga neurovegetativa, con signos electrocardiográficos de lesión subendocárdica en la cara anteroseptal y biomarcadores positivos. La paciente estaba fuera del periodo de ventana de trombólisis, por lo que se decidió realizarle intervención coronaria percutánea, en la que se documentó la existencia de puente muscular sobre la arteria descendente anterior en su tercio medio, que generaba compresión sistólica moderada con disminución del flujo de llenado en el tercio distal, sin otras lesiones coronarias asociadas.
Abstract Myocardial bridges consist of muscle fiber bundle lining an epicardial coronary artery for a variable distance. They are a relatively common finding, with incidence changing on the basis of the study method used (angiographic/necropsy). Although myocardial bridges have usually a benign prognosis, being in many cases asymptomatic and only found by chance, their presence has also been considered a cause of angina, malignant arrhythmia, myocardial infarction and sudden death. They are diagnosed in vivo by angiography when a systolic compression of a coronary artery which disappears during diastole is evidenced. We report the case of a female patient without risk factors, with electrocardiographic signs of severe ischemia in the territory of the anterior descending artery, which was initially assessed as myocardial infarction and treated as such. Eventually, the ECG returned to normal, and no new Q waves of necrosis occurred. An angiohemodynamic study confirmed the existence of an isolated muscular bridge over the middle third of the anterior descending artery, with no other associated coronary lesions.
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Objective To explore the diagnostic value of the percentage of attenuation drop measured by diastolic phase coronary CTA (CCTA) in identifying significant dynamic compression of myocardial bridge (MB).Methods Totally 135 patients with MB confirmed by CCTA were enrolled.The CT value of MB segment and proximal MB segment was measureed respectively.Attenuation of mural coronary artery(％) =(CT value of proximal MB segment-CT value of MB segment)/CT value of MB segment × 100 ％.Systolic compression ≥50 ％ was considered significant.The percentage of attenuation drop of MB vessel,length and depth of MB were measured and correlated with the presence and degree of dynamic compression.Results Attenuation drop of mural coronary artery(％),length of MB in MB patients with significant systolic compression,slight systolic compression and without systolic compression had significant statistical differences (all P＜0.05).ROC curve showed the percentage of attenuation had the best accuracy of 73.3％ in diagnosis of MB with significant systolic compression with the cutoff value of 15％ and the area under the curve (AUC) of 0.75 (95％ CI [0.67,0.82],P＜0.01).Conclusion Attenuation drop of MB segment has relationship with the extent of dynamic compression of MB and it has value to identify significant dynamic compression of MB.
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Objective: To study the characteristics of coronary CT angiography (CTA) in patients with myocardial bridge (MB) with arrhythmia. Methods: Our study included 2 groups: MB+arrhythmia group,n=31, clinical information as medical record, electrocardiogram (ECG), myocardial enzyme, echocardiography and coronary CTA findings were collected; MB group, n=30, the MB patients were without arrhythmia. Results: In MB+arrhythmia group, all patients were with mere MB, coronary artery disease, valve-structural heart diseases and other systemic diseases were excluded. There were 2/31 patients with ventricular fibrillation, 1 with atrial fibrillation, 5 with supraventricular tachycardia and 23 with ventricular tachycardia; 17/31 patients having deep type MB and 14 having superficial type MB. The myocardial systolic end diameter, diastolic end diameter by retrospective ECG gating and the stenosis at cross section of mural coronary MB by CTA were similar between 2 groups,P>0.05. Conclusion: MB+arrhythmia patients had no specific characteristics in coronary CTA; anatomical CTA feature may partly explain the myocardial ischemic symptom while couldn't clarify arrhythmia occurrence in relevant patients.
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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 characteristics of CT images of myocardial bridge(MB)in patients with atherosclerosis.Methods CTA images of MB in 129 patients with atherosclerosis were studied.Another 109 patients without atherosclerosis,in the diagnosis of MB were used as control.The type,age,thickness of MB,length of mural coronary artery and end systolic diameter of mural coronary artery were compared between the two groups.Results In the study group,78 cases (60.5%)were superficial type,51(39.5%) were deep type.While in the control group,70(64%)cases were superficial type and 39(36%)were deep type.There was no significant difference between the two groups.The age,thickness of MB,length of mural coronary artery and end systolic diameter of mural coronary artery in each group were 57.01±10.17 years old,(3.15±1.66)mm,(20.43±7.38)mm,(1.16±0.25)mm and 48.36±9.11 years old,(1.95±1.77)mm,(21.07±6.69)mm,(2.07±0.81)mm.These parameters had significant differences between the two groups except the length of mural coronary artery (P>0.05).Conclusion The MB of the study group is thicker than the control group,and the mural coronary artery diameter of the former is narrower than that of the latter.
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OBJECTIVE: To study the predictive value of transluminal attenuation gradient (TAG) derived from diastolic phase of coronary computed tomography angiography (CCTA) for identifying systolic compression of myocardial bridge (MB). MATERIALS AND METHODS: Consecutive patients diagnosed with MB based on CCTA findings and without obstructive coronary artery disease were retrospectively enrolled. In total, 143 patients with 144 MBs were included in the study. Patients were classified into three groups: without systolic compression, with systolic compression < 50%, and with systolic compression ≥ 50%. TAG was defined as the linear regression coefficient between intraluminal attenuation in Hounsfield units (HU) and length from the vessel ostium. Other indices such as the length and depth of the MB were also recorded. RESULTS: TAG was the lowest in MB patients with systolic compression ≥ 50% (−19.9 ± 8.7 HU/10 mm). Receiver operating characteristic curve analysis was performed to determine the optimal cutoff values for identifying systolic compression ≥ 50%. The result indicated an optimal cutoff value of TAG as −18.8 HU/10 mm (area under curve = 0.778, p < 0.001), which yielded higher sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy (54.1, 80.5, 72.8, and 75.0%, respectively). In addition, the TAG of MB with diastolic compression was significantly lower than the TAG of MB without diastolic compression (−21.4 ± 4.8 HU/10 mm vs. −12.7 ± 8 HU/10 mm, p < 0.001). CONCLUSION: TAG was a better predictor of MB with systolic compression ≥ 50%, compared to the length or depth of the MB. The TAG of MB with persistent diastolic compression was significantly lower than the TAG without diastolic compression.
Subject(s)
Humans , Angiography , Coronary Artery Disease , Linear Models , Myocardial Ischemia , Retrospective Studies , ROC Curve , Sensitivity and SpecificityABSTRACT
Objective To observe the treatment effects of trimetazidine on myocardial bridge. Methods A total of 76 patients with clinical symptoms, such as different degrees of chest tightness, palpitation, breath shortness, chest pain, were diagnosed as coronary myocardial bridge by coronary angiography, and were divided into two groups randomly. While control group (n=40) was given beta-blocker or (and) calcium antagonist as routine treatment. The treatment group (n=36) was given routine treatment and trimetazidine, 20 mg, three times daily. The mean follow-up period was 12 weeks. The episodes of chest pain per week, exercise tolerance, anxiety and depression scores, total ischemic burden in 24 h and walking distance in 6 min were observed in two groups of patients. Results The parameters of chest pain times per week, exercise tolerance, anxiety and depression scores, total ischemic burden in 24 h and walking distance in 6min were improved in treatment group compared with control group, and the symptoms were effectively relieved, the life quality of patients were improved. Conclusion The conventional treatment combined with trimetazidine is safe and effective, which can further improve myocardial energy metabolism and exercise tolerance, and enhance the clinical effect and the life quality of patients.
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Objective To analyze the electrocardiogram and treadmill exercise performance in patients with coronary artery myocardial bridge.Methods 176 patients with myocardial bridging diagnosed by coronary angiography were selected in the study.The performance of myocardial bridge electrocardiogram and treadmill exercise of different depth and stenosis was observed.Results Deep in myocardial bridge ischemic ST segment and T wave changes were significantly higher than superficial type (x2 =11.02,P ＜ 0.01).Systolic myocardial bridge Ⅲ grade stenosis of ischemic ST segment and T wave changes were significantly higher than grade Ⅰ and grade Ⅱ (x2 =12.78,P ＜0.01;x2 =24.45,P ＜ 0.01).The positive rate of myocardial bridge deep in the treadmill exercise test was significantly higher than the superficial type.Myocardial bridge Ⅲ grade systolic stenosis,treadmill exercise test positive rate was significantly higher than grade Ⅰ and grade Ⅱ (x2 =9.23,P ＜ 0.05;x2 =6.76,P ＜ 0.01).Conclusion Patients with myocardial bridge have various changes in the electrocardiogram and treadmill exercise,changes in deep in the type and degree of stenosis Ⅲ grade systolic are obvious.
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Objective: To explore the correlation of left descending anterior (LDA) myocardial bridge (MB) and atherosclerosis at proximal to a segment with MB in patients elderly than 60 years and to identify if LDAMB could become the independent risk factor of atherosclerotic stenosis at proximal to a segment with MB. Methods: A total of 986 patients with multi-slice spiral CT diagnosed coronary artery disease (CAD) were studied and 389 patients with 486 MB in left heart were found. General information as the age, gender, diabetes, hypertension, dyslipidemia and smoking conditions were collected, relationship between LDAMB and atherosclerotic stenosis at proximal to a segment with MB was studied by Logistic regression analysis. Results: There were 48/389 (12.3%) cases with MB at proximal segment of LDA, 254 (65.3%) cases with MB at middle segment of LDA, 51 (13.1%) cases with MB at distal segment of LDA, 19 (4.9%) cases with MB at the ifrst diagonal branch and 17 (4.4%) cases with MB at obtuse marginal branch respectively. Logistic regression analysis presented that age (OR=1.07, 95% CI 0.02-0.09,P0.05. Conclusion: MB at middle segment of LDA was with the higher occurrence rate of atherosclerotic stenosis at proximal to a segment with MB in elderly patients, which could be used as an independence risk factor for clinical diagnosis.
ABSTRACT
Introduction: The segment of epicardial coronary artery that traverses intramurally through the myocardium and bridged by a bunch of cardiac muscle fibers is called tunneled artery or intramural artery. The band of cardiac muscle fibers passing over the tunneled artery segment is named as myocardial bridge. During angiography milking effect is observed during systole due to the external pressure of muscle fibers on the tunneled artery that leads to narrowing of vessel lumen and further ischemia. Materials & Methods: It is a prospective study performed from 2012- 2015 in cardiac centers available around Tirupati, Andhra Pradesh, South India. A total number of 2015 adult patients who underwent diagnostic coronary angiography were evaluated to detect myocardial bridges. With the informed consent the relevant data was collected from the patients and analyzed. Results: The prevalence of myocardial bridges was 3.17%. Among the 2015 patients 70.7% are males and 29.2% are females. Among 64 myocardial bridge positive cases 62.5% were male and 37.5% were female patients. Regarding coronary dominance 84% were right dominant and 14.4% were left dominant and 1.6% are balanced. The percentage incidence of myocardial bridging according to dominance was 3.01% for right dominant patients, 4.12% for left dominant patients and 3.1% for balanced dominant patients. In all the myocardial bridge positive cases they were located on the left anterior descending artery (LAD). According to diagnosis the patients with normal coronaries were 22.6%, patients with MILD CAD were 17.9%, patients with single vessel disease were 23.4%, patients with two vessel disease were 14.7% and the patients with triple vessel disease were 21.3%. The 64 myocardial bridging cases were grouped in to three groups according to their age. Incidence of double bridges was observed in 3 cases of which 66.7% males & 33.3% in females. Conclusion: These results shows that Andhra Pradesh population are with high angiographic incidence of myocardial bridges (MB’s), when compared with other population in India. We observed more lengthy bridges which may cause luminal reduction of coronary vessel and myocardial ischemia (MI), we also observed higher incidence of MB’s in male patients but systolic luminal reduction is more in female patients then in males. These observations suggest that the risk of MI will be more for the female patients with MB’s.
ABSTRACT
El término puente de miocardio es atribuido al conjunto de fibras musculares cardiacas, que a veces se sobreponen a un segmento subepicárdico de una determinada rama de las arterias coronarias derecha e izquierda. Polacek (1959) fue el primero en enfocar esta entidad desde el punto de vista muscular, de aquí nace el nombre de "puente de miocardio" siendo actualmente la más usada en clínica. La presencia de estos puentes, ha sido identificada tanto en humanos como en animales y basados en ello, se estudiaron 50 corazones de avestruz, de la clase African Black, cuyo objetivo fue determinar presencia de puentes de miocardio, número, longitud y principales arterias en donde se ubican. Hubo presencia de puentes de miocardio en 20 (40,0%) de los 50 corazones estudiados; el número total de puentes de miocardio fue de 34, de los cuales 30 (88,2%) se ubicaron sobre la arteria coronaria izquierda y sus ramas y 4 (11,8%) sobre la arteria coronaria derecha y sus ramas. El número de puentes varió de 1 a 4 por corazón. Los vasos donde se observaron con mayor frecuencia fueron: ramas ventriculares de la rama interventricular paraconal con 22 (64,7%) puentes y rama interventricular paraconal con 8 (23,5%) puentes. Los registros métricos de la extensión de los puentes de miocardio variaron entre 1,6 mm y 73,1 mm.
The term myocardial bridge is attributed to all cardiac muscle fibers, which sometimes overlap a subepicardial segment of a particular branch of the right and left coronary arteries. Polacek in 1959 was the first to approach this entity from the standpoint of muscle. From this arises the name of "myocardial bridge" and is currently the term most widely used clinically. The presence of these bridges, has been identified in humans and in animals and based on that, 50 African Black class ostrich hearts were studied, with the aim to determine the presence of myocardial bridges, number, length and main arteries where they are located. There was presence of myocardial bridges in 20 (40.0%) of the 50 hearts studied, the total number of myocardial bridges was 34, of which 30 (88.2%) were located on the left coronary artery and its branches and 4 (11.8%) over the right coronary artery and its branches. The number of bridges ranged from 1 to 4 by heart. The vessels most frequently observed were: ventricular branches paraconal interventricular branch with 22 (64.7%) and interventricular branch paraconal bridges with 8 (23.5%) bridges. Metrical records of the extent of myocardial bridges ranged between 1.6 mm and 73.1 mm.