冠状动脉前降支心肌桥致急性心肌梗死一例

<正>1病例资料患者男性,47岁。主因"间断胸痛12 d"入院。患者入院前12 d,于夜间睡眠中突发胸痛,位于心前区,手掌大小范围,无放射痛,持续不缓解。5 h后于当地医院就诊,诊断"急性前壁心肌梗死",负荷剂量阿司匹林及氯吡格雷口服,并予"尿激酶150万U"溶栓。此后,患者于日常体力活动时仍间断出现胸痛,位于心前区,手掌大小范围,无放射痛,每     

Myocardial infarction associated with a myocardial bridge

A 30-year-old man was admitted with severe chest pain and electrocardiographic evidence of myocardial infarction. Subsequent angiography revealed myocardial bridging of the middle third of the left anterior descending coronary artery and no evidence of coronary atherosclerosis. In the absence of other risk factors, circumstantial evidence points to a possible etiological role of myocardial bridging in the ischemic event in our patient.     

Myocardial bridge: description, significance, treatment

The myocardial bridge is a well known anomalous trajectory of the coronary arteries, the significance of which has been discussed for a long time. It now appears that some myocardial bridges may cause myocardial ischaemia with clinical electrocardiographic, scintigraphic or metabolic signs--even myocardial infarction or sudden death. In these symptomatic cases, treatment is usually medical and rarely surgical. In the last few years, angioplasty and stenting have been used more frequently in cases resistant to medical therapy and appear to be an effective alternative to surgery.     

心肌桥对冠状动脉粥样硬化的作用

目的:探讨心肌桥与冠状动脉粥样硬化病变之间的关系。方法:回顾性分析冠脉造影术中检出的心肌桥患者92例的冠脉病变与临床资料。结果:1500例冠脉造影患者检出心肌桥92例,检出率6.1%;心肌桥近段冠状动脉粥样硬化病变发生率71.7%,远段冠状动脉粥样硬化病变发生率10.9%,两者差异有显著性（P<0.01）。结论:心肌桥可能导致冠状动脉心肌桥近段冠脉粥样硬化病变。     

Myocardial bridge - congenital anomaly of coronary vasculature.

Coronary artery lumen compression during systole by a myocardial bridge can cause myocardial ischemia and even necrosis. Myocardial bridges represent a variant of norm or congenital anomaly of coronary vasculature. They belong to relatively frequent autopsy findings (5.4-85.7%) and are most often located over left anterior descending artery. Main angiographic sign of myocardial bridging is effect of contrast medium pushing out during narrowing of intramural part of a coronary artery during systole. In most cases systolic coronary artery narrowing not associated with any symptoms and bridging is just accidentally found at angiography. However some bridges produce clinical manifestations such as angina pectoris or myocardial infarction which require drug treatment. Therapy failures are managed by stenting or surgery. Under certain conditions systolic coronary artery narrowing can cause sudden death therefore all patients with clinically overt myocardial bridges should be under continuous medical surveillance. A case of clinically successful open heart supracoronary myotomy in a patient with myocardial ischemia due to a bridge causing 80% systolic narrowing of the left anterior descending coronary artery is presented.     

Left anterior descending myocardial bridge: Angiographic prevalence and its association to atherosclerosis

ObjectiveLeft anterior descending Myocardial Bridge (LADMB) is considered a benign condition and actually becomes a forgotten cause of serious cardiac events. This study was conducted to estimate the prevalence of LADMB and its association to atherosclerosis.MethodsAn observational retrospective study was conducted on patients referred for coronary angiography between June 2012 and June 2020. Coronary angiography database was revisedand studied population was divided into 2 groups: LADMB group versus Non-LADMB group.ResultsLADMB was detected in 510 patients out of 35813 included in the study resulting in a prevalence at 1.42%. The mean age was 66.5 years. Male gender was more common than female (70vs30%). The prevalence of significant atherosclerotic LAD disease was more than two times higher in the non-LADMB group compared to the LADMB group. Statistical analysis revealed a significant negative association between LADMB and atherosclerosis (p < 0.001). A significant greater rate of MINOCA cases was observed in acute coronary syndrome LADMB patients.ConclusionsLADMB is an inborn anatomic variation associated to atherosclerotic risk reduction in LAD. Physicians must be aware about the potential complications and pay attention to those classified at high risk for cardiovascular events.     

Coronary atherosclerosis within a myocardial bridge, not a benign condition

In patients with myocardial bridging, the area within the bridge usually remains free from atherosclerotic disease. The case of a 47 year old man is described who had the rare combination of myocardial bridging with an atherosclerotic plaque within the area of bridging, which was detected with intravascular ultrasound but not with coronary angiography. The clinical history of the patient demonstrates that this is not a benign condition. In symptomatic patients the bridged segment should be screened for the presence of plaque with intracoronary ultrasound.

Keywords: myocardial bridging;  intravascular ultrasound;  atherosclerotic plaque     

Myocardial infarct without angiographic coronary atherosclerosis: study of a group of patients]

STUDY OBJECTIVES: Clinical characterization and aspects of subsidiary clinical tests in a group of patients with myocardial infarction with no visible angiographic atherosclerotic stenosis. Etiologic identification, therapeutic approach and prognostic assessment of non atherosclerotic myocardial infarction. PATIENTS: We studied patients admitted with myocardial infarction to coronary care unit over a 4 year period and in whom cardiac catheterism did not show atherosclerotic coronary stenosis (17 patients). METHODOLOGY: Retrospective study; Assessment of clinical characteristics, exercise test parameters, echocardiogram, hemodynamics, heart rate variability (HRV) and signal-averaged electrocardiogram (ECG) of this group of patients; Maximal follow-up of 44 months and minimal of 3 months (average: 19.9 +/- 12.7 months) for the occurrence of ischemic cardiac events (recurrent angina, reinfarction or sudden death). RESULTS: Non atherosclerotic coronary infarction was an unusual situation (2% of the totality of the infarction hospitalized during those 4 years--795 cases), occurring mainly among young men, with few vascular risk factors (except smoking), as small infarctions, without a preferential localization and with good evolution in the acute phase (Killip I). In the predischarge exercise test there was no residual ischemia and functional capacity was generally good. In the majority of cases left ventricular systolic function was preserved (82% of the cases). With cardiac catheterism, we observed two cases of "bridging" and four cases of slow contrast progression. In arrhythmic risk stratification with 24 hours ECG, HRV and high resolution ECG, we observed no adverse prognostic markers in the majority of the cases. The clinical observation of the patients and the tests permitted us to establish probable hypotheses for the etiological diagnoses in 10 of the cases (left main anterior descending artery "bridging"--2 cases; slow contrast progression in the coronary vessels--4 cases, severe aortic stenosis--1 case; left valvular mechanic prosthesis--1 case: probable coronary thrombosis with complete reperfusion after thrombolytic therapy--2 cases). The therapeutic approach in the acute phase was the same as that of atherosclerotic infarctions. Secondary prevention was individualized and according to each case etiology, maintaining the antiplatelet agents. In the follow-up there was unstable angina in 3 patients. There were no cases of reinfarction or sudden death. CONCLUSIONS: This study allowed the characterization of the group of non atherosclerotic myocardial infarction as a group of young men with few vascular risk factors, with small infarctions and good prognosis, without adverse arrhythmic risk markers. It also allowed to identify the probable infarction etiology in 10 patients and the secondary individual prevention for each situation. We noted a good prognosis of this situation at two years.     

心肌桥与冠状动脉粥样硬化关系的探讨

目的探讨心肌桥与冠状动脉粥样硬化之间的关系。方法回顾性分析接受冠状动脉造影的52例心肌桥患者,其中30例有肌桥近段血管粥样硬化者(A组),22例孤立性心肌桥患者(B组),观察A组患者肌桥近段置入支架后预后情况。结果肌桥的检出率1.41%,均发生在左前降支的中、远段,A组和B组的肌桥长度差异无统计学意义,但A组的肌桥收缩期狭窄程度明显重于B组(68.3±14.0)%和(53.2±15.0)%,P<0.05。随访中A组14例行支架置入者,9例出现心绞痛,复查造影,其中7例出现支架内再狭窄(再狭窄率为50%,7/14);B组预后良好。结论心肌桥有促进其近段冠状动脉发生粥样硬化病变的倾向,且与心肌桥的狭窄程度有关。     

Myocardial bridge (MB): an angiographic curiosity?

The coronary angiograms of 1,500 cases performed between 1981 and 1989 were analysed to find out the incidence of Myocardial Bridge (MB) and its significance as regards myocardial ischemia. Sixteen of these (1.06%) were found to have MB. Their ages ranged from 27-70 years (m = 49.2) and male:female ratio was 13:3. Out of 16 patients, 7 (group A) had associated coronary artery disease (CAD) (7 of 1421; 0.49%) and remaining 9 (group B) had no associated CAD (9 of 79; 11.39%). All the MB were found on left anterior descending artery (LAD) (3 on proximal LAD and 13 on mid LAD). No MB was found on right coronary artery (RCA) or circumflex arteries. The location of the MB did not affect the pattern of CAD. Chronic stable angina was the commonest presenting symptom in group A patients (5 out of 7) and atypical angina in group B patients (5 out of 9). Majority of group B patients had either normal or nonspecific ST-T changes in ECG (7 out of 9). However, the presence of previous myocardial infarction or ECG evidence of 'Q' wave infarction (2 out of 2) was always associated with significant CAD. Similarly, regional wall motion abnormalities on echocardiogram were always found in patients with significant CAD and old myocardial infarction. All 9 patients with MB and normal coronary arteries were managed conservatively with good relief of symptoms, whereas other seven patients were managed on the merits of the underlying CAD. In conclusion, the MB is a normal variant found incidentally on coronary angiography, and does not have any definite clinical correlations or pathological significance.     

Myocardial bridge in hypertrophic cardiomyopathy: imaging with color Doppler echocardiography

A 50-year-old man presented with chest pain and recurrent episodesof syncope. Physical examination revealed a loud systolic murmurat the left sternal border with accentuation in erect position.Transthoracic echocardiography demonstrated severe asymmetricalseptal hypertrophy and systolic anterior motion of the anteriormitral valve leaflet which were diagnostic for hypertrophiccardiomyopathy. Interestingly, color Doppler examination ofthe left ventricle showed aliasing of the left anterior descendingcoronary artery and intra-myocardial coronaries.     

Myocardial Bridge: a clinical review.

Human coronary arteries occasionally course intramyocardially--a condition termed Myocardial Bridge. We review the anatomic and pathophysiological basis of the Myocardial Bridge and discuss clinical presentations, prognoses and the current treatment options for this interesting coronary angiographic variant.     

Myocardial bridges are free from atherosclerosis: Overview of the underlying mechanisms

Myocardial bridging constitutes a congenital, usually benign, coronary abnormality defined as a segment of a major epicardial coronary artery that follows an intramural course through the myocardium. On the basis of clinical and histopathological data, myocardial bridges appear to be spared from atherosclerosis. Although the mechanisms involved are largely unknown, the surrounding myocardium appears to be a key factor by generating a unique atheroprotective hemodynamic microenvironment within bridges. The main components of this environment include low tensile stress and high shear stress. Reduced coronary wall motion due to external support of the surrounding myocardium may also play a role. Better investigation of these mechanisms in appropriate animal models is anticipated to advance our understanding of the pathophysiology of atherosclerosis, providing a framework for the development of new atheroprotective strategies.