The combined presence of myocardial bridging and fixed coronary artery stenosis

Myocardial bridging: evaluation using single- and dual-source multidetector cardiac computed tomographic angiography

OBJECTIVE

To evaluate the prevalence and characteristics of myocardial bridging in patients who underwent single- or dual-source multidetector cardiac computed tomographic angiography (MDCTA).

METHODS

Retrospective review of the imaging characteristics of 57 myocardial bridges in 53 patients who underwent cardiac MDCTA examinations was performed.

RESULTS

The prevalence of myocardial bridges was 10.4%, most of which were located in the mid-left anterior descending coronary artery. The average myocardial bridge length was 23.4 mm, and the average tunneled artery depth was 2.6 mm.

CONCLUSIONS

Myocardial bridges are commonly found in patients who undergo cardiac multidetector computed tomographic angiograms on both single- and dual-source computed tomographic scanners and are most frequently located in the mid-left anterior descending coronary artery. Increasing utilization of cardiac MDCTA for noninvasive evaluation of coronary artery disease permits recognition, characterization, and functional assessment of this entity in a single examination.

Stent fracture following stenting of a myocardial bridge: report of two cases

Myocardial bridge is the most common congenital coronary anomaly. Patients with this anomaly are usually asymptomatic, but it may cause myocardial ischemia that may lead to myocardial infarction. Treatment for myocardial bridge remains controversial. Current recommendations include medical therapy, surgical treatment (unroofing myotomy), coronary artery bypass, and percutaneous coronary stenting. We report two cases of stent fracture following stenting of a myocardial bridge. The risk of stent fracture leading to restenosis and/or stent thrombosis should be considered when assessing the risks and benefits of coronary revascularization of a myocardial bridge.

[Long-term prognosis of patients with myocardial bridge and angiographic milking of the left anterior descending coronary artery]

INTRODUCTION

Myocardial bridging with systolic compression (milking) of the left anterior descending coronary artery may be associated with myocardial ischemia. Little information is available about the long-term prognosis of patients with this coronary anomaly.

MATERIAL AND METHODS

A review was made of coronary angiographies of patients diagnosed as ischemic heart disease made between 1994 and 1999 in two centers. The long-term follow-up of patients with myocardial bridging and systolic compression of the left anterior descending coronary artery was analyzed. Data were collected by reviewing medical records and completed by telephone interview.

RESULTS

Prevalence: 0.72%. Milking was observed in 60 patients, but 25 of them were excluded due to associated hypertrophic cardiomyopathy, severe valvular disease, or coronary artery disease. The clinical follow-up was available for all patients (median: 43 months, range: 12-80 months). Mean age 55.7 years (SD = 11.9). Men 74%.

CLINICAL PRESENTATION

angina 26 patients, atypical chest pain with positive non-invasive test 8, acute myocardial infarction 1. During follow-up, 1 patient died of sudden cardiac death. Seven patients continued to present stable angina CCS class I-II, coronary angiography was repeated in 5 patients, and one required percutaneous revascularization for symptoms. In 63% of cases, antianginal drugs were still needed at the end of follow-up period (beta-blockers or calcium antagonists).

CONCLUSIONS

Patients with myocardial bridging and systolic compression of the left anterior descending artery have a good long-term prognosis, although more than half of them continue regular treatment with antianginal drugs. In a small percentage of cases percutaneous intervention must be performed and ischemic heart disease may appear in more aggressive forms (acute myocardial infarction or sudden death).

Clinical Significance of Isolated Coronary Bridges

Myocardial bridging of a coronary artery has been noted in 0.5% to 1.6% of arteriograms but the clinical significance is controversial. We reviewed retrospectively 761 consecutive coronary arteriograms performed in the Chinese PLA General Hospital from 1986 to 1996. Myocardial bridging of a coronary artery was noted in 12 cases (1.5%), located exclusively in the left anterior descending coronary artery and isolated without fixed coronary artery stenosis. The bridges ranged in length from 10 to 50mm (mean 24 mm) and were classified as grade 1 (8% of cases), grade 2 (25%) and grade 3 (67%). All patients were hospitalized because of angina. Eight (67%) of the 12 patients suffered from anterioapical dyskinesia including 2 who had acute myocardial infarction with a left ventricular aneurysm. Three patients (25%) with a small posterior descending coronary artery died. In our view, when there is a hyperdominant left anterior descending coronary artery with a small posterior descending artery and a myocardial bridge, the patient appears to be in jeopardy and myocardial bridging can no longer be considered a benign coronary anomaly, especially when there is grade 3 narrowing of the left anterior descending coronary artery during systole.

Acute myocardial infarction caused by a myocardial bridge treated with intracoronary stenting

The clinical significance of myocardial bridges (MBs) is variable, and most patients are asymptomatic. However, angina, myocardial infarction, and sudden death have been reported in association with MBs. Here we describe the use of intracoronary stenting for the treatment of a patient with an anterior myocardial infarction due to an MB.

Coronary angioplasty of a severe coronary stenosis at the site of a myocardial bridge

We report the case of a patient who underwent coronary angioplasty for a severe stenosis at the site of a myocardial bridge. Although favorable angiographic results and the disappearance of myocardial ischemia were obtained, a significant pressure gradient across the lesion and abnormal myocardial fractional flow reserve remained immediately following angioplasty. These results suggest that pressure measurements may be of limited value in this subset of patients.

PTCA of complex atherosclerotic lesion at site of LAD myocardial bridging

An 86-year-old patient with a history of chronic angina pectoris and a remote cerebrovascular accident presented to the hospital with an acute myocardial infarction complicated by a concomitant nonhemorrhagic cerebrovascular accident. Postmyocardial infarction angina pectoris, refractory to maximal medical therapy, led to coronary angiography. This demonstrated the "culprit" lesion to be a complex and critical atherosclerotic lesion at the distal-most extent of a long area of left anterior descending (LAD) myocardial bridging. This "culprit" lesion was successfully treated by balloon angioplasty. This is the second report in the recent literature of balloon angioplasty revascularization used in this fashion. Similarities and differences between our case report and the prior report in the literature are compared and contrasted.