Myocardial bridging: a review with emphasis on electrocardiographic findings

Myocardial Bridging of Mid-left Anterior Descending Artery (LAD) Presenting As Transient Left Bundle Branch Block During Nuclear Stress Test

Transient left bundle branch block occurring during a nuclear stress test in the setting of myocardial bridging is a relatively rare finding. We report a case of a 75-year-old male who presented with typical stable angina. Serial troponins were negative, and the electrocardiogram revealed normal sinus rhythm with left ventricular hypertrophy and T-wave inversions in the lateral leads. The nuclear stress test was non-ischemic but showed a transient left bundle branch block associated with chest pain and shortness of breath that occurred right after the administration of regadenoson. Coronary angiography revealed non-obstructive coronary artery disease and a mid-LAD myocardial bridge.

Myocardial Bridging: Two Different Clinical Presentations in Young Males Involving Left Anterior Descending Coronary Artery

Myocardial bridging is a rare anatomical variant that can lead to detrimental cardiac consequences when undiagnosed and untreated. This rare variant can induce anginal-type symptoms due to disrupted blood flow to the myocardium during systole. The patients presented in this report of two cases had previously undiagnosed myocardial bridging of the left anterior descending artery, however clinically, they presented quite differently. Here we present two cases discussing the course of diagnosis and treatment of myocardial bridging of these two patients. The goal of this case report is to highlight the significant cardiovascular injuries that can be a result of undiagnosed myocardial bridging.

Left Anterior Descending Artery Bridging and Atypical Chest Pain in a Young Woman

Cardiac-related chest pain is a frequent cause of morbidity and mortality and should be carefully assessed due to its burden on patient health. Its etiology can sometimes prove challenging to discover because of atypical presentations or rare causes of chest pain like myocardial bridging (MB). MB requires a high index of suspicion to be diagnosed. MB is a rare congenital anomaly that occurs due to the passage of a segment of a coronary artery inside the myocardium, causing chest pain due to compression during systole. MB usually has no clinical significance in most cases. However, when severe bridging occurs in the major coronary arteries, patients can experience myocardial ischemia, coronary thrombosis, myocardial infarction, and stress cardiomyopathy, leading to arrhythmias and sudden death. We present the case of a young woman who presented with atypical (rather than ischemic) chest pain due to MB.

Myocardial bridge pathology and preventable accidents during physical activity of healthy subjects: A case report and a literature review

Myocardial bridging is a congenital coronary pathology described as a segment of coronary artery which courses through the myocardial wall under the muscle bridge. Although the prognosis of myocardial bridging is benign, sports medicine recognises myocardial bridging as a leading cause of sudden death among young basketball, football and soccer players. The authors report a case of a 42-year-old man who collapsed while playing football. He died notwithstanding prompt medical assistance and cardiopulmonary resuscitation. At autopsy, gross examination of the heart revealed the intramural course of the left anterior descending coronary artery to be 2 cm from its coronary ostial origin. Histological examination of ventricular septal and left myocardium showed early signs of ischaemic injury without disease of small coronary vessels and hypertrophic cardiomyopathy. The cause of the death was due to malignant ventricular arrhythmia during intense physical activity.

ECG changes and markers of increased risk of arrhythmia in patients with myocardial bridge

BACKGROUND

The clinical significance and prognosis of myocardial bridge (MB) is still a matter of debate.

OBJECTIVES

To assess the novel ECG markers of T peak-to-end (Tp-e) interval, transmural dispersion of repolarization (TDR), is assessed by Tp-e/QT ratio, and index of electrophysiogical index(iCEB),is defined by QT/QRS ratio and changes (ST-T changes) in MB patients.

PATIENTS AND METHODS

Forty one patients who were diagnosed as having MB (MB group) and other 41 patients without MB (non-MB group) at multi-detector CT (MDCT) exam matched by age, sex were enrolled in the study.

RESULTS

iCEB was significantly increased in MB group in comparison to non-MB group particularly in patients with no coronary atherosclerosis (5.3 Vs 4.5, p = 0.04). Tp-e and TDR values were decreased in MB in comparison to non-MB patients particularly in patients with coronary atherosclerosis (69 Vs 80, p = 0.003 and 0.18 Vs 0.2, p = 0.01 respectively). Isolated T inversion in V1 was observed more in MB compared to non-MB patients (58% Vs 5%, p ≤ 0.0001) particularly in patients without coronary atherosclerosis.

CONCLUSION

MB patients have shown decreased Tp-e and TDR markers particularly in MB patients with coronary atherosclerosis.

Extensive unroofing of myocardial bridge: A case report and literature review

Background:

Myocardial bridge is defined as a segment of a coronary artery that takes an intramyocardial course. The presence of myocardial bridge has been observed in as many as 40%–80% of cases on autopsy, angiographically from 0.5% to 16.0%, and often asymptomatic. However, it has been associated with angina, coronary spasm, myocardial infarction, arrhythmias, syncope, sudden cardiac arrest, and death. Conflicting opinions exist on the timing of surgical intervention for myocardial bridge.

Methods:

We present an unusual case of a young female, with prior aortic surgery, who had refractory chest pain despite optimal medical therapy. Stress testing revealed anterior ischemia. Cardiac catherization showed myocardial bridge of the left anterior descending artery with significant compromise of blood flow (fractional flow reserve = 0.75 with adenosine). We proceeded with surgery. Intraoperatively, we found an unusually long (10-cm) intramyocardial segment of the left anterior descending artery which was managed by surgically unroofing. Our patient felt better post procedure. Repeat cardiac catheterization showed no further narrowing of the left anterior descending artery with a fractional flow reserve of 0.87 in its distal segment.

Results/discussion:

Myocardial bridge is present mostly in female patients (74.5%), with median age at 56.2 years and mostly involving the left anterior descending artery (77.2%). The average length of myocardial bridge is 21.85 ± 16.10 mm (range: 5–70 mm). Our case is unique as the involved myocardial bridge was 10 cm in length, the longest ever reported. Multiple imaging modality revealed significant coronary insufficiency, with a subsequent clinical and angiographic improvement upon unroofing of the culprit coronary vessel.

Conclusion:

Management decision on myocardial bridge remains controversial. This is a case of the longest symptomatic myocardial bridge, with a subsequent improvement post unroofing.