Myocardial bridge 12_1_20.mp4 (77.69 MB)

Myocardial Bridge as a Cause of Exertional Chest Pain

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posted on 2021-03-02, 20:36 authored by Camilo Velasquez, Taylor Garza, Lauren McTaggart, Abe DeAnda, Levy Gal

The authors present an interesting cases of a myocardial bridging as a cause of exertional chest pain. This is the case is of a 42-year-old woman with a past medical history of HTN and PAHTN who has been worked up by cardiology for chest pain with minimal exertion. The CXR didn’t show any acute abnormalities, and the EKG showed sinus rhythm with some indeterminate ST segment changes in the anterior leads. A normal EF of 60% was seen on the echocardiogram as well as a flattening ventricular septum consisting of right ventricular pressure overload. Due to her history of PAH, a right heart cath was performed, evidencing a severe pulmonary hypertension with baseline pulmonary artery pressures of 88/36. Finally, and as part of her workup, a left heart cath was performed, and there was evidence of codominance as well as an LAD and the mid-portion had a segment that was compressing during systole, concerning for myocardial bridging. This phenomenon can be clearly seen in the video.

Intramyocardial tunneling of a coronary artery can mimic myocardial ischemia, where the LAD is positioned intramuscular, different to the normal epicardial positioning of the coronary arteries. It is more frequent in females, and it is a benign finding. However, when symptomatic, myocardial bridging produces a decrease in the blood flow to the myocardium, when the vessel gets compressed during systole.

Generally, patients with angina received a regular workup, including an echocardiogram. They are then started on medical management. However, if it doesn’t work, additional imaging is required to prove the presence of a myocardial bridge and these patients are referred for a surgical consultation.

After a median sternotomy, the heart was arrested. The distal LAD was identified distally and was dissected out of the myocardium. Using self-retaining retractors, the authors were able to trace the intramyocardial LAD back to the first diagonal where the LAD was in its normal epicardial anatomic position. After dissection, and to prevent scarring over the LAD again and promote patency, myocardial edges were imbricated with a 4-0 running prolene. Finally, the authors reanimated the heart and came off bypass without any issues.

Postoperatively, the patient was taken to the surgical ICU. She was extubated and taken off pressors and inotropes by postoperative day two. She required CPAP at night and supplemental oxygen secondary to her pulmonary artery hypertension, and aggressive diuresis was started. The patient was discharged on postoperative day six without any additional complications.

References

Boyd JH, Pargaonkar VS, Scoville DH, Rogers IS, Kimura T, Tanaka S, et al. Surgical unroofing of hemodynamically significant left anterior descending myocardial bridges. Ann Thorac Surg. 2017;103(5):1443-1450.
Mok S, Majdalany D, Pettersson GB. Extensive unroofing of myocardial bridge: A case report and literature review. SAGE Open Med Case Rep. 2019;7:2050313X18823380. eCollection 2019.