Abstract 12538: Myocardial Bridge Induced Cardiomyopathy

Abstract

Introduction: A myocardial bridge(MB) is a condition in which the epicardial coronary artery traverses through the myocardium, has an intra-myocardial course of varying length, and then exits the myocardium and appears on the surface of the heart. Clinical Presentation: A 54-year-old male with no significant past medical history except tobacco abuse and anxiety presented to the hospital with retrosternal chest pain radiating to the back and shoulder and associated with nausea and diaphoresis. His SBP was 100/60, and his heart rate 46. His EKG showed ST elevation in inferior leads, and he was given a nitro tablet, which improved the chest pain to 5/10. He was emergently taken to the Cath lab and found to have proximal left circumflex artery occlusion and underwent PCI with a 2.25x23 Xience Drug-eluting stent. Troponin was elevated to 2.35. His cath also showed a significant mid-LAD myocardial bridge. His echocardiogram showed mid and apical anterior, anterior septal, apical wall, and inferior wall hypokinesis. His EF has been reduced to 30%. Coronary CTA showed mid-LAD has myocardial bridging, which is more than 2 cm long and 5 mm deep in the muscle. The patient has persistently low HR in 40-45, beta-blocker was not started. Due to significant cardiomyopathy induced by a myocardial bridge, unroofing of LAD was done off-pump. His EF improved to 55% after three months of surgery. Discussion: CABG or myotomy is the treatment of choice for patients with symptomatic myocardial bridging refractory to medical therapy, evidence of myocardial ischemia or infarction, or >75% systolic coronary compression on angiography. Incidental myocardial bridging finding without ischemia or symptoms does not require any treatment. Symptomatic patients with ischemia on stress tests can be offered beta or calcium channel blockers. Medical therapy is superior to revascularization with percutaneous intervention.