Myocardial Infarction with Non Obstructive Coronary Artery Associated with Myocardial Bridging: A Case Report
Author : A.Sariningrum, Elen, C.Anantaria, M.Kasim
Upload Date : 19-04-2018
Background: 1-14% case of myocardial infarction occur in the absence of obstructive (>50%) CAD and 25% of NSTE-ACS patients have normal epicardial coronary artery in angiography. Myocardial bridging (MB) is a congenital coronary anomaly with a variety of clinical manifestation. It considered a benign condition, but some cases of myocardial ischemia, infarction, and sudden cardiac death due to MB have been reported. MB often found accidentally in coronary angiography or cardiac MSCT.
Case Presentation: A-63-year old-man presented to emergency room of National Cardiovascular Center Harapan Kita with chest discomfort during sleeping. He had history of smoking, diabetes mellitus, and hypertension. He felt dyspneu over 6 month. The blood pressure was 160/90 mmHg and there were rales in basal lungs. Electrocardiogram revealed atrial fibrillation rapid ventricular respons (125 bpm) and Q wave in V1-V2. The CKMB was 34 U/L and hs Troponin T was 40 ng/L. He worked up as NSTE-ACS TIMI 1/7 Grace Score 111 Crusade Score 26 and acute decompensated heart failure. Two months later, patient had ischemic stroke. Coronary angiography was revealed MB in mid left anterior descending (LAD) coronary artery and no evidence of angiographic obstruction or atherosclerosis. Echocardiography showed LVEF 21% with regional wall motion abnormality. An exercise strees test with SPECT revealed ischemic burden 7.35% in LAD, LCx/RCA territority with EF 42%. Cardiac MSCT revealed mild calcium plaque burden, mild stenosis in proximal LAD, minimal stenosis in LM, deep myocardial bridging in mid LAD, and osteal of LCX that comes from right coronary sinus.
Discussion: Myocardial infarction with non obstructive coronary artery was revealed in this patient. MB can cause MI via coronary artery spasm at the bridge LAD segment and atherosclerosis at proximal to the bridge with its shear stress effect. Anomaly origin of LCx in this case didn’t cause any significat ischemia. Treatment of MB has been primarily medical with beta-blocker or calcium channel blocker. If patients are refractory to medical therapy, invasive or surgical therapy may be considered.
Conclusion: Myocardial bridging may predispose to coronary vasospasm or atherosclerosis at proximal to the bridge that may lead to ischemic complication. In this patient, we decided to give medical treatment.
KEYWORDS : MINOCA, myocardial bridging