Myocardial Bridge: Surgical Outcome and Mid-term Follow up

BackgroundMyocardial bridge consists of muscle fiber bundles lining an epicardial coronary artery for a variable distance. Although myocardial bridge is associated with a benign prognosis, its presence has also been considered a cause of angina, myocardial infarction, malignant arrhythmia and sudden death. There is no general consensus about therapeutic strategies in symptomatic patients with myocardial bridge (medical therapy, coronary artery bypass surgery, coronary stenting, supra-arterial myotomy).We report results of surgery and long-term follow up in 26 patients who had disabling symptoms due to myocardial bridge refractory to medical therapy. MethodsFrom 1999 to 2004, among more than 18,800 coronary angiographies which were performed in our department, 290 (1.5%) cases had the angiographic diagnosis of myocardial bridge. From these, 26 (9%) patients underwent surgical myotomy for treatment of myocardial bridge causing significant systolic arterial compression. The patients (19 male, 7 female) had a history of typical chest pain and positive exercise test. All of them were examined with radionuclide study preceding angiography, which was positive for ischemia in 20 cases (76%). Coronary angiography and left heart catheterization revealed impaired blood flow due to myocardial bridge in left anterior descending artery in all patients and there was additional atherosclerotic stenosis of coronary arteries in 6 and mitral valve disease in one patient. Supra arterial myotomy was performed in all patients. ResultsThere was no mortality or major intraoperative complication. Postoperative scintigraphic and angiographic studies demonstrated restoration of coronary blood flow and myocardial perfusion without significant residual compression of the artery, except in one patient who had recurrent anginal chest pain after operation and coronary angiography showed residual narrowing in the LAD despite myotomy. This patient underwent CABG of LIMA to distal LAD. During 7-81 months of follow-up (mean: 34.2± 21), only two patients had symptoms of angina which did not show significant residual compression, and symptoms were controlled by medical treatment. ConclusionIn conclusion, surgical relief of myocardial ischemia due to myocardial bridge can be accomplished with very low operative risk and excellent mid term results (Iranian Heart Journal 2007; 8 (2): 39-43).