Operative Management of Symptomatic MB

Abstract

The relationships between coronary myocardial bridging (MB) and clinical symptoms have been controversial. Five young male patients underwent testing for symptomatic MB, manifested as angina with evidence of ischemia or sudden death. Preoperative testing included atrial stimulation studies for evidence of lactate extraction and serial cardiac catheterization. Positive lactate production and/or extensive milking (>90%) of the proximal left anerior descending artery (LAD) were documented in 4 patients, who were, therefore, treated surgically by supra-arterial myotomy. Associated intraoperative mapping and endocardial resection were required for significant anterior aneurysm and scars. Postopera tive studies demonstrated resolution of the milking and/or intracoronary gradi ents. The remaining patient had recurrent sudden death, but negative lactate study, and was treated by automatic internal cardiac defibrillator (AICD).

Symptomatic young patients can present with pathologic compression of the proximal LAD from extensive MB. Complete supra-arterial myotomies were successful treatments. Other adjunctive surgical procedures: (1) mapping, (2) endocardial resection, and/or (3) AICD, were based on their preoperative stress testing and intraoperative findings.