Criteria for early diagnosis of myocardial perfusion disorders in asymptomatic patients with myocardial bridges

Introduction. Myocardial bridges (MBs) are the most common congenital anomaly of coronary arteries development, mainly affecting the left anterior descending (LAD) artery.Аim. To develop criteria for early diagnosis of myocardial perfusion disorders in asymptomatic patients with MBs of the LAD artery.Materials and methods. The study was conducted in several stages. At the first stage, 811 coronary computed tomography (CT) angiography reports were analyzed to identify patients with MBs of the LAD artery and to assess their anatomical and topographic features. At the second stage, 20 medical histories of patients with MBs of the LAD artery (main group) and 20 medical histories of patients without MBs (comparison group) were analyzed to assess the clinical significance of MBs. At the third stage, 20 patients with asymptomatic MBs of the LAD artery (main group) and 20 patients without MBs (comparison group) were examined, who underwent stress CT myocardial perfusion and speckle tracking echocardiography (STE) to assess the effectiveness of these methods of the early diagnosis of myocardial perfusion disorders in patients with MBs. Based on the obtained results, criteria for early myocardial perfusion disorders in asymptomatic patients with MBs of the LAD artery were developed.Results. Clinical and laboratory parameters: (male gender, age < 60 years, dyslipidemia) and instrumental data: 1) 24-hour Holter monitoring: supraventricular and ventricular heart arrhythmias, silent myocardial ischemia (more than 1 min); 2) treadmill test (bicycle ergometry): ST segment depression or elevation in leads V1–2, the Duke Treadmill Score ≤ -1 point; 3) echocardiography: E/A ≤ 1, e’mean ≤ 8.5 cm/sec, E/e’mean ≥ 9; 4) STE: global longitudinal peak strain of the left ventricle ≤ -20.55%.Conclusions. The developed criteria allow to suspect the presence of myocardial perfusion disorders in asymptomatic patients with MBs of the LAD artery, for confirmation of which it is necessary to perform imaging methods of investigation, in particular, stress CT myocardial perfusion.