The Clinical Application Of Magnetocardiography In Diagnosis Of Coronary Heart Disease

Objective:To evaluate the clinical application of magnetocardiography (MCG) in diagnosis of coronary heart disease (CHD).Methods:(1) MCG measure were performed in493patients by CMI-2409MCG instrument manufactured by CardioMag Imaging company.383cases with coronary heart disease (coronary angiography showed that at least one major branch of coronary artery stenosis≥50%),253male,130female, age59.56±9.60years;110cases with non-coronary heart disease (coronary angiography showed that at least one major branch of coronary artery stenosis<50%),52male,58female, age51.15±8.60years. Seven parameters of MCG were analyzed, which have significant difference between CHD and non-CHD group, Pre-peak repolarization Angle, Pre-peak repolarization Trajectory, Pre-peak repolarization Angular Deviation, Post-peak repolarization Angle, Post-peakre polarization Trajectory, Post-peak repolarization Angular Deviation, Pre-Post Angle Change, Pre-Post Angle Changeand the seven parameters joint.The sensitivity and specificity for diagnosis of coronary heart disease were analyzed in the meantime.(2)CHD patients were divided into mild stenosis group, moderate stenosis group, severe stenosis group and complete occlusion group, according to degree of coronary artery stenosis; CHD patients were divided into single vessel stenosis group, double vessel stenosis group, and triple vessel stenosis group according to the number of stensis vessels. Single vessel patients were divided into LAD group, LCX group, and RCA group according to the coronary artery stenosis; based on a history of coronary heart disease patients were divided into myocardial infarction group and non-myocardial infarction group. The difference between every subgroup in each group of seven parameters and the seven parameters joint were compared, and analyzed the relationship between MCGand the degree of the vessel stensis, the scope of the vessel stensis and the lesion of the vessel stensis.Results:(1) For diagnosis of coronary heart disease, the sensitivity of Pre-Angle Pre-Trajectory, Pre-Angular Deviation, Post-Angle, Post-Trajectory, Post-Angular Deviation, Pre-Post Angle Change were40.73%、51.17%、50.39%、30.81%、52.74%、 55.87%、31.59%respetctively, the specificity were83.64%、71.82%、73.64%、90.91%、70.91%、71.82%、97.27%respectively. Post-Angle, Pre-Post Angle Change the diagnostic specificity all above90%,positive likehood ratio were3.39,11.58respectively. Two or more parameters were positive, the sensitivity for diagnosis of coronary heart disease was70.76%and specificity was63.64%, with the positive number increase, the specificity decrease and specificity gradually increase, five or more parameters were positive, the sensitivity for diagnosis of coronary heart disease was89.09%and specificity was32.64%.(2) Significant difference were found in Pre-peak repolarization Angle and Post-peak repolarization Angular Deviation between single vessel stenosis group, double vessel stenosis group, and triple vessel stenosis group. Significant difference were found in Post-peak repolarization Angle between single vessel stenosis group, and triple vessel stenosis group. For Post-peak repolarization Angular Deviation the sensitivity for diagnosis of triple vessel stenosis was61.70%, specificity was71.82%. Three or more parameters were positive,the sensitivity for diagnosis of coronary heart disease was78.72%, specificity was63.63%.(3) For Post-peak repolarization Trajectory, the sensitivity for diagnosis of RCA group was60.00%, specificity was70.91%.(4) Significant difference were found in Pre-peak repolarization Angle and Post-peak repolarization Angle between mild stenosis group, moderate stenosis grou and complete occlusion group.For Post-peak repolarization Angular Deviation the sensitivity for diagnosis of complete occlusion group67.16%, specificity was71.82%. One or more parameters were positive,the sensitivity for diagnosis of complete occlusion was82.09%, two or more parameters were positive,the sensitivity for diagnosis of complete occlusion was77.61%, three or more parameters were positive,the sensitivity for diagnosis of complete occlusion was71.64%.(5) For Post-peak repolarization Angular Deviation, the sensitivity for diagnosis of myocardial infarction was67.74%, specificity was91.82%. Two or more parameters were positive,the sensitivity for diagnosis of myocardial infarction was80.65%and specificity of63.64%.Conclusion:(1) MCG is a valueable method of the diagnosis of coronary heart disease, with the positive parameters increase, the reliability of diagnosis of coronary heart disease increase, especially Post-peak repolarization Angle, Pre-Post Angle Change can diagnosis coronary heart disease.(2) Post-peak repolarization Angular Deviation is a higher value parameter for diagnosis the sever coronary artery stenosis.(3) Post-peak repolarization Trajectory is higher value parameter for diagnosis the RCA stenosis.