Source:http://linkedlifedata.com/resource/umls/id/C0004247
MSH: A small nodular mass of specialized muscle fibers located in the interatrial septum near the opening of the coronary sinus. It gives rise to the atrioventricular bundle of the conduction system of the heart.,CSP: small nodular mass of specialized muscle fibers located in the interatrial septum near the opening of the coronary sinus.,FMA: Subdivision of conducting system of heart which is located in the muscular part of the interatrial septum that is continuous with the atrioventricular bundle.,NCI: A small mass of specialized cardiac muscle fibers, located near the ostium of the coronary sinus and giving rise to the atrioventricular bundle of the conduction system of the heart.