Myocardium

Myocardium (myocardopathy), a collective term most often used to denote more or less complete anatomical conditions arising in the myocardium for various reasons and causing functional insufficiency of the heart muscle. In essence, therefore, myocardium is one manifestation of cardiopathy (see). Among the pathological processes leading to myocardium, cardiac sclerosis (see) is mainly considered. Myocardium should also include obesity of the heart muscle, especially of the right ventricle, when fatty tissue separates the myocardium into individual fibers or small complexes thereof. Myocardium also includes that functional insufficiency of the myocardium which occurs in hypertrophied and dilated hearts in cases of valve defects, then in various persistent disorders of the heart's conduction system, and finally in prolonged purely toxic effects on the myocardium, for example in Basedow's disease (thyrotoxicosis). It is incorrect to designate inflammatory and degenerative processes in the myocardium (see Myocarditis) as well as necroses of the latter (see Myomalacia) as myocardium. On the other hand, since these processes often lead to persistent disorders of the morphological and functional properties of the myocardium, they can be the cause of myocardium. The clinical signs of myocardium are dilation of the heart's borders, mainly due to dilation of its cavities; sometimes systolic murmurs occur in connection with relative insufficiency of the mitral valve. The tones are usually muffled. High degrees of myocardium give all the symptoms of decompensation of the heart muscle. Lit.—see lit. to article Cardiac Sclerosis.