Myokardosestudien: Pathoklise der Herzkammern auf Grund seitendifferenter Struktureigenheiten

Heterochronia and general pathology illustrated by the example of the human heart

Heterochronia, heterotopia and heterometria are important elements of the pathogenic process. Heterochronia has its historical roots in the philosophy of Aristotle. As the organs of living creatures and especially man have developed, the process has been one of fitting together a variety of evolutionary bricks. Each complex organ shows evidence of a gradual control of its cellular structure. Parts of organs observed at different stages of man's development all appear to retain certain heterologous (identical) organisational features. Thus, the different pathoclisis is explained. Classical Neuropathology has made headway in this field. Its methodical procedure was adopted - mutatis mutandis - by General Pathology. The inherent structural weaknesses within the organisation of the human brain are, in their organic type of differentiation, also present in the muscular heart. The right ventricle has developed mainly from the myoepicardium of the proampulla; the left ventricle has its origin in the metaampulla. The right ventricle consists mainly of priscomyocardium, the left one of neomyocardium. This is the basis on which are founded the main characteristics of the muscular structures, the arrangement of the coronary arteries and the organisation of the conduction system. A. Keith had already discovered in 1906 that the elements of specific muscle texture contain old structures. We believe that the pacemaker cell represents the historical paradigm of the working muscle cell of the heart (the transporter). Atrioventricular collateral connections (anastomoses) are only found within the priscomyocardium, the arteria coronaria dextra being the original. The coronaria sinistra was evolved later. From the summary of facts originating from the heterochronia of heart development we can draw conclusions about the development of the major heart diseases such as: Those which are dependent on interference with the ventricle walls following oxygen deprivation and the resulting toxic stress; Those which are characterised by infarction of the myocardium which occur in areas which have a predilection for such reaction and which can be set out in a predetermined topology; Those characterised by rhythmic interferences of the heart caused by atrioventricular collateral connections; as a result of an anthropological pathomorphology.

Manifestation and ultrastructural typing of amyloid deposits in the heart

Using light and electron microscopy, 65 cases of amyloid deposits in the heart were examined. Five different groups were distinguished: I. isolated atrial amyloidosis, II. senile cardiac amyloidosis, III. cardiac amyloid accompanying chronic infections and tumors, IV. cardiac amyloid accompanying plasma cell dyscrasia, V. idiopathic cardiac amyloidosis. Seen structurally, no principal differences in the precise localization of the amyloid deposits were found in any of the groups investigated. Amyloid is always deposited in the vicinity of cells with myocytic cell differentiation (i.e. the heart muscle cells, non-striated muscle cells of the vessels), whereby the relevant basement membranes serve as conductors. A systematic relationship between amyloid and the collagenous fibers of the interstitium or the tunica adventitia of the vessels could not be demonstrated, which shows the concept "pericollagen" to be inadequate for the morphological characterization of amyloid deposits in the heart. Whereas for group I a localized mechanism for the production of amyloid must be considered, in the case of groups II-V a vascular principle expression of a generalized amyloidosis seems to be the major factor. The question of the differing concentration of amyloid deposits in the heart suggests that localized factors (e.g. changes in the myocytic basement membranes) and quantitative changes of the amyloid-building proteins may also be important.

[Mineral content and morphology of heart muscle in different causes of death (author's transl)]

Mineral and water content of the right and left heart muscle were analyzed by atomic absorption spectrophotometry in 93 autopsy cases. Sodium, potassium, magnesium, and calcium concentrations were measured after acid digestion of tissues. Marked differences of the element distribution of both ventricles are seen constantly, although a significant correlation between water content and sodium as well as potassium and magnesium concentrations in both ventricles in seen. Comparing multiple causes of death (cardiac and non-cardiac) there are no differences in the postmortem mineral contents of heart muscle. Age-dependent correlations of mineral concentrations (as seen by Burger, 1960) were not detectable in this investigation. Postmortem mineral analyses of human heart muscles are excessively influenced by modern intensive care. Most of our cases had several causes of death, one of which was to be declared as the main cause of death in the necropsy record. Postmortem chemical mineral analysis of heart muscle can give an exact description of local variations and-in special cases-signs of general disorders of mineral metabolism, which are not detected by exclusively histologic investigations.

[Myocardial electrolytes in "cardioplegic" myocardosis (author's transl)]

Changes of the mineral concentrations of the heart muscle can point at disturbances of myocardial metabolism. Disturbances of heart muscle with functional loss and without coronary or inflammatory heart disease are called myocardosis, especially cardioplegic myocardosis after open-heart surgery with extracorporal bypass. 30 dogs were examined in three groups varying the method of induced cardiac arrest: 1. ischemic cardiac arrest by clamping the ascending aorta, 2. functional cardiac arrest by electrically induced fibrillation and 3. ischemic cardiac arrest and in addition injection of a Mg-aspartate-procain-solution. Sodium, potassium, magnesium, calcium, copper and zinc were analyzed by atomic absorption spectrophotometry. Specimens from the left and right ventricular wall were examined before and after extracorporal circulation. After a recovery period for one hour the dogs were killed and specimens from the right and left ventricular wall and from the basis and apex of the interventricular septum were taken and reduced to ashes with mineral acids. In all animals changes of the mineral content were most marked after the recovery period. In all forms of cardiac arrest mineral metabolism showed monotone reactions: water content increased, potassium and magnesium decreased. Variations of mineral concentrations were more expressed in the right ventricular wall than in the left. Animals with cardiac arrest by electrically induced fibrillation indicated the smallest deviations from the basic values. The comparison of the values of dogs with sufficient circulation at the end of the experiments and those dogs with medicamentally or mechanically supported circulation at this time showed a more increased water content and simultaneously a decrease of all cations in the group with supported circulation. The decrease of the osmolality of the cations seems to be the metabolic answer to the increased cardioplegic damage of heart muscle.