title: [Theoretical viewpoints of coronary hemodynamics relative to the localization of arterial stenoses and the collateral function with special reference to the so-called steal effect].
abstract: 1. On a simple branched model of the vascular system is deduced that the restriction of the reserve of blood supply (coronary reserve) occurring in arterial constrictions depends not only on the degree of constrictions, but also on their type of distribution, by means of which peculiarities of the univascular diseases in contrast to the multivascular diseases are the result. 2. Constrictions further the formation of the collateral circulation, the size of which in the same initial pressure increases with the degree of constriction and the decrease of the peripheral resistance. 3. The effects of the collateral circulation are fully different for proximally and distally localized stenoses. Proximal stenoses lead the collateral circulation in direction to the narrowed area, peripheral narrowings of the circulation, however, to the counter-direction. 4. A Steal effect is possible only in peripheral narrowings of the circulation. Its haemodynamic conditions are described in detail. 5. As haemodynamic explanation for the positive dipyridamol test the hypothesis arises that it might refer to remarkable peripheral constrictions. 6. The application of vasodilators is from the haemodynamic point of view indicated above all in proximal constrictions, when distally from this there are interarterial anastomoses. Repression is necessary in peripheral narrowings, when their reserve of blood supply is already consumed by vasodilatation. In these cases is to be reckoned with a Steal effect.
mesh_terms: D000787:Angina Pectoris / Q000139:chemically induced; D003097:Collateral Circulation; D003326:Coronary Circulation / Q000187:drug effects; D003327:Coronary Disease / Q000503:physiopathology*; D003331:Coronary Vessels / Q000503:physiopathology*; D004176:Dipyridamole / Q000009:adverse effects / Q000627:therapeutic use; D006801:Humans
chemical_list: D004176:Dipyridamole
vernacular_title: Theoretische Gesichtspunkte der koronaren Hämodynamik in Abhängigkeit von der Lokalisation arterieller Stenosierungen und der Kollateralenfunktion unter besonderer Berücksichtigung des sog. Steal-Effektes.