This symposium on cerebral and coronary vascular disorders and infarcts is probably the first attempt to hold a joint discussion in this field. Despite many difficulties we feel that it has been successful and we hope that it will stimulate further interest and investigations. To hold such a meeting with scientists from far away was possible only with the assistance of Bundesminister fUr Jugend, Familie und Gesundheit, Minister fUr Hissenschaft und Forschung des Lan- des Nordrhein-Westfalen, Max-Planck-Gesellschaft zur Forderung der Wissenschaften e.V., Deutsche Forschungsgemeinschaft, to whom we are very grateful. Moreover the pharmaceutical industry gave assistance in the organization and the transcript of the pro- ceedings. Dr. G TZE of Springer-Verlag, was, as we will explain later, the original promotor of the idea for such a meeting. We should like to thank Springer-verlag for the excellent layout and quality of this book. Koln, Spring 1977 K.J. ZULCH, W. KAUFMANN K.-A. HOSSMANN, V. HOSSMANN Contents Welcome K.J. ZULCH xv Introduction W. KAUFMANN ............................................... XIX Coronary Circulation with Special Remarks on the Extra- vascular Component of Resistance and on Collateral Flow W. LOCHNER, H. P. DIEMER, and J. WICHMANN. With 5 Figures ..