Metabolic and neurohumoral aspects of acute myocardial ischemia in man

This thesis aims at defining the relevance and applicability of some metabolic aspects of acute myocardial ischemia to delineate occurrence and extent of the latter in man. Studies focus on myocardial lactate metabolism and adenine nucleotide catabolism, correlate changes with other markers of ischemia and attempt to define a temporal relation with regional changes in coronary flow. Next, the acute antiischemic properties of different vasoactive compounds are outlined using these metabolites in a properly defined study model. Studies also attempt to differentiate the usefulness of various vasodilator compounds as antiischemic therapy in relation to the underlying cardiac function. In the second part of this thesis the impact of myocardial ischemia on systemic and cardiac neurohormones, i.e. catecholamines and renin-angiotensin system(s), are discussed. The relation between degree of ischemia and neurohumoral activation will be emphasized, potential subsequent systemic and coronary vasoconstrictor effects mentioned, and the usefulness of neurohumoral modulation, i.e. by converting enzyme inhibition in the treatment of myocardial ischemia indicated.