Serum Enzymes in Experimental Myocardial Infarcts

Plasma adrenaline and noradrenaline concentrations and dopamine-beta-hydroxylase activity in myocardial infarction with and without cardiogenic shock.

“…There was a significant correlation between plasma noradrenaline concentrations and maximum observed cardiospecific LDH activities which is a crude index of infarct size (Killen and Tinsley, 1966). A similar relation between urinary excretion of noradrenaline and cardiospecific LDH activities has been noted.…”

Early Estimation of Myocardial Damage in Conscious Dogs and Patients with Evolving Acute Myocardial Infarction

“…Estimation of infarct size from analysis of serial serum CPK changes is based on the concept that myocardial CPK depletion is related quantitatively to the extent of myocardial necrosis. Enzyme release from myocardium into serum has been observed to be associated with irreversible injury by others (19)(20)(21)(22)(23)(24)(25)(26). The magnitude of myocardial CPK depletion has been correlated with the extent of ischemic injury assessed electrocardiographically (5,11), sustained decrease in regional blood flow (9), abnormalities in function of mitochondria isolated from the heart (27), prevalence of histologic changes indicative of necrosis (11), and the magnitude of functional impairment (11).…”

Quantitative assessment of the extent of myocardial infarction in the conscious dog by means of analysis of serial changes in serum creatine phosphokinase activity

“…Application of such techniques to man would be useful in clarifying the relationship between infarct size and ultimate prognosis. Several studies have been concerned with utilizing changes in serum enzyme concentration to assess the extent of myocardial infarction in experimental animals (14)(15)(16)(17)(18)(19) The present study was designed to obviate several of these difficulties. Conscious animals were used in order to avoid changes in serum enzyme activity due to thoracotomy or other invasive procedures at the time of coronary artery occlusion.…”

“…Results of several investigations suggest that there is a relationship between the magnitude of changes in serum enzymes and the extent of infarct size after coronary artery occlusion (14)(15)(16)(17)(18)(19), but the lack of close correlation has been disappointing. There are several reasons for this: (a) enzyme activity appearing in serum after myocardial infarction may reflect release not only from myocardial cells but also from other components in the heart participating in the inflammatory response, skeletal muscle, liver, and other parenchymal tissues (20,21); (b) the magnitude of peak serum enzyme elevation depends not only on infarct size but also on the rate of release of enzyme into the circulation, the enzyme distribution space, and the rate of enzyme disappearance from the circulation (20,22); and (c) current morphologic techniques for measuring infarct size unavoidably lack precision (18,23,24) limiting the validity of conclusions dependent upon anatomic criteria.…”