Serum concentrations of myoglobin, creatine kinase, lactate dehydrogenase and cardiac isoenzymes in euthyroid, hypothyroid and hyperthyroid subjects.

Serum concentrations of myoglobin, creatine kinase and lactate dehydrogenase were measured in 33 euthyroid, 21 hyperthyroid and 15 hypothyroid subjects. The results showed that myoglobin, creatine kinase and lactate dehydrogenase were increased and decreased in the hypo- and hyperthyroid states, respectively. In addition, the concentrations of myoglobin, creatine kinase and lactate dehydrogenase values were inversely related to both the thyroxine and triiodothyronine concentrations. To study the origin of the increased muscle protein values observed in hypothyroidism, the cardiac isoenzyme fractions were measured; the results obtained support the view that the muscle enzymes are mainly derived from skeletal muscles.

[Changes on release of MB isoenzyme of creatine kinase by propranolol in acute myocardial infarction (author's transl)]. / Modificazioni indotte da propranololo sulla liberazione dell'isoenzima MB della creatin-chinasi nell'infarto acuto del miocardio.

MB isoenzyme of creatine kinase was measured every 3 hours during the first 24 hours of admission to C.C.U. and successively every 4-6 hours in the next 24-48 hours in 42 patients with acute transmural myocardial infarction. The pain-C.C.U. admission time interval was less than 6 hours in all cases. 22 patients were treated by propranolol (2 mg bolus followed by 0.1 mg/Kg/die for the next 48 hours in continuous i.v. infusion), 20 patients served as a control. Cumulated activity, peak plasma value, rate of release and total duration of release of MB-CK did not differ significantly between the two groups. In patients treated within 3 hours from pain onset (n = 12) cumulated activity, peak plasma value and rate of release of MB-CK were significantly inferior than control group. In patients treated between the 3rd and 6th hour from pain onset (n = 10) the total duration of release of isoenzyme was significantly prolonged. No treated patients developed clinical or radiologic signs of cardiac insufficiency. The incidence of ventricular arrhythmias was 17% in the treated group vs. 62% in the control group (P < 0.05). The data show that propranolol, if started early in the course of acute myocardial infarction, reduces significantly infarct size and slows down the evolution of necrotic process.

[Effect of cardiopulmonary bypass on serum digoxin concentration (author's transl)]. / Influenza della circolazione extracorporea sul tasso ematico della digitale: osservazioni preliminari

The use of digitalis following cardiopulmonary bypass is studied by digitalemia's radioimmunoassay. The Authors does not find relation between digitalis and post operative arrhytmias. They think digitalis's tolerance is very good but suggest that further studies are necessary to state the correct use of the drug after open heart surgery.