Acute reversible myocardial infarction after blood transfusion in the aged

Seven elderly cases with reversible electrocardiographic changes simulating acute myocardial infarction in the absence of gross myocardial infarction on postmortem examination were observed following the blood transfusion. The underlying diseases were cancer of gastrointestinal tract or gall bladder in 4, gastric ulcer in 2, and 1 of pseudomembranous enterocolitis. The electrocardiogram revealed the abnormal Q waves with monophasic ST elevation and following coronary T inversion. These findings lasted only for 2 to 7 days and returned to the previous normal tracings. The hematocrit was elevated from 28.9 to 47.7 after the blood transfusion of 800 to 1,800 ml. The disseminated intravascular coagulation was shown in 5 cases. GOT levels were within normal ranges except 1 case. Pathological findings in cases with recent electrocardiographic changes were characterized by the mural thromboses, extending into the myocardium through the Thebesian vein. The focal small necroses of the adjacent myocardium or around the thrombosis of small vessels were also observed. In the later phase the fine interstitial fibrosis took place after the resorption of the thrombi and necrotic foci. From these clinical and pathological findings we proposed a new concept of reversible myocardial infarction induced from the hypercoagulability, disseminated intravascular coagulation, and elevated hematocrit.

An adenosine 3':5'-monophosphate-dependent protein kinase from human heart

Protein kinase that phosphorylated histone and lesser amounts of protamine was demonstrated in human heart. It was activated three times by 10(-6) M cyclic adenosine 3':5'-monophosphate (cAMP) and by 10(-3) M other cyclic nucleotides. Km values for cAMP, ATP, Mg2+, and Co2+ were about 2 X 10(-8) M, 4 X 10(-5) M, 2 X 10(-3)M, and 1.7 X 10(-4) M, respectively. On DEAE cellulose column, the main peak of the enzyme eluted at high NaCl concentration. On Sephadex G-200 gel filtration the majority of the holoenzyme eluted at a peak corresponding to a molecular weight of about 300,000. There was an additional peak corresponding to a molecular weight of about 400,000, with relatively high cAMP binding compared to kinase activity. Right atrium and ventricle showed significantly higher enzyme activities than left atrium and ventricle and interventricular septum. On multivariate analysis of the enzyme activity versus 12 clinical and pathological findings of 122 cases, cardiac hypertrophy and coronary sclerosis were slight but significant negative contributors to the enzyme activity. Multiple correlation coefficient was low, indicating the enzyme activity remained at a relatively stable level, despite different clinical situations. This may be suitable for control of intracellular events through the membrane adenylate cyclase system.