Myocardial infarction uptake

Tamaki N, Kawamoto M, Takahashi N, Yonekura Y, Magata Y, Nohara R et al. Prognostic value of an increase in fluorine-18 deoxyglucose uptake in patients with myocardial infarction comparison with stress thallium imaging. J Am Coll Cardiol 1993 22 1621-1627... 

Figure 3.1 Graph showing the ratio between inspired (FJ) and alveolar (FA) end-tidal concentrations of the agents shown. The least soluble agents approach equilibrium (FA/FI=1) the most rapidly. Also, since both inhalation and intravenous anaesthetic drugs tend to reduce cardiac output, they facilitate the uptake of volatile agents. It follows that any inhaled anaesthetic drug must be given with great caution to patients in shocked states, e.g. hypovolaemia, arrhythmias, myocardial infarction.

Nanoparticles formulated with PLGA have been shown to be rapidly uptaken by the endothelial cells, the uptake was shown to depend on the nanoparticle concentration and the particles where mainly shown to localize in the cytoplasm (207). These nanoparticles were also shown to be biocompatible with the cells with no effect on cell viability (207). This is important due to the fact that endothelium is an important target for gene therapy in a number of disorders including angiogenesis, atherosclerosis, tumor growth, myocardial infarction, limb and cardiac ischemia, restenosis (207). 

Rubidium-82 myocardial perfusion images are used to study patients with myocardial ischemia or infarction. An example of this study is shown in Figure 8. Three patients with known myocardial infarction were imaged with Rb-82. Twenty millicuries of Rb-82 were administered in a 20 ml bolus in 20 sec. Data accumulated from 0-90 seconds post infusion show the blood pool as the radioactivity enters the right side of the heart, flows out to the lungs, and returns to the left side of the heart. Data accumulated from 90-300 seconds reflect uptake of Rb-82 in the myocardium as distributed by blood flow. These results by a non-invasive procedure correlated with the results of catheterized contrast x-ray studies (27,28). 

Insulin is an endogenous hormone produced by fi-cells of islets of Langerhans of the pancreas, which consist of two chains of amino acids. It is required to be administered by a parenteral routes as it is destroyed when given orally. Insulin is used for the control of IDDM and in the emergency management of diabetic ketoacidosis.30 Insulin promotes the intracellular uptake of potassium and is used in hyperkalemia. Baker et al.31 have used insulin and glucagon in the treatment of liver disorders. Recent evidence indicates that the effects of insulin with glucose and potassium in ischemic heart disease have proved beneficial.32 It also is used in acute myocardial infarction.32... 

The diagnosis of depression and the use of antidepressant medication are both associated with an increased risk of myocardial infarction. The relative contribution of these two factors is uncertain. In a case-control study of 2247 subjects, taking antidepressants was associated with a 2.2-fold (Cl = 1.3, 3.7) increase in the risk of myocardial infarction (43). This increased risk seemed to be accounted for entirely by the use of tricyclic antidepressants, because selective serotonin re-uptake inhibitors were not associated with an increased risk, although the confidence intervals were wide (relative risk 0.8 Cl = 0.2, 3.5). These findings support the usual clinical advice that... 

Fig. 2 Gamma images of four dogs with acute experimental myocardial infarction, injected with high affinity In-labeled antimyosin Fab (Ka = 0.5-1 x 10 L/M) (A and C), In-labeled non-specific monoclonal Fab (B) and the low affinity In labeled 3H3 antimyosin Fab (Ka = 5 x 10 L/M) (D). At 5h post intravenous administration of these antibodies, only the images with high affinity antimyosin showed unequivocal infarct uptake, whereas the images with non-antimyosin specific monoclonal Fab and the low affinity antimyosin Fab showed only blood pool activity. (From Ref. l)...

Atherosclerosis is a chronic inflammation of the arterial vessel wall resulting in plaque formation that eventually may cause cardiovascular events, such as myocardial infarction or cerebral vascular accidents. The presence of autoimmune components in atherosclerosis is well established. Autoantibodies to heat-shock proteins and oxidized low-density lipoproteins (oxLDL) are prevalent in the circulation of patients with atherosclerosis, but the role of these autoantibodies is debated. While anti-oxLDL IgG antibodies may facilitate uptake of oxLDL by foam cells in the lesions, natural IgM antibodies directed to oxLDL may even protect from atherosclerosis. Atherosclerotic plaques also contain some T cells that are considered to be autoreactive, although the respective autoantigens have not yet been identified. These T cells are probably not involved in the plaque formation as such, but they may cause plaque instability, rupture, and subsequent clinical events. 

Cocaine is a central nervous system stimulant that inhibits the peripheral re-uptake of catecholamines, leading to increased sympathomimetic activity [115]. Its abuse is associated with a variety of medical problems. These include acute myocardial infarction, cardiac arrhythmias, cerebrovascular accidents, hyperpyrexia and stimulated sympathetic activity, seizures and coma, obstetrical complications, intestinal ischemia, and a variety of psychiatric complications [114-117]. The most prominent renal complication of cocaine abuse is acute renal failure associated with rhabdomy-olysis. 

Patients with cardiotoxic lesions resulting from an excess treatment with Adriamycin (doxorubicin) showed a diffuse accumulation of " Tc-PYP in the heart, which otherwise is known only as localized uptake in focal lesions of myocardial infarction. Similar images have been observed in patients after defibrillation and reanimation treatment (Chacko et al. 1977). 

Uptake of Tc-PYP in acute myocardial infarction was detected with higher sensitivity than were the known Tc-diphosphonate complexes (Kelly et al. 1979). Using a rat model, the percentage of injected activity per gram of infarct was approximately 2.4 times higher than with Tc-MDP (Davis et al. 1976). Visualization of the infarct can be effected from 24 h-7 days after the onset of symptoms and with maximum sensitivity (96%) between 48 and 72 h (Kelly et al. 1979). 

The GLP-1 receptor is expressed in the heart [56], In GLP-1 receptor knock-out mice structural and functional cardiac abnormalities are typical [217], In animals, exposure to GLP-1 reduces the size of myocardial necroses in the case of induced infarction [218]. In a pilot study with patients treated for acute myocardial infarction, a 48-h infusion of GLP-1 improved left-ventricular function and a waU-motility index [219]. In a dog model of dilated cardiomyopathy, GLP-1 increased glucose uptake and left-ventricular function [220]. These findings. 

Cardiac scintigraphy can be used to obtain parameters of cardiac perfusion and function. 99mTc-pyrophosphate can be used to assess acute myocardial infarction. In the case of myocardial infarction the agent localizes in the area of necrotic tissue, forming an intense spot of radioactivity. Global uptake of activity in the ventricular myocardium usually represents some other cardiac disease. 

Figure 13.4 (See color insert) SPECT study of myocardial infarction. Notice that the increase in uptake of [ Tc]BTAP annexin V corresponds to the perfusion deficit identified in the [ Tc]MIBI scan. This data is reproduced with permission from Ref. (16).

Tissue, leukocyte, and plasma levels of ascorbic acid are quite variable and tend to fall in a "stress" situation (even myocardial infarction), with a corresponding fall in urinary excretion of ascorbic acid in the unsupplemented state.18 24 xhe amount of vitamin C within leukocytes on the 2nd or 3rd day after the onset of a cold is often at scorbutic levels,19 although the mechanisms of ascorbic acid uptake by leukocytes are not imparled by the stress of infection.23... 

---