Stress heart

Guanylyl cyclase catalyses the reaction GTP — cGMP + pyrophosphate (PP ). Heart stress (e.g. atrial stretch due to increased blood pressure and hence increased cardiac muscle work)... 

Thallium-201 is a radioisotope used by medical professionals to determine the health of a persons heart. During a thallium-201 scan, also called a heart stress test, a patient performs physical activity and is injected with thallium-201 one to two minutes before stopping the activity. The isotope emits gamma rays that are recorded by a detector to display a two-dimensional image of the heart and its blood supply. If gamma rays are not detected in certain areas in and around the heart, the areas are considered cold. This means that the blood supply has been impeded or blocked, a condition that often leads to heart attack or stroke. 

The heat stress plan at Site F detailed methods for monitoring workers heart rate and oral temperature, but did not designate the personnel responsible for performing sueh monitoring, nor did it inelude information about the availability or loeation of instruments for aetually monitoring sueh parameters. In addition, the plan did not identify or diseuss the loeation and availability of drinking water. 

The second method is by use of the heart rate. The total heart rate is regarded as a sum of several components and, in general, is linearly related to the metabolic heat production for heart rates above 120 beats per minute. Heat stress will, however, also increase the heat rate. The third method is to calculate the metabolic heat production from measures of oxygen consumption, and carbon dioxide production during activity and recovery. 

An arrhythmia may occur as a result of heart disease or from a disorder that affects cardiovascular function. Conditions such as emotional stress, hypoxia, and electrolyte imbalance also may trigger an arrhythmia An electrocardiogram (ECG) provides a record of the electrical activity of the heart. Careful interpretation of the ECG along with a thorough physical assessment is necessary to determine the cause and type of arrhythmia The goal of antiarrhythmic drug therapy is to restore normal cardiac function and to prevent life-threatening arrhythmias. 

Gnkgo (maiden hair tree, kew tree) Ginkgo biloba Raynauds disease, cerebral insufficiency anxiety, stress, tinnitus, dementias, circulatory problems, asthma Rare if used as directed possible effects include headache, dizziness, heart palpitations, Gl effects, rash, allergic dermatitis Do not take with antidepressant drugs, such as the MAOIs, or the antiplatelet drugs such as coumarin, unless advised to do so by the primary care provider. 

Currie, R.W. (1987). Effects of ischemia and perfusion temperature on the synthesis of stress-induced (heat shock) proteins in isolated and perfused rat hearts. J. Mol. Cell. Cardiol. 19, 795-808. 

Salo, D.C., Donovan, C.M., Davies, K.J, (1991). Hsp70 and other possible heat shock or oxidative stress proteins are induced in skeletal muscle, heart, and liver during exercise. Free Radic. Biol. Med 11,239-246. 

Several doubts about the correctness of the usual statistical treatment were expressed already in the older literature (31), and later, attention was called to large experimental errors (142) in AH and AS and their mutual dependence (143-145). The possibility of an apparent correlation due only to experimental error also was recognized and discussed (1, 2, 4, 6, 115, 116, 119, 146). However, the full danger of an improper statistical treatment was shown only by this reviewer (147) and by Petersen (148). The first correct statistical treatment of a special case followed (149) and provoked a brisk discussion in which Malawski (150, 151), Leffler (152, 153), Palm (3, 154, 155) and others (156-161) took part. Recently, the necessary formulas for a statistical treatment in common cases have been derived (162-164). The heart of the problem lies not in experimental errors, but in the a priori dependence of the correlated quantities, AH and AS. It is to be stressed in advance that in most cases, the correct statistical treatment has not invalidated the existence of an approximate isokinetic relationship however, the slopes and especially the correlation coefficients reported previously are almost always wrong. 

Oxidant Stress and the Heart Modulation of Ion Transport Mechanisms During Ischaemia and... 

While many biological molecules may be targets for oxidant stress and free radicals, it is clear that the cell membrane and its associated proteins may be particularly vulnerable. The ability of the cell to control its intracellular ionic environment as well as its ability to maintain a polarized membrane potential and electrical excitability depends on the activity of ion-translocating proteins such as channels, pumps and exchangers. Either direct or indirect disturbances of the activity of these ion translocators must ultimately underlie reperfiision and oxidant stress-induced arrhythmias in the heart. A number of studies have therefore investigated the effects of free radicals and oxidant stress on cellular electrophysiology and the activity of key membrane-bound ion translocating proteins. 

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