Cardiovascular system advantages

One claimed advantage of exercise in the elderly is to maintain an effective cardiovascular system so that a mild trauma or infection does not overload the system and the brain receives its required supply of oxygen and fuel under such conditions i.e. physical fitness allows the elderly person to respond adequately to a mild stress not... 

Conclusion -2% selective advantage is adequate to conserve one pathway required in the network controlling the cardiovascular system in pinnipeds... 

Cardiovascular system. Both caffeine and theophylline directly stimulate the myocardium and cause increased cardiac output, tachycardia and sometimes ectopic beats and palpitations. This effect occurs almost at once after i.v. injection and lasts half an hour. Theophylline contributes usefuUy to the relief of acute left ventricular failure. There is peripheral (but not cerebral) vasodilatation due to a direct action of the drugs on the blood vessels, but stimulation of the vasomotor centre tends to counter this. Changes in the blood pressure are therefore somewhat unpredictable, but caffeine 250 mg (single dose) usually causes a transient rise of blood pressure of about 14/10 mmHg in occasional coffee drinkers (but has no additional effect in habitual drinkers) this effect can be used advantageously in patients with autonomic nervous system failure who experience postprandial hypotension (2 cups of coffee with breakfast may suffice for the day). In occasional coffee drinkers 2 cups of coffee (about 160 mg caffeine) per day raise blood pressure by 5/4 mmHg. Increased coronary artery blood flow may occur but increased cardiac work counterbalances this in angina pectoris. 

Atracurium is unique in that it is altered spontaneously in the body to an inactive form (t 30 min) by a passive chemical process (Hofmann elimination). The duration of action (15-35 min) is thus uninfluenced by the state of the circulation, the liver or the kidneys, a significant advantage in patients with hepatic or renal disease and in the aged. It has very little direct effect on the cardiovascular system... 

Reduction of portal pressure. Vasopressin (anti-duiretic hormone, see p. 711), in addition to its action on the renal collecting ducts (through receptors), constricts smooth muscle (Vj receptors) in the cardiovascular system (hence its name), and particularly in splanchnic blood vessels, so reducing blood flow in the portal venous system. Unfortunately, coronary vasoconstriction can also occur, and treatment has to be withdrawn from 20% of patients because of myocardial ischaemia. Glyceryl trinitrate (transdermally, sublingually, or intravenously) reduces the cardiac risk and, advantageously, further reduces portal venous resistance and pressure. 

This simultaneous availability of all data characterizing the anatomy of the cardiovascular system and the changes of structure and blood flow with time, i.e. function is the main reason for the specific advantages of digital over conventional angiocardiographic imaging techniques. 

Cardiovascular tissue engineering aims to create functional tissue scaffolds that can re-establish the structure and function of injured sites of the cardiovascular system. A considerable amount of cardiovascular therapeutics, particularly for major and serious disorders, involves the use of devices. Some of these may be implanted by surgery, whereas others are inserted via minimally invasive procedures involving catheterization. Although different synthetic materials have been used for the development of cardiovascular devices, PUs have several advantages over the others. Besides their biocompatibility and their mechanical flexibility [100-103], PUs have very high flexural endurance compared to most elastomers, making them prime candidates for cardiovascular implants. 

In view of his cardiovascular status and proteinuria, WD should be on anti-ACE therapy of some kind. If he is unable to tolerate an ACE inhibitor, an alternative might be to try an ARB. This has the advantage of blocking the renin-angiotensin system, thereby achieving the required therapeutic effect, but since ACE itself is not affected, the patient should not develop a cough. 

From Goldman L, Hashimoto B, Cook F, et al. Comparative reproducibility and validity of systems for assessing cardiovascular functional class Advantages of a new specific activity scale. Circulation i 981 64 i228, with permission. 

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