Cardiovascular Factors

Defects or imperfections as small as 10 microns [in an artificial heart] were sufficient to form platelet clumps leading to thromboembolic complications. 

FIGURE 7.4.10 Mass of the heart is related to body mass. (From Dawson, T.H., Engineering Design of the Cardiovascular System of Mammals, Prentice Hall, Englewood Cliffs, NJ, 1991. With permission.) 

As a rule, smaller animals have faster heart rates than larger animals (Dukes, 1955). The allometric relationship (Rgure 7.4.11) for this is (Dawson, 1991) 

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The levels of cardiovascular factors could also be influenced by the ability of vitamin E to affect activation of arachidonic acid from membrane phospholipids by phospholipase A2. Vitamin E, either given in the diet or by incubation with platelets themselves, was found to inhibit phospholipase A2 in a dose-dependent manner. a-Tocopheryl acetate had little or no effect on the activity of this enzyme, but tocol, without methyl groups in the chroman ring, was more potent than either (+)- or ( )-a-tocopherol, suggesting that the methyl groups were not important for the inhibition but the hydroxy group in the ring was critical for activity [131]. 

Mikes Z, Ebringer L, Boca M, Dusinsky R, Jahnova E (2005) Some cardiovascular factors after consumption of the traditional Slovak bryndza cheese - pilot study (in Slovak). Geriatria 1 29-36... 

Device Markets. New markets for cardiovascular devices are driven by a least five interrelated factors. Technology, competition, economics, consumer demand, and symbiosis of dmgs and devices all play roles. 

Hypertension is one of the two principal risk factors of many cardiovascular diseases, such as coronary heart disease (CHD), stroke, and CHF. Individuals are considered hypertensive if their systoHc arterial blood pressure is over 140 mm Hg (18.7 Pa) or their diastoHc arterial blood pressure is over 90 mm Hg (12 Pa). Over 60 million people, or one-third of the adult population in the United States are estimated to be hypertensive (163). About 90% of these patients are classified as primary or essential hypertensive because the etiology of their hypertension is unknown. It is generally agreed that there is a very strong genetic or hereditary component to this disease. 

Another study (84), which enrolled men and women between the ages of 21—55 who had mild hypertension and no recognizable cardiovascular risk factors, showed no significant differences in mortaUty between dmg- and placebo-treated patients. Significant reductions in hypertensive complications were noted, but atherosclerotic complications were not reduced. 

Criteria for initiation of drug treatment now take into consideration total cardiovascular risk rather than blood pressure alone, such that treatment is now recommended for persons whose blood pressure is in the normal range but still bear a heavy burden of cardiovascular risk factors. Thus, the role of simultaneous reduction of multiple cardiovascular risk factors in improving prognosis in hypertensive patients is stressed. In addition, more aggressive blood pressure goals are recommended for hypertensive patients with comorbid conditions such as diabetes mellitus or renal insufficiency. 

Cardiovascular disease affects 2.7 million British people and is a major cause of mortality with circulating neutrophils being proposed as contributing factors in ischaemic damage, though damage can still occur in vitro in the absence of blood. Melanocortins have... 

Systolic pressure, or maximum blood pressure, occurs during left ventricular systole. Diastolic pressure, or minimum blood pressure, occurs during ventricular diastole. The difference between systolic and diastolic pressure is the pulse pressure. While diastolic blood pressure has been historically been used as the most relevant clinical blood pressure phenotype, it has now been clearly established that systolic blood pressure is the more important clinical predictor for cardiovascular morbidity and mortality. More recently, additional attention is focussed on the importance of pulse pressure, i.e. the blood pressure amplitude, as a predictive factor for cardiovascular disease. 

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