Blood Pressure Control

Blood Pressure Control Renin-Angiotensin-Aldosteron System... 

Although blood pressure control follows Ohm s law and seems to be simple, it underlies a complex circuit of interrelated systems. Hence, numerous physiologic systems that have pleiotropic effects and interact in complex fashion have been found to modulate blood pressure. Because of their number and complexity it is beyond the scope of the current account to cover all mechanisms and feedback circuits involved in blood pressure control. Rather, an overview of the clinically most relevant ones is presented. These systems include the heart, the blood vessels, the extracellular volume, the kidneys, the nervous system, a variety of humoral factors, and molecular events at the cellular level. They are intertwined to maintain adequate tissue perfusion and nutrition. Normal blood pressure control can be related to cardiac output and the total peripheral resistance. The stroke volume and the heart rate determine cardiac output. Each cycle of cardiac contraction propels a bolus of about 70 ml blood into the systemic arterial system. As one example of the interaction of these multiple systems, the stroke volume is dependent in part on intravascular volume regulated by the kidneys as well as on myocardial contractility. The latter is, in turn, a complex function involving sympathetic and parasympathetic control of heart rate intrinsic activity of the cardiac conduction system complex membrane transport and cellular events requiring influx of calcium, which lead to myocardial fibre shortening and relaxation and affects the humoral substances (e.g., catecholamines) in stimulation heart rate and myocardial fibre tension. 

Blood Pressure Control. Table 1 Definitions and classifications of blood pressure levels... 

Lawton W J, DiBona (2000) Normal blood pressure control and the evaluation of hypertension. In Johnson RJ, Feehally J (eds) Comprehensive clinical nephrology. Mosby, London, pp 37.1-37.11... 

The renin-angiotensin-aldosterone system (RAAS) generates the peptide hormone angiotensin II and subsequently the mineralocorticoid aldosterone, which both exert considerable impact on blood pressure ( blood pressure control) and fluid homeostasis, and... 

ACE Inhibitors Blood Pressure Control Gluco-Mineralocorticoid Receptors... 

The therapeutic effect is achieved and blood pressure controlled. 

Blood pressure control during and after fibrinolytic administration is SBP <180 mmHg and DBP <105 mmHg... 

Hypertension caused by any of these conditions is referred to as secondary hypertension. Identification of a secondary cause of hypertension is often not initially pursued unless suggested by routine clinical and laboratory evaluation of the patient, or failure to achieve blood pressure control. 

What are likely causes of DW s loss of blood pressure control ... 

Limit daily sodium intake to 2.4 grams (6 grams of salt) for blood pressure control. 

Nearly two-thirds of patients with DM will die of coronary heart disease (CHD). Interventions targeting smoking cessation, glycemic control, blood pressure control, lipid management, antiplatelet therapy, and lifestyle changes, including diet and exercise, can reduce the risk of cardiovascular events. Patients with diabetes should receive at least an aspirin daily unless contraindicated. Refer to appropriate chapters in the text concerning CHD. 

Patients with multiple risk factors and established CHD should also be monitored and evaluated for progress in managing their other risk factors such as blood pressure control, smoking cessation, exercise and weight control, and glycemic control (if diabetic). 

Near-normal glycemia reduces the risk of microvascular disease complications, but aggressive management of traditional cardiovascular risk factors (i.e., smoking cessation, treatment of dyslipidemia, intensive blood pressure control, antiplatelet therapy) is needed to reduce macrovascular disease risk. 

Glucose and blood pressure control are most important for prevention of nephropathy, and blood pressure control is most important for retarding the progression of established nephropathy. 

Adequate blood pressure control (Fig. 76-4, see Figs. 76-2 and 76-3) can reduce the rate of decline in GFR and albuminuria in patients with or without diabetes. 

Nitric oxide is important to a wide variety of mammalian physiological processes (1,2), beyond being a constituent of air pollution (3). Natural physiological activities are now known to include roles in blood pressure control, neurotransmission and immune response, and a number of disease states involving NO imbalances have been reported (2,4) as the result of extensive research activity into the chemistry, biology and pharmacology of NO. Understanding the fundamental reaction mechanisms... 

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