Hypertension definition

Carretero OA, Oparil S (2000) Essential hypertension. Part I Definition and etiology. Circulation 101 329—335... 

Data from DeFranchis R Updating consensus in portal hypertension. Report of the Baveno III consensus workshop on definition ... 

It is estimated that approximately 90% of the patients with blood pressure elevation are affected by essential hypertension, which is by definition, hypertension of unknown etiology. Although the mechanisms responsible for essential hypertension remain obscure, extensive hemodynamic studies have now revealed the precise derangements of the systemic hemodynamics of these patients(8). 

The result of the Phase II trial is information needed to determine the effective dose and the dosing regimen of frequency and duration. Specihc chnical endpoints or markers are used to assess interaction of drug and disease. There are two types of markers definitive and surrogate. For example, in the case of cancer or hypertension, the definitive markers are mortality and stroke, respectively, and the surrogate markers may be tumor size, or cancer-associated proteins p53, TGF-a in the case of cancer, and blood pressure or cholesterol level in hypertension. Statistical analysis is carried out to evaluate the... 

MAOIs, although effective, are also problematic for routine use in the treatment of BN. First, like the TCAs, MAOIs have a propensity for lowering blood pressure. Additionally, bulimia patients, who are by definition prone to impulsive out of control eating, are not ideal candidates to maintain the strict tyramine-free diet restrictions imposed by MAOIs. Thus, they run a substantial risk of precipitating dangerous hypertensive crises through dietary noncompliance while taking MAOIs. It remains unclear whether the reversible MAOIs such as moclobemide will prove effective in the treatment of BN without the risks associated with other MAOIs. 

The actual level of pressure that can be considered hypertensive is difficult to define it depends on a number of factors, including the patient s age, sex, race, and lifestyle. As a working definition, many cardiovascular treatment centers consider that a diastolic pressure of 90 mm Hg or higher or a systolic pressure of 140 mm Hg or higher represents hypertension. In this chapter, ref-... 

In Section 3.3.1 we defined the p-value and briefly mentioned a common incorrect definition. We will return now to discuss why this leads to considerable misinterpretation. In the example of Section 3.3.1 we had observed a treatment difference of 5.4 mmHg with a p-value of 4.2 per cent and the proposed definition (incorrect) was that there is a 4.2 per cent probability that pj = 2 -The problem with this definition is the misinterpretation when the p-value is large. As an extreme case suppose that we ran a trial in hypertension with two patients per group and also suppose that even though in truth the true treatment... 

A specific cause of hypertension can be established in only 10-15% of patients. Patients in whom no specific cause of hypertension can be found are said to have essential or primary hypertension. Patients with a specific etiology are said to have secondary hypertension. It is important to consider specific causes in each case, however, because some of them are amenable to definitive surgical treatment renal artery constriction, coarctation of the aorta, pheochromocytoma, Cushing s disease, and primary aldosteronism. 

Thus, the physician must establish with certainty that hypertension is persistent and requires treatment and must exclude secondary causes of hypertension that might be treated by definitive surgical procedures. Persistence of hypertension, particularly in persons with mild elevation of blood pressure, should be established by finding an elevated blood pressure on at least three different office visits. Ambulatory blood pressure monitoring may be the best predictor of risk and therefore of need for therapy in mild hypertension. Isolated systolic hypertension and hypertension in the elderly also benefit from therapy. 

Considerable progress has been made in the development of agents capable of producing a specific and effective blockade of responses to sympatho-adrenal activity. Three groups of compounds show particular promise—the jd-haloalkylamines, the dihydro ergot alkaloids, and the imidazolines. However, lack of information regarding the role of sympatho-adrenal factors in the etiology of essential hypertension prevents a definitive evaluation of their potential usefulness in the therapy of this condition. 

At the present time, pheochromocytoma and intracranial lesions are the only causes of human hypertension which are definitely known to involve overactivity of the sympatho-adrenal system. However, presumptive evidence is accumulating to indicate that neurogenic factors may be involved in early essential hypertension, and it is possible that adequate adrenergic blockade early in the course of such hypertension may be effective in aborting its development. Only additional evidence regarding the etiology of essential... 

Establishment of definable end-points for the investigation of specific differences between normal and abnormal responders poses another problem. Consider the evaluation of drug treatment of hypertension as a case in point. In this instance, the definitive end-point would be measured by the difference in the incidence of strokes and cardiovascular disease between normal and abnormal drug responders, but this would probably occur years after the trait is recognized and modifying treatment undertaken. Another example of pharmacogenetic interest... 

According to the researchers, nearly half of the adverse events definitely, probably, or possibly caused by ephedra were cardiovascular side effects. The most common cardiovascular side effect was hypertension, or high blood pressure. Other reported cardiovascular events were palpitations, tachycardia (an abnormally fast heartbeat), stroke, and seizures. The researchers stated that 10 of the adverse events definitely, probably, or possibly caused by ephedra resulted in death, and 13 of the events caused permanent disability. In one-fifth of the cases, there was not enough evidence or information about the incident, and the remaining complications were not related to ephedra. 

The evidence that a 24-hour fasting and tranquillity have both the ability for a strong antioxidant activity and may create some complexity in the definition of antioxidants. In many instances, subjects suffering from some diseases (hypertension, infection, inflammation) or under particular conditions such as menopause may also have OS, which can be considered as an epiphenomenon of that given condition. Once the disease (or the symptom and/or the condition) is controlled by a therapy, the OS may disappear. This means that a product can be considered as an antioxidant indirectly." These aspects may further complicate the definition of an antioxidant. 

The normative approach to the practice of medicine, based on the definition of thresholds, is a different paradigm from the continuous distribution of most biological parameters and their associated risks, as described by physiologists and epidemiologists (360-362). Blood pressure, cholesterol, and renin have a logarithmic gaussian distribution in populations. Renin dependency, for instance, may be considered as a constant feature of all humans except when they have a positive sodium balance, which more or less mimics schematic animal models such as DOCA hypertension (349). In this extreme situation, cardiac, renal, and vascular damages may be direcdy induced by the excess of salt itself, in the absence of any functional RAS (363). 

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