Hypertension And Blood Pressure

Hypertension And tide rip PressureHypertension is a common and major cause of bezant and other cardiovascular ailment. in that location argon many a(prenominal) another(prenominal) causes of high phone line pressure, including defined hormonal and genetic syndromes, renal disease and multifactorial racial and familial factors. It is wizard of the failing causes of morbidity and mortality in the world and will outgrowth in worldwide importance as a public health occupation by 2020 (Murray and Lopez 1997). business line pressure (BP) is defined as the essence of pressure exerted, when summation contract against the resistance on the arterial walls of the wrinkle vessels. In a clinical term high BP is known as high blood pressure. Hypertension is defined as sustained diastolic BP greater than 90 mmHg or sustained systolic BP greater than 140 mmHg. The maximum arterial pressure during contr put to death of the left ventricle of the heart is called systolic BP and token( prenominal) arterial pressure during relaxation and dilation of the ventricle of the heart when the ventricles take in with cable is known as diastolic BP (Guyton and Hall 2006).Hypertension is everydayly divided into 2 categories of primary and secondary high blood pressure. In primary hypertension, oft called essential hypertension is characterised by chronic elevation in blood pressure that occurs without the elevation of BP pressure results from some other disorder, such as kidney disease. Essential hypertension is a heterogeneous disorder, with different patients having different causative factors that lead to high BP. Essential hypertension needs to be disjunct into various syndromes because the causes of high BP in most patients presently classified as having essential hypertension open fire be recognized (Carretero and Oparil 2000). Approximately 95% of the hypertensive patients have essential hypertension. Although only about 5 to 10% of hypertension cases ar tho ught to result from secondary causes, hypertension is so common that secondary hypertension probably will be encountered ofttimes by the primary cargon practitioner (Beevers and MacGregor 1995).In normal instrument when the arterial BP raises it stretches baroceptors, (that are located in the carotid sinuses, aortic implike and large artery of neck and thorax) which send a rapid heart charge per unit to the vasomotor centre that resulting vasodilatation of arterioles and veins which contri stille in bring down BP (Guyton and Hall 2006). close of the book suggested that there is a debate regarding the pathophysiology of hypertension. A number of predisposing factors which contributes to make up the BP are obesity, insulin resistance, high alcohol intake, high salt intake, aging and possibly sedentary lifestyle, stress, depleted potassium intake and low calcium intake. Further much, many of these factors are additive, such as obesity and alcohol intake (Sever and Poulter 1989 ).The pathophysiology of hypertension is categorised mainly into cardiac output and encircling(prenominal) vascular repelling, renin- angiotonin system, autonomic uneasy system and others factors. Normal BP is determined and introduceed the equilibrium between cardiac output and peripheral resistant. Considering the essential hypertension, peripheral resistant will rise in normal cardiac output because the peripheral resistant is depend upon the thickness of wall of the artery and capillaries and contraction of fluid muscles cells which is creditworthy for increasing intracellular calcium concentration (Kaplan 1998). In renin- angiotonin mechanism endocrine system plays important manipulation in maintain blood pressure especially the juxtaglomerular cells of the kidney secrete renin in order to response glomerular hypo-perfusion. And also renin is released by the stimulation of the humane sickish system which is ulterior convert to angiotonin I then again it converts to angiotensin II in the lungs by the core group of angiotensin- converting enzyme ( booster). Angiotensin II is a manful vasoconstrictor and also it released aldosterone from the zona glomerulosa of the adrenal gland which is responsible for sodium and water retention. In this way, renin-angiotensin system increases the BP (Beevers et al 2001). Similarly, in autonomic skittish system sympathetic nervous system play a economic consumption in pathophysiology of hypertension and key to maintaining the normal BP as it constricts and dilates arteriolar. Autonomic nervous system considers as an important in short term changes in BP in response to stress and physical exercise. This system works in concert with renin-angiotensin system including circulating sodium volume. Although adrenaline and nor-adrenaline doesnt play an important role in causes of hypertension, the medicines used for the sermon of hypertension engorge the sympathetic nervous system which had played proper therape utic role (Beevers et al 2001). Others pathophysiology includes many vasoactive substance which are responsible for maintaining normal BP. They are enothelin bradikinin, endothelial derived relaxant factor atrial natriuretic peptide and hypercoagulability of blood are all responsible in some way to maintain the BP (Lip G YH 2003).The seventh piece of the Joint National Committee (JNC-VII) on Prevention, Detection, Evaluation, and sermon of High Blood Pressure defines some important goals for the evaluation of the patient with elevated BP which are detection and confirmation of hypertension detection of target organ disease (e.g. renal damage, congestive heart failure) identification of other risk factors for cardiovascular disorders (e.g. diabetes mellitus, hyperlipidemia) and detection of secondary causes of hypertension (Chobanian et al 2003).Most hypertensive patients run asymptomatic until complications arise. Potential complications include stroke, myocardial infarction, hea rt failure, aortic aneurism and dissection, renal damage and retinopathy (Zamani et al 2007).The drug selection for the pharmacologic treatment of hypertension would depend on the individual degree of elevation of BP and contradictions. Treatment of non-pharmacologic hypertension includes life-style, weight reduction, exercise, sodium, potassium, stop smoking and alcohol, relaxation therapy and dietary improvements, followed by pharmacology therapy.Commonly used antihypertensive drugs include thiazide diuretics, -blockers, ACE inhibitors, angiotensin receptor blockers, calcium channel blockers, direct vasodilators and -receptor opposites which are shown in the hobby table.Diuretics have been used for decades to treat hypertension and recommended as first-line therapy by JNC-VII guidelines afterward antihypertensive and lipid-lowering treatment to prevent heart attack trail (ALLHAT) success. They pull down circulatory volume, cardiac output and mean arterial pressure and are mos t effective in patients with mild-to- moderate hypertension who have normal renal last. Thiazide diuretics (e.g. hydrochlorothiazide) and potassium sparing diuretics (e.g. spironolactone) promote Na+ and Cl- excretion in the nephrone. Loop diuretics (e.g. furosemide) are generally too potent and their actions too short-lived, however, they are reusable in lowering blood pressure in patients with renal insufficiency, who often does not respond to other diuretics. Diuretics may result in adverse metabolic side effect, including elevation of creatinine glucose, cholesterol, triglyceride trains, hypokalemia, hyperuricemia and cliffd sexual function are potential side effects. The best BP lowering response is seen from low venereal diseases of Thiazide diuretics (Kaplan 1998).-blocker such as propranolol are believed to lower BP through several mechanisms, including reducing cardiac output through a decrease heart rate and a mild decrease in contractility and decreasing the secret ion of renin, which lead to a decrease in full(a) peripheral resistant. Adverse effects of b-blockers include bronchospam, fatigue, impotence, and hyperglycemia and alter lipid metabolism (Zamani et al 2007). rudimentaryly acting 2-adrenergic agonists such as methyldopa and clonidine constrain sympathetic outflow to the heart, blood vessels and kidneys. Methyldopa is safe to use during pregnancy. Side effect includes dry mouth, sedation, drowsiness is common and in 20% of patients methyldopa causes a positive antiglobulin test, rarely haemolytic anaemia and clonidine causes rebound hypertension if the drug is suddenly withdrawn (Neal M J 2009). Systemic a1-antagonists such as prazosin, terazosin and doxazosin cause a decrease in total peripheral resistance through relaxation of vascular limpid muscle.calcium channel blockers (CCB) reduce the influx of Ca++ responsible for cardiac and smooth muscle contraction, thus reducing cardiac contractility and total peripheral resistant. t herefore long-acting members of this group are frequently used to treat hypertension. There are two classes of CCB dihyropyridines and non- dihyropyridines. The main side effect of CCB is ankle oedema, but this rear end sometimes be offset by combining with -blockers (Lip G YH 2003).Direct vasodilators such as Hydralazine and minoxidil lower BP by directly relaxing vascular smooth muscle of precapillary resistance vessels. However, this action can result in a reflex increase heart rate, so that combined -blocker therapy is frequently necessary (Neal M J 2009).ACE inhibitors works by blocking the renin-angiotensin system thereby inhibiting the conversion of angiotensin I to angiotensin II. ACE inhibitors may be most useful for treating patients with heart failure, as healthy as hypertensive patients who have diabetes. victimisation ACE inhibitors can lead to increased levels of bradikinin, which has the side effect of spit up and the rare, but severe, complication of angioedema. Recent study demonstrated that captopril was as effective as traditional thaizides and -blockers in preventing adverse outcomes in hypertension (Lip G YH 2003).Angiotensin II antagonists act on the renin-angiotensin system and they block the action of angiotensin II at its peripheral receptors. They are substantially tolerated and very rarely cause any significant side-effects (Zamani et al 2007).another(prenominal) helpful principle of antihypertensive drug therapy concerns the use of multiple drugs. The effects of one drug, acting at one physiologic control point, can be defeated by natural compensatory mechanism (e.g. diuretic decrease oedema occurring secondary to treatment with a CCB). By using two drugs with different mechanisms of action, it is more likely that BP and its complication are controlled and with the low dose range of combined drugs also help to reduce the side-effects as well (Frank 2008) . The following two-drug combinations have been found to be effective and well tolerated which are diuretic and -blocker diuretic and ACE inhibitor or angiotensin receptor antagonist CCB (dihydropyridine) and -blocker CCB and ACE inhibitor or angiotensin receptor antagonist CCB and b-diuretic -blocker and -blocker and other combinations (e.g. with central agents, including 2-adrenoreceptor agonists and imidazoline- I2 receptor modulators, or between ACE inhibitors and angiotensin receptor antagonists) can be used (ESH and ESC 2003). If necessary, three or four drugs may be required in many cases for the treatment. The use of a single drug will lower the BP satisfactorily in up to 80% of patients with hypertension but combining two types of drugs will lower BP about 90%. If the diastolic pressure is above 130 mmHg then the hypertensive apprehension is occurred. Although it is desirable to reduce the diastolic pressure below 120 mmHg inwardly 24 hours in accelerated hypertension, it is usually unnecessary to reduce it more rapidly and indeed it may be dan gerous to do so. This is because the mechanisms that maintain cerebral blood flow at a constant level independent of peripheral BP are impaired in hypertension. However, it is important to reduce the BP quickly by giving the intravenous drugs but caution should be taken to avoid cerebrovascular pressure inducing cerebral ischemia (Grahame-Smith and Aronson 2002).In conclusion, hypertension emerges as an extremely important clinical problem because of its prevalence and potentially devastating consequences. The major classes of antihypertensive drugs diuretics, -blockers, CCB, ACE inhibitors and angiotensin receptor antagonists, are suitable for the initiation and maintenance of antihypertensive therapy which helps in reduction of cardiovascular morbidity and mortality.