2. Essential hypertension becomes more common as age advances and genetic influences, obesity, excessive salt intake and a variety of other factors are contributory. Hypertension is secondary to defined diseases, particularly renal or endocrine disorders, in about 10-20 percent of hypertensive cases and occasionally can be secondary to the use of oral contraceptives.

3. Acute emotion, particularly anger and anxiety, can cause transient rises in blood pressure by release of catecholamines (epinephrine and norepinephrine) and about 40 percent of hypertensive patients have raised levels of circulating catecholamines (epinephrine and norepinephrine) and may therefore have abnormal sympathetic activity.

4. When the patient has a history of hypertension there is the possibility of both congestive heart failure or angina pectoris. It is natural to think of stroke first when confronted with a history of hypertension, and it is true that hypertension, diabetes, and cerebral hemorrhage are commonly linked, but the fact is that 65 percent of hypertensives die of heart disease, whereas 20 percent demonstrate predominantly cerebral complications, except in hypertensive African American persons. African Americans tend to develop hypertension earlier in life. It is frequently more severe, and resulting in a higher mortality at a younger age, more commonly from stroke than from coronary artery disease. Since hypertension is one of several predisposing factors for premature coronary disease, it is important to look for other factors that may add to that risk, especially hyperlipidemia and cigarette smoking. Diabetes and physical inactivity likewise are important. MANAGEMENT IN CLINICAL DENTAL SITUATIONS<br />Dentists have a unique opportunity to detect cases of hypertension since patient visits at routine intervals are encouraged. It is a professional responsibility of a dental clinician to inform the patient of their hypertensive state and to offer medical advice, including appropriate referrals. <br />There are no recognized oral manifestations of hypertension but antihypertensive drugs can often cause side-effects, such as: <br />xerostomia, <br />gingival overgrowth, <br />salivary gland swelling or pain, <br />lichenoid drug reactions, <br />erythema multiforme, <br />taste sense alteration, and <br />paresthesia. <br />Dental clinician must focus on the actions, interactions and adverse effects of the antihypertensive medications, as well as the overall management of blood pressure of the patient in the dental chair. (see Medications) <br />The appropriate modifications for differing stages of hypertension is outlined in the algorithm presented below. (see ALGORITHM) There are, however, several areas of general dental management to be considered in the hypertensive patients. <br />1. ANESTHESIAA. Local Anesthesia<br />Dental patients with hypertension are best treated under local anesthesia being sure that the anesthesia is complete so that no anxiety induced elevation of blood pressure occurs. The use of vasoconstrictors such as epinephrine in local anesthetic agents is known to have negligible influences on blood pressure in hypertensive patients, according to numerous clinical studies. Data in regard to epinephrine-containing local anesthetics has consistently shown that blood pressure and heart rate are minimally affected by the typically low dose and short duration of the drug use in dentistry, both in healthy and those with existing cardiovascular conditions. Nonetheless, the use of epinephrine-containing anesthetics in patients with uncontrolled hypertension, and elective dental procedures are contraindicated. According to Muzyka & Glick (JADA 1997), <br />quot;
the benefits of the small doses of epinephrine used in dentistry, when administered <br />properly,far outweigh the cardiovascular disadvantagesquot;
<br />The use of aspirating syringes in local anesthetics is imperative to avoid intravenous, intrarterial, intraligamentary and intrabony injections, which could potentially precipitate further anxiety and thus rise in pressure and possible arrhythmias. <br />B. General Anesthesia<br />All antihypertensive drugs are potentiated by general anesthetic agents, especially barbiturates. General anesthesia tends to cause vasodilation. A severely reduced blood supply to vital organs can be dangerous in healthy individuals, but in the hypertensive person with vascular disease there is greater risk as the tissues have become adapted to a raised blood pressure which is needed to overcome the resistance of the vessels and maintain adequate perfusion. A fall in blood pressure below the critical level needed for adequate perfusion of vital organs such as the kidneys, can therefore be fatal. Hypokalemia as a result of diuretics may be associated with arrhythmias. Some inhalant anesthetics (halothane, enfluane, and isoflurane) are similar in action to calcium slow channel antagonists and so reduce blood pressure significantly. <br />2. ANXIETY CONTROL<br />The anxiety and stress associated with dental treatment typically causes a rise in blood pressure and may precipitate cardiac arrest or a cerebrovascular accident. Preoperative reassurance and oral sedation may help in alleviating anxiety related rise in pressure. Use of sedatives the night before a procedure may also be used. <br />Relative analgesia technique using nitrous oxide (N2O) can also reduce both systolic and diastolic pressure by up to 10-15mm Hg, after approximately 10 minutes of use, preoperatively. Use of oral sedation or nitrous oxide sedation may reduce blood pressure to acceptable levels, allowing initiation of local anesthesia (with or with vasoconstrictor). <br />3. TIMING OF DENTAL APPOINTMENTS<br />The increase of blood pressure in hypertensive patient is associated with the hours surrounding awakening that peaks by midmorning. This fluctuation of blood pressure tends to be less likely in the afternoon. Afternoon appointments are recommended over mornings for this reason. <br />4. ORTHOSTATIC HYPOTENSION <br />Orthostatic hypotension may be a problem in patients using antihypertensive agents that reduce sympathetic outflow or peripheral vasodilatory actions, such as centrally acting a-2-adrenergic agonists, post-ganglionic adrenergic inhibitors, a-1-adrenergic antagonists, and diuretics. Management of orthostatic hypotension includes avoiding sudden postural changes, such as return to sitting position from the supine operating position. The patient should also be instructed to stay seated for a short period until such time that adequate cerebral perfusion has occurred. <br />5. OTHER DENTAL CONCERNS<br />Aspirin is now commonly taken by patients with hypertension to decrease associated coronary or cerebral vascular thrombotic disease, and aspirin may cause bleeding problems. Many patients with hypertension develop systolic heart murmurs, in which case prophylaxis for endocarditis <br />Algorithm for Management of Hypertensive Dental Patient<br />* SELECTIVE DENTAL PROCEDURE may include, but not limited to;<br />dental prophylaxis <br />restorative procedures <br />nonsurgical periodontal therapy <br />nonsurgical endodontic procedures <br /># EMERGENT NONSTRESSFUL DENTAL PROCEDURE may include, but not limited to dental procedures that may help alleviate pain, infection or masticatory dysfunction. e.g., simple incision and drainage of intraoral fluctuant dental abscess. The medical benefits should outweigh the risk of complications secondary to the hypertensive state, in stage III and IV hypertensive patients<br />