Hypertension is a common disease encountered in dental setting., and life-long treatment require an attentive approach by dentists. Hypertension management in dental office includes disease recognition and correct measurement, knowledge of its treatment and oral adverse effects, and risk assessment for dental treatment. Dentist role in screening undiagnosed and undertreated hypertension is very important since this may lead to improved monitoring and treatment.
Normal Systolic Diastolic Optimal < 120 < 80Normal < 130 < 85High normal 130-139 85-89HypertensionGrade 1 (mild)140-159 90-99Grade 2 (moderate)160-179 100-109Grade 3 (severe)≥180 ≥110
In more than 95% of cases, a specific underlying cause of hypertension cannot be found. Such patients are said to have essential hypertension. The pathogenesis of essential hypertension is not clearly understood. Different investigators have proposed the kidney, the peripheral resistance vessels and the sympathetic nervous system as the seat of the primary abnormality.
In reality the problem is probably multifactorial. Hypertension is more common in some ethnic groups, particularly Black Americans and Japanese, and approximately 40-60% is explained by genetic factors. Important environmental factors include a high salt intake, heavy consumption of alcohol, obesity, lack of exercise and impaired intrauterine growth. There is very little evidence that 'stress' causes hypertension.,
Alcohol Obesity Pregnancy (pre-eclampsia) Renal disease . Renal vascular disease Parenchymal renal disease, particularly glomerulonephritis Polycystic kidney disease Endocrine disease Phaeochromocytoma Cushing's syndrome Primary hyperaldosteronism (Conn's syndrome) Hyperparathyroidism
Use a machine that has been validated, well maintained and properly calibrated Measure sitting BP routinely, with additional standing BP in elderly and diabetic patients and those with possible postural hypotension Remove tight clothing from the arm Support the arm at the level of the heart Use a cuff of appropriate size (the bladder must encompass > two-thirds of the arm) Lower the mercury slowly (2 mm per second) Read the BP to the nearest 2 mmHg Use phase V (disappearance of sounds) to measure diastolic BP Take two measurements at each visit
Patients can also measure their own BP at home using a range of variable-quality semi-automatic devices; the real value of such measurements is not well established but similar considerations apply. Home or ambulatory BP measurements may be particularly helpful in patients with unusually labile blood pressure, those with refractory hypertension, those who may be experiencing symptomatic hypotension, and those in whom white coat hypertension is suspected.
Family history, lifestyle (exercise, salt intake, smoking habit) and other risk factors should be recorded. A careful history will also identify those patients with drug- or alcohol-induced hypertension and may elicit the symptoms of other causes of secondary hypertension such as phaeochromocytoma (paroxysmal headache, palpitation and sweating) or complications such as coronary artery disease (e.g. angina, breathlessness).
Radio-femoral delay (coarctation of the aorta), enlarged kidneys (polycystic kidney disease), abdominal bruits (renal artery stenosis) and the characteristic facies and habitus of Cushing's syndrome are all examples of physical signs that may help to identify one of the causes of secondary hypertension . Examination may also reveal features of important risk factors such as central obesity and hyperlipidaemia (tendon xanthomas etc.). Nevertheless, the majority of abnormal signs are due to the complications of hypertension.
The adverse effects of hypertension principally involve the blood vessels, central nervous system, retina, heart and kidneys, and can often be detected clinically. Blood vessIe larger arteries (over 1 mm in diameter) the internal elastic lamina is thickened, smooth muscle is hypertrophied and fibrous tissue is deposited. The vessels dilate and become tortuous and their walls become less compliant.
In larger arteries (over 1 mm in diameter) the internal elastic lamina is thickened, smooth muscle is hypertrophied and fibrous tissue is deposited. The vessels dilate and become tortuous and their walls become less compliant. In smaller arteries (under 1 mm) hyaline arteriosclerosis occurs in the wall, the lumen narrows and aneurysms may develop. Widespread atheroma develops and may lead to coronary and/or cerebrovascular disease, particularly if other risk factors (e.g. smoking, hyperlipidaemia, diabetes) are present.
These structural changes in the vasculature often perpetuate and aggravate hypertension by increasing peripheral vascular resistance and reducing renal function.
Hypertension is also implicated in the pathogenesis of aortic aneurysm and aortic dissection.
In larger arteries (over 1 mm in diameter) the internal elastic lamina is thickened, smooth muscle is hypertrophied and fibrous tissue is deposited. The vessels dilate and become tortuous and their walls become less compliant. In smaller arteries (under 1 mm) hyaline arteriosclerosis occurs in the wall, the lumen narrows and aneurysms may develop. Widespread atheroma develops and may lead to coronary and/or cerebrovascular disease, particularly if other risk factors (e.g. smoking, hyperlipidaemia, diabetes) are present.
These structural changes in the vasculature often perpetuate and aggravate hypertension by increasing peripheral vascular resistance and reducing renal function.
Hypertension is also implicated in the pathogenesis of aortic aneurysm and aortic dissection.
Stroke is a common complication of hypertension and may be due to cerebral haemorrhage or cerebral infarction. Carotid atheroma and transient cerebral ischaemic attacks are more common in hypertensive patients. Subarachnoid haemorrhage is also associated with hypertension. Hypertensive encephalopathy is a rare condition characterised by high blood pressure and neurological symptoms, including transient disturbances of speech or vision, paraesthesiae, disorientation, fits and loss of consciousness. Papilloedema is common. A CT scan of the brain often shows haemorrhage in and around the basal ganglia; however, the neurological deficit is usually reversible if the hypertension is properly controlled
The optic fundi reveal a gradation of changes linked to the severity of hypertension; fundoscopy can, therefore, provide an indication of the arteriolar damage occurring elsewhere. 'Cotton wool' exudates are associated with retinal ischaemia or infarction, and fade in a few weeks . 'Hard' exudates (small, white, dense deposits of lipid) and microaneurysms ('dot' haemorrhages) are more characteristic of diabetic retinopathy . Hypertension is also associated with central retinal vein thrombosis .
Retinopathy 1
Retinopathy 2The excess cardiac mortality and morbidity associated with hypertension are largely due to a higher incidence of coronary artery disease. High blood pressure places a pressure load on the heart and may lead to left ventricular hypertrophy with a forceful apex beat and fourth heart sound. ECG or echocardiographic evidence of left ventricular hypertrophy is highly predictive of cardiovascular complications and therefore particularly useful in risk assessment.
Long-standing hypertension may cause proteinuria and progressive renal failure by damaging the renal vasculature.
All hypertensive patients should undergo a limited number of investigations. Additional investigations are appropriate in selected patients.
INVESTIGATION OF ALL PATIENTS Urinalysis for blood, protein and glucose Blood urea, electrolytes and creatinine N.B. Hypokalaemic alkalosis may indicate primary hyperaldosteronism but is usually due to diuretic therapy Blood glucose Serum total and high-density lipoprotein (HDL) cholesterol 12-lead ECG (left ventricular hypertrophy, coronary artery disease)
HYPERTENSION: INVESTIGATION OF SELECTED PATIENTS Chest X-ray: to detect cardiomegaly, heart failure, coarctation of the aorta Ambulatory BP recording: to assess borderline or 'white coat' hypertension Echocardiogram: to detect or quantify left ventricular hypertrophy Renal ultrasound: to detect possible renal disease Renal angiography: to detect or confirm presence of renal artery stenosis
Correcting obesity, reducing alcohol intake, restricting salt intake, taking regular physical exercise and increasing consumption of fruit and vegetables can all lower blood pressure..
1- Thiazide and other diuretics. The mechanism of action of these drugs is incompletely understood, and it may take up to a month for the maximum effect to be observed.
2-Beta--blockers Metoprolol (100-200 mg daily), atenolol (50-100 mg daily) and bisoprolol (5-10 mg daily) are cardioselective and therefore preferentially block the cardiac β1-adrenoceptors.
3-Angiotensin-converting enzyme (ACE) inhibitors. These drugs (e.g. enalapril 20 mg daily, ramipril 5-10 mg daily or lisinopril 10-40 mg daily) inhibit the conversion of angiotensin I to angiotensin II and are usually well tolerated.. Electrolytes and creatinine should be checked before and 1-2 weeks after commencing therapy. Side-effects include first-dose hypotension, cough, rash, hyperkalaemia and renal dysfunction.
4-Angiotensin receptor blockers. These drugs (e.g. losartan 50-100 mg daily, valsartan 40-160 mg daily) block the angiotensin II type I receptor and have similar effects to ACE inhibitors but do not cause cough and are better tolerated. 5-Calcium antagonists. The dihydropyridines (e.g. amlodipine 5-10 mg daily, nifedipine 30-90 mg daily) are effective and usually well-tolerated antihypertensive drugs that are particularly useful in the elderly. Side-effects include flushing, palpitations and fluid retention.
Xerostomia Many antihypertensives medications like ACEIs, thiazide diuretics, loop diuretics, and clonidine are associated with xerostomia. Its likelihood increases with the number of concomitant medications. Xerostomia has many consequences, like decay, difficulty in chewing, swallowing, and speaking, candidiasis, and oral burning syndrome. Sometimes the feeling is transient and salivary function is adjusted by the patient itself. There are situations when is required to change the antihypertensive medication
Gingival Hyperplasia It can be caused by calcium channel blockers, with an incidence ranging from 6 to 83%]. The majority of cases are associated with nifedipine. The effect could be dose related. Gingival hyperplasia is manifested by pain, gingival bleeding, and difficulty in mastication. A good oral hygiene greatly reduces its incidence. By changing antihypertensive medication hyperplasia can be reverse
Drug Interactions between Antihypertensives and Drugs Used in Dentistry Most antihypertensive drugs have drug interactions with LA (local anesthetic) and analgesics.(i)Interaction of LA with nonselective beta-blockers may increase LA toxicity].(ii)The cardiovascular effects of epinephrine used during dental procedures may be potentiated by the use of medications such as nonselective b-blockers (propranolol and nadolol). Guidelines recommend decreasing the dose and increasing the time interval between epinephrine injections