CONTENTS

Section 1: Introduction Section 2: Definition and classification Section 3 : Diagnosis & Measurement Section 4: Treatment Section 5 : Hypertension in Pregnancy Section 6 : Management at various Health Care levels Annexures Section 1: Introduction GLOBAL SITUATION Cardiovascular diseases are a leading cause of mortality and morbidity in industrialized countries, and they are also emerging as prominent public health problems in developing countries. They are a major cause of preventable morbidity and premature mortality. In developed countries, coronary heart disease and cerebrovascular diseases are responsible for 40 to 50% of all deaths. High blood pressure is common in all industrialized societies and in many developing countries. It is a major cause of stroke and contributes importantly to coronary heart disease. Studies indicate that subjects with diastolic blood pressure of 105 mmHg have a ten fold increase in the risk of stroke and a five fold increase in risk of coronary events compared to those with diastolic blood pressure of 76 mmHg.

There is a large body of literature estimating the prevalence of hypertension in various parts of the world. However, these estimates depend on the cut-off point by which hypertension is defined, and vary according to the measurement methods used and the population sample studied. Despite these limitations, prevalence estimates indicate that hypertension is an important public health problem of global dimensions. The prevalence increases with age and shows a relative age preponderance below the age of 50 years (WHO). Some geographic diversity has been noted, with industrialized countries generally reporting higher prevalence rates than most developing countries. Differences between urban and rural areas have been reported in some developing countries including those of the WHO Eastern Mediterranean Region, with higher prevalence in urban communities. Ethnic differences, such as higher prevalence rates in blacks than whites, have been reported from some countries.

SITUATION IN OMAN

Cardiovascular diseases are emerging as a major and growing health problem in the Sultanate of Oman. The rapid socio-economic development which started in 1970 has led to a rapid proliferation of educational establishments, hospitals and other medical facilities, private and commercial transport system and commerce. These were accompanied by changes in dietary patterns, decreased physical activity and the emergence of non-communicable diseases as one of the dominant features of ill health in the community.

GLOBAL SITUATION Cardiovascular diseases are a leading cause of mortality and morbidity in industrialized countries, and they are also emerging as prominent public health problems in developing countries. They are a major cause of preventable morbidity and premature mortality. In developed countries, coronary heart disease and cerebrovascular diseases are responsible for 40 to 50% of all deaths. High blood pressure is common in all industrialized societies and in many developing countries. It is a major cause of stroke and contributes importantly to coronary heart disease. Studies indicate that subjects with diastolic blood pressure of 105 mmHg have a ten fold increase in the risk of stroke and a five fold increase in risk of coronary events compared to those with diastolic blood pressure of 76 mmHg.

There is a large body of literature estimating the prevalence of hypertension in various parts of the world. However, these estimates depend on the cut-off point by which hypertension is defined, and vary according to the measurement methods used and the population sample studied. Despite these limitations, prevalence estimates indicate that hypertension is an important public health problem of global dimensions. The prevalence increases with age and shows a relative age preponderance below the age of 50 years (WHO). Some geographic diversity has been noted, with industrialized countries generally reporting higher prevalence rates than most developing countries. Differences between urban and rural areas have been reported in some developing countries including those of the WHO Eastern Mediterranean Region, with higher prevalence in urban communities. Ethnic differences, such as higher prevalence rates in blacks than whites, have been reported from some countries.

SITUATION IN OMAN Cardiovascular diseases are emerging as a major and growing health problem in the Sultanate of Oman. The rapid socio-economic development which started in 1970 has led to a rapid proliferation of educational establishments, hospitals and other medical facilities, private and commercial transport system and commerce. These were accompanied by changes in dietary patterns, decreased physical activity and the emergence of non-communicable diseases as one of the dominant features of ill health in the community.

Cardiovascular diseases were the fifth leading cause of inpatient morbidity in 1994 and 1995, compared to the sixth in 1993. However they constitute the leading cause of hospital mortality in Oman, comprising 34% of the total mortality. Despite the increasing magnitude of cardiovascular diseases, hospital deaths reported in 1985, showed diseases of the circulatory system constituting 50.4% in age group 15 years and above. On comparison in 1995 deaths due to diseases of the circulatory system contributed 43.5% of

the total deaths in the age group of 15 years and above. While several factors may be responsible for this slight difference the improved diagnostic and emergency services may be a contributing factor. The National Blood Pressure and Coronary Heart Disease Survey was done in Oman in 1994. Out of the 4239 persons above the age of 20 years screened, 23.7% were found to

be hypertensive on a single measurement (diastolic 90 mmHg or systolic 140 mmHg). The rate was 25.4% among males and 22.2% among females. The prevalence of smoking in the sample studied was 12%. It was 23.9% among males and 1.7% among females. Obesity (BMI ›25 Kg / m2 ) was reported in 37.1%.

OBJECTIVES OF THE NATIONAL CARDIOVASCULAR DISEASE PROGRAMME. National Goal To provide comprehensive care for all people with Hypertension and Coronary Heart Disease in Oman with special emphasis on early detection and prevention of

complications. Programme Objectives

• To promote early detection of Hypertension and Coronary Heart Disease. • To achieve optimum control of Hypertension and prompt treatment of Coronary Heart Disease. • To encourage uniformity in management of Hypertension.

• To prevent long term complications of Hypertension thereby lowering morbidity and mortality.

• To maintain health and quality of life of individuals with Cardiovascular diseases through effective care and education.

• To decrease hospitalization for treatment and management of Hypertension. • To support research on the prevention and control of cardiovascular diseases.

M.O.H- CARDIOVASCULAR DISEASES CONTROL AND PREVENTION POLICY It is the policy of the Ministry of Health • that this manual describes the guidelines and standard procedures for the management of Hypertension to be used in all MOH institutions. • to encourage sister organizations e.g. the Sultan Qaboos University Hospital, the Palace Health Service, the Sultan’s Armed Forces, The Royal Oman Police, Petroleum Development Oman and the Private Sector to implement these standardized procedures in all their health facilities. • that the prevention and treatment of cardiovascular diseases are integrated with Primary Health Care. • to promote early detection of hypertension particularly at the Primary Health Care level.

• that the NCD Section of the DSDC in the Directorate General of Health Affairs in collaboration with the Department of Cardiology at the Royal Hospital be the coordinators of the National Cardiovascular Disease Programme implementation. • that in each hospital a focal person will be responsible for the cardiovascular diseases control programme in addition to their regular duties. This would help prompt and effective secondary prevention and treatment of the disease.

• that every region will undertake appropriate and regular training programmes for health care providers who are involved in management of cardiovascular diseases. All necessary support will be provided by the Department of Cardiology at the Royal hospital and the Non-communicable Disease Section of the DSDC.

SECTION 2: DEFINITION AND CLASSIFICATION DEFINITION Arterial Hypertension is defined as a chronically elevated systolic and/or diastolic blood pressure, and is taken as a level of systolic blood pressure of ›140 mmHg and/or a level of diastolic pressure of ›90 mmHg under satisfactory conditions of measurements. It is extremely important to confirm the diagnosis by repeated accurate measurements over a period of time.

CLASSIFICATION Classification is important in determining the most appropriate type of management for each individual. Classification also considers the additional risks represented by associated factors and the development of hypertension- related organ damage.

Hypertension has been commonly classified by the degree of blood pressure elevation into “mild”, “moderate” and “severe” hypertension. However, these terms do not really refer to the severity of the overall risk to the patient but simply to the extent of the blood pressure elevation at the time of the assessment. The severity of the clinical condition also depends on the overall cardiovascular risk of the patient such as concomitant risk factors like age, gender, smoking habits, plasma lipids and in particular associated organ damage. The extent of organ damage often, but not necessarily, correlates with the level of blood pressure elevation and the rate of progression of organ damage varies from one individual to another depending on many influences, most of which are incompletely understood. The presence of signs of organ damage confers an increase in cardiovascular risk at any level of blood pressure. Objective signs of organ damage include left ventricular hypertrophy, retinal changes and arterial disease, heart failure, stroke, microalbuminuria and elevation of the plasma creatinine concentration.

Thus, for practical purposes hypertension may be classified as follows: 1. Hypertension with no other cardiovascular risk factors and no target organ damage

2. Hypertension with other cardiovascular risk factors 3. Hypertension with evidence of target organ damage

4. Hypertension with other cardiovascular risk factors and evidence of target organ damage

CAUSES OF HYPERTENSION 1. ESSENTIAL OR PRIMARY HYPERTENSION Primary Hypertension is defined as high blood pressure without evident organic cause. This type of hypertension constitutes about 95% of cases. The development of high blood pressure depends on the interaction of genetic and environmental influences. The risk factors for essential hypertension can be classified into non-modifiable risk factors and modifiable risk factors.

A) NON-MODIFIABLE RISK FACTORS • Age and Gender Blood pressure rises with age in both sexes. The rise is more in those with higher initial blood pressure. The increase in blood pressure is more marked in women after the age of 50 years. The increase in systolic pressure appears to continue throughout life, whereas there is a tendency for diastolic pressure to round off around the age of 55 to 60 years. • Genetic Factors

A family history of elevated blood pressure is a strong risk factor for the future development of hypertension in individuals. The precise mode of inheritance of hypertension is not known. While some monogenic hypertensive disorders have been described, hypertension for the most part is currently regarded to be polygenic. Children of two normotensive parents have a 3% possibility of developing hypertension, and this possibility becomes 45% in children of two hypertensive parents.

B) MODIFIABLE RISK FACTORS Obesity

All epidemiological studies have shown a close relationship between blood pressure and weight. Hypertension is three times greater in the Obese (20% over normal weight) than in the non-obese. For every 1 Kg reduction in weight in obese hypertensive patients the blood pressure falls by 2.5/1.5 mmHg.

• Sedentary Life Style Sedentary life style can result in coronary heart disease. Increased physical activity has beneficial effects on blood pressure and serum lipoproteins. Dynamic isotonic exercise such as walking is more effective than static isometric exercise like weight lifting.

• Salt intake. Intake of sodium chloride in excess of physiological requirements, is associated with high blood pressure. Communities with a daily sodium chloride intake of 3 g or less (about 1/2 teaspoon) have low average blood pressures. Studies demonstrate a reduction in systolic

and diastolic blood pressures with reduced daily sodium intake. However, the reduction in blood pressure may take several weeks to become evident (WHO, TRS

862). • Alcohol.

Regular alcohol intake is associated with an increased risk of high blood pressure and contributes significantly to the prevalence of hypertension where drinking is a habit (WHO, TRS 862). Reduction of alcohol consumption results in lowering of blood pressure.

2. SECONDARY HYPERTENSION This is defined as hypertension secondary to an identifiable cause. It constitutes only a minority of people with hypertension. Special attention should be given in identifying curable or reversible causes of secondary hypertension. The causes can be divided into:

A) Hypertension Due to Drug Administration: • Hormonal preparations

Oestrogen- Progesterone oral contraceptives. Steroids: An increase in the blood pressure may follow administration of

ACTH or corticosteroids. With ACTH the rise in the blood pressure is mainly due to the adrenal release of mineralocorticoids.

• Other Drugs Carbenoxolone administration may elevate blood pressure. This is due to the mineralocorticoid activity of the medication. The hypertension usually resolves when the treatment is withdrawn. Other drugs like ephedrine, amphetamine, monoamine oxidase inhibitors, NSAIDs and tricyclic antidepressants may rarely increase the arterial blood pressure.

B) Hypertension Due to Organic Disease. • Renal Diseases

Renal Artery Lesions: Unilateral or bilateral renal artery stenosis causes hypertension. Surgical treatment of correctable lesions may alleviate hypertension and thus avoid the indefinite use of anti-hypertensives. Renal Parenchymal Lesions: These lesions typically affect both kidneys, and impairment of renal function accompanies blood pressure elevation. Examples include acute or chronic glomerulonephritis, analgesic nephropathy, polycystic disease, and chronic pyelonephritis. Unilateral Renal Lesions: When these lesions are found in a hypertensive patient, removal of the affected kidney may sometimes reduce the blood pressure. Examples include hydronephrosis, single cysts, renal tumours and renal tuberculosis.

• Diseases of the Adrenal Gland

Primary Hyperaldosteronism: This is caused by a single adenoma of the adrenal cortex or bilateral adrenocortical hyperplasia, and is associated with an increase in the body sodium and a decrease in the potassium. If due to a solitary adenoma of the adrenal cortex, the condition can be cured by surgical excision.

Cushing’s Syndrome: Patients with Cushing’s syndrome develop hypertension due to sodium and fluid retention. Treatment must be directed to the cause of the disease.

Phaeochromocytoma: This condition is characterized by excessive catecholamine secretion which produces paroxysmal hypertension.

Coarctation of the Aorta: In this condition, hypertension is associated with absent or diminished femoral pulses in comparison with the radial pulses. An extensive collateral circulation usually develops around the thorax.

C) Hypertensive disease of pregnancy This condition, otherwise known as toxaemia of pregnancy or pre-eclampsia, is a major cause of premature birth and perinatal death. Diagnosis is based on the presence of hypertension, proteinurea and oedema. For details on diagnosis and management of this type of hypertension, see section on hypertension & pregnancy in the ANC manual.

Section 3 : Diagnosis & Measurement • Diagnosis The diagnosis should be made after three measurements on at least two separate occasions and the blood pressure has to be 140/90 mmHg or over. • Apparatus

Mercury Sphygmomanometers should be kept in good working condition. There should be no dust in the rubber tubes linking the inflation bulb with the mercury reservoir. Ensure that there is no foreign matter in the space above the mercury column. The deflation valve must be in good working order, and the cuff itself must be in good condition. The standard cuff for adults must have a bladder 13-15 cm wide and 30-35 cm long so as to encircle the average upper arm. Cuffs of different widths are required for blood pressure measurement in children and in obese adults. Inadequate cuff sizes may result in over estimation of the true blood pressure. Aeronoid sphygmomanometers are subject to inaccuracies and should be regularly checked against mercury devices. • Recording

The sphygmomanometer should be placed on a horizontal surface. Measurements should be taken with the patient in the sitting position and the arm should not be constricted by any clothing. There should be no exertion, eating, smoking or exposure to cold immediately preceding the measurement. The cuff should be inflated to 20-30 mmHg above the pressure at which the radial pulse disappears to palpation, and the stethoscope is placed over the brachial artery in the antecubital fossa. The cuff is then slowly deflated at a constant rate and the reading is watched carefully. Systolic pressure is taken as the pressure at which the ear distinguishes the first arterial sound (phase I). The point at which the last arterial sound disappears, is usually taken as the diastolic pressure (phase V). The systolic and diastolic pressures should be measured at least twice over a period of

no less than three minutes. Both should be recorded and the mean value for both should be used. In children and in pregnant women, the phase IV sound (muffling), rather than phase V, may be used as an indication of the diastolic pressure.

Section 4 : Clinical Assessment Assessment of the individual with high blood pressure has the following objectives: • to confirm a persistent elevation of blood pressure

• to assess the overall cardiovascular risk • to evaluate existing organ damage or concomitant disease

• to search for possible causes of the hypertension Clinical assessment includes history taking, physical examination and laboratory investigation. Laboratory investigation can be more or less extended accordingjo the evidence obtained by history, physical examination and initial laboratory tests.

Blood pressure assessment can also be supported by home blood pressure measurements, provided the differences between “clinic” and home readings are considered.

History taking: On taking history try to elicit the following: A. Risk factors

• Family history of hypertension and cardiovascular disease • Family and personal history of hyperlipidaemia

• Family and personal history of diabetes mellitus • Smoking habits

• Dietary habits • Obesity, amount of physical exercise

B. Look for clues suggestive of secondary hypertension and these include:

• Young age • Family history of renal disease (polycystic kidney)

• Renal disease, urinary tract infection, haematuria, analgesic abuse (parenchymal renal disease)

• Oral contraceptives, liquorice, carbenoxolone, nasal drops, NSAIDs, etc. (hypertension due to drugs)

• Episodes of sweating, headache, anxiety (phaeochromocytoma) • Episodes of muscle weakness and tetany (hyperaldosteronism)

C. Symptoms of organ damage • Brain and eyes: Headache, vertigo, impaired vision, transient ischaemic attacks, sensory or motor deficit.

• Heart: Palpitations, chest pain, shortness of breath, ankle-swelling • Kidney: Thirst, polyuria, nocturia, haematuria

• Peripheral arteries: Cold extremities, intermittent claudication Physical examination: Accurate and full physical examination are vital and should focus on signs suggesting secondary hypertension and possible signs of organ damage. Signs suggesting secondary hypertension include:

• Features of Cushing’s syndrome • Skin signs of neurofibromatosis (pheochromocytoma)

• Palpable kidneys (polycystic kidney) • Diminished and delayed femoral pulses and reduced leg blood pressure (aortic coarctation or aortitis) • Precordial or chest murmurs (aortic coarctation or aortitis)

• Abdominal bruit (renal artery stenosis) Signs of organ damage

• Vascular bruits • Motor or sensory defects

• Retinal changes • Abnormal apical impulse, cardiac arrhythmias, ventricular gallop, pulmonary rales, dependent oedema. • Absence, reduction or asymmetry of peripheral pulses, ischaemic skin lesions

Laboratory Tests: The following are the minimal lab tests which should be done for an individual

diagnosed to have hypertension • Urine analysis including microscopy.

• Blood glucose. • Serum urea, creatinine, sodium and potassium.

• Full blood count, haematocrit and ESR • ECG (looking for SV1 + RV5 or 6)

• Fasting serum cholesterol. The minimum data set that should be obtained in every case of newly diagnosed hypertension appears in Annexure Section 5 : Treatment of Hypertension

Generally there are no identifiable causes for most patients with sustained arterial hypertension. If a cause is identified, it should be treated in the appropriate manner.

Section 4: Treatment Objectives of Treatment • To achieve maximum tolerated reduction in Blood Pressure (see therapy targets below).

• To correct other CVD risk factors. • To reverse target organ damage whenever possible.

Therapy Targets In young patients, the aim of therapy should be to lower the blood pressure to

140/90 mmHg or lower, whereas in the elderly, the aim should be to achieve a target of 140/90 mmHg, if this is tolerated.

NON-PHARMACOLOGICAL INTERVENTIONS Non-pharmacological interventions are used for the following reasons:

• To lower blood pressure • To reduce the need for antihypertensive drugs

• To minimise associated risk factors in an individual • To provide primary prevention of hypertension and associated cardiovascular diseases

Since Non-pharmacological interventions reduce the overall risk of cardiovascular disease as well as lower blood pressure, they should be applied before considering drug treatment, and should form an integral component of the overall management programme for all hypertensive patients.

Non-pharmacological interventions that contribute to lowering of blood pressure: • Weight reduction

• Avoidance of alcohol • Regular mild exercise in sedentary subjects, such as walking, cycling, jogging or swimming. • Salt restriction ( No added salt and avoidance of salty and pickled food)

Control of Associated Risks Tobacco

Hypertensives who smoke have a greater incidence of stroke and coronary artery disease than those who do not smoke. Therefore if the individual is a smoker, he should be advised to quit smoking. Control of Diabetes and Reduction of Dietary Fat Intake.

Raised serum cholesterol levels and diabetes are risk factors for cardiovascular diseases and their control will reduce the overall risk of cardiovascular disease. Intake of dietary fat should be reduced and consumption of fiber rich foods should be encouraged. Oral Contraceptive Pills

Oral Contraceptive pills containing oestrogen and progesterone raise the blood pressure levels and therefore alternative methods of contraception should be considered in hypertensive women.

PHARMACOLOGICAL AGENTS Antihypertensive Drugs Include the Following • Diuretics

• Beta-blockers • ACE inhibitors

• Calcium antagonists • Alpha-adrenoceptor blocking drugs.

Although the five groups of drugs are effective in treating hypertension, diuretics and beta-blockers should be used as first line drugs unless they are specifically contraindicated.

Diuretics Diuretics are the first-line anti-hypertensive therapy and are useful in the prevention of Cardiovascular morbidity and mortality. In 1arge doses they produce side effects like potassium depletion, reduced glucose tolerance, ventricular ectopics and impotence. These can be reduced if the dose is kept low. Diuretics are inexpensive, and can be used along with other antihypertensive drugs.

Beta-adrenoceptor-blocking drugs Several beta-blocking drugs are available, some with cardioselective properties, others with partial agonist activity or with alpha blocking or vasodilator properties. Beta blocking drugs are useful in hypertensive patients with effort angina, tachyarrhythmias, or with previous history of myocardial infarction. The absolute contraindication for use of these drugs is bronchial asthma and the relative contraindications include heart failure and peripheral vascular disease. Their use in patients with dyslipidaemia or reduced glucose tolerance is limited. Guidelines for Selecting First-line Drugs for Hypertension

ACE inhibitors These drugs are well tolerated and do not exert untoward effects on serum lipids or glucose homeostasis. Adverse effects include persistent cough, angio-oedema and hyperkalaemia. ACE inhibitors are to be avoided in women considering child bearing and are contraindicated in the second half of pregnancy, since it can increase the fetal and neonatal death. These drugs reduce the cardiovascular mortality and morbidity in patients with congestive heart failure and those with previous myocardial infarction. ACE inhibitors have also been shown to be very effective in reducing the development of left ventricular hypertrophy in hypertensive patients and retarding the progression of renal disease in patients with insulin- dependent diabetes mellitus and moderate renal impairment.

Calcium Antagonists The three major groups of calcium antagonists are phenylalkylamines (verapamil), dihydropyridines (nifedipine) and benzothiazepine (diltiazem).This class of drugs is effective in lowering blood pressure. Side effects include tachycardia, headache, flushing, ankle oedema, and constipation. The safety of these drugs in early pregnancy is not fully established.

Alpha-adrenoceptor-blocking drugs These drugs effectively reduce blood pressure and have limited side effects. Their main side effect is postural hypotension. Assessment of blood pressure when the patient is standing is essential when using alpha-blockers. Their dose should be carefully adjusted to avoid postural hypotension. Alpha-blockers may have advantages in patients with hyperlipidaemia or glucose intolerance.

Centrally Acting Drugs These drugs have been used for several years mostly in association with diuretics and are effective antihypertensive agents. Methyldopa remains an important agent in the treatment of hypertension in pregnancy.

Direct vasodilators, such as hydralazine are also quite effective in lowering blood pressure, but some of their side effects like tachycardia, headache and sodium and water retention make them difficult to be used as single drug therapy.

Combination of drugs If a drug from any of the five major classes is ineffective in lowering blood pressure in a given patient, it is advisable to substitute a drug from a different class. If therapy with a single drug is only partly effective, it may be preferable to add a small dose of a second drug from another class rather than increase the dose.

The following combinations have an additive effect • a diuretic with a beta blocker, ACE inhibitor or alpha blocker.

• a beta blocker with an alpha blocker or a dihydropyridine calcium antagonist • an ACE inhibitor with a calcium antagonist

When prescribing, the cost of medicines should be taken into consideration. Every effort should be made to avoid unnecessary prescription of expensive medications when less expensive alternatives are equally effective and safe. The following table gives the comparative cost of treatment and dosage of Some of the anti-hypertensive drugs approved by the Ministry of Health*.

* The above are approximate costs to the Ministry of Health. They do not reflect the cost of these drugs at the private sector.

Section 5 : Hypertension in Pregnancy Hypertensive disease of pregnancy is the major cause of premature birth and perinatal death, and is also responsible for 20-33% of all maternal deaths.

Diagnosis and Classification Hypertension in pregnancy is defined on the basis of diastolic blood pressure measurement by sphygmomanometry using phase IV Korotkoff sounds (muffling) in women lying on their sides at an angle of 15 to the horizontal in order to eliminate the haemodynamic changes associated with pregnancy. Diagnosis requires two consecutive measurements of DBP of 90 mmHg, at least four hours apart or one DBP measurement of 100 mmHg.

Classification Hypertensive disorders of pregnancy is classified into four categories based on the clinical findings of hypertension and br proteinuria duringpregnancy • pre-eclampsia/eclampsia

• chronic hypertension of whatever cause • chronic hypertension with superimposed pre-eclampsia/eclampsia

• transient or late hypertension

Pre-eclampsia/eclampsia Pre-eclampsia is characterised by hypertension with proteinuria (>300 mg/day) and at times coagulation abnormalities or liver abnormalities or both. Oedema is not used as a criterion. It occurs primarily in a woman’s first pregnancy after the 20th week of

gestation and most frequently near to full term. Women suspected of having eclampsia should be admitted to hospital.

Chronic Hypertension in pregnancy The diagnosis of chronic hypertension is made on the evidence of raised blood pressure before pregnancy or before the 20th week of gestation. The majority of patients in this category have uncomplicated hypertension and a benign course of pregnancy.

Late or transient hypertension This condition is characterised by the development of hypertension alone during the later stages of pregnancy or in the early puerperium, accompanied by a return to normal blood pressure within 10 days of delivery. Long-term follow up of women with hypertensive pregnancy is important, since a significant proportion will later develop essential hypertension.

Management Women diagnosed of having hypertension in pregnancy should be referred to the nearest hospital where facilities exist for the management of this condition Section 7 : Complications of Hypertension

Complications associated with blood pressure elevation fall into the following categories:

Heart. There are two main cardiac complications of hypertension; heart failure and ischaemic heart disease. Left ventricular hypertrophy results from increased total peripheral resistance and left ventricular work. This progresses to heart failure and the condition may prove fatal. Ischaemic heart disease is more common in hypertensive than in normotensive individuals and can be manifested by angina pectoris, myocardial infarction cardiac failure and sudden death.

Brain. Stroke is a major complication of hypertension. Cerebral, Cerebellar and brain stem haemorrhage is more closely associated with hypertension than is cerebral thrombosis. Transient ischaemic attacks may be one of the earliest manifestations of cerebrovascular disease and early detection and management of is important for the prevention of stroke. Hypertensive encephalopathy is often associated with an extreme elevation of arterial pressure and is characterized by variable disturbance of consciousness ranging from transient confusion to coma. This can be promptly reversed by antihypertensive therapy.

Kidney.: The renal complications of hypertension include premature or accelerated atherosclerosis of the renal arteries, nephrosclerosis, and with the development of the malignant phase, necrotizing arteriolar fibrinoid changes. Blood Vessels: Dissecting aortic aneurysm is encountered more often in persons with hypertension.

Accelerated (Malignant) phase The pathological feature of this complication is fibrinoid arterial necrosis. The practical criterion for diagnosis appears to be retinal haemorrhages with or without papilloedema.

Section 6 : Management at various Health Care levels AT PRIMARY HEALTH CARE LEVEL Every adult patient visiting the primary health centre should have his blood pressure checked. This would help in the early detection of hypertension in the community.

A plan for the treatment of Hypertension The decision to treat should be based not only on the diastolic and systolic blood pressure but also on the total cardiovascular risk and presence or absence of target organ damage. Unless the blood pressure is markedly raised, ie., diastolic pressure of 105 mmHg or over, the decision to treat should be made after careful initial assessment and repeated measurements.

Individuals with high blood pressure levels (diastolic blood pressure of 105 mmHg or over and/or systolic blood pressure of 180 mmHg or over) should be referred for immediate evaluation. Drug therapy should not be delayed in patients with target organ damage or in those with high risk. Otherwise, on finding an individual with a raised blood pressure, measurements should be repeated on at least two further occasions during the next four weeks. If hypertension is not confirmed, blood pressure should be checked in six months. On the other hand, if hypertension is confirmed, the individual should be assessed clinically, investigated and the cardiovascular risk should be evaluated. Advice should be given to modify lifestyle by stopping smoking, reducing obesity, limiting alcohol and saturated fat intake, restricting salt intake and encouraging physical exercise. The non-drug therapy can be continued for four weeks. If the blood pressure falls below 140/90 mmHg, all that is needed is to continue following the same measures and to monitor the blood pressure regularly (every three months during the first year and at longer intervals later). If the blood pressure remains high, the action taken depends on the total cardiovascular risk. If the total cardiovascular risk is high, i.e., the presence of other cardiovascular risk factors and br target organ damage, drug therapy should be started. In the absence of other cardiovascular risk factors and target organ damage, non-pharmacological measures should be reinforced and the blood pressure monitored for three to six months depending on the blood pressure level. At the end of this period, persistent elevation of blood pressure (systolic blood pressure 160 or over and diastolic blood pressure of 95 or over) is an indication for starting drug therapy.

Investigations Once hypertension has been diagnosed, do a thorough clinical examination, and if secondary hypertension is suspected, refer the patient to the secondary hospital.(see annexure for quick reference)

• Arrange for a complete blood count, urine analysis, blood urea, serum electrolytes, creatinine, and a random blood sugar. If any of these results is abnormal, refer the patient to the district/regional hospital.

• Arrange for a total serum lipid estimation. If the cholesterol level is high (above 5.2 mmol/L), put the patient on a low cholesterol diet and repeat after one month on a fasting sample. If it is still high, refer the patient to the district/regional hospital. • Send the patient for an ECG and a Chest x-ray. If the ECG shows LVH (sum of S in Vi or V2 and R in V5 or V6 = 35 mm or more), either with or without strain, refer the patient to the district/regional hospital for possible echocardiography. If there is evidence of cardiomegaly on Chest x-ray, refer the patient to the district/regional hospital.

Treatment As mentioned above treatment should initially be based on non-pharmacological measures. However failure of these measures is an indication for drug therapy. The majority of individuals with mild hypertension, can be successfully treated by a diuretic or a beta-blocker. The choice between the two groups of drugs depends on the condition of the patient and on the co-existing disorder. Hydrochlorothiazide is given in an initial dose of 25 mg, which may be increased to 50 mg if no response is achieved after a period of 2-3 weeks. Alternatively Atenolol could be used in a dose of 50 mg daily, which may be increased to 100 mg if no response is achieved

after 2 to 3 weeks. If the blood pressure is not reduced to the desired level, a combination of hydrochiorothiazide and Atenolol may be used. If the blood pressure is still not controlled, refer the patient to the district/regional hospital.

Follow-Up • Hypertensive patients who are well stabilized, should be followed up every two to three months. Blood investigations should be repeated once every year, an ECG once every two years or as indicated and a Chest x-ray once every five years.

AT SECONDARY HEALTH CARE LEVEL • If the patient is first diagnosed to be hypertensive at the district/regional hospital, follow the above management and refer to the primary health care level for subsequent follow-up. • If the patient is referred from the primary health centre for an abnormal finding on investigations re-assess the patient, for the concerned health problem like doing an echocardiography confirming diabetes mellitus, rechecking lipid status, ruling out end organ effect of hypertension, doing a treadmill exercise test and assessing the peripheral vascular status.

• If the patient is referred because of failure to control the hypertension, consider the following causes of lack of response like lack of patient compliance, “white coat effect”, inadequate drug dosage, the presence of secondary forms of hypertension and excess salt and alcohol intake. If these have been excluded, consider addition of calcium channel blockers or an ACE inhibitor. An ACE inhibitor is particularly indicated in people with Diabetes Mellitus and especially those with incipient nephropathy.

• If Diltiazem is given, start with 60 mg twice a day. Recheck the blood pressure after one month, and if still raised, increase the dose to three times a day, and review the patient after one month. If the BP is still uncontrolled, refer the patient to the tertiary hospital. If the blood pressure is controlled, refer the patient back to the primary health centre.

• If Nifedipine is prescribed, start with 10 mg twice daily, raising it to three times a day in the same manner as for Diltiazem. If Nifedipine retard (20 mg) is used start with one tablet and increase it to twice a day. • All these calcium channel blockers have the side effects of headache, pins and needles in the limbs, hot flushes, burning feet and sometimes oedema. Rarely one may get chest pain with nifedipine.

• Patients on calcium channel blockers should be followed up at the district/regional hospital every six months.

• ACE inhibitors include drugs like Lisinopril (Zestril), Captopril (Capoten) Cilazapril (Inhibace). Prior to the addition of these, consider withholding chlorothiazide for 24 hours to avoid the first dose effect of severe hypotension. (Note: Calcium channel blockers in combination with beta blockers may produce unacceptable bradycardia and hypotension.)

AT TERTIARY HEALTH CARE LEVEL • Patients are to be referred to the tertiary centre to conduct specialized tests not available at the secondary or primary health centre, (e.g. renal, peripheral and coronary angiogram, echocardiogram, thallium scan) and specialist opinion. • If the blood pressure is controlled, and no further investigations are required, refer the patient back to the primary health centre for regular follow-up. These patients have to be reviewed at the district/regional hospital every six months.

Annexures A QUICK REFERENCE GUIDE FOR HYPERTENSION * • Definition : Blood pressure sustained above 140/90 mmllg after repeated measurement

• Classification : Hypertension/Hypertension + risk factors alone/Hypertension with risk factors and/or

concurrent organ damage • Measurement of Blood : Sitting or supine, repeated x 2 after 3 minutes

Pressure if initial BP is ›140/90; (observers require training) • High risk groups : Smokers - elderly

Diabetes Mellitus - family history Evidence of organ damage

Previous MI - hyperlipidaemia • Minimum data set : History, Examination, Investigations Medical record (please see overleaf) • Target blood pressures : To achieve the maximum tolerated reduction in blood pressure › 140/90 mmHg • Management : Non pharmacological:

- Reduce fat intake - Reduce alcohol - Salt: do not add - Reduce weight (if obese)

- Regular dynamic exercise (e.g. walking)

Pharmacological therapy (Drug therapy) - Diuretic or Beta blockers as first line unless contraindicated - ACE inhibitors esp. in diabetes with incipient nephropathy

- Calcium antagonists, Alpha blockers - Others

(The choice of drug is influenced by associated disease, risk factors or organ damage) • Education : - Public awareness, attitudes

- Compliance with regimen - Doctors, nurses : Levels to treat

BP measurement Continuing education

(Adequate time should be given to each patient during the consultation) * World Health Organization, Eastern Mediterranean Regional Office : Prevention and Management of Hypertension - A Regional Publication, 1996

Annexure: HYPERTENSION MINIMUM DATA SET History: - Presenting complaints and duration - Previous history of MI, stroke, diabetes, renal disease and PVD

- Family history of HT, MI, stroke, diabetes and PYD - Drug history, e.g. NSAIDs, oral contraceptives, corticosteroids

- Previous therapies/previous adverse reactions of drugs - Risky behaviours like smoking

Physical Examination: - Clinical examination includes looking for signs of secondary hypertension e.g.

Cushing’s syndrome Yes / No Phaeochromocytoma Yes / No

Polycystic kidney Yes / No Coarutation Yes / No

Renal artery stenosis Yes / No

- Clinical examination includes looking for signs of organ damage e.g. LVH (edema, displaced apical impulse, gallop, rales) Yes / No

Retinal changes Yes / No if yes specify Peripheral pulses reduced Yes / No

Peripheral pulses synchronous Yes / No Cerebrovascular disease Yes / No

Laboratory Tests: - Urine analysis - Serum creatinine or BUN

- Blood Glucose - Serum potassium (and sodium) - ECG (SV1 + RV5 or 6) - Serum cholesterol

- Haematocrit - ESR

Annexure ABBREVIATIONS ACE - Angiotensin Converting Enzyme ACTH - Adreno Corticotrophic Hormone

ANC - Antenatal Care BMI - Body Mass Index

BP - Blood Pressure BUN - Blood Urea Nitrogen

CCF - Congestive Cardiac Failure COAD - Chronic Obstructive Airway Disease

CVD - Cardiovascular Disease DBP - Diastolic Blood Pressure

DSDC - Department of Surveillance and Disease Control ECG - Electrocardiogram

ESR - Eiythrocyte Sedimentation Rate GIT - Gastrointestinal Tract

LVF - Left Ventricular Failure LVH - Left Ventricular Hypertrophy

M - MyocardiaJ Infarction MOH - Ministry of Health

NCD - Non-Communicable Diseases

NSAIDs - Non-steroidal Anti Inflammatory Drugs PHC - Primary Health Care

PVD - Peripheral Vascular Disease SBP - Systolic Blood Pressure

SLE - Systemic Lupus Erythromatosis TRS - Technical Report services

WHO - World Health Organization