History

Fact Explanation
Non-specific symptoms: Fatigue, malaise, dizziness In about 95% of patients diagnosed with elevated blood pressure, a specific aetiology cannot be found. These patients are said to have essential hypertension.[1] The aetiology of essential hypertension is multifactorial with factors such as genetic predisposition, obesity, high salt intake, alcohol consumption, sedentary lifestyle, stress etc playing a role.[2] [3]
Incidental finding during physical examination This is a common presentation. The patient is asymptomatic and hypertension (HT) is identified during physical examination.[4]
Presentation with end organ damage The common organs which are affected are central nervous system, heart, blood vessels, retina and kidney.[5] The patient may have a history stable angina or a past history of myocardial infarction. Palpitations due to atrial fibrillation may occur. The patient may have a history of stroke or transient ischemic attacks. Hypertension predisposes to development of chronic renal failure. Questions should be asked from the patient to determine the presence/ absence of target organ damage related to each organ.
Exclude the possibility of a secondary cause Causes for secondary hypertension could be classified as renal, endocrine, cardiovascular causes. Factors which support a diagnosis of secondary hypertension are onset of HT at a young age, hypertension that responds poorly to medication etc.[6]
Assess other cardiovascular risk factors Look for the presence of other cardiovascular risk factor such as diabetes, hyperlipidaemia, smoking & family history of early onset cardiovascular disease.[7] The patient may have a previous history of cardiovascular disease. Assess the patient’s level of exercise and life style.
References
  1. CARRETERO O. A., OPARIL S.. Essential Hypertension : Part I: Definition and Etiology. Circulation [online] 2000 January, 101(3):329-335 [viewed 25 June 2014] Available from: doi:10.1161/01.CIR.101.3.329
  2. JOHNSON RJ, FEIG DI, NAKAGAWA T, SANCHEZ-LOZADA LG, RODRIGUEZ-ITURBE B. Pathogenesis of essential hypertension: historical paradigms and modern insights J Hypertens [online] 2008 Mar, 26(3):381-391 [viewed 25 June 2014] Available from: doi:10.1097/HJH.0b013e3282f29876
  3. OPARIL S, ZAMAN A.M, CALHOUN D.A. Pathogenesis of Hypertension. Ann Intern Med, 2003, 139, 761-776.
  4. BINDER A. A review of the genetics of essential hypertension. Curr Opin Cardiol [online] 2007 May, 22(3):176-84 [viewed 25 June 2014] Available from: doi:10.1097/HCO.0b013e3280d357f9
  5. SCHMIEDER RE. End Organ Damage In Hypertension Dtsch Arztebl Int [online] 2010 Dec, 107(49):866-873 [viewed 26 June 2014] Available from: doi:10.3238/arztebl.2010.0866
  6. ONUSKO E. Diagnosing secondary hypertension. Am Fam Physician [online] 2003 Jan 1, 67(1):67-74 [viewed 16 September 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/12537168
  7. MESSERLI FRANZ H, WILLIAMS BRYAN, RITZ EBERHARD. Essential hypertension. The Lancet [online] 2007 August, 370(9587):591-603 [viewed 25 June 2014] Available from: doi:10.1016/S0140-6736(07)61299-9

Examination

Fact Explanation
Measurement of blood pressure (BP) Accurate measurement of BP is essential for diagnosis and follow-up. A mercury sphygmomanometer is the preferred measurement instrument while electronic BP devices may also be used. Use a machine that is well maintained and properly calibrated. Criteria to be followed when measuring the BP are keep the patient seated with back support, rest the arm at the level of the heart, use the appropriate cuff size, allow the patient to relax for 5 minutes before measurement. Patient should be advised to avoid smoking or drinking caffeine 30 minutes prior to BP measurement. Ideally 2-3 measurements should be taken and the average calculated.[1]
General examination : Height, Weight and Waist circumference Height and weight measurements can be used to calculate the body mass index (BMI).[2] BMI and waist circumference can be compared on charts to determine the degree of obesity. A BMI value of over 23.5 in Asians and a value above 25 in Caucasians carries a high cardiovascular risk. A waist–hip ratio above 0.90 in males and above 0.85 in females carry a high risk of cardiovascular disease.
Funduscopic examination Hypertensive retinopathy is classified into 4 grades. Grade 1 – Arterioles are thickened, tortuous and have increased reflectiveness ( Silver-wiring). Grade 2 – Grade 1 and the presence of arteriovenous nipping. Grade 3 – Grade 2 plus the evidence of retinal ischaemia. Grade 4 is the presence of papilloedema.[3]
Examine for end organ damage Examine the cardiovascular system and the nervous system for evidence of target organ damage.[4]
References
  1. PERLOFF D., GRIM C., FLACK J., FROHLICH E. D., HILL M., MCDONALD M., MORGENSTERN B. Z.. Human blood pressure determination by sphygmomanometry. Circulation [online] 1993 November, 88(5):2460-2470 [viewed 25 June 2014] Available from: doi:10.1161/01.CIR.88.5.2460
  2. MESSERLI FRANZ H, WILLIAMS BRYAN, RITZ EBERHARD. Essential hypertension. The Lancet [online] 2007 August, 370(9587):591-603 [viewed 25 June 2014] Available from: doi:10.1016/S0140-6736(07)61299-9
  3. WONG TY, MITCHELL P. Hypertensive retinopathy. N Engl J Med [online] 2004 Nov 25, 351(22):2310-7 [viewed 16 September 2014] Available from: doi:10.1056/NEJMra032865
  4. CARRETERO O. A., OPARIL S.. Essential Hypertension : Part I: Definition and Etiology. Circulation [online] 2000 January, 101(3):329-335 [viewed 25 June 2014] Available from: doi:10.1161/01.CIR.101.3.329

Differential Diagnoses

Fact Explanation
Elevation of blood pressure due to anxiety It has been observed that patients may have elevated BP measurements in the healthcare setting (white coat hypertension). Allowing the patient to rest for 5 minutes prior to BP assessment may reduce this error.[1]
Secondary hypertension Common causes for secondary hypertension could be classified as renal, endocrine, cardiovascular causes. Renal causes - Renal artery stenosis, Acute and chronic pyelonephritis, chronic renal failure, polycystic kidney disease. Endocrine causes – Cushing’s syndrome, hyperaldosteronism, phaeochromocytoma, hyperthyroidism, hyperparathyroidism etc.[2] Coarctation of the aorta presents with elevated blood pressure in the upper limbs while the lower limbs have a lowered BP.
Cushing’s syndrome Cushing’s syndrome is the chronic exposure to excess glucocorticoid which may result from various causes.[3] Prolonged administration of excess exogenous glucocorticoid treatment is the commonest cause. Other causes are tumors which secrete ACTH and ectopic tumors which secrete glucocorticoids. Clinical features of the condition are hirsutism, acne, hair thinning, easy bruising, central obesity and striae. The patient may also develop complications such as peptic ulcers, osteoporosis, myopathies, menstrual disturbances and psychosis. Diagnosis is a two step process where the first step is to confirm Cushing’s syndrome by dexamethasone suppression test or 24h urinary cortisol measurement. Investigations are planned accordingly from here-on to find the aetiology.
Phaeochromocytoma Phaeochromocytoma is a neuro-endocrine tumor which secretes excess catecholamine.[4] The tumor may be situated in the adrenal gland or in an extra-adrenal site. The tumor may occur at any age. Phaeochromocytoma may be inherited as a multiple endocrine neoplasm syndrome (MENS type 2). The patient presents with headache, palpitations, excessive sweating and anxiety. Blood pressure fluctuations are episodic coinciding with catecholamine release. Diagnosis is confirmed by measurement of hormones or by product levels in serum or urine. Localization of the tumor can be achieved with CT scan or MRI.
Poly-cystic kidney disease (PCKD) PCKD is an adult onset autosomal recessive disorder where gradual development of cysts occurs in the kidneys.[5] The normal renal parenchyma is destroyed with the expansion of the cysts. Patients present at about 30-40 years of age with abdominal pain, haematuria, hypertension or chronic renal failure. Examination will show bilateral enlarged ballotable kidneys. Other associations with PCKD are hepatic cysts and Berry aneurysms of cerebral vasculature. Ultrasound examination usually confirms the diagnosis.
Drug induced hypertension Drugs which may lead to elevated blood pressure are estrogenic oral contraceptives, corticosteroids, NSAIDs etc.[6] Erythropoietin can also lead to elevated blood pressure.
References
  1. CELIS H, FAGARD RH. White-coat hypertension: a clinical review. Eur J Intern Med [online] 2004 Oct, 15(6):348-357 [viewed 16 September 2014] Available from: doi:10.1016/j.ejim.2004.08.001
  2. BIANCHI GIUSEPPE. Book Review Secondary Hypertension: Clinical Presentation, Diagnosis, and Treatment (Clinical Hypertension and Vascular Diseases.) Edited by George A. Mansoor. 352 pp., illustrated. Totowa, N.J., Humana Press, 2004. $99.50. 1-58829-141-3. N Engl J Med [online] 2004 August, 351(8):838-839 [viewed 25 June 2014] Available from: doi:10.1056/NEJM200408193510827
  3. PRAGUE J. K., MAY S., WHITELAW B. C.. Cushing's syndrome. BMJ [online] December, 346(mar27 3):f945-f945 [viewed 25 June 2014] Available from: doi:10.1136/bmj.f945
  4. TSIRLIN A, OO Y, SHARMA R, KANSARA A, GLIWA A, BANERJI MA. Pheochromocytoma: a review. Maturitas [online] 2014 Mar, 77(3):229-38 [viewed 25 June 2014] Available from: doi:10.1016/j.maturitas.2013.12.009
  5. WILSON PD. Polycystic kidney disease. New England Journal of Medicine, 2004, 350, 151-64.
  6. STOKES GS. Drug-induced hypertension: pathogenesis and management. Drugs [online] 1976, 12(3):222-30 [viewed 16 September 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/185040

Investigations - for Diagnosis

Fact Explanation
Diagnosis of hypertension depends on accurate measurement of blood pressure during physical examination. The correct technique of blood pressure measurement should be followed.[1] Grade the degree of hypertension according to both the systolic and diastolic BP.
Exclusion of secondary causes If the history and examination support a diagnosis of secondary hypertension extra investigations may be needed. Choice of investigation should be guided by the clinical information.[2]
Renal ultrasound, Renal angiography Renal ultrasound scan can be used to detect renal pathology. Renal artery stenosis can be diagnosed by renal angiography.[3]
Urinary catecholamines To exclude the possibility of phaeochromocytoma.[4]
Urinary cortisol and dexamethasone suppression test To investigate for possible Cushing's syndrome.[5]
Chest X-ray/ ECG In coarctation of aorta chest X-ray may show cardiomegaly and notching of the ribs. ECG will show features of left ventricular hypertrophy.[6]
References
  1. CARRETERO O. A., OPARIL S.. Essential Hypertension : Part I: Definition and Etiology. Circulation [online] 2000 January, 101(3):329-335 [viewed 25 June 2014] Available from: doi:10.1161/01.CIR.101.3.329
  2. AKPUNONU BE, MULROW PJ, HOFFMAN EA. Secondary hypertension: evaluation and treatment. Dis Mon [online] 1996 Oct, 42(10):609-722 [viewed 18 September 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/8948319
  3. BRAVO EL. Secondary hypertension. A streamlined approach to diagnosis. Postgrad Med [online] 1986 Jul, 80(1):139-46, 148, 150-1 [viewed 18 September 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/3725709
  4. TSIRLIN A, OO Y, SHARMA R, KANSARA A, GLIWA A, BANERJI MA. Pheochromocytoma: a review. Maturitas [online] 2014 Mar, 77(3):229-38 [viewed 25 June 2014] Available from: doi:10.1016/j.maturitas.2013.12.009
  5. PRAGUE J. K., MAY S., WHITELAW B. C.. Cushing's syndrome. BMJ [online] December, 346(mar27 3):f945-f945 [viewed 25 June 2014] Available from: doi:10.1136/bmj.f945
  6. AGARWALA BN. Coarctation of the Aorta: Echocardiographic Diagnosis in a Child Tex Heart Inst J [online] 2001, 28(2):156-157 [viewed 26 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC101161

Investigations - Screening/Staging

Fact Explanation
Blood glucose Investigate for diabetes mellitus.[1]
Lipid profile Hypercholesterolemia is an important cardiovascular risk factor.[1]
Electrocardiography (ECG) Look for previous myocardial infarction. The ECG may show left ventricular hypertrophy.[2]
Urinalysis : Check for protein, blood and glucose Investigate for kidney damage from long standing hypertension. Glycosuria and microalbuminuria may be present in diabetes mellitus.[3]
Serum creatinine/ serum electrolytes/ Blood urea Assess renal function.[3]
References
  1. CARRETERO O. A., OPARIL S.. Essential Hypertension : Part I: Definition and Etiology. Circulation [online] 2000 January, 101(3):329-335 [viewed 25 June 2014] Available from: doi:10.1161/01.CIR.101.3.329
  2. BLACK H.R, WELTIN G, JAFFE CC. The limited echocardiogram: a modification of standard echocardiography for use in the routine evaluation of patients with systemic hypertension. Am J Cardiol, 1991, 67, 1027–1030.
  3. HART PD, BAKRIS GL. Hypertensive nephropathy: prevention and treatment recommendations. Expert Opin Pharmacother [online] 2010 Nov, 11(16):2675-86 [viewed 25 June 2014] Available from: doi:10.1517/14656566.2010.485612

Management - General Measures

Fact Explanation
Patient education Patient education is important to motivate and empower the patient for proper management. The patient should be educated about the natural history of the disease, long term complications, management option and importance of compliance to therapy.[1]
Non drug therapy Lifestyle modification is an important component of management. Measures such as regular exercise, reducing alcohol consumption, quitting smoking lower the blood pressure and reduces the need for drug therapy.[2]
Dietary changes Correct obesity. Increase the consumption of fruits and vegetables, cut down on saturated fat products. Restricting the salt intake also lowers blood pressure.[3]
Follow-up Regular follow-up is necessary for optimal management. At follow-up clinic visits assess blood pressure control, evidence of target organ damage, drug side effects and effort in non-pharmacological measures.[1]
References
  1. Hypertension: management of hypertension in adults in primary care. National Institute for Health and Clinical Excellence, June 2006[Viewed on 22 June 2014]. Available from : http://www.nice.org.uk/nicemedia/pdf/CG034NICEguideline.pdf
  2. KAPLAN NM. Non-drug treatment of hypertension. Ann Intern Med [online] 1985 Mar, 102(3):359-73 [viewed 25 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/3882040
  3. HADDY FJ, PAMNANI MB. Role of dietary salt in hypertension. J Am Coll Nutr [online] 1995 Oct, 14(5):428-38 [viewed 25 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/8522721

Management - Specific Treatments

Fact Explanation
Cardiovascular(CV) risk assessment Assessment of absolute CV risk helps in risk stratification of the patient and determining the need for drug therapy.[1] Joint British Societies risk assessor are charts that are developed for this purpose. These charts take into account the sex, age of the patient and the presence of other CV risk factors such as smoking, diabetes and hyperlipidaemia.
Threshold for drug therapy Patients with blood pressure values above 160/100 warrant treatment.[2] Hypertensive patients with a 10yr cardiovascular risk of 20% or who have evidence of end organ damage or existing cardiovascular disease also require anti-hypertensive drug therapy.
Anti-hypertensive drugs Anti-hypertensive drug classes commonly used are diuretics, beta blockers, ACE inhibitors, angiotensin 2 receptor blockers and calcium channel blockers. Trials comparing these main drugs have shown that efficacy and outcome are similar to each other.[3] Hence drug choice depends mainly on drug side effects, cost and convenience to the patient. Other drug classes that are also used are alpha blockers, methyldopa etc.
Choice of anti-hypertensive Choice anti-hypertensive agent usually depends on patient preference and effectiveness in patient. An algorithm has being developed for initiation of drug therapy. Younger patients (55yrs) are usually started on ACE inhibitors while older patients and black patients are started on CCB or thiazide type diuretic (step 1). In step 2 a combination of ACE inhibitor and CCB or diuretic is used. In step 3 all three drugs are used together. Patients who fail to respond to all three drugs should be considered on adding either a beta-blocker/ spironolactone/ other diuretic.[4] [5]
Choice of anti-hypertensive in co-morbid conditions Certain anti-hypertensives are used in certain co-morbid conditions. In patients with benign prostatic hypertrophy alpha blockers are preferred since it may alleviate the urinary symptoms.[6] Beta blockers are used in patients with angina but are contra-indicated in asthmatic patients. ACE inhibitors are preferred in patients with heart failure. In the elderly thiazide diuretics or CCB are considered suitable drug therapy.
Targets of therapy In otherwise healthy patients a target BP of less than 140/90mmHg is aimed for. Patients who are diabetic or have chronic renal failure have a lower target of 130/80.[7] Chronic renal failure patients who have gross proteinuria are targeted to have a BP target of 125/75mmHg.
Failure to treatment Common causes for treatment failure are non compliance to drug regime, inadequate treatment or failure to recognize a secondary cause.[1]
Adjuvant treatment High risk patients with hyperlipidaemia benefit from therapy with statins.[8] Aspirin is effective at lowering the cardiovascular risk but carries the risk of bleeding - intracerebral bleeds. Hence aspirin is used in high risk patients where the benefits outweigh the risks (older patients with evidence of target organ damage/ who are diabetic/ have a 10yr cardiovascular risk of 15%).
References
  1. Hypertension: management of hypertension in adults in primary care. National Institute for Health and Clinical Excellence, June 2006[Viewed on 22 June 2014]. Available from : http://www.nice.org.uk/nicemedia/pdf/CG034NICEguideline.pdf
  2. MESSERLI FRANZ H, WILLIAMS BRYAN, RITZ EBERHARD. Essential hypertension. The Lancet [online] 2007 August, 370(9587):591-603 [viewed 23 June 2014] Available from: doi:10.1016/S0140-6736(07)61299-9
  3. ALLHAT OFFICERS AND COORDINATORS FOR THE ALLHAT COLLABORATIVE RESEARCH GROUP. THE ANTIHYPERTENSIVE AND LIPID-LOWERING TREATMENT TO PREVENT HEART ATTACK TRIAL. Major outcomes in high-risk hypertensive patients randomized to angiotensin-converting enzyme inhibitor or calcium channel blocker vs diuretic: The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). JAMA [online] 2002 Dec 18, 288(23):2981-97 [viewed 25 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/12479763
  4. SEVER P, BEEVERS G, BULPITT C, LEVER A, RAMSAY L, REID J, SWALES J. Management guidelines in essential hypertension: report of the second working party of the British Hypertension Society. BMJ [online] 1993 Apr 10, 306(6883):983-987 [viewed 25 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1677457
  5. Treating mild hypertension. Report of the British Hypertension Society working party. BMJ [online] 1989 Mar 18, 298(6675):694-698 [viewed 25 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1836038
  6. TEWARI A, NARAYAN P. Alpha-adrenergic blocking drugs in the management of benign prostatic hyperplasia: interactions with antihypertensive therapy. Urology [online] 1999 Mar, 53(3 Suppl 3a):14-20; discussion 41-2 [viewed 25 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/10094096
  7. NILSSON PM. Target blood pressure in diabetes patients with hypertension--what is the accumulated evidence in 2011? J Zhejiang Univ Sci B [online] 2011 Aug, 12(8):611-23 [viewed 18 September 2014] Available from: doi:10.1631/jzus.B1101001
  8. BORGHI C, PRANDIN MG, COSTA FV, BACCHELLI S, DEGLI ESPOSTI D, AMBROSIONI E. Use of statins and blood pressure control in treated hypertensive patients with hypercholesterolemia. J Cardiovasc Pharmacol [online] 2000 Apr, 35(4):549-55 [viewed 25 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/10774784