HYPERTENTION


HYPERTENTION

Edited By :

Dr.Salim Al Mamun

MBBS(Raj);CCD(BIRDEM);

CMU(DU);DMUD(Course)

 

What is HYPERTENSION?                                      

Persistent raised blood pressure, systolic or diastolic or both are ≥140/90 mm Hg and measured at the past two visits.

A decision to prescribe antihypertensive therapy effectively commits the pt. to lifelong treatment. So, blood pressure measurement must be as accurate as possible1.

BP measuring devices

The auscultatory method using mercury sphygmomanometer has been the main stay of clinical BP measurement for many years.

1. Mercury sphygmomanometers is the gold standard if properly maintained

2. Aneroid devices are used widely

3. Automated devices for self and ambulatory blood pressure measurement, but these are expensive1

Avoid fatty food (Fast Food) to reduce BP

Procedure of measurement of blood pressure

  1. Measurement should begin after at least 5 minutes of rest.
  2. Measure sitting blood pressure routinely
  3. Standing blood pressure should be recorded in elderly or in diabetic patients
  4. Remove tight clothing
  5. Use cuff of appropriate size, the cuff should cover at least 2/3 rd of arm circumference.
  6. Avoid talking during the measurement procedure
  7. Patients should refrain from smoking, ingesting caffeine for 30 minutes prior to measurement of BP
  8. Measure in both arms at 1st visit2
  9. Lower mercury column slowly (2mm/Sec) 1
  10. Measurement should be made to the nearest 2 mm Hg
  11. At least 2 measurements should taken in each visit (1-2 minutes apart) 2. More measurement should be taken if >10mmHg difference in systolic or >5mmHg difference in diastolic BP is found.
  12.   Measure systolic BP as the appearance of korotkoff  sound (phase I)
  13. Measure diastolic BP as the disappearance of korotkoff  sound (phase V)
  14. Nevertheless, in those condition where korotkoff sounds remain audible despite complete deflation of the cuff (aortic regurgitation, arteriovenous fistula, pregnancy) phase 4 must be used for the diastolic BP3.
  15. Clinicians should provide measured BP to pt. verbally and in writing the specific BP numbers and BP goals.
  16. Do not treat on the basis of an isolated reading2

Reduce salt intake to < 100mmol/day (<6g NaCI day, 1 TSF) reduce BP

Self and ambulatory measurement of BP

Self measurement of BP

BP self measurement may benefit patients by providing information on

1.Response to antihypertensive medication

2.Improving patient adherence with therapy

3.Help in evaluation of white coat hypertension

Persons with an average BP >135/85 mm Hg measured at home are generally considered to be hypertension2.

BP level classification for adult and older

This classification is based on average of 2 or more properly measured  seated BP readings.

    BP Classification SBP mmHg DBP mmHg2
                Normal <120 and <80
                Prehypertension 120-139 or 80-89
               Stage 1 Hypertension 140-159 or 90-99
               Stage 2 hypertension ≥160 or≥100
Isolated systolic hypertension Systolic Diastolic1
Grade 1 140-159 <90
Grade 2 >160 <90

Pt. with Prehypertension are increased risk of developing hypertension (50 % in 4 year) 2.

Routine investigations for all hypertensive pt.

  1. Urine strip test for protein, blood and glucose
  2.  Serum creatinine and electrolytes
  3. Blood glucose – ideally fasted
  4.  Blood lipid profile ideally fasting
  5.  Electrocardiogram (ECG)

Hypertension investigation of selected pt.

1.  Chest x-ray to detect cardiomegaly, heart failure, coarctation of the aorta

2.Ambulatory BP recording

3.Echocardiogram to detect or quantify LVH

4.Renal ultrasound to detect possible renal disease

5.Renal angiography to detect or confirm presence of renal artery stenosis

6.Urinary catecholamines to detect possible phaeochromocytoma

7.Urinary cortisol and dexamethasone suppression test to detect possible Cushing syndrome

8.Plasma renin activity and aldosterone to detect possible primary aldosteronism4.

Goal of therapy

“The Goal is to get to Goal!”

Hypertension    Hypertension 

PLUS

Diabetes or Renal Disease

< 140/90 mmHg  < 130/80 mmHg

Management of hypertension

2 components of management of hypertension

•      Life style measure

•      Pharmacological treatment

Who should offer life style measure?

1.   In all hypertensive pt.

2.   In prehypertensive pt.

Life style measures are…

1.   Maintain normal weight  (BMI should be 18.5-24.9 kg/m2)

2.   Physical activity

3.   Regular physical exercise (Brisk walking for at least 30 minutes per day, ideally on most of days of the week)

4.   DASH (Dietary approach to stop hypertension)

a.    Reduce salt intake to < 100mmol/day (<6g NaCI day, 1 TSF)

b.   Consume fresh fruits and vegetables

c.    Reduce the intake of total and saturated fat

d.   Limit alcohol consumption to < 3 units/day for men and < 2 units/day for women)

e.    Stop smoking

f.     Increase intake of potassium, calcium and magnesium containing food2

Antihypertensive drugs and doses

A) Thiazide & other diuretic

1.    Bendroflumethiazide 2.5 mg/day

2.    Cyclopenthiazide 0.5 mg/day

3.    Frusemide 40 mg/day (In renal impairement or along with ACEi)

4.    Bumetanide 1 mg/day (In renal impairement or along with ACEi)

B)  ACEi

1.    Enalapril 20 mg daily

2.    Ramipril 5-10 mg daily

Electrolytes and S. creatinine should be checked before and 1-2 week after commencing therapy with ACEi.

C)  ARB

1.    Loartan 50-100 mg daily

2.    Irbesartan 150-300 mg daily

3.    Valsartan 40- 160 mg daily

D) Calcium channel blocker

Dihydropyridines

1.    Amlodipine 5-10 mg daily

2.    Nifedipine 30-90 mg daily

Rate limiting CCB

1.    Diltiazem 200-300mg daily (useful when hypertension coexist with angina)

2.    Verapamil 240 mg daily (useful when hypertension coexist with angina)

E)  Betablockers

These are no longer used as first line antihypertensive therapy except in pt. with another indication for the drugs (e.g. angina)

1.    Atenolol 50 -100 mg daily

2.    BIsoprolol 5-10 mg daily

3.    Metoprolol 100-200 mg daily

F)   Carvedilol- 6.25- 25 mg 12 hourly

G) Alpha adrenoceptors blockers – Prazosin 0.5-20 mg daily in divided doses4

H) Others vasodilators

1.    Hydralazine up to 100 mg daily

2.    Minoxidil up to 50 mg daily

3.    Sodium nitroprusside now only use intravenously in hypertensive emergencies

I)     Centrally acting drugs

1.    Reserpine 0.05 mg/ day

2.    Methyldopa 500-2000 mg/ day in 2 doses

3.    Clonidine5

Algorithm for treatment of hypertension

Life style modifications

Not at goal BP

Initial drug choices

↓                               ↓

Without compelling indications          With compelling indications

Without compelling indications

                       ↓                                  ↓

Stage 1 hypertension                Stage 2 hypertension

Thiazide type diuretic               2 drug combination

May consider ACEi,                   usually diuretic and

ARB, CCB.                                   ACEi, ARB, CCB2.

Compelling indication

Compelling indications

                 

ACEi

Heart failure
Left ventricular dysfunction
Post MI or established CHD
Type 1 diabetic nephropathy
Secondary stroke prevention

Electrolytes and S. creatinine should be checked before and 1-2 week after

commencing therapy with ACEi.

    ARB

LVH
Type 2 diabetic nephropathy
Heart failure in ACEi intolerant
ACEi intolerant

Betablockers

These are now not used as 1st line antihypertensive agent unless there is compelling indication.

 

Betblocker

           MI
           Angina
           Heart failure
 

Thiazide or thiazide like diuretics

Hypertension with Secondary stroke prevention
Isolated systolic hypertension
Hypertension in old age

Hypertension in old age

CCB (dihydropyridines)

Thiazide or thiazide like diuretics

 

Alpha adrenoceptors- Prazosin BEP4

Combination  therapy

Vein                                     Heart                                   Vein

Diuretic

ACEI

ARB

Beta Blockers

CCB-Rate limiting

CCB-Dihydropyridines

Alpha1 Blockers

ACEI

ARB

Choose one agent from each category

Alternative approach for Antihypertensive drug combination

< 55 years                                              > 55 years or black pt. of any age

↓                                                                          ↓

A                                                                         C or D                    Step 1

↓                                                                           ↓

Step 2   A+ C or A + D

Step 3   A+ C + D

Add

Further diuretic therapy or

Alpha blocker or

Betablocker

Consider seeking specialist advice1

A= ACEi, B= Betablocker, C= Calcium channel blocker, D= diuretics.

Hypertensive urgency, emergency and malignant hypertension

Hypertensive urgency

Asymptomatic severe hypertension (SBP>220 or DBP>125 mm of Hg) in the absence of new or progressive target organ damage is hypertensive urgency.

Hypertensive emergency

High BP (DBP> 130 mm of Hg) with emergencies like hypertensive encephalopathy, hypertensive nephropathy, intracranial hemorrhage, aortic dissection, pre-eclampsia, pulmonary edema. Unstable angina, MI etc.

Malignant hypertension

Is by historical definition characterized by encephalopathy or nephropathy with accompanying papilloedema.

Parenteral therapy is indicated in most hypertensive emergencies, especially if encephalopathy is present. The initial goal in hypertensive emergencies is to reduce the pressure no more than 25% within minutes to 1 or 2 hour and then toward a level of 160/100 mm of Hg within next 2-6 hours. Excessive reduction of Bp may precipitate coronary, cerebral or renal ischemia5.

Follow-up and Monitoring

1.   Every 1-2 months until the BP goal is reached

2.   After BP at goal and stable, follow-up visits at 3- to 6 months intervals

3.   More frequent visits for

a.   Stage 2 HTN or

b.   With complicating co morbid conditions

4.   Serum potassium and Creatinine monitored 1–2 times per year2

5.   Yearly monitoring of blood lipids is recommended

6.   ECG should be repeated at 2- to 4-year intervals depending on whether initial abnormalities are present, the presence of coronary risk factors, and age5.

Step down therapy

Patients who have had excellent blood pressure control for several years, especially if they have lost weight and initiated favorable lifestyle modifications, should be considered for “step-down” of therapy to determine whether lower doses or discontinuatio

Primary Prevention

The following measures delays the onset of hypertension in prehypertensives and high risk individuals. These are…

•      Avoid the lifestyle risk factors that lead to hypertension

•      Be active

•      Eat healthy

•      Don’t smoke

•      Don’t drink large amounts of alcohol2

 

When and whom should screen for hypertension??

Hypertension is usually asymptomatic, when pt. present to the doctor usually present with complications; so it is mandatory to screen for hypertension to minimize complications.

•         5 yearly – adults up to 80 years

Annually – high normal (130-139 or 85-89) & anyone with high readings at any time5.

Screen for hypertension

When and whom should screen for hypertension??

Hypertension is usually asymptomatic, when pt. present to the doctor usually present with complications; so it is mandatory to screen for hypertension to minimize complications.

•         5 yearly – adults up to 80 years

•         Annually – high normal (130-139 or 85-89) & anyone with high readings at any time5.

Hypertension in special situation

Pregnant Women

•         Chronic hypertension is high blood pressure present before pregnancy or diagnosed before 20th week of gestation.

•         Gestational hypertension is increased blood pressure that occurs
in pregnancy (generally after the 20th week) and in absence of proteinuria.

•         Preeclampsia is increased blood pressure that occurs
in pregnancy (generally after the 20th week) and is accompanied by edema, proteinuria, or both.

•         ACE inhibitors and angiotensin II receptor blockers
are contraindicated for pregnant women.

•         Methyldopa is recommended for women diagnosed during pregnancy2.

Hypertension and surgery

•         When possible, surgery should be delayed until blood pressure is < 180/110 mm Hg.

•         Those not on prior drug therapy may be best treated with cardioselective b-blockers before and after surgery.

•         Those with controlled blood pressure should continue medication until surgery and begin as soon after surgery as possible1.

 

Hypertension and asthma

Asthma pt. with hypertension should avoid betablockers1.

Resistant Hypertension

The term resistant hypertension refers to patients with blood pressures persistently >140/90 mmHg despite taking three or more antihypertensive agents, including a diuretic, in reasonable combination and at full doses6.

In this situation, the clinician should consider-

  • Patients compliance
  • ·          Identifiable causes(secondary causes) of hypertension
  • ·          The clinician should see type of diuretic being used in relation to the patient’s kidney function.
  • ·          Aldosterone may play an important role in resistant hypertension and aldosterone receptor blockers can be very useful.
  • ·           If goal blood pressure cannot be achieved by these measures, consultation with a hypertension specialist should be considered.5

Hypertension  in diabetic Patients

  • Hypertensive patients with diabetes are at particularly high risk for cardiovascular events.
  • Because of their beneficial effects in diabetic nephropathy, ACE inhibitors or ARBs should be part of the initial treatment regimen.
  •  However, most diabetics require combinations of three to five agents to achieve target blood pressure5.

Hypertension and Chronic Kidney Disease

  • The goals of treatment of hypertension in chronic kidney disease are both to slow decline in renal function and to reduce risk for cardiovascular disease7.
  • ACE inhibitors and ARBs have been shown to delay progression of kidney disease in persons with type 1 and type 2 diabetes, respectively.
  • It is also likely that inhibition of the renin-angiotensin system protects kidney function in nondiabetic kidney disease associated with significant proteinuria.
  • Transition from thiazide to loop diuretic is often necessary to control volume expansion as kidney function worsens.
  • Evidence has demonstrated that ACE inhibitors remain protective and safe in kidney disease associated with significant proteinuria and serum creatinine as high as 5 mg/dL5.
  • A limited rise in serum creatinine of as much as 35 percent above baseline with ACEI or ARB is acceptable and is not a reason to withhold treatment unless hyperkalaemia develops2.

Hypertensive patient with impotence

  • Erectile dysfunction is common in hypertensive patients, especially in those who are also diabetic. The problem may be exacerbated by diuretic therapy, even in appropriately low doses. Fortunately, 5-phosphodiesterase inhibitors often return erectile ability, even in the presence of various antihypertensive drugs, with no greater likelihood of adverse events than in those not receiving antihypertensive therapy, with the exception of nitrates8.

Hypertension with IHD

  • Beta blockers and calcium antagonists are particularly useful if angina or arrhythmia is present.
  • The often markedly high levels of blood pressure during the early phase of an acute myocardial infarction may reflect sympathetic nervous hyperreactivity to pain.
  • Antihypertensive drugs that do not decrease cardiac output may be used cautiously in the immediate postinfarction period, whereas beta blockers and ACEIs provide long-term benefit8.

Hypertension and stroke

  • ·          Do not reduce BP in the first week
  • ·          Reduce BP in first week if there is heart failure, or renal failure, evidence of hypertensive encephalopathy or aortic dissection
  • ·          BP often returns normal level with in first few days
  • ·          Lower BP if BP is >130/70 1-2 week after onset of stroke
  • ·          Choice of drugs is Thiazide diuretic, ACEI9.

References:

  1. British hypertension society guideline on management of hypertension
  2. “ Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC-7)
  3. A Timmis, P Mills, The cardiovascular system.Michael Swash, 22nd edition;Hutchison’s clinical methods. W.B. Saunders,2007:70-116.
  4. D.E. Newby, N.R. Grubb, A. Bradbury, Cardiovascular disease In:  Colledge NR,  Walker B R, Ralstone S H Davidson’s Principles & Practice of Medicine, 21th edition, Churchill Livingstone Elsevier, 2010; 521-640.
  5. Stephen J. McPhee, Barry M.Massie; Systemic hypertension,Lawrence M. Tierney, Jr. Stephen J. McPhee, Maxine A. Papadakia 49th edition, 2010: 419-445.
  6.    Theodore A. Kotchen,Hypertensive vascular disease, In: Kasper, Braunwald, Fauci, Hauser, Longo, Jameson, et al., Harrison’s Principles of Internal Medicine. 17th edition. New York: The McGraw- Hill Companies, 2005:1549- 1562.
  7. Fuster, Orourke, Walsh, Poole-Wilson, Systemic arterial hypertension, Hurts the heart 12th edition
  8. Libby, Bonow, Mann, Zipes, Systemic Hypertension: Therapy, Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine, 8th edition.
  9. C.M.C. Allen, C.J.Lueck, M. Dennis; Neurological disease In:  Colledge NR,  Walker B R, Ralstone S H Davidson’s Principles & Practice of Medicine, 21th edition, Churchill Livingstone Elsevier, 2010; 1131-1235.

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