hypertension

AuthorsAbhinavMuktaSajaniDollySonia

VikramPawanPoornaAditya

(JAN 2004 MBBS BATCH) (Manipal College of Medical

Sciences,Pokhara,Nepal)

Dorland’s Medical Dictionary “Persistently high arterial blood pressure”

Diastolic Hypertension Elevated diastolic blood pressure with a

normal systolic pressure Essential Hypertension

Elevated blood pressure “having no obvious external cause,” or “idiopathic”

Statistically 2 SD above mean is uncommon or hyper Hypertension is the level of BPat which action is

warranted, balance between risk & benefit,not easy to estimate

So an specific cut off point is difficult WHO (1972) –systolic above 160/diastolic (phase V) more

than 95 Currently Optimal-<120mmHg and<80 mmHg Normal- < 130 and <85 High normal 130-139 or 85 to 89 High stage I –140 to 159 or 90 to 99 Stage II –160 to-179 or 100 to 109 Stage III –more than 180 or more than 110 mm Hg

Accuracy is essential Reliability is questionable as wide variability in

individual. Source of ERROR-1. Observer error e.g. hearing acuity,,interpretation

of Karotkow sound 2 Instrumental error eg loose cuff,leaking valve

etc3 subject error eg position , external stimuli-

fear ,anxiety, physical environment

Rule of halves

Uniform policy in all clinics &institutions to use rt or left arm

Recording in sitting position than supine Systolic at which sound first (phase I) heard Diastolic -sound muffled (phase IV) disappear

(phase V).most cases phase V is taken as Diastolic

Measured at least 3 times over a period of 3 minutes & lowest reading is taken

For comparability data should be taken every where in uniform way

Incidence has limitation.due to 1. individual variation,2. ambiguity of normal BP 3. insidious nature of condition Prevalence-Developed countries-25% in adult populationDeveloping countries-10 to 20% in adult popolationHigh altitude & places belonging to premitive

culture-very low

In some studies in India shows morbidity as in- Urban -male 6%, female 7% Rural –male 3.5%, female 4.0%

Mortality In western world:deaths due to coronary heart

disease In eastern parts of the world: stroke deaths more

common Decline in mortality in last 2 decades Fall is equal in both sexes Fall attributed to, use of effective drugs,modern

diagnosis &treatment

Tracking is phenomenon of ranking order of BP level through time

Follow up of cohort of individual BP level from childhood to adulthood

Initial low BP level will follow the same track up to adult

Initial high BP will tend to become higher in adult life

Child likely to be in risk in later life can be screened

1 & 2 Age /gender BP rises with age Responsible factor may be accumulation of environment

factors,or effect of genetically programmed senescence in body system

Genetic factor-partly determines Twin study-BP is correlated to mono zygotic twin than that

of zygotic twin No significant correlation between husband & wife or

adopted child & adopter parent Family study-chd of high BP parent has 45% chance but

with normotensive only 3%

OBESITY SALT INTAKE SATURATED FAT ALCOHOL PHYSICAL ACTIVITY ENVIRONMENTAL STRESS OTHERS - ORAL CONTRACEPTIVES -NOISE ,VIBRATION,TEMPERATURE, HUMIDITY

ETC LIKELY, NEEDS FURTHER STUDIES

Hypertension Cigarette smoking Obesity (BMI>30) Inactivity Dyslipidemia Diabetes Mellitus

Age >55 for men >65 for women

Microalbuminuria Or GFR <60mL/min

FH of Premature CVD Men <55 Women <65

GENETICS A history of hypertension tends to run in

families The closest correlation exists between sibs

rather parent and child It is also possible that environmental

factors common to members of the family also have a role in the development of hypertension

AGE

BP tends to rise with age, possibly as a result of decreased arterial compliance.

Hypertension in the elderly should be treated as aggressively as in the young.

Race

Caucasians have a lower BP than black populations living in the same environment

Black populations living in rural Africa have a lower BP than those living in towns

Respond in different ways to changes in diet

Birth weight is also associated with the development of hypertension in later life.

The lower the birth weight the higher the likelihood of developing hypertension and heart disease

Clearly in-utero factors affect health at a later stage.

Environment Mental and physical stress both increase

blood pressure However removing stress does not

necessarily return blood pressure to normal values

The scope of the problem: 50 million Americans have hypertension One billion people in the world are affected 30% don’t know they have it

Category Systolic BP Diastolic BP Optimal < 120 < 80 High normal 130 – 139 85 - 89 Mild HTN 140 – 159 90 - 99 Mod HTN 160 – 179 100 - 109 Severe HTN >180 > 110

Blood pressure is a continuous variable which fluctuates widely during the day physical stress mental stress

The definition of hypertension has been arbitrarily set as: That blood pressure above which the benefits of treatment outweigh the risks in terms of morbidity and mortality

Hypertension is not a disease

It is an arbitrarily defined disorder to which both environmental and genetic factors contribute

Histology of Elastic Arteries

POISIEULLI’S LAW

>> 100 100OrOr>160>160Hypertension,Hypertension,

Stage 2Stage 2

90-9990-99OrOr140-159140-159Hpyertension, Hpyertension, Stage 1Stage 1

80-9080-90OrOr120-139120-139PrehypertensiPrehypertensionon

<80<80AndAnd< 120< 120NormalNormal

DiastolicDiastolicSystolicSystolicCategoryCategory

Maximum Pressure exerted by the Blood against the arterial walls.

Results of ventricular Systole.

Renal disease 20% of resistant hypertensive patients chronic pyelonephritis renal artery stenosis polycystic kidneys

Drug Induced NSAIDs Oral contraceptive Corticosteroids

Sleep Apnea Chronic Kidney Ds. Primary

aldosteronism Renovascular Ds. Thyroid,

Parathyroid

Pheochromocytoma Coarctation of

aorta Steroids, Cushing

syndrome Drug-induced

Illicit Drugs Cocaine, amphetamines

Oral Contraceptives

Adrenal Steroids Prednisone

Licorice (in some chewing tobacco)

Decongestants (sympathomimetics)

Non-adherence, inadequate doses, inappropriate combinations

Non steroidal Anti-inflammatory drugs

Leathery Granularity due to minute scarring

Onion Skin ThickeningOnion Skin ThickeningOf arterioles.Of arterioles.

Narrow LumenNarrow Lumen

Fibrinoid NecrosisFibrinoid Necrosis

ThrombosisThrombosis

May complicate any type of HTN. Necrotizing arteriolitis. Intravascular thrombosis. Rapidly progressive end organ damage. Renal failure Hypertensive encephalopathy. Left ventricular failure.

Blood Vessels Atherosclerosis and its complications

aneurism, Dissection, Rupture, necrosis. Arteriolosclerosis,

Heart Hypertensive cardiomyopathy, IHD, MI.

Kidney Benign/Malignant nephrosclerosis. Infarction

Eyes: Hypertensive retinopathy

Brain: Haemorrhage, infarction, splinter & Lacunar hemorrhages

Left Ventricular HypertrophyLeft Ventricular Hypertrophy

HaemorrhagicHaemorrhagicNecrosisNecrosis

Chronic hypertension

Arteriolosclerosis of deep penetrating arterioles of brain stem.

Single or multiple cavitary infarcts – lacunes.

Lenticular nucleus, thalamus

Slit Haemorrhages.

Leathery GranularityBenign Nephrosclerosis

Grade I – Thickening of arterioles.

Grade II – Focal Arteriolar spasms. Vein constriction.

Grade III – Hemorrhages (Flame shape), dot-blot and Cotton wool and hard waxy exudates.

Grade IV - Papilloedema

Principle:- “lower the pressure, the better”

Goal:- to have maximally tolerated reduction in blood pressure

Monodrug therapy Drug of choice: 1. Thiazide diuretic eg. Hydrochlorthiazide 2. β1 blocker eg. PropanololIf monotherapy doesn’t work other drug

can be added eg.Thiazide+ β1blocker

Combination therapy: Advantages: synergistic action counter balance of ADRs balance in hemodynamic

ACE inhibitor=A β1 blocker = B Ca++ channel blocker = C Diuretics = D eg. Propanolol (β1 blocker) + Hydralazine

Bradycardia Tachycardia

1.PREGNANCY Toxemia of pregnancy Drug of choice: β1blocker vasodilator Ca++ channel blocker-Contraindicated drugs are Diuretics,Resperine,Na nitroprusside, Non selective β -blocker

2.Heart Disease All A,B,C and D are useful β 1 blocker are contraindicated in left

ventricular failure & bradycardia3.Diabetic ACE inhibitor (Captopril) low dose thiazide, beta 1 blocker and Ca

channel blocker for long term therapy contraindicated diuretics

4. Hypertensive Emergency Life threatening, DP > 130 mmHg Sodium nitroprusside (vasodilator) Diazoxide (arterial dilator ) Labetolol ( non selective adrenergic blocker )5. Hypertensive urgency Nifedipine (Sub lingual) Clonidine (oral or IM every 1-2 hrs) Captopril ( oral) Hydralazine (IM or IV slowly)

Divided into

PrimaryPopulation StrategyHigh-risk strategy

Secondary

Weight Reduction Maintain normal body weight

BMI: 18.5 – 24.9 BP reduction: 5-20 mmHg/10 kg loss

DASH Eating Plan Dietary Approaches to Stop Hypertension

Fruits, Vegetables, Low-fat dairy Reduce saturated and total fat 8-14 mmHg BP reduction

Dietary Sodium Reduction 2.4 grams Sodium or 6 grams Sodium

Chloride 2-8 mmHg BP reduction

Physical Activity Regular aerobic physical activity

Brisk walking, treadmill, exercise bike, bicycling, swimming (30 min. a day, most days of the week)

4-9 mmHg BP reduction

Moderation of alcohol consumption No more than 2 drinks per day in most men No more than 1 drink per day in women and

lighter weight individuals One drink equals:

½ ounce liquor or 12 oz. Beer or 5 oz. Wine or 1 ½ oz. 80 proof whisky

Duration and prior Rx Pharmaceutical profile Family history Symptoms of secondary

causes Target organ damage Presence of other risk factors

Concomitant Diseases Dietary History Sexual Function Features of Sleep Apnea Ability to modify life-style

Accurate measure of BP, BMI Fundoscopy Carotid and thyroid abnormalities Heart sounds, rhythm, size Rales, rhonchi on lung exam

Renal masses, waist circumference Aorta bruits, femoral pulses Peripheral pulses and edema Neurologic assessment, i.e.

cognitive

Chest X-ray Abdominal Ultrasound 24 hour urine collection

Sodium and Potassium Thyroid function tests Kidney function tests Blood sugar & cholesterol (screening) Others: hormonal, etc.

Hematocrit Urinalysis Lipid profile ECG

Determine type of hypertension Identify target organ damage Assess risk for early CV event

JNC VI on Prevention, Detection, Evaluation, and Rx of High Blood Pressure (1997) 50 million hypertensive patients in the U.S.

National Health and Nutrition Examination Survey III (NHANES III) (1995) only 21% are controlled to <140/90 mm Hg 35% are unaware of their condition

High-normal BP is associated with an increased risk of cardiovascular disease

Department of

Biochemistry

Physiology

Anatomy

Pathology

Pharmacology

Community MedicineMCOMS,Pokhara,Nepal