Transcript stroke volume

HYPERTENSION
Dr. Abdul-Ameer Al- khalidy
Al-Sadder Medical City
in Najaf
Important statement
The Physician who
diagnose HT
depending on BP
reading only is poorly
understood HT.
Introduction
Blood pressure is the force of blood pushing against
the walls of arteries as it flows through them . Arteries
are the blood vessels that carry oxygenated blood from
the heart to the tissues of the body . Blood pressure is
summarized by two measurements, systolic and
diastolic, which depend on whether the heart muscle
is contracted (systole) or relaxed between beats
(diastole)
Definition
Hypertension ( HTN) or high blood pressure : Is a
chronic medical condition in which the blood pressure
in the arteries is elevated therefore sometimes called
arterial hypertension
(JNC 7)
The Seventh Report of the
Joint National Committee
on Prevention, Detection,
Evaluation, and Treatment
Of High Blood Pressure
CLASSIFICATION OF HYPERTENSION (JNC- 7)
Blood pressure, mm Hg
Category
Systolic
Diastolic
Normal
<120
and
<80
Pre-hypertension120-139 or
80-89
Hypertension
Stage 1
140 - 159 or 90 – 99
Stage 2
≥160
or
≥100
Isolated Systolic Hypertension
G.1:
G.2:
S.140-159
S. ≥ 160
D.<90
D.<90
Prehypertension
JNC VII report, emphasizes that patients with
prehypertension are at risk for progression to
hypertension and that lifestyle modifications are
important preventive strategies. Healthy life style
could reduce BP , decrease the rate of progression
of BP to hypertensive levels with age, or prevent
hypertension entirely .
 prehypertension is not a disease category. They
are not intended to have drug therapy, but should
be advised to practice lifestyle modification to
reduce risk of developing HT .
 Individuals with prehypertension who also have
D.M or kidney diseases should be considered
candidates for appropriate drug therapy if a trial
of lifestyle modification fails to reduce their BP to
130/80 mmHg or less .

 All patients with stage 1 or 2 should be
treated and the goal is to reduce BP in HTN
patients with no other compelling
conditions < 140/90 .
 The goal for individuals with
prehypertension with no compelling
conditions is to lower BP to normal levels
with lifestyle changes, and prevent the
progressive rise in BP using the
recommended lifestyle modifications .
Target BP
Low and intermediate risk group
< 140/90 mmHg.
High-risk group < 135/85 mmHg.
Acute stroke : 160/100mmHg.
>1g/day protienuria:
125/75.mmHg.
Pathophysiology
Arterial blood pressure is a product of cardiac output
and systemic vascular resistance.
Mean arterial pressure = CO *total peripheral
resistance (TPR) = diastolic arterial pressure + 1/3
pulse pressure
Pulse pressure = systolic arterial pressure - diastolic
arterial pressure
BP = CO x TPR (CO = HR x SV)
 Stroke volume – affected by contractility and
venous return
 TPR is regulated by Norepinephrine,
Epinephrine, Angiotensin II
1.CO increases during exercise, initially by increasing SV and
later by increasing HR.
2. Heart rate (HR)
a. Number of cardiac contractions per unit
time; commonly expressed as beats per
minute (bpm)
b. If HR is too high (normal = 60 to 100 bpm),
then diastolic filling is decreased.
3. Stroke volume (SV)
a. SV is the change in blood volume from
immediately before initiation of
contraction to completion of contraction
(i.e., SV from end diastolic volume to end
systolic volume). i.e
stroke
volume (SV)
is
the
volume
of blood pumped
from
the
left ventricle of
the heart per beat. Stroke volume is calculated
using measurements of ventricle volumes from
an echocardiogram and subtracting the volume
of the blood in the ventricle at the end of a beat
(called end-systolic volume) from the volume of
blood just prior to the beat (called end-diastolic
volume). The term stroke volume can apply to
each of the two ventricles of the heart, although it
usually refers to the left ventricle. The stroke
volumes for each ventricle are generally equal,
both being approximately 70 mL in a healthy 70kg man.
b. It is determined by contractility (i.e., SV = [end
diastolic volume]-[end systolic volume]),
preload (amount of myocardial stretch at end of
diastole), and after load (resistance ventricles
must overcome to empty their contents).
c. Stroke volume is an important determinant
of cardiac output, which is the product of
stroke volume and heart rate, and is also used
to calculate ejection fraction, which is stroke
volume divided by end-diastolic volume.
Because stroke volume decreases in certain
conditions and disease states, stroke volume
itself correlates with cardiac function.
d. SV increases with catecholamine
release, an increase in intracellular
Ca, a decrease in extracellular Na,
digoxin use, anxiety, and exercise.
e. SV decreases with b-blockers, heart
failure, acidosis, and hypoxia.
Example values in healthy 70-kg man
Measure
Typical value
Normal range
end-diastolic
volume (EDV)
120 mL
65–240 mL
end-systolic
volume (ESV)
50 mL
16–143 mL
stroke
volume (SV)
70 mL
55–100 mL
ejection
fraction (Ef)
58%
55–70%
heart rate (HR)
75 bpm
60–100 bpm
cardiac output (CO) 5.25 L/minute
4.0–8.0 L/min
Pathogenesis of hypertension
Multiple factors modulate the blood
pressure for adequate tissue perfusion
and include humoral mediators,
vascular reactivity, circulating blood
volume, vascular caliber, blood viscosity,
cardiac output, blood vessel elasticity,
and neural stimulation.
Genetic predisposition, excess dietary salt
intake, and adrenergic tone, may
interact to produce hypertension.
Factors influencing BP level :
1. Age : a positive association between BP level
and age in most populations of different
geographical, cultural, and socio-economic
characteristics. The rise in SBP continue
throughout life in contrast to DBP which rises
until the age 50 , tends to level off over the next
decade, and may remain the same or fall later
in life .
2. Sex : early in life, there is no difference
between males and females in BP level, but
after puberty males tend to have higher BP
level than females. After menopause the
difference gets narrower .
3. Ethnicity : Blacks have higher BP level than others .
4. Hereditary factors : positive family history .
5. Genetic factors: certain genes as ACE gene . 40-60% of
essential HTN PATIENTS have genetic factors.
6. Early life exposure to certain events in early life as LBW,
maternal smoking and lack of breast feeding .
7. Body weight: over weight individual has 2-6 times higher
risk having HT compared to a normal weight individual .
8. Central obesity and metabolic syndrome : high waist/hip
ratio is positively associated with HT .
9. Nutritional factors: positive association between NaCl
intake and HTN , negative association between potassium
intake and HTN , and no relation with other nutrients .
10.Alcohol intake :.
11. Physical inactivity : sedentary unfit individual has 20-50%
excess risk to have HTN .
12.Psychological factors : acute mental stress causes increase
in BP level .
Obesity and metabolic syndrome:
Obesity (BMI >30 Kg/m2 ) is prevalent risk
factor for the development of HTN .
Metabolic syndrome patient has three or
more of the following conditions :
1. Abdominal obesity ( waist circumference >
102 cm in men or 88 cm in women )
2.Glucose intolerance ( fasting glucose > 110
mg/dl
3. BP > 130/85 mmHg
4.High Triglycerides > 150 mg/dl) or low HDL
( <40 mg/dl in men or <50 mg/dl in women )
MAJOR RISK FACTORS for Hypertension (JNC-7)
1.
2.
3.
4.
5.
6.
Smoking
BMI ≥ 30
Physical inactivity
Dyslipidaemia
Diabetes mellitus
Microalbuminuria or estimated GFR
( glomerular filtration rate) < 60
ml/min
7. Age > 55 for Males, > 65 years for
females
8. Family history of premature CVS
disease (Men <55 and Women < 65 )
Classification of HTN by causes :
Aetiological classification :
1. Primary(Essential HTN) 90- 95%.
Primary HTN means high blood pressure with no
obvious underlying medical cause .
It is the most common form of HTN .
Accounting for 90-95% of all cases of HTN .
2. Secondary HT 5 - 10%
Hypertension due to an identifiable cause
Causes of secondary hypertension
1. Renal disease
 vascular, parenchymal, PCkD
 Chronic parenchymal diseases
 Renal artery stenosis
2. Endocrinal: Pheochromocytoma, carcinoid
tumors. Cushing syndrome, congenital adrenal
hyperplasia, Conn syndrome(primary
hyperaldosteronism, hyperparathyroidism,
acromegaly, hypothyroidism, thyrotoxicosis .
 Primary hyper aldosteronism
 Pheochromocytoma
 Hypo or hyperthyroidism .
 Cushing s syndrome. ( truncal obesity, glucose
intolerance, moon faces, a buffalo hump and
purple striae)
3. Coarctation of Aorta and Aoartitis .
4. Drug induced. OCP, corticosteroids, NSAIDs,
sympathomimetcs , licorice .
5. Pregnancy induced HT.
Target organ damage
After a long invariable asymptomatic period,
persistent hypertension develops into
complicated hypertension, in which target
organ damage to the aorta and small
arteries, heart, kidneys, retina, and central
nervous system is evident.
TOD (JNC-7)
IHD
CABG
CCF
Stroke or TIA
Chronic kidney disease
PVD
retinopathy
Target organ damage
1.Blood vessels lamina thickened
(>1mm)
smooth muscle hypertrophied
fibrous tissue deposited
Dilate, tortuous and less compliant
(<1mm)
arteriosclerosis, narrow lumen
and aneurysm.
Atheroma
CAD, CVA, increase vascular
resistance and reduce the renal function.
Aortic aneurysm (AAA) and aortic dissection.
Pulse pressure > 65 mmHg
Atherosclerosis: infiltration of cholesterol in the arterial
walls followed by a complex sequence of changes
involving platelets , macrophages , smooth muscle cells
and growth factors aggregation which lead to increased
arterial intima to media thickness and distortion of blood
vessels and make them rigid. Arteriosclerosis means loss
of elasticity or hardness of the arteries from any cause .
Target organ damage
2.CNS
a- Stroke
hemorrhages
infarction
 HTN is the most important and the most
modifiable RF of all types of stroke .
 5 mmHg reduction in DBP can decrease
incidence of stroke by 40%
 Carotid stenosis is frequent cause of stroke .
b- TIA ulcerated plaques can be a source of
emboli
causing TIA
c- Subarachnoid hemorrhages
d- Hypertensive encephalopathy (high BP +
neurological symptoms +/- papilloedema)
Target organ damage
3. Retina
G1- silver wiring
G2- +AV nipping
G3- +evidence of retinal ischemia
G4- +papilloedema
Central retinal vein thrombosis.
4. Heart
CAD :
CHF : progressive LV dilatation .
LVH+ coronary atherosclerosis mark the
development of CHF
Anti HTN can decrease incidence of CHF by 50%
IHD : MI, angina, previous stent OR previous CABG .
LVF :
(Best diagnosed by Echo., and reversible by anti-HTN,
and causes improvement of diastolic function with no
improvement of systolic function )
Target organ damage
5. Kidney proteinuria and progressive RF.
 Severe accelerated HTN causes fibrinoid
necroses of small blood vessels leading to
renal insufficiency .
 Renal damage in HTN is heralded by
protienuria
 Microalbuminuria and protienuria are
independent RF of all CV mortality .
 Effective BP reduction can decrease risk of
protienuria .
 Estimated GFR < 60 mls/min.
Hypertensive patient can be categorized
according to their risk profile:
 Group A (low risk): no TOD, no other risk
factors and no associated cardiovascular
disease.
 Group B (intermediate risk): one or more
additional risk factors but not diabetes or
TOD.
 Group C (high risk): diabetes, TOD and/or
associated cardiovascular disease.
TOD:
How to measure blood pressure?
Cuff size:
12 X 26cm bladder in most adults.
12 X 40cm bladder in obese (arm
circumference > 33cm).
10 X 18cm bladder in thin adults or
children (arm circumference <
26cm).
Before taking blood pressure the patient
should:
 Avoid smoking , eating and coffee for at
least two hours prior to measurement.
 Urine should be voided if necessary.
 Talking should be avoided five minutes
before and during blood pressure
measurement.
 Blood pressure should be measured in
quiet room with comfortable
temperature.
 Right arm (if volume of pulse is
equal in both arms).
 Supine or sitting (standing in
special conditions).
 Arm should be supported.
 Cuff is directly to skin.
 Bladder is centered on brachial
artery.
 Edge of the cuff is 3cm above the
elbow.
 Use palpatory method first.
 Inflate to 30 mmHg above pulse occlusion
pressure.
 Use the cone of stethoscope.
 Cone is firmly applied over brachial artery.
 Cone is not touching cuff.
 It isn’t essential to keep manometer at
heart level
Use phase 5 Korotkoff sounds
(disappearance) to measure the diastolic
pressure
 Repeated inflation with incomplete
deflation will damp korotkov sounds.
Standing BP should be taking in:
 First visit evaluation.
 Elderly patients above 60 years.
 Diabetic patients.
 Patients with postural symptoms.
 Patients on potent vasodilator drug
or large doses of diuretics.
 Standing BP should be measured 2
minutes after standing.
1. Previous levels of high BP and history of
treatment :
Obtain a history of over-the-counter medication
use, current and previous unsuccessful
antihypertensive medication trials
2. Symptoms of TOD:
Patients may have undiagnosed hypertension for
years without having had their blood pressure
checked. Therefore, a careful history of end
organ
damage should be obtained.
3. Symptoms suggestive secondary hypertension:
A history of cold or heat tolerance, sweating,
lack of energy, and bradycardia or tachycardia
may indicate hypothyroidism or
hyperthyroidism
A history of sweating, and palpitations
suggests the diagnosis of pheochromocytoma
A history of weakness suggests
hyperaldosteronism.
Kidney stones raise the possibility of
hyperparathyroidism
History of known renal disease, abdominal
masses, anemia, and pigmentation.
Medical history:
4. history of Current drug intake :(including
NSADs, oral contraceptive pills, licorice, and
sympathomimetics ) should be obtained
5. history of Co-morbid conditions:
(hypercholesterolemia ,diabetes mellitus,
bronchial asthma, gout, migraine,
depression).
6. Family history of diabetes, CAD, stroke or
renal disease.
7. Life style factors: salt and fat intake,
smoking, physical and alcohol consumption.
Clinical examination:
1. BP measurements.
2. Weight and height.
3. Palpation of all peripheral, femoral pulses
and neck bruits should be performed
4. A funduscopic evaluation of the eyes
should be performed to detect any
evidence of hypertensive retinopathy
5. Cardiac examination is performed to
evaluate signs of LVH, 3rd HS, loud 2nd
sound, ejection murmur over aortic area
and AR murmur.
Clinical examination:
6. Chest examination: OLD.
7. Abdominal examination: renal
mass, aortic aneurysm or bruits.
Look for renal artery bruit over the
upper abdomen; the presence of a
unilateral bruit with both a systolic
and diastolic component suggests
renal artery stenosis.
8. Neurological examination: level of
consciousness speech, motor power.
12.Investigations
For all patients
For Renal system:
Microscopical Urinanalysis, B.urea, and serum
creatinine
Endocrine:
Electrolytes(serum Na,Serum K, serum Ca) and
TFT
Metabolic:
Fasting B.sugar, Total S.cholesterol
Others:
Hb ECG.
Investigations
For Selected Patients
1. CXR
2.Fundus
3. ECHO study.
4. Renal U/S.
5. Renal angiography.
6. Urinary catecholamines.
7. Urinary cortisol and dexamethasoe sup. Test.
8. Plasma renin activity and aldosterone.
9.Serum uric acid.
10.Lipid profile.
JNC-7 Management of BP for Adults
BP classification
Normal
Lifestyle 
No compelling
indication
Compelling indication
Encourage
< 120/80
Prehypertension
Yes
No drug tx
Drugs targeted for the
compelling indications
Yes
Thiazide for most
Drugs targeted for the
compelling indications
Yes
2 drug combo
including thiazide
Drugs targeted for the
compelling indications
120-139 / 80-89
Stage I HTN
140-159 / 90-99
Stage II HTN
> 160 / > 100
Lifestyle Modification
1. Weight reduction
2. Adopt DASH diet
3. Dietary Na+ restriction
4. Physical activity
5. Moderation of alcohol consumption
6. Reduce or stop smoking .
Lifestyle Modification
1. Weight reduction : in those individuals who are
overweight or obese .
 decrease BP in HT patients .
 Decrease insulin resistance .
 Improves lipid profile .
2. Adoption Dietary Approaches to Stop Hypertension
(DASH diet): Encourage intake of diet rich in fresh
fruit , vegetables and in low fat dairy products with a
reduced contents of saturated and total fats . Eating
plan which is rich in potassium and calcium .
3. Dietary Na+ restriction
 Reduce dietary sodium intake to no more than 1oo mmole per
day(6 gm of sodium chloride or 2.4 gm of sodium per day) .
 Individuals who are 51 years and older and those of any age,
including children, who are African American or people who
have high BP, D.M, OR CHRONIC KIDNEY DISEASES) limit
their intake to ≤ 1500 mg/day .
 Table salt provides iodine therefore Reducing of table salt
intake lead to iodine deficiency .
Elderly people and blacks, Type 1 diabetes, Secondary
hypertension demonstrate more sensitivity to Na restriction .
4. Physical activity
 Regular aerobic physical activity such as brisk walking (30-45
minutes/day for 5 times/week .
Guidelines for moderate salt restriction
1. Talk with your grocer or favorite restaurants about stocking
lower sodium food choices .
2. Read the Nutrition Facts Label while shopping to find the
lowest Na options of your favorite foods .
3. Choose fresh, frozen or canned food items without added
salts .
4. Select fat free or low-fat milk, low-sodium, low-fat cheeses,
as well as low-fat yogurt .
5. Select unsalted nuts or seeds, dried beans, peas and lentils .
6. Limit processed foods high in Na .
7. When eating out, request lower Na options .
8. Avoid the use of fast foods (e.g. hamburger, pizza, chips) .
9. Use spices and herbs to enhance the taste of food .
10.Recognize the Na- content of some antacids and
other medications .
Na- measurement:
1.
2.
3.
4.
Sodium chloride ,commonly known as
salt, consists of 40 percent sodium and
60 percent chloride .
One level teaspoon of salt contains
approximately 2300 mg of sodium .
To convert mg of sodium to mmole of
sodium, the mg of sodium divided by
24 .
To convert mmole of sodium to mg of
sodium, multiply mmole of sodium by
24 .
Dietary potassium:
 Maintain adequate intake of dietary
potassium(approximately 90 mmol/day
or 225o mg/day).
 Diet rich in fruits and vegetables is
superior to pills.
 Potassium supplements should be
avoided in: renal insufficiency, with
diuretics, ACE inhibitors or ARBs.
Food rich in potassium:
Oral antihypertensive drugs in pregnancy:
Methyldopa, labetalol and
nifedipine are safe.
Diuretics , ACE-inhibitors and
ARBs are contraindicated.
Beta-blockers cause fetal growth
retardation and bradycardia.
Oral antihypertensive drugs in lactation:
Atenolol and nifedipine are avoided.
Antihypertensive Agents:
Nursing Implications
 Showers, or baths; hot weather; prolonged
sitting or standing; physical exercise; and
alcohol ingestion may aggravate low blood
pressure, leading to fainting and injury.
Patients should sit or lie down until
symptoms subside.
 Patients should not take any other
medications, without first getting the
approval of their physician.
Antihypertensive Agents:
Nursing Implications
 Educate patients about the importance of not
missing a dose and taking the medications
exactly as prescribed.
 Patients should never double up on doses if a
dose is missed; check with physician for
instructions on what to do if a dose is missed.
 Monitor BP during therapy. Instruct patients
to keep a journal of regular BP checks.
Resistant hypertension
is the failure to reach goal BP in patients
who are adhering to full doses of an
appropriate three drug regimen that
includes a diuretic
Causes of Resistant HTN
1. Improper BP measurement
2. Excess sodium intake
3. Inadequate diuretic therapy
4. Excess alcohol intake
5. identifiable causes of HTN
6. Obesity
7. Drug-Iduced
Inadequate doses
Compliance or non adherence
Drug interactions or inappropriate
combination
Oral contraceptive
Adrenal steroids
NSADs
Sympathomimetic drugs
licorice
ANTIHYPERTENSIVE DRUGS Categories
1. DIURETICS
thiazide(moduretic) , loop diuretics (lasix)
2.Adrenergic agents
a. ALPHA -BLOCKERS
b. BETA-BLOCKERS
a. ALPHA -BLOCKERS
1.ALPHA 1-BLOCKERS doxazosin (Cardura)
2. Centrally acting alpha blockers methyldopa
(Aldomet)
(drug of choice for hypertension in pregnancy)
b.BETA-BLOCKERS cardioselective and
nonselective)metoprolol,atenolol,bisoprolol,
carvedilol,labetalol
3. ACE INHIBITERS
(Angiotensin-converting enzyme inhibitors)
captopril(capoten), enalapril, lisinopril
4. ANGIOTENSIN R BLOCKERS
(Angiotensin II receptor blockers)
losartan,
valsartan (Diovan),
candesartan (Atacand),
telmisartan (Micardis)
5. CALCIUM ANTAGONIST:
(Calcium channel blockers)
a. Dihydropyridines: amilodipine, nifedipine
b. Non Dihydropyridines (diltiazem)
6. Vasodilators - hydralazine HCl (Apresoline)
CHOICE OF ANTIHYPERTENSIVE DRUGS
 YOUNG,WHITE,MALE------- B
 FEMALE ,ELDERLY----------- D
 NEGRO--------------------------C
 HT+DM--------------------------A,C
 HT+RF---------------------------C,D
 HT+ASTHMA------------------ C,A
 HT+IHD-------------------------B,A,C
 HT+HF---------------------------A,D
 SYST HT-------------------------C,D
 HT+BPH-------------------------ALPHA-BLOCKER
 TH+CORPULMONALE-------ANGIOTENSIN R
BLOCKERS
 HT+PREGNANCY-------------METHYLDOPA,HYDRALASIN,C