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Hypertension
Dr. Meg-angela Christi Amores
Hypertension
• doubles the risk of cardiovascular diseases
• present in all populations except for a small
number of individuals living in primitive,
culturally isolated societies
• accounts for 6% of deaths worldwide
Mechanism of hypertension
• Cardiac output and peripheral resistance are
the two determinants of arterial pressure
Mechanism
•
•
•
•
Vascular Volume
Autonomic Nervous System
Renin-Angiotensin Aldosterone
Vascular Mechanisms
Vascular Volume
• Vascular volume is a primary determinant of
arterial pressure over the long term
• alterations in total extracellular fluid volume
are associated with proportional changes of
blood volume
• Sodium is predominantly an extracellular ion
Autonomic Nervous System
• Adrenergic reflexes:
– norepinephrine, epinephrine, and dopamine
• Baroreceptor reflexes:
– Carotid sinus, aortic arch
Renin-Angiotensin Aldosterone
Pathologic consequences
• Heart
– most common cause of death in hypertensive patients
• Brain
– Hypertension is an important risk factor for brain
infarction and hemorrhage
• Kidney
– Primary renal disease is the most common etiology of
secondary hypertension
• Peripheral Arteries
– blood vessels may be a target organ for
atherosclerotic disease secondary to long-standing
elevated blood pressure
Defining hypertension
• based on the average of two or more seated
blood pressure readings during each of two or
more outpatient visits
Blood Pressure Classification
Systolic, mmHg
Diastolic, mmHg
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
140
and <90
• Home blood pressure and average 24-h
ambulatory blood pressure measurements are
generally lower than clinic blood pressures
• Increasing evidence suggests that home blood
pressures, including 24-h blood pressure
recordings, more reliably predict target organ
damage than office blood pressures
• Blood pressure tends to be higher in the early
morning hours, soon after waking, than at
other times of day
• Myocardial infarction and stroke are more
frequent in the early morning hours
• white coat hypertension : 15 – 20 % with stage
1 hypertension have
Clinical disorders
• Essential hypertension
– 80 – 95%
– primary or idiopathic hypertension
– No identifiable cause
• Secondary hypertension
– 5 – 20 %
– a specific underlying disorder causing the
elevation of blood pressure can be identified
Essential Hypertension
• likely to be the consequence of an interaction
between environmental and genetic factors
• increases with age
Secondary Hypertension
• Renal (Parenchymal disease, tumors)
• Renovascular (Arteriosclerotic)
• Adrenal (Primary aldosteronism, Cushing's
syndrome)
• Aortic coarctation
• Obstructive sleep apnea
• Preeclampsia/ Eclampsia
Secondary Hypertension
• Neurogenic (psychogenic, polyneuritis)
• Endocrine (hypo/hyperthyroidism)
• Medications (estrogen, decongestant)
Approach to patient
• HISTORY
– Duration
– Associated symptoms (headache, etc)
• Occipital, early morning
– Previous meds
– Family history
– Diet and social history
– Risk factors: weight change, DM, smoking
– Evidence of secondary causes
Approach to patient
• Measurement of BP
– Before taking the blood pressure measurement,
the individual should be seated quietly for 5 min
in a private, quiet setting with a comfortable room
temperature
– center of the cuff should be at heart level
– width of the bladder cuff should equal at least
40% of the arm circumference
– length of the cuff bladder should encircle at least
80% of the arm circumference
Methods in determining BP
• Auscultatory method
– Stethoscope over antecubital area
– BP cuff inflated over upper arm
– Korotkoff sounds
– Mechanism:
• When cuff pressure is higher than systolic P, brachial
artery remains occluded
• As cuff pressure is reduced, blood jets through the
artery, hearing tapping sounds from antecubital artery
• When cuff pressure is equal diastolic pressure, blood
no longer jets through squeezed artery, tapping stops
Approach to patient
• PE
– Body habitus, weight, height
– Arterial pulse, upper and lower extremities
– Heart rate
– Neck palpated
– Eye exam
– Abdominal palpation
– Neurologic exam
Treatment
• LIFESTYLE intervention
Weight reduction
Attain and maintain BMI < 25 kg/m2
Dietary salt reduction
< 6 g NaCl/d
Adapt DASH-type dietary plan
Diet rich in fruits, vegetables, and lowfat dairy products with reduced content
of saturated and total fat
Moderation of alcohol consumption
For those who drink alcohol, consume 2
drinks/day in men and 1 drink/day in
women
Physical activity
Regular aerobic activity, e.g., brisk
walking for 30 min/d
• Blood pressure may be lowered by 30 min of
moderately intense physical activity, such as
brisk walking, 6–7 days a week, or by more
intense, less frequent workouts
• Alcohol use in persons consuming three or
more drinks per day
• DASH (Dietary Approaches to Stop
Hypertension) - 8-week period a diet
Pharmacologic therapy
• Drug therapy is recommended for individuals
with blood pressures 140/90 mmHg
• Examples of drugs:
– Diuretics : Thiazides: HCTZ
– Beta blockers: Metoprolol
– ACE Inhibitors: Captopril
– Angiotensin II Antagonists: Losartan
– Calcium blockers: Verapamil