Lecture 3 Flashcards
Definition of Hypertension
- chronically elevated resting blood pressure
- SBP
- — >140 mmHg
DBP
- —– >90 mmHg
- Antihypertensive Medication
Etiology of Hypertension
ESSENTIAL
- unknown cause
- 95% of causes
SECONDARY
- known cause
- —renal
- —endocrine
- —other pathologies
Prevalence of Hypertension
70 million Americans aged > 20 years old
- about 1 to 3
- prevalence increases with age
- more common in Blacks
Impact of Hypertension
A major cause of death
Risk factor for
- CAO
- Myocardial Infarcation
- Heart Failure
- Stroke
Direct and Indirect Economic Costs
-93.5 billion in 2007
Risk factors for HTTN
- dietary sodium
- overweight/obesity
- physical inactivity
- excessive alcohol use
- tobbaco use
- older age
- heredity
- –race
- –family history
- medical conditions
- –diabetes
Control of Blood Pressure
BP: exerted by blood upon the walls of blood vessels
BP=CO * TPR
Factors that control BP
AUTONOMIC NEURAL CONTROL
- medulla
- sympathetic vs. vagal
HUMORAL CONTROL (circulating)
- epinephrine
- angiotensin II
- aldosterone
- atrial natriuetic peptide
- arginine vasopressin
LOCAL VASCULAR FACTOR
-nitric oxide
Pathophysiology of HTN
Essential HTN
-mechanism not known
Secondary HTN
- renal
- –problems in renal handling of sodium
- ——may increase BP
- –altered renal secretion of vaso-active substances
- endocrine
- –problems in adrenal glands
Complications of HTN
- endothelial dysfunction
- atherosclerosis
- ventricular hypertrophy
- congestive heart failure
- stroke
- renal disease
Signs and Symptoms of HTN
Often NO Symptoms
“silent killer”
- headache
- dizziness
- fatiguability
- palpitations
- epistaxis
- hematuria
- blurring of vision
Diagnosis of HTN
average of 2 or more readings
-over 2 or more visits
Auscultation
- during sitting and arm supported at heart level
- after 5 min of rest
- no caffeine, exercise, and smoking for 30 min prior
- phase 1 Korotkoff sound
- -SBP
- phase 5 Korotoff sound
- -DBP
- white coat hypertension
- other tests for organ damage
Laboratory Tests
- urinalysis
- hematocrit
- blood chemistry
- electrocardiogram
Treatment of Hypertension
- depends on stage
- lifestyle modification
- –also required in pre-hypertension
- –weight loss
- –diet
- –physical activity
- Medication
- Resistant Hypertension
- Usually both medication and lifestyle modifications
Medications
- ACE Inhibitors
- Beta Blockers
- Calcium Channel Blockers
- Diuretics
- Other vasodilators (lower BP)
The Role of Exercise
SEDENTARY PEOPLE
-20-50% greater risk for hypertension than Active People
Acute response in recovery from exercise
-reduction of BP
CHRONIC RESPONSES
- endurance exercise
- –lowers BP
- –lowers age assumption increase in BP in people with HTN risk
- –Also decrease in BP
May lower need for medication
