Force exerted by blood against artery wall during ventricular contraction (systolic) and ventricular relaxation (diastolic) must be adequate to maintain tissue perfusion during activity and rest.
What are the two main factors that influence BP?
Systemic Vascular Resistance
What regulates BP?
Sympathetic Nervous System (SNS)
Renal and Endocrine System
What is hypertension?
Sustained elevation of BP
Systolic is > or = 140 mmHg and diastolic is > or = to 90 mmHg for extended periods of time
Diagnosis based on 3 occasions of elevation within a several week period.
What effects does hypertension have on the body?
High BP means the heart is working harder than normal, both heart and blood vessels are under strain
Endothelial damage occurs
What are hypertensive patients at risk for?
What are the symptoms of HTN?
Who is at risk for HTN?
More prevalent in men than women
Women after the age of 55
Equal risk for men and women from 55-75 years of age and after 75 years of age more prevalent in women.
What is Primary HTN?
Elevated BP without an underlying disease
Accounts for 90-95% of all cases of Htn
Caused by high sodium diets, obesity, sedentary lifestyles, etc
What is Secondary HTN?
-Elevated BP with specific underlying cause—identify and correct underlying problem which usually corrects HTN as well
-Its the main cause of Htn in children (80%)
-narrowing of the aorta
-Neurologic disorders (brain tumors)
-endocrine disorders (Hyperaldosteronism)
-Obstructive Sleep Apnea
Clinical Manifestations of HTN
May be asymptomatic, also known as “silent killer”, until it causes damage to target organs
-decrease in activity
Complications (Target Organ Diseases): CAD
Htn is major risk factor
exact mechanism unknown
thought to be caused by a disruption of coronary artery endothelium due to high pressures
Complications (Target Organ Diseases): Left Ventricular Hypertrophy
Sustained high pressures increase cardiac workload
Adaptive mechanism to increase CO by increasing contraction
Heart failure occurs when the heart can no longer compensate for the increased pressures and demand to supply oxygen (enlarged heart on X-ray, SOB on exertion, fatigue, ECG changes-wide QRS, inverted T wave).
Complications (Target Organ Diseases): CVD
Atherosclerosis is the most common cause of CVD
Risk for stroke is 4 times higher in people with Htn
If atherosclerotic plaques in carotid arteries can break off and cause TIA’s or a stroke
Hypertensive encephalopathy may occur after prolonged Htn
When blood pressure remains high, the cerebral blood vessels dilate producing edema and marked loss of consciousness and death may occur from brain damage
Complications (Target Organ Diseases): PVD
Htn speeds up the process of atherosclerosis in the peripheral blood vessels
Classic symptom: Intermittent claudication (ischemic muscle pain caused by activity, relieved with rest).
Complications (Target Organ Diseases): Nephrosclerosis
Htn is the leading cause of end-stage renal disease!
Direct result of ischemia caused by the narrowed lumen of intrarenal blood vessels
Leads to atrophy of the tubules, destruction of the glomeruli, and eventual death of the nephron itself
Lab tests to confirm are: BUN, creatinine, proteinuria, albuminuria, hematuria
Nocturia is the earliest sign of renal dysfunction
Complications (Target Organ Diseases): Retinal damage
The retina is the only place in the body where blood vessels can be directly visualized
Includes blurring of vision, retinal hemorrhages, loss of vision
Damage to the retina gives an indication of cardiac vessel damage