hypertension Flashcards
blood pressure
- force of blood against arteries & the force of arteries against blood
- -“the force exerted against the walls of the arteries and veins by the blood as it’s being pumped from the heart; it’s also the pressure exerted by the walls of the arteries and veins against the blood”
hypertension
- a systolic BP >140mmHg or a diastolic BP >90 mmHg of the average of at least 3 different readings
- 120-139 and/or 80-89= prehypertensive
- 140-159 and/or 90-99 = stage 1 hypertension
- > 160 and/or >100= stage 2 hypertension
hypertension stats
- called “silent killer”
- the WHO identifies it as being responsible for 62%of cerebrovascular incidents and 49% of ischemic heart disease
- CDC estimates that approximately 1 in 4 adults are hypertensive. many do not realize
BP cont
- systolic pressure is the highest amount of pressure exerted on the arterial wall at the peak of ventricular contraction
- diastolic pressure is the lowest pressure exerted during ventricular relaxation
Mean Arterial Pressure
-average amount of pressure exerted throughout cardiac cycle
-measured as CO multiplied by the vascular resistance
MAP=COxPVR
MAP= [SBP + 2DBP] / 3
Why is MAP important?
-gives us a picture of the cardiac cycle
-monitors perfusion of organs
-MAP 70-110 is normal
> 60 is enough to perfuse all organs
-less than 60 or greater than 110 could lead to multiple organ death
how is BP controlled/ maintained?
- Sympathetic nervous system: baroreceptors in the carotid arteries can activate SNS
- Vascular Endothelium: produces several vasoactive substances
- Renal System: controls extracellular fluids; renin, angiotensin, aldosterone system; prostaglandins= vasodilators
primary HTN
-elevated BP without a single identified cause
no one direct cause
contributing factors:
-elevated SNS activity (like chronic pain)
-increased body weight
-diabetes
-tobacco/alcohol consumption
-elevated sodium retaining/ vasoconstricting hormones
secondary HTN
- elevated BP with specific cause which can be identified and corrected
- congenital heart defects; etc
preeclampsia
elevated BP during pregnancy, usually after 20 weeks. possible organ damage especially kidneys. very dangerous
risk factors
- age
- body weight
- diet
- exercise
- genetics
- sex
- ethnicity/socioeconomic status
- alcohol/tobacco
- stress
manifestations
- early on; only high BP
- headache
- nocturia
- mental status changes later on
- nausea, vomiting
- visual changes, papilledema (swelling of optic nerve)
secondary
- coarctation or congenital narrowing of aorta
- side effects of drugs or hormones (corticosteriods, estrogen, etc)
- traumatic brain injury, tumors
- glomerulonephritis, kidney disease
- cirrhosis
hypertensive crisis/ emergency
- develops over several hours, days, or even weeks
- situation when BP rises to severe levels (180/120 in book, could be higher)
- the rate of rise is more important then the end value however (pts. with chronic HTN can usually tolerate higher BPS normally)
- typically in pts with Hx of HTN who do not adhere to medical regimen or whose BP is undermediated
- can aslo result from drug use (cocaine, LSD)
HTN crisis manifestations
- encephalopathy (increased cerebral capillary permeability) -headace, N/V, seizure, coma, confusion
- renal insufficiency
- angina, MI, chest pain, SOB