Alterations in BP exam 3 (slide show 3) Flashcards
1
Q
what are some determinates of systemic bp?
A
- cardiac output (CO)
- resistance to the ejection of blood from the heart
- BP = CO X SVR (systemic vascular resistance
2
Q
what 3 factors is cardiac output determined by?
A
- preload
- contractability
- afterload
3
Q
define cardiac output
A
- amount of blood that the heart can pump out per min
4
Q
what is the equation for cardiac output?
A
- CO = SV (stroke volume) x HR
5
Q
what is stroke volume?
A
- volume of blood ejected during each ventricular contraction
- amount of blood that gets out of the heart in 1 ventricular contraction
- another def: per HB how much blood goes out or the force of it
6
Q
what is SVR
A
- systemic vascular resistance
7
Q
define SVR?
A
- resistance to blood flow offered by all the systemic vasculature, excluding the pulmonary vasculature
- Systemic Vascular Resistance (SVR) is kind of like that. It’s how hard your heart has to push to get blood through all those tiny tubes (blood vessels). If the tubes are wide, blood flows easily. But if they get narrow, the heart has to push harder to get the blood through.
8
Q
what determines the SVR?
A
- radius (size) of arteries and degree of vessel compliance
8
Q
what is pre load?
A
- amount if blood in the ventricles at the end of diastole
- how much blood gets poured into the heart during relaxation
8
Q
what is afterload ?
A
- pressure AGAINST your heart has to fight when pumping the blood
8
Q
define contractility
A
- represents innate ability of the heart muscle to contract
8
Q
when does preload increase?
A
- hypervolemia
- regulation of cardiac valves
- heart failure
9
Q
what makes afterload?
A
- HTN
- vasoconstriction
9
Q
what increases when afterload increases?
A
- cardiac workload bc the pressure that the heart has to fight
9
Q
what is systolic blood pressure?
A
- peak pressure during cardiac systole (heart contraction)
9
Q
what effects systolic blood pressure the most?
A
- SV is the primary factor influencing systolic pressure (strove volume)
9
Q
what is diastolic blood pressure?
A
- lowest pressure during cardiac diastole (heart relaxation)
10
Q
what is the major determinant of diastolic pressure?
A
- SVR is the major determinant of diastolic pressure (systemic vascular resistance)
11
Q
what is the first response to changes in BP
A
- mediated through the sympathetic nervous system as it releases catecholamines
12
Q
define catecholamines
A
- category of substances released as the SNS
13
Q
what detects the changes in BP
A
- baroreceptors and chemoreceptors
14
Q
what triggers vasoconstriction?
A
- catecholamines activates alpha 1 receptors in smooth muscle of arterioles
15
Q
what in triggers the increases heart rate?
A
- catecholamines activates beta 1 receptors of the heart to increase heart rate
16
Q
what does the parasympathetic nervous system do
A
- slows the heart rate
17
how is HNT dangerous to the heart?
- increases risk for anthracosis bc BP causes endothelial damage & plaque forms which increases BP
18
what is primary (essential) hpertension?
- does not have a reason why it has occurred
19
what is secondary hypertension?
- other known specific cause
20
what is the most common complication of hypertension?
- stroke
- heart attack
- kidney failure
21
why does hypertension cause complications
- increases workload of heart (left ventricle)
- increases afterload
22
what is the goal when hypertension is caught?
- initiate interventions early to prevent or deter progression of the disease process
23
what is hypertensive crisis?
- over 180 or 120
24
what is normal BP?
- less than 120 nd less than 80
25
if pt has BP of 120/80 what bp do they have?
- stage 1 hypertension
26
is systolic or diastolic BP the major risk factor for cardiovascular disease?
- systolic
27
is primary or secondary BP most common?
- primary
- Sometimes called the “silent killer” as damage has already
occurred to organs before diagnosis is made
28
what are the risk factors for primary HTN?
- Dietary factors
* Sedentary lifestyle
* Obesity/weight gain
* Metabolic syndrome
multi things
* Elevated blood glucose levels/diabetes
* Elevated total cholesterol (bc LDL = increase in athrosicrosis)
* Excessive alcohol intake
* Smoking (bc nicotine is a stimulant which increased BP and HR)
29
what are drug classifications used to treat hypertension?
- loop diuretics
- angiotensin II
- angiotensin ACE inhibitors
30
31
what is the most common form of secondary hypertension?
- in infants / preschool children (renal disease and coarctation)
32
what is the most common case of secondary hypertension in adults?
- hyperaldosteronism and kidney related disease
- pregnancy
- obesity/obstructive sleep apnea
33
what is orthostatic hypotension
-- Causes a decrease in systolic blood pressure ≥ 20 mm Hg or ≥ 10 mm Hg diastolic within 2-5 minutes, when moving to an upright position
- Results in dizziness, syncope, fainting, blurred vision, and confusion
34
what may be the cause of orthostatic hypotension?
- May be caused by medications/drugs,
dehydration, hypovolemia, prolonged immobility, hypoglycemia, thyroid conditions
35
how to diagnose orthostatic hypotension
- take BP 3 times
- laying down
- sitting
- standing
36
what are treatments for orthostatic hypotension?
- review meds
- slow position changes
- avoid hot environment
- avoid large or carb heavy foods
- When symptoms begin, squatting/bending forward or crossing legs may reduce effects
- Elastic compression stockings, abdominal binders, elevate head of bed
- Increase salt and fluid intake if not contraindicated
