C12: Systemic Hypertension Flashcards
define systemic hypertension
high BP reading of >140/90 on 2 separate occasions
Values for: pre-HTN Stage 1 HTN Stage 2 HTN Isolated systolic HTN
pre-HTN: 130-139 / 85-89
Stage 1 HTN: 140-159 / 90-99
Stage 2 HTN: >160 / 100
Isolated systolic HTN: >/= 140 / <90
Isolated systolic HTN is more common in which demographic
why is it dangerous
older patients
dangerous for stroke
describe primary hypertension
due to metabolic causes: metabolic syndromes obesity diabetes mellitus sedentary lifestyle mental stress
this type is hereditary
another name for primary hypertension
essential HTN
describe secondary hypertension
due to: renal disease - increased angiotension endocrine/hormonal causes pituitary/hypothalamic syndrome - cushings syndrome thyroid - hyperthyroidism CNS - increased sympathetic tone AO coarctation
endocrine/hormonal causes of secondary hypertension
increased catecholamines
primary aldosteronism
adrenal hyperplasia
increased cortisol - cushings disease
risk factors for essential HTN
age ethnicity (African decent) male obesity dyslipidemia diabetes mellitus
lifestyle factors that can lead to essential HTN
stress excessive sodium and alcohol intake inadequate calcium and potassium sedentary lifestyle smoking
what is the mean pressure
2 forumlas
avg pressure over the cardiac cycle
MAP = [ (2 x diastolic BP) + systolic BP ] / 3 MAP = CO x SVR
how does the length of systole change with tachy and Brady cardia
tachy: systole occupies > 1/3 of the cycle
diastole: systole occupies < 1/3 of the cycle
pulse pressure
SBP - DBP
what happens to pulse pressure w/ severe AO regurg
it will increase b/c systolic press must increase to get blood out and diastolic BP will go down
what 2 factors can increase BP
CO and any factors that increase systemic vascular resistance
how can HTN appear in a clinical setting
can appear as:
heart failure w/ preserved EF… will have compensatory hyper dynamic contraction, hypertensive hypertrophic cardiomyopathy… main mechanism is diastolic dysfunction
1 symptom of HTN
dyspnea… also a sign of diastolic dysfunction
1 way to alter peripheral resistance
alter the vessel diameter
formula for BP
BP = peripheral resistance x cardiac output
3 things that affect BP
peripheral resistance
stoke volume and isotropy
heart rate
what can cause vasodilation in the high resistance vascular beds
exercise and relaxation techniques
how does pulse pressure relate to compliance
more compliant vessel = lower pulse pressure
how does inspiration and expiration affect right heart filling
inspiration = increased R heart filling expiration = decreased R heart filling
term for total blood volume
how does it affect BP
volemia
more volume = more press
factors that increase volemia
water retention
total body mass
how does salt alter BP
higher salt intake leads to water retention in order to maintain proper salinity of blood…. more water leads to more pressure on the arterial walls and higher BP
what is salinity
water, sodium ratio
how many mg or sodium a day
1500 mg - 2300 mg
high BP is equal to what
high afterload
effects of HTN… what can it cause
CHF - HTN increases the workload to an already overworked heart
CAD
PVD
renal failure -press is too high for kidneys to function well
angina - increased workload to muscle and decreased coronary artery profusion
how can HTN cause PVD
increased pressure and velocity in the arteries speeds up the process of athersclerosis…. same for CAD
what is the function of endothelium relaxation factor
allows the smooth muscle cells of the tunica intimal and media to relax and will lower BP
main factors of HTN that need to be addressed
blood volume
CO (SV and HR)
peripheral arterial resistance
first step to HTN management
lifestyle modifications: exercise control salt and fat intake stop smoking reduce stres
how does exercise help to reduce BP
muscle contraction leads to vasodilation to provide more 02 to muscles and remove C02, this dilation leads to lower systemic vascular resistance which lowers BP
how does smoking affect BP
stress makes people want to smoke…. smoking decreases 02 to the brain and introduces toxins… this stressed the body and causes the release of catecholamines in order to try to get more 02, leading to higher BP and HR.. feeling more stressed
after the first year of smoking, risk of an MI and CVA is reduced by how much
… 5 years?
50%
50%
irreversible lung damage occurs after how many years
5
main effect of diuretics
lower total blood volume to reduce preload, afterload and excrete salt w/ urine
main effect of beta blockers
lower HR which reduced SBP and DBP and allow more effective contraction and more time for perfusion
main effect of calcium channel blockers and ACE inhibitors
vasodilation
calcium: block calcium from entering muscle cells and lowers afterload
ACE: prevent angiotensin from causing arterial contrition… lowers afterload
which areas of the heart in specific are we assessing for size
LV, LA, IVS, LVPW
AO: root, ascending and descending, also look at abdo AO
what should we assess w/ HTN
systolic function diastolic function values dilation of ventricles size
what does dilation mean w/ HTN
the heart is failing and compensatory mechanisms arent enough anymore
what kind of LVH is seen w/ early HTN
concentric remodelling
2D echo findings w/ HTN patient
LVH AO root & ascending dilated \+/- AV sclerosis or MAC LA enlargement RV dilation due to high RVSP
strain findings w/ HTN patient
reduced global strain
diastolic dysfunction findings w/ HTN patient
increased LV filling press
PV flow reversal
reduced longitudinal motion w/ TDI
RVSP increase in late HTN
if a patient has increase peripheral resistance, how will the diastolic flow change in the descending and AO arch
it will be reversed.. so much resistance that flow cant go forwards.
no AR seen
in what circumstance could a patient go from normal geometry to eccentric geometry
from an MI
what type of LV geometry will you always see w/ late heart failure
eccentric
how can asymmetric LVH affect the MV
can cause SAM - systolic anterior motion of the mitral valve… b/c the suction from the LV contraction is so strong the it pulls the leaflet up… will see aliasing in the ventircle
what variables are needed to calculate the LV mass linear technique
simplified formula
PWd, IVSd, LVIDd, LVID
LV mass index = total LV mass / BSA
when can the LV mass be too high, but the LV mass index be normal?
what can you do instead
due to increased BSA
use height to index LV mass instead
how do you do LV mass using the area length method
trace around the epicardium and the endocardium… subtract the 2 areas to get the area of the myocardium, then add the length of the LV measured in A4CH view
forumla for relative wall thickness
why do we use PW and not IVS
RWT = 2 (LVPW)/LVIDd
often the IVS is thickened in the basal segment of the LV in older patients
normal RWT
<0.42
