Hypertension Flashcards
Which component of the heart is responsible for initiating contraction?
SA node
At what rate does the SA node depolarize?
every second OR 70 times per minute
What is sick sinus syndrome?
SA node not firing at regular pace
SA node no longer driving depolarization
fairly common problem among elderly
What is the solution to sick sinus syndrome?
pacemakers
-little electrode inserted in chest wall
-pumps 60-70 times per minute
-no longer have to rely on SA node
What is the role of the AV node?
gateway for electrical impulses into ventricles
-delays ventricular contraction=allows time for ventricle to
fill
located between atrium and ventricles, allows impulses to pass between the two
only way for an impulse to trigger ventricles in a healthy heart
Describe what is happening to cardiac cells prior to conduction.
cardiac cells are polarized
-80-90mV negative compared to outside the cell
ion pumps work to maintain this resting membrane potential
Na+ atoms sitting outside the polarized cell wanting to get inside due to the negative charge
Describe each phase of cardiac action potential.
prior to AP, cardiac cells are polarized at -80-90mV and some
Na+ will start to leak into the cell and reach a point (-75mV)
where Na voltage-dependent channels open
Phase 0:
-increase in permeability to Na+ influx
-Ca channels open at around -60mV
=depolarization has been coupled with contraction
Phase 1:
-brief re-polarization from K+ escaping cell
Phase 2:
-Ca continues to enter center (started in phase 0)
-Ca enters through L type calcium channels
-Ca movement initiates muscle contraction
Phase 3:
-membrane remains permeable
-Na and K ejected to repolarize the cell
Phase 4:
-Na+ is cleared from the cell and K+ loss slows
-eventually, an abrupt increase in Na+ permeability will occur
when a certain threshold potential is reached
Which part of the heart will have the steepest slope in phase 4 of an action potential?
SA node
depolarizes once every second
True or false: muscle cannot contract again until repolarization occurs
true
What is an ECG?
graph of electrical activity in heart
detected by electrodes (i.e. leads) attached to the patient
the location of the leads allows different angles of the heart to be examined
6-12 leads are often used
What does each lead of an ECG measure?
2, 3, and aVF=inferior region
1 and aVL=lateral activity
aVR=rightward
V1, V2=septal activity (wall between atria and ventricle)
V3, V4=apical activity
V5, V6=lateral regions
What is the most sensitive and effective way to detect a heart attack?
ECG
What does the P-wave represent?
depolarization (contraction) of atria
normal duration=0.12 seconds
What does the QRS complex represent?
depolarization (contraction) of the ventricles
normal duration=0.12 seconds
What does a normal QRS complex look like on an ECG?
narrow
should happen in a short period of time
ventricle is wired via Purkinje fibers and Bundle of His, thus allowing for ventricle to contract all at one time
What does the QT interval represent?
time from Q to T
=time it takes from ventricular contraction to ventricular repolarization (full cycle)
What could a wide QRS complex be a sign of?
sign that ventricular impulse did not originate from the AV node
could be okay, but eventually can lead to ventricular fibrillation
What does does a prolonged QT interval represent?
prolonging means it takes longer to repolarize and some cells dont depolarize at the right time
=takes longer to recharge between beats
What does the T-wave represent?
ventricular repolarization
What does the PR interval represent?
AV node conduction
long PR=AV node block
True or false: Canadian guidelines recognizes pharmacy blood pressure machines
false
What approach to assess blood pressure is considered the gold standard?
ambulatory blood pressure monitor
-wearing a cuff for 24hrs
-takes bp every 30 mins
-shows a full 24 hour series of measurements
List off each approach to assess blood pressure and the values that are considered high with each approach.
automated office blood pressure:
-mean SBP>135mmHg or DBP>85mmHg is high
office blood pressure monitoring:
-mean SBP 130-139mmHg or mean DBP 85-89 mmHg is high-
normal
-mean SBP >140mmHg or DBP>90mmHg is high
ambulatory blood pressure monitor:
-mean awake SBP>135mmHg or DBP>85mmHg or mean 24-
hour SBP>130mmHg or DBP>80mmHg are high
home blood pressure monitor:
-mean SBP>135mmHg or DBP>85mmHg are high and
associated with an increased overall mortality risk
What is the role of pharmacy blood pressure monitors?
they should serve as screening tools only
they have not been evaluated for their association with clinical outcomes
Which approach to blood pressure monitoring is more highly correlated with BP-related risk?
out-of-office BP measurements
-HBPM or ABPM
-ambulatory wins in predicting damage
in doc offices bp can be elevated
Describe good posture while taking blood pressure.
sitting position with back supported
arm bare and supported
cuff size appropriate for your arm
middle of the cuff at heart level
lower edge of cuff 3cm above elbow crease
do not talk or move before or during the measurement
legs uncrossed
feet flat on floor
What are the proper conditions for taking home blood pressure?
resting
low stimulation/stimulants/irritants
-avoid exercise, caffeine or full bladder prior to taking bp
(30min)
not a bright room
take duplicate measures
-2nd could be lower than 1st
What is a good rule for when to be measuring blood pressure at home?
one week blocks during times of interest
do not have to measure every day for extended periods if stable
Which cuffs are preferred for taking blood pressure?
brachial cuffs
When can validated wrist devices be used for BP estimation?
patients with large arm circumference when standard methods cannot be used
How prevalent is hypertension in Canada?
approximately 23% of Canadian adults have hypertension
more prescriptions for hypertension than any other disorder
-4 million Rx’s every month in Canada
cost of hypertension approaches 10% of all health care spending
What is the benefit of high blood pressure during activity?
increased blood flow=increased oxygen and glucose delivered to muscle
regular activity (with rest) will trigger cellular changes such as increased protein and increased mitochondria
What is the issue with high blood pressure during rest (long term)?
increased afterload=increased energy to pump blood
-wastes energy
-fatigues tissues/cells–>adverse changes over long term
damages specific tissues/cells
Describe the damage the results from hypertension. (flow chart)
increased afterload:
-systolic dysfunction, LVH, increased myocardial oxygen
demand
-LVH–>diastolic dysfunction–>heart failure
-systolic dysfunction–>heart failure
-increased myocardial oxygen demand–>ischemia and
infarction
arterial damage:
-accelerated atherosclerosis, weakened vessel walls
-accelerated atherosclerosis can hit coronary vessels
(myocardial ischemia or infarction), cerebral
vessels (ischemic stroke), or the aorta (aneurysm)
-weakened vessel walls–>hemorrhagic stroke, renal failure,
retinopathy
True or false: hypertension risk increases with age
true
lose 1ml/min of GFR every year after age 18
What are the origins of hypertension?
fluid an electrolyte imbalances
-RAAS, natriuretic hormone, electrolyte imbalance, renal
dysfunction/poor renal perfusion
sympathetic nervous system/baroreceptor function
-increased SNS activity
metabolic syndrome
-hyperinsulinemia/insulin resistance, abdominal obesity, low
HDL, high BP, high TG
vascular endothelial function
-prostacyclin, NO production
HYPERTENSION IS MULTI-FACTORIAL
What is essential (primary) hypertension?
chronically increased bp resulting from multiple factors, no single factor predominates
most commonly diagnosed form of hypertension
Will single antihypertensive drug regimens have great success in control of primary hypertension?
limited success in control (-10/-5)
What is primary hypertension commonly associated with?
metabolic syndrome
What is secondary hypertension?
hypertension caused by significant dysfunction of a single system
often not recognized until patients show resistance to conventional treatment
much less common
90-100% of heart attacks occur in people with at least 1 of: ____,____,____,____.
HTN
dyslipidemia
diabetes
smoking
True or false: most CV risk factors are silent
true
Why is early screening for hypertension important?
earlier in life is the greatest opportunity to reverse/slow impact of hypertension
What are the diseases that hypertension is a risk factor for?
atherosclerosis
diabetes
cardiac dysfunction
atrial fibrillation
What are the modifiable risk factors for developing hypertension?
obesity
poor dietary habits
high sodium intake
sedentary lifestyle
high alcohol consumption
high-normal blood pressure
diabetes or metabolic syndrome (pre-diabetes)
What are the goals of therapy for hypertensives?
ultimate goal: prevent CV complications
control blood pressure
reduce/prevent myocardial cell dysfunction
reduce/stabilize atherosclerosis burden and endothelial cell dysfunction
reduce/prevent weakened vessel walls
What are the values for the following categories of hypertension: optimal, normal, high-normal, grade 1 (mild htn), grade 2 (moderate htn), grade 3 (severe htn), isolated systolic hypertension
optimal: <120 and or <80
normal: <130 and or <85
high-normal: 130-139 and/or 85-89
grade 1: 140-159 and/or 90-99
grade 2: 160-179 and/or 100-109
grade 3: >180 and/or >110
ISH: >140 and/or <90
What would be a scenario where a patient would be diagnosed immediately with hypertension at the doctors?
extremely high bp (>180/110)
What would be the presentation of hypertension in the following in a healthcare setting compared to at home?
normotensive
sustained hypertension
masked hypertension
white coat hypertension
normotensive:
-healthcare setting: no HTN
-home: no HTN
sustained hypertension:
-healthcare setting: HTN
-home: HTN
masked hypertension
-healthcare setting: no HTN
-home: HTN
white coat hypertension:
-healthcare setting: HTN
-home: no HTN
What are the key cardiovascular risk factors that are non-modifiable?
age >55 years
male
family history of premature CV disease (age <55 in men and <65 in women doubles FRS)
What are the key cardiovascular risk factors that are modifiable?
sedentary lifestyle
poor dietary habits
abdominal obesity
dysglycemia (or diabetes)
smoking (even 2nd hand)
dyslipidemia
stress
hypertension
True or false: two people with the same blood pressure (ex: 151/96) can have different CV risk
true
one person can have clear, relatively healthy vessels
the other person can have atherosclerosis, therefore they are higher risk even though they have the same bp as the first person
What is target organ damage?
damage that occurs from long-standing hypertension
sign that damage has already been done
What are some examples of target organ damage?
cerebrovascular disease
-transient ischemic attack
-ischemic or hemorrhagic stroke
-vascular dementia
hypertensive retinopathy
left ventricular dysfunction
left ventricular hypertrophy
coronary artery disease
-myocardial infarction
-angina pectoris
-congestive heart failure
chronic kidney disease
-hypertensive nephropathy (GFR <60ml/min/1.73m2)
-albuminuria
peripheral artery disease
-intermittent claudication
-ankle brachial index <0.9
What is a Framingham risk calculator?
a widely used tool to assess overall CV risk in Canada
a simple algorithm estimates an individuals 10-year risk of experiencing a major CV event (MI, stroke, etc) or death
What are the limitations of the Framingham risk calculator?
just an estimate
poor performance in extremes of age (young, old)
10-year risk may not always correlate to lifetime risk
If a patient comes into your pharmacy and takes their blood pressure on the pharmacy blood pressure machine and the results are very high, what should you do?
not necessarily an emergency
check technique and re-take bp
ask patient if they are experiencing symptoms
if no signs/symptoms of danger, ask patient to make an appointment within a day or two, might have to go to a walk in clinic
What are the symptoms of concern if a person just had a high blood pressure reading?
neurologic:
-severe headache, numbness, weakness, slurred speech
-vision problems
cardio-respiratory:
-chest pain, difficulty breathing
What is the difference between hypertensive urgency and hypertensive emergency?
hypertensive urgency: situation where bp should be reduced within hours
-bp >180/130 AND
-papilledema or other target organ changes
hypertensive emergency: situations that require immediate bp reduction
-ex: hypertensive encephalopathy, intracranial bleed, unstable
angina/MI, acute heart failure
What are the physical assessments commonly documented in medical charts?
jugular venous pressure (JVP):
-indirect assessment of right atrial pressure
edema:
-may represent ‘volume’ or tissue-specific fluid
pulse:
-heart rate
-pressure/circulation (feet)
heart sounds:
-normal: S1=systole (lub); S2=diastole (dub)
-not normal: murmur, S3 or S4 (may indicate disease)
blood pressure
point of maximal impulse (PMI):
-normal=4-5 ICS, mid clavicular line
-assessment of LVH
bruit:
-carotid and renal