Week 2 Flashcards
What is the epidemiology of HTN?
- HTN is the leading risk factor for CVD mortality (13% of global deaths)
- Only about half % of people with HTN are compliant with medications
- Leading cause of CVD worldwide
- “Silent killer” often asymptomatic even at extremes
What kind of disabilities increases the chances of a patient getting HTN?
- Mobility limitation
- Cognitive limitation
- Vision limitation
- Hearing limitation
What are the fast mechanisms for the regulation of fast BP?
Baroreceptor located primarily in the Aortic Arch and Carotid Sinuses
What are the slow mechanisms for the regulation of fast B
• Renin-Angiotensin System (Kidneys)
• Natriuretic peptides (ANP in the atria and BNP in the ventricles) (Heart)
- Act as a counter to RAAS system. released from heart
How does the regulation of arterial blood flow work?
• Sympathetic neural activity: norepinephrine (norEph)
- Goal is to redistribute blood to areas of need, more global
- Arterioles are innervated by sympathetic, which release norEph
- norEph binds to alpha-1 receptors causing vasoconstriction
• Circulating epinephrine
• Circulating hormones: angiotensin II
• Local metabolites: prostaglandins
• Mechanical Factors: muscle contraction, vessel stretch (CA2+ influx)
What does circulating epinephrine bind to?
Beta 2 receptors located in arterial cells. Beta 2 receptors dilate blood vessels, bu they aren’t that many of them
What do local metabolites cause in working muscle?
They cause vasodilation to the working tissue which will allow us to deliver more blood flow, and oxygen and to get rid of waste
What is functional sympatholysis?
How our body regulates BP during exercise
What is functional sympatholysis tightly related to?
The endothelial function, if there is impaired endothelial tissues in the blood some of the function of the functional sympatholysis can be impaired
What is hemodynamics?
Blood flow parallels Cardiac Output
CO = HR X SV
How do you find CO?
Driving pressure divided by resistance to flow.
Or
(MAP-CVP) divided by total peripheral resistance (TPR)
What are the things that affects BP within blood vessels?
- Radius
- Viscosity (hematocrit)
- Length of vessel
- Resistance
Though our larger vessels can undergo larger changes in diameter, the bulk of the resistance in our bodies is in the _____
Though our larger vessels can undergo larger changes in diameter, the bulk of the resistance in our bodies is in the *micorvasculature (smaller vessels), which is why its so important to maintain normal endothelial function in that tissue
What is the role that the PT plays to reduce the risk of hypertension?
- Exercise
- Education
- Interdisciplinary communication
What is the mean arterial pressure for the regulation of BP using baroreflex/baroreceptors?
85 to 100mmHg in adults
What do baroreceptors respond to?
Stretching of the arterial wall
What are the characteristics of baroreceptors responding to stretching of arterial walls?
- Negative feedback loop with the Vagus and Glossopharyngeal nerves
- Arterial pressure suddenly rises, the walls of these vessels passively expand, increases the firing frequency of receptor action potentials.
- If arterial blood pressure suddenly falls, decreased stretch of the arterial walls leads to a decrease in receptor firing.
In the regulation of BP using baroreceptors, what pressures do carotid sinus receptors respond to?
Pressures ranging from 60-180 mmHg
What is the difference between aortic arch receptors and carotid sinus receptors in the regulation of BP with the use of baroreceptors?
Aortic arch receptors have a higher threshold pressure and are less sensitive than the carotid sinus receptors
What is renin?
An enzyme that is released into the circulation by the kidneys due to the detection of low blood flow through the arteries
What is the release of renin stimulated by?
• Sympathetic nerve activation (acting
through β1 -adrenoceptors)
• Renal artery hypotension (caused by systemic hypotension or renal artery
stenosis)
• Decreased sodium delivery to the distal tubules of the kidney
What is an essential hypertension?
Interaction between environmental factors and genetics. Accounts for 95-99% of cases
What is a secondary hypertension?
Result of some biochemical or mechanical pathology, potentially reversible
What are the contributors to HTN?
- Diet…Salt Sensitivity
- Inactivity
- Obesity
- Abnormalities of the adrenal cortex
- Sleep Apnea
- Sympathetic Nervous System Activity
- Kidney Disease
- Congenital Vascular Disorders
- Recreational Drugs and Alcohol
What are the normal BP values for adults?
- Systolic: 100-120mmHg
* Diastolic: 60-80mmHg
How does the RAAS system work?
- Renin is released from the kidneys due to a number of possible causes
- Renin interacts with angiotensinogen with is released from the liver
- Angiotensinogen converts renin to angiotensin 1
- Angiotensin 1 travels through blood flow to the lungs, and interacts with angiotensin converting enzyme, which converts angiotensin 1 to angiotensin 2
What are some causes for the release of renin?
- SNS activity
- Low perfusion of the juxtoglomerular apparatus
What is angiotensin 2?
A potent vasoconstrictor that also works to increase fluid retention. And may also facilitate further SNS activity
What is aortic coarctation?
A congenital narrowing of the aorta
What is the “ideal” BP?
110/70
What is elevatedd BP?
SBP: 120–129 mm Hg
DBP: <80 mm Hg
What is HBP (hypertension) stage 1 BP?
SBP: 130–139 mm Hg
DBP: 80–89 mm Hg
What is HBP (hypertension) stage 2 BP?
SBP: ≥140 mm Hg
DBP: ≥90 mm Hg
What is an hypertensive crisis BP, where emergency care is needed?
Higher than 180 or higher than 110
What is a hypertensive urgency?
A patient with elevated pressures with BP > 180/110 and they show no signs of organ damage
What is a hypertensive emergency?
A patient with elevated pressures with BP > 180/120 and they show signs and symptoms of organ damage
What are the signs of a hypertensive urgency?
- Headache (22%)
- Epistaxis (Nose Bleed) (17%)
- Faintness/SOB (10%)
- Agitation/Anxiety (10%)
What are the signs of a hypertensive emergency?
- Chest pain (27%)
- Dyspnea (22%), and
- Neurological deficit (21%)
What are the common end-organ damage associated with HTN emergencies?
- Acute pulmonary edema
- Acute left ventricular dysfunction
- Acute coronary syndrome (including acute myocardial infarction).
- Cerebral infarction
- Hypertensive encephalopathy
In very severe cases of elevated pressure, we can see acute hypertensive nephrosclerosis, what is it?
An acute injury to the kidneys which occurs typically when pressures exceed 300/150 mm Hg
What is hematuria?
The kidney demonstrates focal small hemorrhages, resulting in blood in the urine. (more common)
What is another way to assess BP?
Pulse pressure
What is pulse pressure?
The value retrieved when you subtract systolic BP - diastolic BP (SBP-DBP)
What is normal pulse pressure?
~40-60mmHg
Why might pulse pressure be a better predictor of CV risk than SBP?
• Low: <40mmHg may indicate pulse narrowing
• Elevated: >60mmHg PP associated with higher CVD morbidity and mortality rates.
• More reflective of microcirculation dysfunction
• Mechanism may be due to endothelial damage from large oscillations in pressure
each cardiac cycle.
How is heart rate assessed?
By palpation or ECG
What is normal heart rate in normal adults?
60-100bpm adults
What is higher resting heart rate independently associated with?
Increased risks of all cause and cardiovascular mortality
• Risk of all-cause and cardiovascular mortality increases by 9% and 8% for every
10 beats/min increment of resting heart rate.
• Especially HR >90
Is HR higher in children or in adults and why?
Higher in children, because their heart is not fully developed yet and doesn’t do so until the age of 12
What is brachial BP?
Standard BP measurement on the upper arm
What are some errors with brachial blood pressures?
• Brachial BP may not accurately reflect central pressure
• A lot of cuffs underestimate systolic and over estimate diastolic
- Better than NOT taking though
• Static/Rest BP is only a snap shot, doesn’t reflect response to load
- Though the more often we take, the better it helps clarify patients normal hemodynamics and aids medical assessment
- Exercise is when adverse events happen
• Might be best to assess response to low to moderate exercise
- Unmasks masked HTN, identifies hyper/hypo responders
- This should be a component of all exams
What are some confounding variables with taking a BP?
• Ambulatory (ABPM) vs home readings (HBPM)
- Every 20min vs 4 times per day, ABPM found to be more accurate however expensive.
• Normal Diurnal variation (Higher in AM vs PM)
- Most people demonstrate a 10%–20% decrease in BP during the evening
• Masked HTN
- Normal office blood pressure and elevated out-of-office blood pressure
• White Coat Syndrome
- Elevated BP in clinic (140/90mmHg) despite normal ABPM or HBPM
• Reading Errors
What can a full bladder do to BP?
Make BP appear higher by 10-15 mmHg
What can an unsupported back do to BP?
Make BP appear higher by 5-10 mmHg
What can an unsupported feet do to BP?
Make BP appear higher by 5-10 mmHg
What can crossed legs do to BP?
Make BP appear higher by 2-8 mmHg
What can an unsupported arm do to BP?
Make BP appear higher by 10 mmHg
What can a cuff over clothing do to BP?
Make BP appear higher by 10-40 mmHg
What can a patient talking or having a conversation do to BP?
Make BP appear higher by 10-15 mmHg
What are the normal results of BP when a patient is in pain?
- Systolic BP increases by 15-25mmHg
- Diastolic BP increases by 10-20mmHg
Values greater than normal considered to
be “hyper-reactive”. Hyper-reactors have increased risk of developing HTN
What are the characteristics of chronic pain and hemodynamics?
• Diminished tolerance to painful stimuli
• Reduced blood pressure response and baroreflex to painful stimuli
• Higher (HR) than healthy subjects at baseline and to painful stimuli
• Lower parasympathetic and increased sympathetic activity.
- Significantly lower HRV
• Increased prevalence of HTN
Why is exercising BP better?
- Resting BP not necessarily indicative of true BP
* Response to exercise may be more useful
What is a hypertensive response?
- Exaggerated hemodynamic response to exercise at maximal efforts
- (SBP) >220mmHg for men; >190mmHg for women.
- (DBP) >10 mmHg or >90 mmHg
What are the characteristics of a hypertensive response?
• Demonstrated in normal and patients with HTN
- Even with well controlled resting BP.
- Can be predictive of future HTN diagnosis
• However can be demonstrated at even low to moderate intensities (3-5METs)
- May be useful for the unmasking of HTN in clinical settings
What is the normal BP response to exercise?
10 mmHg/met systolic
0- 10 mmHg/met diastolic
What are the characteristics of an hypotensive response to exercise?
• LowExBP was associated with increased risk regardless of clinical presentation
exercise mode or exercise intensity (moderate or max)
• 10 mmHg decrease in exercise SBP was associated with higher risk for fatal and
non-fatal cardiovascular events and all-cause mortality.
- An earlier (<5min) the decrease may be worse
What are the characteristics of pulse pressure and risk?
• Pulse pressure (PP=SBP-DBP) might be a better predictor of CV risk than SBP
• Elevated >60mmHg PP associated with higher CVD morbidity and mortality rates
• Mechanism may be due to endothelial damage from large oscillations in pressure
each cardiac cycle.
• More reflective of microcirculation dysfunction
What are the characteristics of pulse pressure and cervical manipulation?
• The results of BP testing, specifically Pulse Pressure may provide direction for risk assessment and/or the management of patients across populations.
• Elevated Pulse Pressures have been associated with increased arterial stiffness
and the development of atherosclerosis.
• Vascular profiling may enhance the risk assessment and clinical reasoning process for manual therapists.
What are the risk factors that are associated with an increased risk of either internal carotid or vertebrobasilar arterial pathology and should be thoroughly assessed during the patient history?
• Past history of trauma to cervical spine
/ cervical vessels
• History of migraine-type headache
• Hypertension
• Hypercholesterolemia / hyperlipidemia
• Cardiac disease, vascular disease, previous cerebrovascular accident or transient ischemic attack
• Diabetes mellitus
• Long-term use of steroids
• Blood clotting disorders / alterations in blood properties (e.g. Anticoagulant Rx)
• History of smoking
• Recent infection
• Immediately post partum
• Trivial head or neck trauma Absence of a plausible mechanical explanation for the patient’s symptoms.
What are the recommendations for a patient with resting vitals of >140/90?
Proceed with usual care
• Contact PCP
• Monitor closely
What are the recommendations for a patient with resting vitals of >160/100?
Hold resistance exercise, consider aerobic
exercise
• Contact PCP
• Monitor closely
What are the recommendations for a patient with resting vitals of >180/110 ?
Hold Exam
• Examine for organ damage
• Contact PCP
• Consider contacting EMS/911
What are the characteristics of using the effects of post exercise hypotension that should be considered?
• Acutely lower blood pressure in an “asymptomatic” (ie not in crisis) patient with
elevated BP
• The cutoff scores for aerobic exercise is 180/110
• Try low grade exercise 5-10minutes, monitor response and recovery
• Effects can last long enough and gives you a reflection on appropriateness for therapeutic interventions
• Use your judgement to manage each case, if you don’t feel comfortable contact referring provider.
What are the characteristics of the use of eccentrics to be considered?
• Improves strength comparable to concentric training.
• Lower RPE, SVR, oxygen consumption, Cardiac Index, peak SBP and HR at similar workloads to concentric.
• May increase muscle soreness more
than CON training
What are the characteristics of thoracic spinal manipulation for neck pain to be considered?
• Patients neck pain with CVD are at greater potential risk for adverse events following cSMT
• Thoracic manipulation is an effective
intervention for neck pain
• Very little response to hemodynamics or
autonomic system
• Does not involve perturbation to cervical
arteries or carotid sinus
What are the characteristics of questionnaires to be considered?
• Physical Activity Readiness Questionnaire (PARQ) - Easy to use, Medicare • Duke Activity Status Index (DASI) - Predictive for Mortality - Related to Peak VO2 • AHA/ACSM Physical Questionnaire - Easy to use, Fitness Industry • Questionnaires can be effective for investigating heath history in PT practice
What is Cardiovascular Disease?
Disease and dysfunction to the myocardium and blood vessels, includes numerous problems, many of which are related to a process called atherosclerosis. Defined by the presence of stenosis which impairs blood flow, flow limiting lesion.
What are the major causes of Cardiovascular Disease?
- Atherosclerosis
- Thrombo-embolism
- Vasculitis
What are the Non Modifiable Risk Factors for Cardiovascular Disease?
• Gender (Male>Female) • Age - Male >40 - Female >50 (post menopause) • Race (African American or Asian) • Family History: 1st degree blood relative that has had coronary heart disease, stroke or heart attack before the age of 55 for males or 65 for females
What are the Modifiable Risk Factors for Cardiovascular Disease?
• Hypertension • Tobacco use • Elevated blood glucose (IFG/diabetes) • Physical inactivity - 150min/week Moderate (3-6METs) - 75min/week Vigorous (<6METs) • Overweight and obesity - Overweight BMI 25-29.9 - Obese BMI >30 • Cholesterol/lipids - Total <180 mg/dL is considered optimal. - HDL 40-60mg/dL - LDL 100-129mg/DL
What is Atherosclerosis?
The hardening of the arteries.
What kind of condition is Atherosclerosis?
A dynamic chronic inflammatory condition
What are the characteristics of Atherosclerosis?
• Slow, progressive disease • Starts in 2nd & 3rd decade of life • Very long incubation period • Often undetectable - Even with moderate to high grade • Initially Plaques are sparsely distributed • Increase in number and size over time • Can affect any artery
What is the role of Endothelial Cells (EC)?
• EC normally produce antithrombotic molecules that prevent blood clots.
• EC modulate the immune response by resisting leukocyte adhesion and therefore inhibiting inflammation.
• Laminar shear stress favors leads to
- NO production
- Kruppel Like Factor 2 (KLF-2); mediates the immune response, prevents deposition
- ++ Superoxide Disumutase (SOD) protects against reactive oxygen species (ROS).
• Branch points are subjected to turbulent flow and tend to lack these effects.