Hypertension Part 1 Flashcards
What are the major forms of CD? (HIP-HA)
Hypertension Ischemic heart disease Peripheral vascular disease Heart failure Atherosclerosis
What is the leading cause of death in Canada? Second leading cause?
Cancer
CVD
Why are CVD now second leading?
CVD much better diagnosed, better medications and medical treatment
What was they key point in the graph comparing men and women and prevalence of HTN?
- Men linearly increases
- Women increase, but flatten over time
Why are both trends upwards in HTN and gender?
Probably associated with the increase in obesity, as obesity is a major cause of hypertension
Are most people aware of their HTN?
Yes 65% treated and aware, but 18% unaware - meaning that the prevalence of HTN could actually be greater
Development of HTN is very much based on what?
Age
Stat of HTN and Age?
Lifetime risk for adults aged 55-65 y/o with NORMAL BP to develop HTN is 90%
HTN Affect …
1/5 of Canadians
22% of adults > 20 y/o
HTN risk similar between ….
Men and post-menopausal women
1 reason of doctor visits Canada?
HTN
Rates of HTN increase and decrease in which ethnicities?
Increase in blacks
Decrease in chinese, korean
BP=
Cardiac output x peripheral resistance
CO=
Heart rate x stroke volume
PR=
Length of vessel x viscosity of blood / radius ^4
How is radius determined?
By vasonconstriction or vasodilation of blood vessels
An increase in ____ will increase BP
- Heart rate
- Stroke volume
- Viscosity of blood
- Length of vessel
A decrease in ___ will increase BP
-Radius of blood vessel
What are some major factors involved in the regulation of Mean Arterial Blood Pressure?
- Sympathetic nervous system
- RAAS
- Renal function
- Epi, vasopressin, Ang II
Explain what influences cardiac output (SRC-B)
Primarily determined by heart rate and stroke volume. heart rate influenced by nervous system (sympathetic and parasympathetic), where the stroke volume is influenced by SNS and venous return, Venous return influenced by skeletal muscle, respiratory, cardiac suction and blood volume.
Explain what influences peripheral resistance
Radius is under local metabolic control which is influenced by skeletal muscle, and extrinsic vasoconstriction control which is mediated by SNS and epi, vasporessin, Ang II which will influence RAAS system. Viscosity will be determined by hydration status and # of RBCs.
Main effects of increase SNS and Epi
- Increase HR
- Increase SV
- Increase extrinsic vasoconstriction
- Decrease radius
- Increase BP
Explain RAAS in 3-4 sentences
Decrease in sodium in ECF and circulation - where baroreceptors in Kindey detects decrease in BP. Kidneys secrete renin, allow for conversion of ANG (Liver) –> Ang I. Ang-1 –> Ang II possible by ACE-1 released by lungs. ANG-II is a potent vasoconstrictor, will increase BP.
Effects of ANG II
- Stimulate adrenal cortex to release aldosterone (increase sodium pumps)
- Vasonstriction
- Thirst
- Pituitiary to release vasopressin (more water reabsorption, increase BV_
HTN is ….
Asymptomatic
Primary HTN
Unknown etiology or gene/environment, dietary, behavioural causes
Secondary HTN
Symptom from another disease - renal, endocrine, neurological
Non-modifiable risk factors?
- Age < 60y/o
- Men, post-menopausal women, ethnicity
- Family history
Modifiable risk factors?
- Smoking
- Sedentary
- Abdominal Obesity
- Excessive Sodium
- Poor diet quality
- Stress
Normal SBP
90-119
Pre HTN SBP
120-139
Stage 1 SBP
140-159
Stage 2 SPB
160-179
Stage 3 SBP
> 180
Normal DBP
60-79
Pre HTN DBP
80-89
Stage 1 DBP
90-99
Stage 2 DBP
100-109
Stage 3 DBP
> 110
What is TOD?
Target Organ Damage
What kind of major TOD may result from HTN or may put patients at a higher risk for HTN complications?
- Coronary Artery Disease
- Left-ventricular hypertrophy
- Heat Failure
- Stroke
- Transient Ischemic Attack
- Hemorrhage
- Demential
What kind of mino TOD may result from HTN or may put patients at a higher risk for HTN complications?
Retinopathy
Peripheral Artery Resistance
Nephropathy (Albuminuria, Chronic Kidney Disease)
What classifies a high risk patient?
One or more of the following:
- Clinical or subclinical CVD risk
- Chronic Kidney Disease
- FRS global CVD risk >15%
- Age >/= 75
What is considered Chronic Kidney Disease?
- Non-diabetic neuropathy
- Proteinuria <1g/dl
- GFR 20-59 ml/min/1.73m^2
What classifies a moderate/high risk patient?
-Multiple CVD risk FACTORS
and FRS global CVD risk >15%
What classifies a low risk patient?
-No CVD risk factors or TOD
How is DM classified?
High Risk
Initiation of treatment for High Risk patient
130 SBP
Initiation of treatment for DM patient
130/80
Initiation of treatment for Mod/High risk patient
140/90
Initiation of treatment for Low risk patient
150/100
Target for High Risk Patient
120 SBP
Target for DM
130/80
Target for Mod/High risk
140/90
Target for Low risk
140/90
(T/F) BP Threshold and targets for High Risk patient based on non-AOBP
False, based on AOBP
(T/F) BP Threshold targets for DM, Mod/High and Low risk patient based on non-AOBP
True
Effects of increased vasopressin and ANG II on HTN
May be due to gene mutation
Increase aldosterone, thirst, vasopressin release, vasoconstriction, water and sodium retention to increase BP
Effects of smoking on HTN
Will inhibit NO, limit vasodilation
Effects of renal disease on HTN
Decrease blood flow through kidney will increase ANG I (recall RAAS and baroreceptors), increase in BP
Effect of adrenal disorders on HTN
Increase epi/norepi to increase cardiac output (stroke volume, heart rate), vasoconstriction (peripheral resistance)
What else may contribute to the pathogenesis of HTN?
- Hyperinsulinemia
- Neurological disorders
AOBP
Automated Office Blood Pressure
Preferred method?
AOBP
AOPB uses …
Electric –> Oscillometric
What are some general guidelines when measuring BP?
- Supine position
- Quiet room
- Cuff 3 cm above elbow and at brachial artery
- Arm at heart level
- Take BP at both arms, higher BP should be used as actual measurement
AOBP threshold HTN
135/85
NON-AOBP uses what?
Non electronic, sphygomanometer and tends to overestimate BP
Non-AOBP threshold HTN
140/90
Non-AOBP threshold HTN for diabetics
130/80
When is home blood pressure monitoring used?
When HTN is DIAGNOSED and often used in patients w/:
- Chronic Kidney Disease
- DM
- Suspected non-adherence
- White coat HTN
- BP controlled in office, not at home
Home BP threshold HTN
Two reading taken each morning/evening for 7 days, where the first reading is discarded and average is equal or greater to:
135/85
What is Ambulatory BP monitoring?
At home, will serve to measure BP every 20 mins over 24 hours
When is Amb BP used?
- Not responsive to HTN therapy
- Symptoms are suggestive of HTN
- Inconsistent readings
Amb threshold HTN? (2)
Mean 24 hr: 130/80 (and/or)
Mean day-time: 135/85 (and/or)
Explain the HTN diagnostic algorithm for adults
Patient has concern of HTN, makes appointment with doctor where 180/110 is an immediate positive for HTN/ If no, both diabetics and diabetics must then exceed non-AOBP/AOBP. If diabetics exceed, positive for HTN. If non-diabetics exceed, require final at-home BP monitoring to confirm HTN.
Patient comes on with BP of 170/100, and has diabetes, what is the next step?
170/100 exceeds thresholds for AOBP and non-AOBP for diabetics –> Intervention
Non-diabetic patient reports BP of 140/90 on non-AOBP, and then doctor sends for Amb-BP, where patient reports daytime mean BP of 135/85. What is the diagnostic?
HTN
Non-diabetic patient reports BP of 135/85 on non-AOBP and then doctor suggests home BP where patient reports 130/80. What is the diagnostic? What if the same result was achieved on Amb BP?
If home BP –> White Coat HTN
If Amb BP –> HTN
What would be needed for the doctor to prescribe Home or Amb monitoring according to the algorithm?
Non-diabetic patient that exceeds non-AOBP of 140/90 or AOBP of 135/85
When is White Coat HTN ruled out?
If after home BP and AmbBP, patient stays above 135/85 and 130/80 (24 hour AmbP)
(T/F) Mean 24-hour Amb BP is 130/82 patient has HTN
True (Recall threshold fro 24-hr is 130/80)
(T/F) Mean Daytime Amb BP is 130/82 patient has HTN
False (Recall threshold for daytime is 135/85)
What are the key nutritional factors in HTN?
- Excess cal, weight, obesity
- Potassium, sodium, calcium, magnesium, fibre
- Alcohol
What is the most potent non-pharmacological agent for HTN reduction?
Weight loss
Decease of ____ per 10 kg weight loss
15-20 mmHg SBP
(T/F) Decrease BP will only be seen when a healthy weight is acheived
False, 5-15% weight loss has a significant impact
Why does obesity contribute to HTN?
- Insulin resistance
- Leptin will increased SNS activity (vasoconstriction, heart rate, stroke volume)
- RAAS alteration
Link between leptin and HTN
Increased leptin will increases SNS activity, recall leptin resistance in obesity where although it wont affect satiety, large amount that remain in circulation affect BP
General recommendation for HTN and weight loss
Aim for normal BMI, waist circumference
All OW patients should aim for 5% weight loss to reduce BP and TOD
What may impede weight loss?
B-blockers
Key point of intersalt study
Linear relationship between increased urinary sodium excretion and BP, where urinary sodium excretion is a very accurate marker of sodium intake
According to intersalt study, each increase of 100mmol/sodium increased SBP by ____ and DBP by ____
3-6
0-3
Key point of intersalt study and decreased sodium intake?
Linear relationship between decreased urinary sodium excretion and BP, where more drastic reductions in BP were seen in hypertensive individuals despite same urinary sodium excretion (same sodium intake)
Key FINDING from study that compared SAD an DASH diet at 3 levels of sodium intake?
That SAD diet and reducing sodium had the most drastic decrease, where DASH remained relatively linear when decreasing sodium.
What was the key POINT from study that compared SAD and DASH diet at 3 levels of sodium intake?
The composition of the diet as a whole is more important than the salt reduction, as evidenced by those who consumed the DASH diet + high salt demonstrated similar reduction on BP as those on SAD + low salt.
Reduction of BP stems from the ___ and not ____ only
Composition of the diet as a whole
Sodium reduction
Define salt sensitivity
The increase in BP as a dose-dependant response to sodium chloride intake
Whats is the issue with reducing salt?
Not all individuals are salt-sensitive, and will not reduce their BP in response to a decrease in salt (1/3 of population)
What can induce salt-sensitivity?
Increased potassium
When is decreased salt-sensitivity a good thing?
When induced by an increase in potassium, where the HTN effects of sodium are blunted
When is decreased sensitivity a bad thing?
When we reduce our sodium intake with no change in BP, or even an increase in BP
What influences salt-sensitivity?
- Genetics
- Age
- Severity of HTN
- Low RENIN
- High Epi/SNS
- Increased K+
Sodium AI 14-50 y/o
1500 mg/day
Sodium AI 51-70 y/o
1300 mg/day
Sodium AI 71 y/o
1200 mg/day
UL Sodium?
2300 mg/day
Usual sodium consumption in Canada?
3.5 g
Recommendations for salt intake?
Decrease intake towards UL (2300 mg/day) or 5 g of salt (2.5 g of Na+ and 2.5 g of Cl-)
How much sodium in 1/2 tsp of salt?
1120 mg
____ sodium from processed foods
80%
____ from “conscious” sodium and natural content of foods
20% (~10% each)
Official recommendations on Salt
Choose unsalted, lower sodium or sodium reduced foods with <120 mg sodium, serving or <5% DV
Why are there official recommendations on reducing salt although large amount of population is salt insensitive?
Large insensitive, but majority (2/3) is sensitivity which is grounds for Public Health Messaging
3000 mg sodium hospital diet discludes …
High Na+ processed foods and bev
Allow 1/4 salt added during cooking/table
2000 mg sodium diet discludes …
- High Na processed foods/bev
- Limit milk/milk products <2 cups/day
- NO salt added in cooking/table
1000 mg sodium diet discludes …
Same as 2000 mg
- No canned, frozen foods
- No deli, cheese, margarines
- Limit regular bread to <2 servings/day
When are 1000 mg diets prescribed?
Chronic renal diseases only
As dietary potassium increases what happens? (2)
Salt sensitivity decreases
BP decreases
As dietary sodium increases, what happens?
Potassium excretion increases
BP increases
Explain why increased K+ may decrease BP
- Increase natriuresis
- Suppression of renin
- Attenuates vascular constriction
- Decreases SNS
- Protect against familial susceptibility
What will increase the impact of increasing dietary potassium in the diet?
If the patient is salt sensitive, and has a high sodium intake
The relationship between sodium and potassium is ____
interpendent (Effects of BP dependant on the relationship between sodium and potassium)
What are the consequences of long-term exposure to high sodium diet?
Retention of sodium, excretion of potassium
Chronic high sodium impairs _____, and a deficit of potassium encouraged the retention of ____
potassium conservation
sodium
Explain what happens in the kidney cell when there is high amounts of sodium and a deficit of potassium
Digitalis-like-factor and aldosterone released from the kidney to STIMULATE sodium pump activity. Results in more Na+ to bloodstream and more K+ to tubule lumen for excretion –> Increase BP
Explain what happens in the vascular endothelium smooth muscle cell when there is an excess of sodium and deficit of potassium?
Digitalis-like factor will INHIBIT sodium pump, causing even more retention of sodium. Causes depolarization of membrane, and opening of Na+/calcium channels. Calcium allows for contraction, and upon depolarization K+ channels open, more depletion of K+ –> Increase BP
(T/F) Potassium supplements are recommended to prevent HTN in normotensives or in the treatment of HTN
False, potassium should be easily obtained through dietary intake
(T/F) Potassium supplements are recommended if patient on K+ losing diuretic to reduce risk/treat hypokalemia
True, and also recommend increasing dietary potassium
Intake of K+ associated with decreased risk of stroke/mortality?
> 60mmol/day
Average intake of K+ in adults?
2800 mg/day for women and 330 mg/day for men
What is the RDA for potassium?
4700 mg
Risk factors for hyperkalemia
RAAS inhibitors
Chronic Kidney Disease
Medications
Basal serum levels >4.5 mmol/L
(T/F) Increase in calcium associated with increase in BP
False, opposite effects
Why does calcium reduce BOP?
- Parahormone suppression
- Natriuresis
- NO sensitivity
- Recuced vasoconstrictors
How does magnesium reduce BP?
Reduces vascular reactivity and contractility
Alcohol intake has a ______ relationship with BP, where an intake greater than ____ increased BP
Dose-responsive
2 drink/day
(T/F) Alcohol has a vasodilation effect
TRUE - but will then be followed by an increase in BP 10-15 hours after
Alcohol recommendations men
2 drinks/day
Alcohol recommendations women
1 drink/day
SD Bee @ 5%
12 oz/ 360 ml
SD Wine @ 12%
5 oz / 150 ml
SD Spirits @ 42%
1.5 oz/ 45 ml
