Hypertension 1 Flashcards
What are the major forms of cardiovascular disease?
- hypertension
- atherosclerosis
- ischemic heart disease
- peripheral vascular disease
- heart failure
- cerebrovascular disease
Cardiovascular disease =
disease of heart and/or vessels
What are the top leading causes of death in Canada?
- Cancer
- Diseases of the heart
- Cerebrovascular disease
What used to be the leading cause of death?
Diseases of the heart (but new drugs and understanding)
Between males & females, what is the prevalence of hypertension?
Why is there a difference?
- increasing chance for males versus females
- because of higher obesity and overweight rates among males
Which age category has the highest prevalence of hypertension?
75+
bigger prevalence among females (because they live longer)
What is the number 1 reason for visits to physicians in Canada?
Hypertension
it is the number 1 reason for taking medication
How many in Canada are affected by hypertension?
more than 1/5 = 20% aged +20
What is the % of people unaware they have HTN?
18%
What is the % risk of developing HTN between 55-65yo with normal BP?
90%
What is the HTN prevalence among adults in the USA?
1/3 have hypertension
1/3 have pre-hypertension
HTN increases with/for:
- age
- males>females
- African-Americans> whites > hispanic
What are the 2 phases of the cardiac cycle?
- contraction = systolic
- resting = diastolic
MAP =
Mean Arterial Pressure
= Cardiac output x peripheral resistance
= the average of systolic and diastolic pressure
MAP is regulated by :
- sympathetic nervous system (autonomous)
- renin-angiotensin-aldosterone system
- renal function
- hormones: epinephrin, vasopressin, angiotensin II
Cardiac output formula
CO (L/min)= stroke volume (L/beat) x heart rate (beats/min)
Resistance formula
R= (length vessel x viscosity of blood) / (radius^4)
Which has the biggest impact on resistance?
- viscosity of blood
- radius of vessel
- length of vessel
- radius of vessel : a small change has a big impact on the resistance
Vasoconstriction: resistance high/low
high
Vasodilation: resistance high/low
low
Heart rate is controlled by:
- Parasympathetic NS (decreases HR)
- Sympathetic NS + epinephrine (increases HR)
What controls blood volume on:
- the short term
- the long term
- ST: fluid shifts
- LT: salt and water balance in the kidneys
What increases blood viscosity?
- high number of RBCs
Liver releases ->
Kidney releases ->
Lunges release ->
Adrenal cortex releases
Liver -> angiotensinogen
Kidney -> renin
Lungs -> angiotensin-converting enzyme
AC -> aldosterone
__ stimulates vasopressin release + thirst + arterial vasoconstriction + aldosterone production
Angiotensin II
Vasopressin role
increases water reabsorption by kidney tubules
What are the different organs damaged by hypertension?
- heart
- kidney
- peripheral vascular system
- eye
- brain
What damages does HTN have on heart?
- LVH : left ventricular hypertrophy
- CHD : coronary heart disease
- CHF : congestive heart failure
What damages does HTN have on kidneys?
- renal failure
- proteinuria (albumin)
What damages does HTN have on eyes?
- retinopathy
What damages does HTN have on brain?
- hemorrhage
- stroke
- vascular dementia
What instruments measure BP?
sphygmomanometer
What is the unit of BP?
in mmHG (mercury)
Primary/essential/idiopathic causes of HTN?
- interaction from environmental and genetics factors
- dietary and behavioural factors
Secondary causes of HTN?
0ccurs secondary to another condition such as renal, endocrine or neurological disorders
Why is HTN the “silent killer”?
It is typically asymptomatic
Non-modifiable risk factors of HTN
- age > 60y
- men, postmeno women, ethnicity (African-American, Russians, Finns)
- family history of CVD : women <65y or men <55yo
Modifiable risk factors of HTN
- smoking
- sedentary lifestyle
- abdominal obesity, insulin resistance
- excess sodium intake
- poor diet quality
- stress
Which other mechanisms can contribute to HTN?
- excessive sécession of vasopressin + ANG2
- renal disease
- adrenal disorders
- hyperinsulinemia
- neurological diseases
Reason why smoking contributes to HTN
Interferes with nitric oxide (dilates vessels) –> impairs epithelial vasodilation
Reason why renal disease contributes to HTN
reduced blood flow -> high ANG2 -> vasoconstriction + sodium, chloride, water retention -> blood volume
Reason why adrenal disorders contribute to HTN
increase secretion of epinephrine and norepinephrine -> vasoconstriction / increased cardiac output
Reason why excessive secretion of ANG2 and vasopressin contributes to HTN
increase vasoconstriction and fluid retention
Values of NORMAL systolic and diastolic BP
SBP: 90-119 mmHG
DBP: 60-79 mmHG
Values of PRE-HTN systolic and diastolic BP
SBP: 120-139 mmHg
DBP: 80-89 mmHg
Values of STAGE 1 HTN systolic and diastolic BP
SBP: 140-159 mmHg
DBP: 90-99 mmHg
Values of STAGE 2 HTN systolic and diastolic BP
SBP: 160-179 mmHg
DBP: 100-109 mmHg
Values of STAGE 3 HTN systolic and diastolic BP
SBP: >= 180mmHg
DBP: >=110 mmHg
According to HTN Canada:
LOW risk patients =
don’t have target organ damage or cvd risk factors
According to HTN Canada:
MODERATE-HIGH risk patients =
multiple cvd risk factors and 10-year global risk <15%
According to HTN Canada:
HIGH risk patients =
With 1 or + :
- clinical or sub-clinical cvd disease
- chronic kidney disease (non-diabetic nephropathy, proteinuria <1g/d)
- estimates 10year global cvd risk >=15%
- Age >= 75yo
Patients with Diabetes Mellitus are at which risk?
High risk