Hypertension and Smoking Cessation Flashcards
Which organs are involved in blood pressure regulation?
- Heart (cardiac output)
- Kidneys (water balance)
- Brain (coordination of signaling & controls messengers like hormones)
- Nerves (send messages in short distances & controls dilation)
What is BP = CO x SVR?
Blood pressure = Cardiac Output x Systemic Vascular Resistance
What does BP = CO x SVR tell us?
Causes of why BP might be high
Different meds will act on different components of it
What is Systemic Vascular Resistance?
The force opposing the movement of blood in your blood vessels
What is the CO made up of?
Cardiac output = heart rate x stroke volume
CO = HR x SV
How does the Sympathetic Nervous System affect HR?
It can increase contractility (how hard the heart will pump) which can then increase SV
What else effects the SV?
The renal fluid volume (how much fluid is there that can get pushed around). This has to do w/ renin angiotensin aldosterone system, natriuretic peptides & antidiuretic hormones
Why does the SNS have the biggest affect on HR?
Baroreceptors: can increase or decrease HR
Norepinephrine
- α1: vasoconstriction, ↑ contractility
- α2: inhibit NE release, vasoconstriction
- β1: ↑ contractility, ↑HR, ↑ conduction, ↑ renin
- β2: vasodilation, gluconeogenesis
What are baroreceptors?
They’re specialized nerve cells in the carotid sinus; if stimulated b/w BP is high, they’ll try to decrease your sympathetic activity which will lower HR & contractility & have vasodilation. This is a negative feedback loop.
Ex: low BP - SNS constricts arterials, increased HR & increased contractility
What is a downside to baroreceptors?
If you constantly have a high BP, your baroreceptors can eventually get used to it & lose the ability to regulate it
What is norepinephrine used for?
Used in critical care to increase BP if it’s dangerously low
Where does the Parasympathetic Nervous System have an effect on?
Has a big affect through Vegas nerve (CN10)
What is RAAS? What does it do?
It sense that there is a low BP or a decreased Na. It’s also affected by the Sympathetic Nervous System
This Juxtaglomerular apparatus releases renin
Renin then converts angiotensin → angiotensin I
Angiotensin I goes to lungs where angiotensin converting enzyme (ACE) → angiotensin II
- Angiotensin II is a potent vasoconstrictor
- Angiotensin II stimulates kidney to secrete aldosterone (retain sodium and water)
Increase in fluid = increase in SV
What substances affect the Systemic Vascular Resistance (SVR?
Affected by SNS (alpha & beta adrenergic receptors)
RAAS causes vasoconstriction via angiotensin II
Neurohormonal vasoconstrictors like angiotensin & norepinephrine
Local regulation
- Working on blood vessels
- Nitric oxides
- Endothelin
What is the vascular endothelium?
Single layer of cells lining blood vessels
- Nitric oxide (NO) – lowers arterial tone, inhibits smooth muscle growth
- Endothelin (ET) – vasoconstrictor, promotes smooth muscle growth
What is hypertension?
Sustained elevation of systemic arterial BP
SBP equal to or greater than 140 mm Hg
Or DBP equal to or greater than 90 mm Hg
What is the etiology of hypertension?
Primary hypertension
- 90-95% adults
- Complex interactions
Secondary hypertension
- 5-10% adults, 80% children
- Coarctation of aorta, renal disease, endocrine disorder, neurological disorder, sleep apnea, medication, pregnancy
What are the risk factors of HTN? (13)
- Age
- Alcohol consumption
- Cigarette smoking
- Glucose intolerance
- Elevated lipids
- High sodium intake
- Gender
- Family history
- Obesity
- Ethnicity
- Sedentary lifestyle
- Socioeconomic status
- Psychosocial stress
What is the pathophysiology of HTN? (7)
- Genes
- Sodium/water retention
- Altered renin-angiotensin-aldosterone mechanism
- Stress and increased SNS activity
- Insulin resistance and hyperinsulinemia
- Endothelial cell dysfunction
- Obesity
What are the clinical manifestations of HTN?
Lanthanic (silent) disease – asymptomatic until target-organ disease has occurred
Secondary symptoms: fatigue, reduced activity tolerance, dizziness, palpitations, angina, dyspnea
What target-organ diseases may result from diabetes?
Heart
- Hypertensive heart disease
Brain
- Cerebrovascular disease
Peripheral vasculature
- Peripheral arterial disease
Kidneys
- Nephrosclerosis
Eyes
- Retinal damage
How is HTN diagnosed?
Ambulatory BP measurement
Laboratory tests - Urinalysis - Blood chemistry (Na, K, Cr, BUN) - Fasting blood glucose - Fasting total cholesterol, HDL, LDL, triglycerides ECG
How is collaborative care implemented?
Risk stratification
- Target organ damage, cardiovascular risk
Lifestyle modifications
- DASH diet
- Weight reduction (BMI 18.5-24.9)
- Alcohol consumption (2/day, w 9/wk, m 14/wk)
- 30-60 min physical activity 4-7 days/week
- Avoid tobacco
- Stress management
True or false: we prefer to have pts on long-acting meds
True
