Cardiovascular Pharmacology Flashcards
Blood pressure (BP)
A measure of the pressure/force of blood against the walls of the arteries. Measured in mmHg
What are the 2 readings of blood pressure?
Systolic (SBP) - the highest pressure when the heart contracts
Diastolic (DBP) - the lowest pressure when the heart relaxes (this is between beats)
Fun fact: a normal BP reading is 120/80 (SBP/DBP) :D omg
2 factors that affect BP. Also, what affects these factors?
- Cardiac output. Factors that affect - blood volume, heart rate and contractility, and venous tone
- Total peripheral resistance. Factors that affect - diameter of blood vessels, particularly the arterioles
Cardiac output
Volume of blood pumped by the heart per minute
Total peripheral resistance
Resistance to blood flow throughout the circulatory system
Arterioles
Smallest diameter arteries and the primary site of vascular resistance
4 facts about hypertension
- Aka high BP. Defined as the chronic elevation of resting BP ≥140/90mmHg
- It affects ~1/4 adults in Canada
- Usually asymptomatic
- Increases the risk of morbidity and mortality (stroke, myocardial infarction, heart failure, renal failure)
Subtypes of hypertension
- High SBP only - isolated systolic hypertension. This is due to increased stiffness of large arteries. This is prominent in adults >50 years old
- High DBP only - isolated diastolic hypertension. This is due to narrowing of arterioles. Prominent in adults <40 years old
- High SBP and DBP - systolic-diastolic hypertension. Due to a combination of causes
Primary (essential) hypertension
This is one of the etiologies of hypertension. It has an unknown cause as it results from complex interactions between multiple genetic and environmental factors
This is the most common etiology (90-95% of cases)
Secondary hypertension
This is one of the etiologies of hypertension. Causes: medical conditions (chronic kidney disease, sleep apnea) , maybe drugs
Pathophysiology of hypertension - name 3 pathogenic mechanisms
- Upregulation of renin-angiotensin-aldosterone system
- Increased sympathetic nervous system activity
- Vasodilator deficiency
These changes increase cardiac output and/or total peripheral resistance
Non-pharmacological intervention examples (8)
- Diet and weight control
- Reduced salt/sodium intake
- Reduced alcohol intake (heavy drinkers)
- DASH diet
- Physical activity
- Smoking cessation
- Relaxation therapies
- Multiple interventions
Name the 4 first-line antihypertensive drugs
- Angiotensin converting enzyme (ACE) inhibitors
- Angiotensin II receptor blockers (ARBs)
- Thiazide diuretics
- Calcium channel blockers (CCBs)
First-line drugs are only for uncomplicated hypertension (hypertension without other co-morbidities)
ACE inhibitors and ARBs should not be used in combination as it impairs kidney function
What is the MOA of Angiotensin converting enzyme (ACE) inhibitors? Give an example and its side effects
It inhibits the angiotensin converting enzyme (ACE), which blocks the production of angiotensin II. This decreases the constriction of arteries and veins, aldosterone secretion, renal Na+ reabsorption, and SNS activity
Ex. captopril
May cause dry cough, hyperkalemia (too much K+ in blood), angioedema
What is the MOA of Angiotensin II receptor blockers (ARBs)? Give an example and its side effects
Prevents the action of angiotensin II by blocking the AT1 receptors. The effects are similar to ACE inhibitors
Ex. Losartan
May cause dizziness and hyperkalemia. Lower risk of cough and angioedema (swelling beneath the skin due to fluid buildup)
