Cardiovascular Drugs Flashcards
Is the pressure higher in the arteries or in the veins?
Arteries (120). Veins are about (2).
Why is their lower pressure in the right ventricle?
To make sure it does not drown the lungs.
Why is the left ventricle thicker than the right ventricle?
Thickness allows for increased pressure to help move blood.
How does one calculate BP?
Cardiac output * Total Peripheral Resistance
What is Total Peripheral Resistance?
(constriction) it is a measure of total resistance to the flow of the system.
What is cardiac output?
The amount of blood pumped from the left ventricle per minute. Which is also stroke volume * heart rate
What is pulse pressure?
The difference between the systolic and diastolic pressure.
What is stroke volume?
the amount of blood pumped per beat from left ventricle
What is venous return?
The amount of blood that returns to the right heart per minute.
What is cardiac contractility?
The ability for the heart to contract, and measure of muscular strength.
Where is blood pressure measured?
arteries because they experience the most pressure
What is the blood pressure of an individual who has hypertension?
it is >140/90mmHg.
What is systolic blood pressure?
The maximum arterial pressure during contraction of the heart. (the higher number)
What is diastolic blood pressure?
The relaxation/re-filling of the heart between beats. (the lower number)
What is isolated systolic pressure?
If you only have a high systolic pressure. (due to stiffness of arteries)
What is isolated diastolic pressure?
If you only have a high diastolic pressure (narrowing of arteries)
What is systolic-diastolic blood pressure?
Both the systolic and diastolic pressures are too high.
In the elderly population, what is the most common form of hypertension?
Isolated systolic hypertension.
Who else is at risk for hypertension?
Pregnant women
What is essential hypertension?
The most common form of hypertension (> 80%) of cases. It due to an unknown reason.
What is secondary hypertension?
Hypertension causes by a secondary medical condition. For example: Reno-vascular hypertension (narrowing or arteries).
Pheochromocytoma: tumour that releases too much epinephrine. Epinephrine is a hormone that controls heart rate and blood pressure.
Aldosteronism: Causes sodium retention (increases blood volume)
What does high blood pressure do to the heart?
High blood pressure makes the arteries less stretchy and damages the arterial walls. This causes microtears in the walls that make it easier for fatty deposits to build up and limit circulation.
What are the symptoms of hypertension?
Usually it is asymptomatic but in severe cases there can be kidney damage, increased mortality, heart failure or stroke.
What kind of strokes are there?
Bloot clot (ischemic stroke) haemorrhage stroke (blood pressure causes vessels to damage and burst)
What kind of antihypertensives are used to treat hypertension?
A - ACE inhibitors, Alpha 1 Receptor, Angiotensin receptor blockers
B - Beta Blockers
D - Diuretics
How do diuretics work?
Too much sodium in the diet will cause water retention. Too much water in the blood increase BV which as a result increases BP. Diuretics decrease Na+ reabsorption and and increase urine flow. They also help dilate arterial vessels, which as a result make them less narrow.
Diuretics…
Decrease BV, decrease CO, and decrease TPR.
What kind of drug is a diuretic?
-thiazides
What other diseases can diuretics help to treat?
Edema, which is the accumulation of fluid in certain tissues.
The process for ACE inhibitors
The liver produces a molecule known as Angiotensin. When a decrease of BP is sensed in the arteries, the kidney detects this change and produces Renin. Renin enters the bloodstream and converts Angiotensin into Angiotensin 1. Angiotensin 1 circulates the blood until it comes into contact with a membrane bound enzyme known as ACE. ACE has the responsibility of converting Angiotensin 1 to Angiotensin 2.
What does Angiotensin 2 do?
It increases blood pressure through a variety of mechanisms.
- Vasoconstriction (Increase in TPR), or it also initiates the release of the Aldosterone hormone. Aldosterone sends signals that’s will increase sodium in the body, and cause BV to increase, hence increasing CO.
How do ACE inhibitors work?
They prevent A2 from being formed by inhibiting its synthesis hence decreasing aldosterone synthesis as well.
What drugs are considered ACE inhibitors?
Captopril
What are A2 Receptor Blockers?
They block A2 from binding to receptors. This decreases aldosterone synthesis and BP. It can also prevent heart failure.
What drugs are categorized as A2 receptor blockers?
Losartan
What do Alpha 1 receptor blockers do?
Blocks E and NE from stimulating receptors that cause contraction. In the lumen of the blood vessels, there are smooth muscle cells that can contract or widen the lumen. The smooth muscles have Alpha 1 Receptors. These receptors are stimulated by E and NE. This ends up stimulating contractions.
(Decrease TPR, BP, VR and CO.)
What drugs are categorized as Alpha 1 Receptor Blockers?
Prazosin
What are the side effects of Prazosin?
- reflex tachycardia (the sudden decrease in BP causes body to react by rapidly increasing the HR again)
- Orthostatic hypotension (low venous return) standing too quickly causes blood pressure to fall too fast, and causes blood to pool. As a result, and individual may experience syncope (fainting).
What are Beta Blockers?
Beta Blockers inhibit beta receptors which are important for sympathetic activity. Pacemaker cells in the heart regulate how fast your heart is pumping. Pacemaker cells have beta receptors on them. When E and NE bind to them, it increases the BP.
- Additionally cardiomyocytes, (cardiac muscle cells) are used for contraction and eject blood. Beta receptors in that area increase power of contractions.
What are the side effects of Beta Blockers?
myocardial depression, less exercise tolerance and bronchospasm.
What drugs are classified as Beta Blockers?
Propranol and Metroporol.
Metropolol is selective for…
B1 receptors.
Proporonal blocks
both B1 and B2.
The side effect of Bronchospasms occur in which drug?
Propronal
Beta blockers are also used to treat….?
Angina (severe pain in the chest).
