When dealing with stable and unstable angina, what you have to keep in mind is that both are due to low oxygenation of the heart. Angina technically means chest or heart pain.
Vasoconstriction versus Vasodilation
If a client has coronary artery disease (CAD) which is caused by high cholesterol, there is increased plaque formation within the lining of the blood vessels, and this causes the passageway to get constricted.
When a person becomes physically active or is caught up in a stressful situation, the fight and flight response is activated by the sympathetic nervous system. Once this happens, the blood vessels shrink and go into vasoconstriction. On the other hand, when a person is relaxed, like resting on a beach somewhere, vasodilation occurs. During vasodilation, rest and digest are activated.
Why Blood Vessels Constrict
When the body is exerting effort doing strenuous activities, the blood vessels constrict, and the heart rate and blood pressure increases.
The blood vessels constrict to increase oxygen delivery to the vital parts of the body like the heart, lungs, and brain. There is increased blood pressure and heart rate because the body is shunting all that oxygen into the blood vessels where it’s needed most.
Stable angina is also known as the exercise-induced chest pain. This means that whenever a person exercises or does physical exertion, the plaque or inflamed vessels become very narrow which causes decreased oxygen delivery to the heart. The moment the person stops what he or she is doing, the chest pain also goes away, and breathing would go back to normal.
On the other hand, unstable angina happens when a person still experiences pain even after stopping a stressful physical activity. The blood vessels have expanded, but the pain has remained consistent. This is most likely a case of unstable angina which means that there is a blood clot that’s blocking the coronary artery.
Why does this happen?
When a person is exercising, the blood vessels shrink or become smaller to adequately and effectively deliver oxygenated blood to the vital organs in the body. As the body relaxes, the blood vessels expand, there will be tiny clots or platelets that are attached to the edges of the plaque, occluding the entire vessel.
So just a reminder, stable angina is relieved by rest while unstable angina still causes chest pain even during rest.
Unstable Angina Pharmacology
Since unstable angina is not relieved by rest, the suspected client will get started on MONA – morphine, oxygen, nitrogen, and aspirin.
MONA is a type of recipe or what is otherwise known as a core measure or best practice that the United States or the governing bodies of different hospitals have come up with. MONA has shown promising results to decrease events that can lead to death.
MONA is actually given as ANOM. How?
- Aspirin – is the first recipe that will be given to the clients to thin out the congregated platelets. Aspirin will break up the platelets to make sure that they will not form around the plaque.
- Nitrogen – is given for vasodilation or vaso-expansion.
- Oxygen – is given after vasodilation.
- Morphine – is the last recipe to be given, especially if the top three recipes weren’t able to take the chest pain away. Morphine is given last to determine if the client is experiencing myocardial infarction because if after administration of morphine and the client is still in pain, this would mean that the client is going to have a heart attack.
In our next lecture, we will focus on the different tests and studies done to determine a heart attack.
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