Ischemic Heart Disease: Part 1 Flashcards
What is something you need to know for EKG interpretations for leads?
If you see ST elevation in certain leads, you should know the potential arteries affected
What is the classic patient with a silent MI?
Diabetic female
What does estrogen do?
Increases risks of blood clots, leading to a more likely cardiology.
What do you likely see in EKG of a silent MI?
Q-waves
What is the most common, serious, chronic, life-threatening illness?
Ischemic heart disease
What are the MC risk factors for Ischemic Hear disease?
genetic influences, high-fat and energy-rich diet, smoking, sedentary lifestyle
more common in low income groups
What is the MC cause of myocardial ischemia (MI)?
Atherosclerosis
What is the pathogenesis of an MI in a nutshell?
supply < demand
less supply: hypotension, Atherosclerosis, anemia, decreases supply
demand: exercise
What are the multifactorial causes of an MI?
Generally an imbalance between oxygen supply and demand
Oxygen supply → determined by blood flow
Blood flow is regulated by pressure vs. resistance ratio
Most critical factor is the radius of the blood vessel
This is influenced by atherosclerosis hardening of vessels, vascular tone, and endothelial cell dysfunction in cardiac ischemia
When are we most concerned about symptoms of an MI?
If they are symptomatic at rest - meaning that the demand is high even at rest
What is prinzmetal angina?
What is stable angina?
Have not ruptured the plaque, and it is stable.
May present with chest pain during exertion
What is unstable angina?
Not stable, or walled off block
What is the progression of stable angina to MI? Which of these are consider Acute coronary syndrome?
Stable angina –> unstable angina –> MI (stemi or NSTEMI)
unstable angina and MI (NSTEMIs, STEMIs) are EMERGENCIES, and are considered acute coronary syndrome because it needs to be addressed
Dead meat don’t beat
When does ACS result?
plaque rupture and thrombus formation. The amount of coronary blood flow restriction determines the severity:
Unstable angina - no occluded blood flow → symptoms at rest
NSTEMIs - partially impeded blood flow through the coronary vessels
STEMIs - completely impeded blood flow through the coronary vessels
What are the symptoms of stable angina (fixed stenosis)
A typical pattern; predictable
Occurs when the heart is under stress and needs more oxygen (exercise, cold, emotion)
Typically lasts 1-15 min
Goes away with rest and/or NTG
It may continue without much change for years
Not a risk at this moment and time that they will die.
What are the symptoms of unstable angina (Caused by a transient formation and dissolution of a thrombus)
Unexpected; a change in your usual pattern of stable angina
Occurs when blood flow to the heart is suddenly slowed by narrowed vessels or thrombus in the coronary arteries
It may happen at rest or with light activity. It does NOT go away with rest or nitroglycerin.
Warning sign that an MIis impending. An EMERGENCY!
When is something more likely to infarct and what is it?
Complete absence of blood supply for long time
Describe ischemia and symptoms?
Present as SOON as there is a decrease or complete absence of blood supply to myocardial tissue
Cardiac cells can tolerate mild-moderate anoxia (chest pain) for a short time without greatly affecting their function
When adequate blood flow / reoxygenation return, these cells usually return to a normal
Explain injury of coronary artery
If ischemia is severe or prolonged, the anoxic cardiac cells sustain damage and stop functioning normally
Damage to the cells still remains reversible so that injured cells remain viable and salvageable for some time
Cells may return to normal or near normal after the return of adequate blood flow and reoxygenation
Describe infarct
Severe myocardial ischemia continues because of continued complete absence of blood supply
The anoxic cardiac cells will sustain irreversible injury and die.
Dead meat don’t beat!
Explain the progress of ischemia to infarct
Ischemia –> injury –> infarct
What is transmural?
Entire transverse portion of the heart is infarcted.