Ischemic Heart Disease I - Exam 2 Flashcards
In general, why does mycocardial ischemia occur? What is the most critical factor?
occurs when there is an imbalance between oxygen supply and demand
radius of the blood vessel
What are the 3 factors that influence the radius of the blood vessel?
atherosclerosis hardening of vessels
vascular tone
endothelial cell dysfunction in cardiac ischemia
What is the difference between stable and unstable angina?
stable: chest pain on exertion
unstable: constant chest pain even at rest
What conditions are included in Acute Coronary Syndrome (ACS)? What conditions are included in Ischemic Heart Disease?
unstable angina
MI: including STEMI and NSTEMI
What is Prinzmetal angina?
not scary spasms of the blood vessels
What is Acute Coronary Syndrome a result of? What determines the severity?
ACS results when there is plaque rupture and thrombus formation
the amount of coronary blood flow
What are the differences in blood flow between unstable angina, NSTEMI and STEMI?
What are the differences between stable and unstable angina?
When does ischemia present? Can cardiac cells tolerate mild-moderate anoxia?
Present as soon as there is a decrease or complete absence of blood supply to myocardial tissue
Cardiac cells can tolerate mild-moderate anoxia for a short time without greatly affecting their function. When oxygen is restored the cells usually return to normal
When does cardiac injury appear? Is it usually reversible?
If ischemia is severe or prolonged, the anoxic cardiac cells sustain damage and stop functioning normally
damage to cells still remains reversible and cell may return to normal or near normal after the return of adequate blood flow and reoxygenation
When does an infarct occur? Is it reversible?
Severe myocardial ischemia continues because of continued complete absence of blood supply
The anoxic cardiac cells will sustain IRREVERSIBLE injury and die
aka dead meat, don’t beat!!
What is a transmural infarct?
When the tissue dies through all the layers of the heart
aka VERY BAD
What areas are common for NSTEMI? What area is particularly susceptible to ischemia?
Involves small area in the subendocardial wall of the LV, ventricular septum, or papillary muscle
subendocardial area
What are the EKG changes associated with NSTEMI? Will there be an increase in cardiac enzymes?
ST depression or T-wave inversion (or no EKG changes)
will see an increase in cardiac enzymes
Will there be an increase in cardiac enzymes with unstable angina?
NO increase in cardiac enzymes
What is the cause of a STEMI?
infarct through the extend through the whole thickness of the heart muscle wall, that is caused by the complete occlusion of a coronary artery
What are EKG changes that will appear with a STEMI? ______ is the classic description of the wave
ST elevation!!! and SOMETIMES develop a Q wave (but not always)
“tombstone” appearance