Cardio - IHD Flashcards
condition in which there is an inadequate
supply of blood and oxygen to a portion of the myocardium
Ischemic heart disease
Most common cause of ACS
a. atherosclerotic disease of an endocardial artery
b. atherosclerotic disease of myocardial artery
c. atherosclerotic disease of epicardial artery
d. NOTA
C
The major determinants of myocardial oxygen demand
MVO2) are (3
(1) heart rate
(2) myocardial contractility
(3) myocardial wall tension (stress).
2 requirements for adequate supplt of oxygen to the myocardium
- satisfactory level of oxygen-carrying capacity of the blood
- adequate level of coronary blood flow
3 things that determine level of oxygen carrying capacity of blood
- inspired level of oxygen
- pulmonary function
- hemoglobin (concentration and function)
75% of the total coronary resistance to flow occurs across three sets
of arteries:
- large epicardial arteries
- prearteriolar areteries (R2)
- arteriolar and intramyocardial capillary vessels (R3)
True about coronary circulation
a. large epicardial arteries are R2
b. prearteriolar arteries are R3 arteries
c. major determinant of coronary resistance is found in R1 and R2
d. normal circulatory circulation is dominated by the brain’s demand for oxygen
a. they are R1
b. R2 and R3 are the major determinant of coronary resistance
d. it is dominated by the heart’s requirements for oxygen
answer: C
The changing oxygen needs of the heart with exercise and
emotional stress affect coronary vascular resistance and in this manner
regulate the supply of oxygen and substrate to the myocardium. This is an example of what kind of regulation?
metabolic regulation
The coronary resistance vessels also adapt to
physiologic alterations in blood pressure to maintain coronary blood
flow at levels appropriate to myocardial needs. This is an example of what kind of regulation?
autoregulation
Reduction of lumen of coronary arteries due to atherosclerosis causes
a. decrease in perfusion when demand for flow is augmented
b. increase in perfusion during exercise
c. both
d. neither
A
The following statements are true EXCEPT
a. coronary embolism rarely cause myocardial ischemia
b. coronary blood flow can be limited by spasm as in Prinzmetal angina
c. Myocardial ischemia can occur in LVH
d. NOTA
D
for letter C, there can be increase myocardial oxygen demand
Abnormal constriction or failure of normal dilation of the coronary resistance vessels also can cause ischemia. When it causes angina, this condition
is referred to as
microvascular angina
major site of coronary atherosclerotic disease
a. epicardial coronary arteries
b. endocardial coronary arteries
c. myocardial arteries
A
Major risk factors for atherosclerosis
- high levels of
plasma low-density lipoprotein [LDL] - low plasma high-density lipoprotein [HDL]
- cigarette smoking
- hypertension
- diabetes
mellitus
Atherosclerosis is a problem of
a. vulnerable vessel
b. vulnerable blood
c. both
d. neither
C
Predilection for atherosclerotic plaques
a. turbulence in coronary flow
b. branch points in epicardial arteries
c. both
d. neither
C
limitation of ability to increase flow to meet increased myocardial demand is observed when there’s __% reduction in the diameter of an epicardial artery
50%
when there’s __% reduction in the diameter of an epicardial artery, blood flow at rest may be reduced
80%
The severity and duration of
the imbalance between myocardial oxygen supply and demand determine
whether the damage is reversible if duration of total occlusion is
<=20min
The severity and duration of
the imbalance between myocardial oxygen supply and demand determine
whether the damage is permanent if duration of total occlusion is
> 20min
Transient T wave inversion
a. non-transmural, intramyocardial ischmia
b. patchy subendocardial ischemia
c. severe transmural ischemia
A
Transient ST-segment depression
a. non-transmural, intramyocardial ischmia
b. patchy subendocardial ischemia
c. severe transmural ischemia
B