QUESTIONS AND 100% CORRECT WELL DETAILED
ANSWERS|LATEST
UPDATE!!!!2025/2026|GUARANTEED
How much oxygen does the myocardium extract from blood? - ANSWER 60-70% O2
True or false: The greater the ventricular wall tension, the greater the O2 consumption -
ANSWER TRUE
Is contractility independent of preload and afterload? - ANSWER YES, according to Dr.
Stone's PPT
Conditions that affect contractility - ANSWER Hypoxia and acidosis- How?
-Anaerobic metabolism
Hyperkalemia too- How?
- ↑RMP →→ inability to repolarize and voltage gated channels get stuck
True or False: LV afterload does not equal SVR - ANSWER True: Afterload also includes
factors such as blood viscosity, LV wall tension, etc.
Myocardial oxygen balance - ANSWER -↑O2 supply - inc. arterial oxygen content or
coronary blood flow
-↑ Myocardial oxygen demand w/o ↑ O2 supply= ↓ tissue O2 levels
-MVO2 - the most important determinant of myocardial blood flow
1
, -Myocardium cannot compensate for reductions in blood flow by extracting more oxygen
from hemoglobin
True or false: Increased contractility increases O2 demand - ANSWER True
Test yourself on these relationships - ANSWER What effect does tachycardia have on
supply & demand?
↓supply, ↑ demand
What effect does increased Ao diastolic pressure have on supply &demand?
↑ supply & demand
What effect does increased preload have on supply & demand?
↓supply, ↑ demand
Law of LaPlace - ANSWER Wall stress= Intraventricular pressure X Vessel radius ÷
2 (ventricular thickness)
Wall stress ↓ by ↑ wall thickness, ↓ intraventricular pressure, & ↓vessel radius
Things that ↑wall stress ↑myocardial oxygen consumption
Most common layer of vessel for atherosclerotic plaques to form - ANSWER Tunica
intima
ST elevation is indicative of ....... ischemia - ANSWER transmural
ST depression is indicative of ........ ischemia - ANSWER subendocardium
2
ANSWERS|LATEST
UPDATE!!!!2025/2026|GUARANTEED
How much oxygen does the myocardium extract from blood? - ANSWER 60-70% O2
True or false: The greater the ventricular wall tension, the greater the O2 consumption -
ANSWER TRUE
Is contractility independent of preload and afterload? - ANSWER YES, according to Dr.
Stone's PPT
Conditions that affect contractility - ANSWER Hypoxia and acidosis- How?
-Anaerobic metabolism
Hyperkalemia too- How?
- ↑RMP →→ inability to repolarize and voltage gated channels get stuck
True or False: LV afterload does not equal SVR - ANSWER True: Afterload also includes
factors such as blood viscosity, LV wall tension, etc.
Myocardial oxygen balance - ANSWER -↑O2 supply - inc. arterial oxygen content or
coronary blood flow
-↑ Myocardial oxygen demand w/o ↑ O2 supply= ↓ tissue O2 levels
-MVO2 - the most important determinant of myocardial blood flow
1
, -Myocardium cannot compensate for reductions in blood flow by extracting more oxygen
from hemoglobin
True or false: Increased contractility increases O2 demand - ANSWER True
Test yourself on these relationships - ANSWER What effect does tachycardia have on
supply & demand?
↓supply, ↑ demand
What effect does increased Ao diastolic pressure have on supply &demand?
↑ supply & demand
What effect does increased preload have on supply & demand?
↓supply, ↑ demand
Law of LaPlace - ANSWER Wall stress= Intraventricular pressure X Vessel radius ÷
2 (ventricular thickness)
Wall stress ↓ by ↑ wall thickness, ↓ intraventricular pressure, & ↓vessel radius
Things that ↑wall stress ↑myocardial oxygen consumption
Most common layer of vessel for atherosclerotic plaques to form - ANSWER Tunica
intima
ST elevation is indicative of ....... ischemia - ANSWER transmural
ST depression is indicative of ........ ischemia - ANSWER subendocardium
2
