Pressure, Energy, and Gradients
This form of energy exists when pressure differences are present but no movement has occurred yet.
What is potential energy?
This phase begins when ventricular pressure first exceeds atrial pressure.
hat is isovolumic contraction?
These valves are closed at the exact moment of S1.
What are the atrioventricular valves?
This filling phase accounts for approximately 75% of ventricular inflow.
What is rapid filling?
This moment represents maximum ventricular volume and minimum myocardial thickness.
What is end-diastole?
Blood velocity is most directly determined by this relationship between two locations.
What is a pressure gradient?
This phase occurs when ventricular pressure is falling but all valves remain closed.
What is isovolumic relaxation?
These valves are closed throughout both isovolumic phases.
What are all four cardiac valves?
This wave is generated primarily by ventricular relaxation rather than atrial contraction.
What is the E wave?
This volume is measured immediately after semilunar valve closure.
What is end-systolic volume?
If resistance remains constant, increasing this variable will proportionally increase flow velocity.
What is the pressure difference (gradient)?
During this phase, ventricular pressure is lowest while volume is increasing rapidly.
What is rapid filling?
This valve opens only after ventricular pressure exceeds great vessel pressure.
What is the aortic valve?
This phase occurs when atrial and ventricular pressures are nearly equalized.
What is diastasis?
This variable is most directly increased by increasing venous return.
What is preload?
Explain why pressure gradients are required for any cardiac chamber to empty effectively.
What is because blood only moves when a pressure gradient exists to drive flow from high to low pressure?
Identify the only phase in which ventricular volume is increasing while ventricular pressure is decreasing.
What is rapid filling?
Identify the phase in which all valves are closed AND ventricular pressure is changing.
What is isovolumic contraction or isovolumic relaxation?
Identify the phase in which mitral valve leaflets begin drifting toward closure before atrial contraction.
What is diastasis?
Identify which chamber is at maximum volume at the moment of end-systole and explain why.
What is the left atrium, because it fills throughout systole while the ventricle is ejecting?
Describe how potential energy is transformed into kinetic energy during ventricular systole.
What is ventricular contraction creates potential energy that is converted into kinetic energy as blood accelerates through the aortic valve?
Describe the precise mechanical and pressure events that lead to opening of the mitral valve.
What is ventricular relaxation lowers pressure below atrial pressure, allowing the mitral valve to open and blood to flow into the ventricle?
Explain why semilunar valves cannot open until after AV valves have fully closed.
What is AV valves must close to allow ventricular pressure to rise high enough to overcome great vessel pressure before semilunar valves can open?
Explain why ventricular relaxation, not atrial pressure, is the dominant driver of early diastolic filling.
What is ventricular relaxation creates the pressure gradient that pulls blood from the atrium, making relaxation the dominant force in early filling?
Describe the chamber pressures, valve positions, and ventricular dimensions present at true end-diastole.
What is low ventricular pressure, AV valves open, semilunar valves closed, maximum ventricular volume, thin ventricular walls, and minimal atrial volume?