Cardiovascular Physiology 33 Flashcards
What does the pressure volume loop depict?
Changes in ventricular pressure and volume as the heart undergoes contraction and relaxation
What is the pressure-volume loop generated by?
The pressure changes and volume changes in the left ventricle during one cardiac cycle
What is isovolumetric ventricular contraction initiated by?
The QRS complex or ventricular depolarization
What is the state of the valves during isovolumetric ventricular contraction?
Both valves are closed
What does the T wave signify?
Ventricular relaxation
What causes the pressure in the ventricle to increase but only slightly?
The ventricle filling with blood from the aorta
What are four different phases of the pressure volume loop?
- Ventricular filling
- Isovolumetric ventricular contraction
- Ejection
- Isovolumetric ventricular relaxation
What is represented by the width of the pressure volume loop?
The stroke volume
What does the Area of the pressure volume curve demonstrate?
The stroke work
What is stroke work?
The work done by the ventricle to eject the volume of blood or to eject its stroke volume
What does the end-diastolic pressure volume relationship reflect?
The increase in pressure observed in the left ventricle which occurs when it fills during diastole
What does the slope of the ESPVR line represent?
The maximum pressure that can be developed by the left ventricle at any volume when the aortic valve is closed
