Class 5 Flashcards
What comes first in signaling, electrical or mechanical?
Electrical
What are the two main events for a complete cardiac cycle?
- Ventricular systole (contraction)
- Ventricular diastole (relaxation)
What are the two events of ventricular systole?
a. Isovolumetric ventricular contraction
b. Ventricular ejection
What are the two main events of ventricular ejection?
i. Rapid ejection phase
ii. Reduced ejection phase
What are the two main events of ventricular diastole? 
a. Isovolumetric ventricular relaxation
b. Ventricular filling
What are the two events of ventricular filling?
i. Rapid filling phase
ii. Reduced filling phase
What is the volume of preload?
Blood volume in the ventricle during the end diastolic volume
Isovolumic ventricular contraction begin with the close of what?
AV valve
What generates the first heart sound?
Closing of the AV valve, isovolumetric ventricular contraction
Ventricular ejection begins with the opening of what?
Semi lunar valve, AV valves are closed
There is a sharp increase in the ventricular and aortic pressure in what phase of the cardiac cycle?
Ventricular ejection, rapid ejection face
There is a sudden drop of left atrial pressure in what phase and why?
Ventricular ejection phase, mitral valve is closed
The rapid ejection phase is followed by what?
Reduced ejection phase
The reduced ejection face is associated with which wave?
T-wave
Ventricular volume at the end of ejection phase is known as what?
End systolic volume
Peak of the left ventricular pressure coincides with what?
Arterial systolic pressure
Do you ever expel all of the blood out of your heart?
No
Blood volume in the ventricle during isovolumetric ventricular relaxation is known as what?
End systolic volume
Isovolumetric ventricular relaxation begins with what?
Semilunar (aortic) valve closure
When is the second heart sound?
Isovolumic ventricular relaxation, aortic valve closure
What is stroke volume?
SV = EDV - ESV
Ventricular filling begins with what?
Opening of the AV valve, semi lunar valves are closed
Majority of ventricular passive filling occurs in which phase?
Rapid filling phase of ventricular filling
Identifies the sequential dynamic changes of pressure and volume within the left ventricle for one complete cardiac cycle describes what?
Ventricular pressure and volume loop
Ventricular pressure volume loop is generated by what?
Plotting the left ventricular pressure against the left ventricular volume
What are the four determinants for cardiac output?
Heart rate, myocardial contractility, preload, afterload
The amount of blood pumped out of the ventricular per beat describes what?
Stroke volume
Output of the heart per unit time describes what?
Cardiac output
How can you calculate cardiac output?
SV x HR
Cardiac output per body surface area describes what?
Cardiac index
Ejection of blood by the left ventricle is closely associated with two parameters that are
Blood pressure and volume in arterial circulation
Increased heart rate does what to stroke volume?
Decrease
Increase in heart rate will do what to cardiac output?
Increase but to a limit
Three primary parameters that can affect stroke volume
I. Preload
II. Afterload
III. Contractibility
Afterload in contractility will have an direct effect on ESV or EDV?
ESV
Anything that affects EDV or ESV will also affect
Stroke volume
An increase in preload will do what to stroke volume?
Increased it
Preload is directly related to what?
End diastolic ventricular blood volume and intra-myocardial wall stress of ventricle at the end of diastole 
Pre-load is indirectly related to what?
Ventricular end diastolic pressure
Preload is affected by the degree of stretching of the cardiac myocytes prior to contraction and therefore related to
Sarcomere length
Pre-load is mainly determined by what four factors?
- Ventricular compliance
- Venous return
- Length tension relationship
- Heart rate to a lesser extent
What is defined as a change in volume divided by the change in pressure?
Ventricular compliance
The stiffer the heart, the higher the
Compliance
What does high compliance mean?
The heart can easily be stretched during diastole, enhance venous return
What does low compliance mean?
The heart will resist expansion during diastole, stiff
When does compliance decrease?
When the myocytes reach their elastic limit, changes per person
The ventricle becomes less compliant or stiffer with a (higher or lower) ventricular blood volume
Higher
Decrease compliance leads to (-) preload, and (-) stroke volume
Decrease, decrease
A decrease in left ventricular compliance will result in a decrease or increase in left ventricular pressure
Increase
