Lecture 15 - The heart as a pump

Question 1

Heart Valves?

Answer 1

pulmonary, aortic and atrioventricular valves: bicuspid (left) and tricuspid (right)

Question 2

Wiggers diagram?

Answer 2

shows different phases of the cardiac cycle - starts with onset of ventricular systole

Question 3

Isovolumic contraction?

Answer 3

phase between start of ventricular systole and opening of semilunar valves - abrupt rise in pressure same volume

Question 4

Isovolumetric contraction coincides with?

Answer 4

peak of R wave, S1 sound, earliest rise in ventricular pressure

Question 5

Ejection?

Answer 5

begins with semilunar valve opening, subdivided into earlier rapid ejection phase, and later longer reduced ejection phase

Question 6

3 key characteristics of rapid ejection?

Answer 6

sharp rise in ventricular and aortic pressure, abrupt decrease in ventricular volume, pronounced increase in aortic blood flow

Question 7

Reduced ejection phase - aortic pressure?

Answer 7

decreases due to aorta flow greater than LV outflow

Question 8

Reduced ejection phase - ventricular-aortic P gradient?

Answer 8

reversal due to stored potential energy in stretched ventricular walls

Question 9

Reduced ejection phase - LV to aorta flow?

Answer 9

decelerated

Question 10

Isovolumic relaxation?

Answer 10

closure of aortic valve causing notch on aortic P curve and S2 sound - is the period between closing of semilunar valves and opening of AV valves, rapid fall in pressure without loss of volume

Question 11

Rapid filling phase?

Answer 11

atria blood released into relaxed ventricles, LV P becomes lower than LA P causing mitral valve opening

Question 12

Rapid filling phase - pressures?

Answer 12

rapid blood flow causes transient decrease in A and V pressures

Question 13

Diastasis?

Answer 13

slow ventricular filling, indicated by gradual rise in atrial, ventricular and venous pressure (and ventricular volume)

Question 14

Atria systole?

Answer 14

just after P wave, completes ventricular filling, small increase in ventricular pressure and volume also venous and atrial pressure

Question 15

Venous A wave?

Answer 15

retrograde pressure pulse in jugular when atria contract

Question 16

Venous C wave?

Answer 16

early phase of ventricular systole

Question 17

Venous V wave?

Answer 17

gradual pressure increase during ejection and isovolumic relaxation

Question 18

Abnormal auscaltations?

Answer 18

regurgitation (backflow), mitral valve prolapse, stenosis

Question 19

Thermodilution?

Answer 19

meausre temperature of injected saline using inserted catheder, higher cardiac output coincides with a lesser change in measured pressure