cardiac cycle 2

Question 1

atrial kick

Answer 1

• spurt of blood that gets spurted into ventricles during atrial systole
• non-pathological hearts don’t really need it because they are already passively filling and should have enough blood for their own systole
• HOWEVER, PATHOLOGIC HEARTS DEFINITELY NEED IT

Question 2

what occurs during isovolumic contraction in the ventricles?

Answer 2

-both valves are closed but the ventricles are still beginning to contract so you see a large increase in pressure in LV

Question 3

when does the aortic valve open?

Answer 3

-when the pressure in the LV is higher than that of the aorta

Question 4

why do we need very dispensible aorta

Answer 4

because such a large amount of blood coming from the LV that it balloons the aorta

Question 5

what corresponds with the T wave on the ECG

Answer 5

-the end of the declined ejection of the blood from the LV and the closing of the aortic valve

Question 6

once the LV (or RV) pressure is low enough, we can get an opening of the mitral and tricuspid valves to….

Answer 6

start passive filling again but stays below pressure in atria to keep valves open for filling (rapid to reduced)

Question 7

as the blood is ejected out into the aorta, when does the AV close?

Answer 7

• remains open even thru reduced ejection because the forward momentum of the blood
• end of reduced ejection occurs when the AV closes

Question 8

what phase of the cardiac cycle is signified by isovolumic relaxation?

Answer 8

-aortic valve closure

Question 9

dicrotic notch aka incisura

Answer 9

-uptick of the aortic pressure after the AV closes
-due to backwards pressure wave coming from the periphery
-basically, the wave form is a measure of pulses (ck slides 28-29)
-blood moving into the aorta causes pulse that leads to first peak of the figure…. then as the pulse hits the abdominal aorta and it’s bifurcation, you see a reflection coming back to the aortic root
= DOES NOT HAVE TO DO WITH BLOOD- IT’S ABOUT PULSATION

Question 10

is the dicrotic notch higher in pathologic or healthy pt? why?

Answer 10

-it is higher in pathologic pt because their arteries are stiffer and they do not cushion the pulse as well as healthy pt

Question 11

when are the valves open

Answer 11

av valves open during atrial contraction and rapid and decreased ventricular filling

Question 12

what is going on with the valves during isovolumic contraction

Answer 12

all valves are closed- systole

Question 13

what is going on with the valves during isovolumic relaxation

Answer 13

-all valves are closed-diastole

Question 14

what is occurring when the semilunar valves are open

Answer 14

-systole: rapid ventricular ejection and decreased vent. ejection

Question 15

stroke volume

Answer 15

SV = left ventricular end diastolic volume/ left ventricular end systolic volume
(how much is entering the periphery/Ao)

Question 16

what are the first and second heart sounds

Answer 16

first- closure of AV valves-low pitch, longer duration

second-closure of pv and av- higher pitch, shorter duration

Question 17

what is physiological splitting of the heart sounds of s2

Answer 17

• it is a sort of mixing up of heart sounds that makes them run together
• occurs during inspiration due to either delayed closure of the PV or early closure of the aortic v.

Question 18

what is the mechanism of physiological splitting of s2

Answer 18

-delayed closure of PV: during inspiration- greater venous return to right heart so time it tales to expel blood will be longer so pulm closes a bit later after Aortic
-early AV closure- during inspiration, less blood returns to left heart because its trapped in the lungs so less time to change the pressure and close av
=EITHER WAY, AV BEFORE PV

Question 19

opening snap

Answer 19

• when MV and TV open- may or may not be when heart of pt has fibrosis or stenosis of the valves and it is difficult for them to open
• ventricular dilation can also contribute to sound

Question 20

fourth heart sound

Answer 20

• always abnormal
  -caused by increase in ventricular pressure at end of atrial systole
  -louder with decreased ventricular compliance
  =groaning of tired and overworked ventricle

Question 21

sound 3

Answer 21

• between rapid and reduced filling as the chordae tendinae are stretching and AV ring is pulled taut

Question 22

diastolic murmur

Answer 22

• sound heard after s2 and before s1

- mv stenosis will produce diastolic murmur

Question 23

systolic murmur

Answer 23

• after s1 but before s2

- mitral regurge since leaflets done close completely and have blood flow during closed valve stage

Question 24

Paradoxical splitting

Answer 24

• when get conduction thru one ventricle more than another
• can cause a change in the physiological split in s2
• ex? left bundle branch block causes conduction thru the LV to de delayed- get no split at inhalation and at exhalation, get split where pv closes BEFORE AV