Cardiac Cycle

Question 1

2 branches from the right coronary artery

Answer 1

Acute marginal

Posterior descending artery

Question 2

2 branches from the left coronary artery

Answer 2

Left anterior descending artery (diagonal branches)

Left circumflex artery (branches are the obtuse marginals)

Question 3

Mean pressure in aorta

Answer 3

95 mmHg

Question 4

When does mitral valve close?

Answer 4

When the LV pressure becomes greater than the LA pressure

Question 5

What causes the

1. A wave
2. C wave
3. V wave

Answer 5

1. Atrial contraction and transient increase of the LA pressure
2. Isovolumetric contraction causes LA pressure to increase transiently as MV bulges into LA
3. Blood flowing into LA while MV is closed

Question 6

Incisura

Answer 6

Also called the dicrotic notch

From a transient increase in aortic pressure from the abrupt closure of the aortic valve

Question 7

What opens the mitral valve?

Answer 7

When the LV pressure dips below the LA pressure

Question 8

Y descent

Answer 8

From the LA pressure dipping early in diastole, because the LA and LV effectively form a common diastolic chamber

Question 9

What causes
1. S1
2. S2
heart sounds?

Answer 9

S1: atrioventricular valve closure (mitral and tricuspid)
S2: AV valve closure (aortic and pulmonary valves)

Question 10

Ventricular systole is defined as…

Answer 10

The period of time between S1 and S2

Question 11

What causes the abnormal heart sounds

1. S3
2. S4

Answer 11

S3: Occurs in early diastole in the presence of a volume overloaded ventricle. The rapid cessation of blood flow when atrial and ventricular pressures equilibrate causes a heart sound
S4: Occurs in late diastole from a pressure overloaded ventricle (extra pressure and volume from atria into a stiff ventricle causes a heart sound)

Question 12

1. Ejection click

2. Opening snap

Answer 12

1. Can be heard with an abnormal opening of a semilunar valve
2. Rheumatoid mitral valve stenosis

Question 13

What happens to the pressures during inspiration

Answer 13

Both pulmonary and aortic pressures decrease
When you inspire, the volume of blood to the right heart increases because of the negative intrathoracic pressure
The time between M1 and T1, and A2 and P2 increase as well

Question 14

Do the valves on the left or right side close first?

Answer 14

Left side

Because the right side has lower pressure

Question 15

3 scenarios that cause murmurs

Answer 15

Increased flow through normal structures (anemia, pregnancy, high metabolic states)
Turbulent flow through narrow orifices (stenosis, regurgitation, shunt)
Flow into a larger distal chamber (aortic aneurysm)

Question 16

When does the QRS complex occur?

Answer 16

At the end of diastole

Serves as the electrical signal for ventricular contraction

Question 17

T wave

Answer 17

Late systolic event

LV relaxation