Cardiac cycle Flashcards Preview

Physiology > Cardiac cycle > Flashcards

Flashcards in Cardiac cycle Deck (40)
Loading flashcards...
1
Q

Left ventricle

A

thick-walled and circular
generates greater pressures
prominent papillary muscles seen in LV which anchor the mitral valve leaflets

2
Q

right ventricle

A

thin-walled and crescentic lower pressures

3
Q

what does raised pulmonary artery wedge pressure indicate?

A
vasoconstriction
fluid overloaded
right to left shunt VSD
left ventricular failure
mitral valve failure
pulmonary hypertension
4
Q

what does decreased pulmonary artery wedge pressure indicate?

A

vasodilation

hypovolaemia

5
Q

right atrial pressure

A

is equivalent to the central venous pressure and jugular venous pulse

6
Q

central venous pressure waveform

A
a wave
c wave
x descent
v wave
y descent
7
Q

a wave

A

atrial contraction

8
Q

c wave

A

tricuspid valve bulging back into RA

9
Q

x descent

A

atrial relaxation

10
Q

v wave

A

atrial filling with closed tricuspid valve

11
Q

y descent

A

atria empties into ventricle

12
Q

what is an arterial line used for?

A

measure pressure

no blood in the line

13
Q

what is the dicrotic notch?

A

when the aortic valve closes

14
Q

what is isovolumetric contraction?

A

occurs in early systole during which the ventricles contract with no corresponding volume change

15
Q

what is isovolumetric relaxation?

A

beginning of diastole

16
Q

perfusion of heart

A

rise in LV pressure during systole acts to occlude coronary vessels running through it so most perfusion occurs in diastole

17
Q

what causes coronary vasoconstriction?

A
increases pp O2
decreased pp CO2 - alkalosis
alpha 1 stimulation
ADH
Angiotensin
Thromboxane
18
Q

what causes coronary vasodilation?

A
decreased ppO2
increased ppCO2 - acidosis
lactate
adenosine
beta 2 stimulation
prostacyclin
19
Q

heart sounds

A

2 major sounds
due to valve closure
s1 = represents closure of mitral and tricuspid valves
s2 = represents closure of aortic and pulmonary valves
left sided valves normally close fractionally ahead of the right.

20
Q

heart murmurs

A

usually associated with heart pathology
blood flow normally laminar but when there is turbulent flow it produces abnormal sound due to vibrations in the surrounding structures

21
Q

what are the types of valvular murmurs?

A

stenotic valve

regurgitant/ incompetent valve

22
Q

stenotic valve

A

stiff or narrowed valve that doesn’t open completely

blood forced through narrowed opening - ejection murmur

23
Q

regurgitant/ incompetent valve

A

valve edges are scarred - don’t close completely so there is some backflow of blood

24
Q

what could non-valvular murmurs be a sign of?

A

pregnancy
ASD
VSD
PDA

25
Q

what is ASD?

A

atrial septal defect

26
Q

what is VSD?

A

ventricular septal defect

27
Q

what is PDA?

A

patent ductus arteriosus

28
Q

when do stenotic mitral and tricuspid valve murmurs occur?

A

diastole

29
Q

when do incompetent mitral and tricuspid valve murmurs occur?

A

systole

30
Q

when do stenotic aortic and pulmonary valve murmurs occur?

A

systole

31
Q

when do stenotic aortic and pulmonary valve murmurs occur?

A

diastole

32
Q

murmur in aortic stenosis

A

systolic crescendo-diminuendo with radiation to carotids

33
Q

clinical presentation of aortic stenosis

A

dyspnoea
fainting/ syncope
chest pain
palpitations

34
Q

treatment for aortic stenosis

A

catheterisation

valve replacement

35
Q

when do the waves on the ECG happen?

A

just before pressure changes

36
Q

what is the ideal resting cardiac output?

A

5L/min

37
Q

emptying of ventricles

A

ventricles are not completely emptied during ventricular systole

38
Q

what is an indication of valve stenosis?

A

significant difference between highest pressure in ventricles and aorta

39
Q

mechanical valves

A

last 20 years
require anticoagulants for life
very expensive
given to younger people

40
Q

tissue valves

A

last 10 years
given to older people
cheaper