cardiac cycle Flashcards
what is stenosis ?
narrowing and increased resistance of valve?
what is regurg?
valve incomplete closure
what initiates the cardiac cycle?
AP from sa node
what constitutes cardiac cycle?
period of diastole and period of systole –> relaxation and contraction
what are the sequence of events in cardiac cycle?
1- electrical ( depolarization ) –> visualized as ecg?
2- Mechanical –> coordinated muscle tension development
3- pressure development ( blood squeezed by contracting muscles)
4- Flow occurs when valves are open and pressure gradient drives blood flow
what are the phases the systole phase?
1- isovolumic contraction ( isometric )
2- Rapid ventricular ejection
3- reduced ventricular ejection –> this is after rapid js to get rid of some of the left blood in the ventricle after ejection
what are the phases of diastole phase?
1- isovulmic relaxation ( isometric ) after the reduced ventricular ejection
2- rapid venticular filling
3- reduced ventricular filling diastasis
4- atrial systole
when are the av valves opened?
during the filling phase, mid to late ventricle diastole
when the atrium pressure is higher than ventricle
when do the av valves close?
when the ventricle pressure is higher than atrium –> isovolumetric contraction
when do the SL valves open ?
when the ventricle pressure is higher than aorta or trunk more than 80
mid to late systole
when do the SL valves close
when ventricle pressure is less than aorta less than 80
isovolumetric relaxation
when is the first heart sound produced?
S1 lub is produced when the av valves closes
Isovolumetric contraction
when is the second heart sound produced?
s2 dub produced when SL valves closes
isovolumetric relaxations
whats the normal sound in relation to the phases ?
S1 —> SYSTOLE –> S2 —> DIASTOLE —> S1
when are the abnormal heart sound heard?
S4 is b4 the normal sounds
S4 - S1 - S2 -S4 - S1
SHH LUB DUB SHHH LUB DUB
S3 is heard after the normal sounds
S1-S2-S3-S1-S2-S3
LUB DUB SHH LUB DUB SHH
whats the anatomical location and asculation location of mitral valve
anatomical –> 4th left costal cartilage
ausculation —-> apex of the heart
whats the anatomical location and asculation location of tricuspid valve?
anatomical —> 4th left intercostal space
auscultation –> left sternal border
whats the anatomical location and asculation location of pulmonary valve
anatomical —> left third costal cartilage
auscultation –> left second intercostal space
whats the anatomical location and asculation location of aorta valve
anatomical —> right third intercostal space
auscultation —> right second intercostal space
what are the causes of aortic stenosis?
senile degeneration ;
congenital deformity
Rheumatic heart disease
what happens in aortic stenosis?
increased left ventricle pressure to overcome the resistance of the small opening of the valve –> LV hypertrophy
- Large systolic pressure gradient between LV and Aorta due to the struggle of opening of the valve
what are the consequences of aortic stenosis?
1- CHF
2- Angina due to increased work of the heart
3- syncope during exercise due to decreased Ejection fraction
what are the abnormal sounds of aortic stenosis
1- diminished S2 —> s2 is the closure of SL valve, since in stenosis its not open enough it will not produce a loud closing sound at the beginning of isovolumetric relaxation
2- ejection systolic murmur —-> CUZ THE VENTRICLE STRUGGLES TO EJECT BLOOD = PRODUCE SOUNDS at MID TO LATE SYSTOLE PHASE
what are the causes of mitral stenosis?
mainly acute rheumatic fever