Cardiac cycle Flashcards
what is the first event in the cardiac cycle?
atrial contraction
is there isovolumic contraction during AV valve opening?
no
will there be isovolumic contraction with aortic regurgitation?
no
how is central venous pressure assessed?
right atrial pressure
what are three common causes of increased CVP?
heart failure
tricuspid valve disorders
pulmonary arterial HTN
what two waves are most prominent on a jugular venous wave form? what do they correspond to?
X - fall in RA pressure after a wave peak
X’ - descent of cardiac base, atrial relaxation
what is the dominant motion of the normal JVP?
X - X’ descent
what do normal jugular venous pulsations provide information about?
right heart pressure
congestion
abnormal RA pressure
hydration status
what is the cause of a very high A wave in jugular venous pulsations?
RA contracting against a closed RV
complete heart block TV disorders (stenosis)
what is the cause of a CV wave in jugular venous pulsations?
ventricularization of RA pressure
TV regurgitation (CHV)
S1 corresponds to what?
closure of mitral and tricuspid valves
S2 corresponds to what?
aortic (A2) and pulmonic (P2) closure
varies with respiratory cycle
what is the cause of physiological splitting of S2?
inspiration increased venous return to RV increased RVEDV increased time to expel blood from RV pulmonic valve stays open longer
when is widened splitting of S2 heard? why?
expiration
- RBBB - delay in RV contraction - delay in pulmonic closure
- pulmonic stenosis - more time to open - delay in closure
when does fixed splitting of S2 occur? why?
atrial septal defect
high capacitance, low resistance of pulmonary vasculature
delayed back pressure responsible for pulmonic valve closure
P2 is delayed
what are the causes of paradoxical splitting of S2? when does it occur, and why?
LBBB
advanced aortic stenosis
expiration - abnormal delay in closure of aortic valve (A2 follows P2)
does timing of opening snap in mitral stenosis change with respiration?
no
what is the third heart sound S3?
- early diastole following opening of AV valves during rapid ventricular filling
- produced by tension of chordae tendinae during rapid filling
what is the fourth heart sound S4? when in the cardiac cycle is it heard?
produced when trying to fill a stiff ventricle - coincides with atrial contraction
presystolic (late diastole)
in which situations is S4 heard?
low compliance / hypertrophy / acute MI
where is an early diastolic murmur heard?
left sternal border
what type of murmur is heard at the left sternal border?
early diastolic murmur
where is a pansystolic murmur heard?
tricuspid area
mitral area
what types of murmurs are heard at the tricuspid area?
pansystolic
mid to late diastolic
what type of murmur is heard at the mitral area?
pansystolic
ejection type murmurs are due to what causes?
aortic stenosis
pulmonic stenosis
pansystolic type murmurs are due to what causes?
mitral regurg
tricsupid regurg
VSD
late systolic type murmurs are due to what cause?
mitral valve prolapse
aortic and pulmonic stenoses cause what type of murmur?
ejection type
mitral and tricuspid regurg, and VSD cause what type of murmur?
pansystolic
mitral valve prolapse cause what type of murmur?
late systolic
aortic stenosis is heard best at what area? what does it sound like?
2nd ICS pt leaning forward
harsh quality between S1 and S2
mitral regurg is common in patients with what condition?
heart failure
mitral regurg is heard best at what area? what does it sound like?
apex, radiates to axilla
holo-systolic of constant intensity, plateau shaped extending from S1 to S2
aortic regurg is heard best at what area? what does it sound like?
3rd or 4th ICS
high pitched and blowing in quality
what can increase aortic regurg heart sounds?
tightening of fists
