Heart Valves, Sounds, and Murmurs
Anatomy
Atrioventricular valves:
chorde tendinae/papillary muscles - keep leaflets from flapping back into atria
dysfunction leads to regurgitation
leaflets/cusps - area of each is about twice orifice size
annulus fibrosis - stiff ring around the orifice
Semilunar valves:
three cuplike cusps attached to valve rings; closed by slight backflow at early diastole
Sinuses of Valsalva: cusps do not lie against vessel wall due to slight outpocketings
cause eddy currents that keep cusps from walls
keeps cusps from covering orifices of coronary arteries
Heart sounds
caused by reverberations of bloodflow on chamber walls, and vibrations of actual valve closings
S
1
- mitral and tricuspid closing (M
1
, T
1
) – splitting
S
2
- pulmonary and aortic closing (P
2
, A
2
) – splitting
S
3
- caused by abrupt cessation of distention in early diastole; heard in young patients and in adults with LV failure
S
4
- atrial sound
split sound - splitting of either S
1
or S
2
from asynchrony of the valves may indicate abnormal functioning – early sign of pulmonary edema
gallops - presystolic gallop from accentuated S
4
; prodiastolic gallop from accentuated S
3
APT M to find heart sounds
Abnormalities
stenosis (murmurs): causes valve to not open enough; insufficiency: does not close properly
mitral insufficiency: systolic murmur
Þ
mitral does not close properly
Þ
mitral regurgitation
mitral stenosis: diastolic murmur; opening snap
Þ
mitral does not open enough
Þ
Ý
velocity,
Ý
P
aortic insufficiency: diastolic murmur
Þ
aortic does not close properly
Þ
backflow into LV
aortic stenosis: systolic murmur
Þ
aortic does not open enough
Þ
Ý
velocity,
Ý
pressure
papillary dysfunction: leads to regurgitation
Þ
murmurs
generalized or localized dilation
ruptured papillary muscles
ischemia
Diagnostic Techniques
doppler
echocardiogram
EKG
color flow doppler