Flashcards in Hearts Sounds and Murmurs Deck (39)
What does S1 represent?
Closing of mitral and tricuspid valves, beginning of systole
What does S2 represent?
Closing of aortic/pulmonary valves, beginning of diastole
What does S3 represent? When does it occur?
An extra heart sound heart during the rapid ventricular filling phase (after S2) - represents a "sloshing in" sound, associating with elevated filling pressures, eg HF or mitral regurg
What does S4 represent? When does it occur?
An extra heart sound heard during ATRIAL systole, just prior to opening of mitral and tricuspid valves (prior to S1); represents an atrial "kick"; associated with high atrial pressure, eg LVH; atrium must push against a stiff wall.
Which murmur is associated with crescendo-descendo systolic murmur? Why?
Aortic stenosis. LV>>>aortic pressure during systole.
Where can aortic stenosis be heard?
Over the aortic valve, radiates to carotids.
What are associated findings with aortic stenosis?
Pulsus parvus et tardus - weak pulses with delayed peak. Can lead to syncope, angina, and dyspnea on exertion.
What are two causes of aortic stenosis?
Age-related calcification or early onset calcification of bicuspid aortic valve.
Which murmur is associated with holo-systolic, high-pitched "blowing" sound? Why?
Mitral or tricuspid regurgitation. Sound is due to constant backflow across valve that sound be closed during systole.
Where can mitral regurgitation be heard best?
Loudest at apex, radiates towards axilla.
What are common causes of mitral regurgitation?
Ischemia heart disease (post MI), mitral valve prolapse or LV dilation. Rheumatic fever, infective endocarditis.
Where can tricuspid regurgitation be heard best?
Loudest at left lower sternal border, radiates to right sternal border
What is tricuspid regurgitation commonly caused by?
Right ventricular dilation. Rheumatic fever, infective endocarditis.
What murmur is associated with a late systolic crescendo murmur with midsystolic click? Why?
Mitral valve prolapse. Mitral valve prolapse is essentially caused by a failure of the papillary muscle/chordae tendinae to completely pull the valve shut, allowing a segment of it to flail back into the atrium during systole; the mid-systolic click is due to sudden tensing of the chordae tendinae.
Where is mitral valve prolapse best heard?
Over apex, loudest just before S2.
What can cause mitral valve prolapse?
Can be caused by myxomatous degeneration, either primary or secondary to connective tissue disease such as Marfan's or Ehler'sDanlos. Can be caused by chordae rupture and rheumatic fever as well.
What is the prognosis of MVP?
Usually benign. Can predispose to infective endocarditis.
Which murmur is associated with a holosystolic, harsh sounding sound? Where is it found?
VSD. Loudest at tricuspid area.
Which murmur is associated with a high-pitched, blowing early diastolic decrescendo murmur? Why?
Aortic regurgitation. Backflow of blood over aortic valve when pressure in aorta is highest (beginning of diastole).
Why does aortic regurgitation caused widened pulse pressure?
By backflowing, it DECREASES diastolic BP in the aorta; therefore, the difference between systolic and diastolic is greater.
What are causes of aortic regurgitation?
Aortic root dilation, bicuspid aortic valve, endocarditis, rheumatic fever. Can progress to heart failure.
What murmur is associated with a delayed late diastolic rumbling murmur following an opening snap? Why?
Mitral stenosis. The snap is caused because initially, the leaflets are fused together and don't open, but then they snap open.
Why does a shorter interval between S2 and the opening snap indicate INCREASED severity of mitral stenosis?
The S2-O2 interval depends on the pressure gradient between LA and LV. If LA>>>>LV, the interval will be shorter, indicating worse disease. Chronic MS can result in LA dilation.
What is the most common cause of mitral stenosis?
What does inspiration do to circulation?
Venous return to the right atrium; preload.
What does handgrip do to circulation?
What does Valsalva do to circulation? Why?
Decreases preload (Increases intrathoracic pressure, thereby decreasing venous return).
What does standing up do to circulation?
What does rapid squatting do to circulation?
Increases venous return, increases preload.