Heart sounds and murmurs Flashcards
What causes wide splitting of S2?
delayed RV emptying. this may be due to pulmonary stenosis or right bundle branch block. this exaggerates normal splitting
What causes fixed splitting?
atrial septal defect: ASD causes a left to right shunt –> incr. RA and RV volumes –> incr. flow through pulmonic valve –> increased flow through pulmonic valve such that, regardless of breath, pulmonic closure is greatly delayed.
What causes paradoxical splitting of the S2?
conditions that either delay LV emptying: left bundle branch, aortic stenosis. In this case, there is splitting on expiration (pulm closure first, THEN aortic). On inspiration, pulm closure is delayed and moves closer to aortic closure –> elimination of splitting.
How does the murmur of an ASD present, and how does it progress?
you can’t hear the flow across the ASD itself.
at first, you hear the systolic murmur d/t incr. flow into the pulm artery, and a diastolic rumble from incr. flow across the tricuspid. as disease progresses, increased flow into the pulm artery will dilate the artery and cause pulm. artery insufficiency –> diastolic mumur.
What is mitral valve prolapse? What do you hear?
late systolic crescendo murmur with a midsystolic click from sudden tensing of the cordae tendoneae. most common valvular lesion best heard over the apex. usually loudest just before S2 and usually benign, though it can predispose to infective endocarditis.
causes: myxamatous degeneration, rheumatic fever, chordae rupture, (Marfan)
Maneuvers: I am going to think of these in two ways. The cordae tendonae work best when they are stretched, so the valve is also working best when venous return is high. A valve that is relatively functional will have LATE click; a valve that is not working as well will have an EARLY click. Thus, the click is earliest when venous return is low (valsalva, standing). It is latest when venous return is high (squatting) or systemic vascular resistance is high (more blood in LV = better cordae).
The murmur is basically a regurg murmur, so it will be loudest when there is lots of blood in the ventricle (incr. with hand grip)
handgrip effect on different heart conditions
handgrip: incr. systemic vascular resistance.
exacerbates murmur of aortic regurg, mitral regurg, VSD
reduces murmur of hypertrophic cardiomyopathy and aortic stenosis
increases the murmur intensity of mitral valve prolapse and casues later onset of click
valsalva effect on different heart conditions
valsalva reduces venous return.
this decreases the intesity of most murmurs (VSD, aortic and mitral regurg, AND aortic stensosis)
increases the intensity of the murmur in hypertrophic cardiomyopathy
causes less intense mitral valve prolapse murmur that occurs earlier.
standing does the same thing
rapid squatting effect on different heart conditions
incr. venous return, incr. preload, and incr. afterload
this will decr. with intensity of the hyperptrophic cardiomyopathy murmur
it will incr. intensity of aortic stenosis murmur.
it will increase murmur intensity and cause a later click for MVP.
causes and clinical manifestations of aortic stenosis
pulses weak with a delayed peak.
casues: age-related calcific aortic stenosis or bicuspid aortic valve. can cause syncope, angina, dyspnea
causes of mitral regurg
ischemic heart disease, mitral valve prolapse, LV dilation, rheumatic fever, and infective endocarditis
causes of tricuspid regurg
caused by rheumatic fever and infective endocarditis, or RV dilation.
cuases of mitral valve prolapse
myxomatous degeneration (pathologic weakening of CT), rheumatic fever, or chordae rupture.
causes of aortic regurg
aortic root dilation, bicuspid aortic valve, endocarditis, rheumatic fever.
mitral stenosis causes
Often secondary to rheumatic fever.
PDA murmur
continuous machine-like murmur that is loudest during S2. patient may have bounding pulse and palpable thrill. often d/t congenital rubella or prematurity. best heard at left infraclavicular area.
