Heart sounds Flashcards Preview

CVS > Heart sounds > Flashcards

Flashcards in Heart sounds Deck (13):

Normally heard heart sounds

-S1 (lub): closure of the AV valves (tricuspid and mitral)
-S2 (dub): closure of semilunar (Ao and pulm) valves
-S2 can be split up into A2P2: A2 is closure of Ao valve and P2 is closure of pulmonary valve (Ao valve normally closes a little before pulm valve)
-There is wider splitting of A2P2 during inspiration (physiologic splitting)


Third heart sound (S3)

-Early diastolic sound (right after S2), possibly due to tensing of chord tendinae as rapid filling of ventricles happens
-Normal in children and young adults
-Corresponds to volume overload or CHF in adults


Fourth heart sound (S4)

-Late diastolic sound (right before S1), caused by atrial contraction and blood hitting a noncompliant ventricle
-Usually due to ventricular hypertrophy or myocardial ischemia


Opening snap (OS)

-Sharp, high-pitched sound shortly after S2
-Associated w/ mitral or tricuspid stenosis
-Heard best btwn apex and left sternal border
-Midsystolic click: mitral prolapse


Paradoxical splitting of S2 (LBBB)

-In LBBB the RV contracts slightly before the LV, so the plum valve closes before the Ao valve (P2 before A2)
-Inspiration will always delay the closure of pulm valve, so for paradoxical splitting inspiration moves the P2 sound back and more in-line w/ A2 (makes it better)


Wide splitting of S2 (RBBB and ASD)

-RBBB and ASD cause the opposite of paradoxical splitting, which is a wider A2-P2 gap
-However, now inspiration does not change P2 any further


Mechanisms of murmurs

-Flow across partial obstruction (AS, MS)
-Increased flow through normal structures: Ao systolic ejection murmur
-Ejection into a dilated chamber: Ao systolic murmur from Ao aneurysm
-Regurgitant flow (MR/AR)
-Abnormal shunting of blood from high-low pressure (VSD)


Characteristics of murmurs

-Timing (systolic vs diastolic)
-Response to maneuvers


Grading of murmurs

-Systolic: out of 6 (may be physiologic)
-1-3 subjective: based on how loud (3/6 means audible in multiple locations)
-4: easily heard and palpable thrill
-5: audible w/ scope at angle
-6: audible w/ scope off chest
-Diastolic: out of 4 (always pathologic)
-Always subjective based on volume


Characteristics of Ao stenosis murmur

-Systolic, high-pitched
-Heard best in Ao area
-Radiates to carotids


Characteristics of Ao regurg murmur

-Early diastolic (right after S2), high-pitched
-Best heard at left sternal border w/ pt sitting, leaning forward, exhaling


Characteristics of mitral regurg murmur

-Holosystolic, high-pitched and blowing
-Uniform intensity
-Heard best at apex, radiates to left axilla


Characteristics of mitral stenosis murmur

-Mid-late diastole, low-pitched
-Decrescendo w/ late diastolic intensification
-Heard best with bell at apex w/ pt in left lateral DQ position