3.2.1. Heart Sounds Flashcards Preview

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Flashcards in 3.2.1. Heart Sounds Deck (45):

How do you properly use the Bell on your stethoscope? Do we use it for high or low frequency sounds?

Bell = apply LIGHTLY. Used for low-frequency sounds (not a lot of gallops (S3, S4), rumbling of mitral stenosis)


How do you properly use the Diaphragm on your stethoscope? Do we use it for high or low frequency sounds?

Diaphragm = used for everything else – can’t pick up low freq sounds like gallops or rumbling


What are the proper auscultation areas and where are they?

Aortic: 2nd Right Intercostal Space (RICS)- (sternal border) Pulmonic: 2nd LICS (sternal border) Tricuspid: lower left sternal border (LLSB) Listen here for VSDs Apex: wherever you feel the PMI best; varies from person to person, but typically along the midclavicular line Mitral closure and murmurs can be felt here


What is the S1 and what can happen to it?

MV and tricuspid valve closure; the MV closes before the tricuspid, so S1 may be split.


What is the S2 and what can happen to it?


Aortic and pulmonary valve closure; the AoV closes before the pulmonic valve; inspiration causes increased splitting of S2.


When does S3 occur and what may it indicate?

During rapid ventricular filling (early diastole); normal in children, in adults, associated with dilated ventricles (i.e., dilated CHF) and increased filling pressures.


When does S4 occur and what may it indicate?

Late diastole; not audible in normal adults; its presence suggests high atrial pressure or a stiff ventricle (i.e. ventricular hypertrophy). The left atrium must push against a stiff LV wall (“atrial kick”).


What are all heart sounds due to?


opening of valves is normally a silent event, but can have sound ass’d w/ejection


What does isovolumetric Contraction mean in the heart?

  • Isovolumic contraction: no blood enters or leaves the ventricles

    • UNTIL the pressure in the LV is made greater than the aorta

    • The opening of the semilunar valve is SILENT – when blood in the aorta begins to flow backward, the aortic semilunar valves SHUT and generate S2


Where can you hear a normal S2 split?

An audible splitting (“ba-dah” sound, split second apart) can be heard at the pulmonic area


What might a loud P2 indicate? (P2 = S2 as heard at pulmonic area)

  • Loud P2 (you can hear it OUTSIDE of the pulmonic area)

    • typically means pulmonary hypertension

    • systolic BP in pulm artery >50 mmHg

    • ass’d with:

      • left heart failure

      • mitral valve disease

      • pulmonary arteriolar constriction

      • pulmonary vessel occlusion (thrombus, tumor, other…)


What might a single S2 sound indicate?

single S2 = A2 or P2 missing


What might a widened S2 split mean?

  • Delayed activation of RV (right bundle branch block, or RV overload from pressure/volume)

    • The delay in RV emptying causes a delayed pulmonic sound (P2) that is independent of breathing.

  • The RV is late to begin with, so it’ll be even more delayed b/w sounds


What might paradoxical splitting of S2 mean? What is paradoxical S2 splitting?

(P2 comes before A2 – reversed order (due to delayed aortic valve closure))

Seen with any condition in which LV emptying is delayed (aortic stenosis, left bundle branch block). Inspiration causes the delayed A2 and earlier P2 sounds to move closer, effectively eliminating the split.


What is an atrial septal defect? How common is it?

  • ASD- atrial septal defect = hole in wall between atria

    • Relatively common problem that can lead to irreversible heart/lung damage if left untreated

    • 1% of population born w/this


What can an ASD lead to?

  • Leads to RV volume overload

    • Prolongs RV systole

    • Widely splits S2 due to delay in P2

    • PERSISTENT, FIXED SPLITTING of S2 (won’t change sound during breathing in or out) – classically diagnostic of ASD


What happens with an ASD during inspiration?

  • Sucking blood back into the RA from the LA because of the pressure differential during INSPIRATION

    • Also decreases the loading of the LV

    • Increased volume on the right will also delay pulmonic closure


What happens to an ASD during expiration?


    • Intrathoracic pressure is positive, so blood is squeezed out of the pulmonary veins, into the LA, and shunted preferentially into the RA and RV because they’re more compliant to changes in pressure

    • This allows the RV to fill to its proper capacity just like normal


What are some common pitfalls with auscultating a split S1?

  • Split S1

    • Listening w/the diaphragm INSTEAD OF THE BELL (you’d hear high freq sounds instead of low like you’re supposed to)

    • M1 and T1 intensity similar


What are some common pitfalls with auscultating S4, S1 sounds?

  • S4, S1

    • Low freq, only heard @ apex w/the bell

    • S4 is subtle and less intense than S1


Where is S3 in the phonocardiogram? Up to what age is it normal?

  • S3: follows S2 by 120-160 ms

    • Caused by rapid filling phase of diastole

    • NORMAL up to 30 y.o.

      • As the heart stiffens w/age, the sound disappears


With what event does S4 occur (regular heart event). 

  • S4: sounds exactly like S3, but at a different time

    • Occurs w/atrial systole, so right before S1

    • ALWAYS PATHOLOGIC – mostly w/aortic stenosis, hypertension, or LV hypertrophy

      • Anything that presents w/a stiff, noncompliant ventricle



What cause ejection sounds? What are they typically caused by?

  • Ejection sounds

    • Abnormal valves are usually less compliant, and may VIBRATE WHEN OPENING

    • The high freq sound generated immediately follows S1 and is usually caused by congenitally abnormal aortic valve

      • Biscuspid “fish-mouth” valve is restricted and can’t open fully


What are some possible origins of Mitral Regurgitation (MR)? What does it sound like?

Rheumatic heart disease, infective endocarditis, myxomatous degeneration, papillary muscle dysfunction, MVP, hypertrophic cardiomyopathy

Holosystolic blowing murmur radiating toward the apex


What are some possible origins of Mitral Stenosis (MS)? What does it sound like?

Rheumatic heart disease, calcification, endocarditis

Late diastolic decrescendo rumble preceded by an opening snap


What are some possible origins of Mitral Valve Prolapse (MVP)? What does it sound like?

Connective tissue disorder, autosomal dominant

Late systolic murmur preceded by a midsystolic click


What are some possible origins of Aortic Regurgitation (AR)? What does it sound like?

Rheumatic heart disease, syphilis, Marfan syndrome, aortic aneurysm, bicuspid AoV, endocarditis

Early blowing decrescendo diastolic murmur


What are some possible origins of Aortic Stenosis (AS)? What does it sound like?

Senile (thickening and calcification), bicuspid AoV

Crescendo-decrescendo systolic ejection murmur


What are some signs of severity for Aortic Stenosis?

  • signs of severity

    • chest pain, dyspnea, syncope

    • signs/symptoms of heart failure

    • S4 presence


What are the three different origins of Aortic Stenosis?

  • three different etiologies:

    • valvular

    • subvalvular: fixed (membrane) and dynamic (HCM, IHSS)

    • supravalvular


What are some signs of critical Aortic Stenosis?

  • delayed, small volume carotid upstrokes that allow you to feel shuddering of the carotid aa (most useful cardinal sign)

  • loss of A2 (if the valve is diseased, it won’t close properly)

  • late peaking murmur (if it takes a long time to develop a sound)


What is Aortic Regurgitation and what are some important findings that come with it?

Loss of cardiac output backwards from the aorta into the LV during diastole


Wide pulse pressures

Austin Flint murmur; a mid-diastolic, low-pitched rumbling that occurs when the regurgitated blood hits the MV leaflet in diastole, preventing an opening snap (differentiating AR from MS).


When does a mitral opening snap occur? Where might we find it in the auscultory areas? What does it indicate?

  • Occurs when a rheumatic mitral valve opens

  • Frequently heard at the aortic area

  • A2-OS interval = 30-130 ms

  • First sign of mitral stenosis

  • The worse the stenosis is, the closer the sounds are in time


With an enlarged apex, what are you more susceptible to?

More susceptible to arrhythmias and can predispose to CHF

The increased flow in the LA can lead to increased LA pressure and pulmonary edema.


What are some causes of tricuspid regurgitation?

  • Functional = overload

    • Pulmonary hypertension

    • RV dilation from infarction or myopathy

  • Structural = leaflet abnormalities

    • Infectious endocarditis

    • Congenital (“Ebstein’s anomaly”)

    • Acquired (carcinoid, plantain diet, ergot drugs)


What are some signs of severity in tricuspid regurgitation?

  • Large pulsations of neck veins

  • Pulsatile, enlarged liver

    • Perform hepatojugular reflux maneuver (HJR) to send more blood to the jugular

  • Widespread edema (anasarca)


What are holosystolic murmurs? What cuase them?

  • Constant sound from S1 to after S2

  • Caused by flow from high pressure area to much lower pressure area

    • Ventricle to atrium

    • LV to RV

  • Heard well with diaphragm of stethoscope


What are the two main kinds of holosystolic murmurs?

  • AV valve leakage

  • Interventricular shunt

    • VSD


What are the causes of ejection murmurs?


Aortic Stenosis

Pulmonic stenosis


What are the causes of holosystolic murmurs?



Tricuspid regurgitation


What are the causes of late systolic murmurs?





What are the causes of early diastolic murmurs?


Aortic regurgitation

Pulmonic regurgitation


What are the causes for late systolic murmurs?


Mitral stenosis

Tricuspid stenosis


What are the causes for continuous murmurs?





What is an innocent systolic murmur?

NORMAL S2 splitting (no other abnormalities present)

common in children; seen in Pts w/anemia, fever, or other high output states; always seen in pregnancy

caused by high flow in outflow tracts

pattern: crescendo-decrescendo ejection murmur