Lecture 4: Heart Sounds Flashcards
What generates the S1 sound?
- MV & TV closing
- AV (aortic) & PV (pulmonic) opening
Systole
Lub sound.
A-V valves refer to the MV and TV.
What generates the S2 sound?
- MV & TV open
- AV & PV close
Diastole
Dub sound.
Cardiac Cycle Image
What is longer in duration: S1 to S2 or S2 to S1?
S2 to S1 is longer, which is diastole.
Filling blood takes longer than ejecting it.
What part of the stethoscope is for low-pitched sounds preferably? What are the low-pitched sounds?
- S3, S4, mitral stenosis.
- Use the Bell!
What part of the stethoscope is for high-pitched sounds preferably? What are the high-pitched sounds?
- S1, S2, AR, MR, pericardial friction rub
- Diaphragm
Diaphragm = Ding! which is high pitched
What are the 5 listening posts for the heart?
- Aortic (2nd ICS)
- Pulmonic (2nd ICS)
- Erb’s point (3rd ICS)
- Tricuspid (4th ICS)
- Mitral (5th ICS, mid-clavicular)
A PET Monkey
What positions should we listen to the heart in?
- 30 supine for all precordial areas using diaphragm.
- Left lateral decubitus for MV post using bell.
- Leaning forward post deep exhalation for aortic post for aortic murmurs using diaphragm.
H&P skills!
What does standing do to venous return, arterial BP, and SV? What murmurs can it affect?
- Lowers all of 3.
- Increases MV prolapse.
- Outflow obstruction of hypertrophic cardiomyopathy (HCM)
- Decreases AS murmur
MVP => MR, which is leaking of blood back into the left atrium.
Low LV filling => increased oHCM.
Less blood flowing through the aortic valve = less pronounced AS sound.
What does squatting do to venous return, arterial BP, and SV? What murmurs can it affect?
- Increases all 3.
- Decreases MVP.
- Decreases obstruction of HCM.
- Increases AS murmur.
What maneuver do we have patients perform and what is the physiological effect?
Valsalva.
Valsalva decreases preload (venous return) and increases intrathoracic pressure.
Decreased preload leads to decreased SV.
What primarily generates the S1 sound?
MV closure.
What primarily generates the S2 sound?
Aortic closure
What is an Ej/Ec or ejection click?
Opening of either the AV or PV valve.
It immediately follows S1.
What is an OS or opening snap?
Opening of the MV (such as in MS)
It immediately follows S2.
What is S3?
- S3, occurring early in diastole.
- Best heard with bell at apex in left lateral decubitus.
- NORMAL in children, young adults, and 3rd trimester.
- Dull, low-pitched
Kentucky gallop
K before T = 3 before 4.
3 before 4 = 3 is early diastole, 4 is late diastole.
What does the presence of S3 imply in an older patient?
- Decreased myocardial contractility
- CHF
- Volume overload of ventricle
What is S4?
- S4, occurring late in diastole, right before S1.
- Best heard with bell at apex in left lateral decubitus (same as S3)
- Marks atrial contraction
Tennessee gallop
What does the presence of S4 imply in a patient?
Increased resistance to ventricular filling.
Suggestive of HTN, CAD, AS, or cardiomyopathy.
Image of Extra/Abnormal Heart Sounds
When and where is S1 louder than S2?
- Louder at apex.
- Accentuated in tachycardia, high cardiac output states, and MS.
S1 is MV closure.
When does splitting of S1 occur?
- Normal along left lower sternal border.
- Abnormal is present in RBBB and PVCs.
RBBB= right bundle branch block
sounds like 2 S1 occurring simultaneously
You are hearing both the MV and TV closing.
What is physiologic splitting of S2?
- 2nd and 3rd ICS for pulmonic valve listening.
- Heard best during inspiration.
What is pathologic splitting of S2?
- Persistent throughout respiratory cycle.
- Implies delayed closure of PV. (PS, RBBB)
- Implies early closure of AV. (MR)
