Murmurs

Question 1

What are normal heart sounds?

Answer 1

short: S1 (closure of the mitral and tricuspid valves) and S2 (closure of the aortic and pulmonic valves) - best heard with the diaphragm of the stethoscope
=> S3 and S4 are additional sounds, often pathologic best heard with the bell of the stethoscope

Question 2

What is a murmur?

Answer 2

a prolonged sound caused by turbulent blood flow over the valves

Question 3

What is a thrill?

Answer 3

a palpable murmur (4/6 intensity)

Question 4

What is a bruit?

Answer 4

a murmur that occurs outside the heart (e.g., carotid - risk for stroke; abdominal - risk for renal artery stenosis)

Question 5

What is S3?

Answer 5

abnormal heart sound heard at the beginning of diastole - occurs when heart is dilated => indicates systolic dysfunction (e.g., CHF)

Question 6

What is S4?

Answer 6

abnormal heart sound heard at the end of diastole - occurs when the heart is hypertrophic (ventricles are stiff and the muscle is enlarged) => indicates diastolic dysfunction (e.g., long-standing HTN)

Question 7

What occurs to blood flow in the setting of systolic heart failure?

Answer 7

the weakened heart muscle can’t squeeze as well - less blood is pumped out of the ventricle

Question 8

What occurs to blood flow in the setting of diastolic heart failure?

Answer 8

the heart muscle is stiff and can’t relax - less blood fills the ventricle

Question 9

What does the acronym APT M stand for?

Answer 9

names of the valves of the heart - aortic, pulmonic, tricuspid, mitral => aortic and mitral are most important in assessment of murmurs (easiest to hear)

Question 10

How are heart murmurs classified?

Answer 10

timing (systole or diastole), location (where it is heard the best), shape, radiation, intensity (1-6), response to maneuvers => timing and location are most important

Question 11

What is the classification system for intensity of heart murmurs?

Answer 11

Grades:
1 - faint (S1/S2 are louder than murmur)
2 - quiet (murmur is as loud as S1/S2)
3 - moderately loud (murmur is louder than S1/S2)
4 - loud with palpable thrill
5 - very loud, with thrill - may be heard with stethoscope partly off the chest
6 - very loud, with thrill - may be heard with stethoscope entirely off the chest

Question 12

Where is an aortic murmur best heard?

Answer 12

2nd intercostal space at right sternal border

Question 13

Where is a mitral murmur best heard?

Answer 13

5th intercostal space at the midclavicular line (apex)

Question 14

What are the causes of the 2 types of systolic murmurs?

Answer 14

=> aortic stenosis - heard at the 2nd intercostal space at right sternal border and radiating to neck
=> mitral regurgitation - heard at the 5th intercostal space at the midclavicular line and radiating to the axilla

Question 15

What are the causes of the 2 types of diastolic murmurs?

Answer 15

=> aortic regurgitation - heard at 2nd intercostal space at the right sternal border
=> mitral stenosis - heard at the 5th intercostal space at the midclavicular line

Question 16

What is the result on the heart of volume overload?

Answer 16

dilation

Question 17

What is the result on the heart of pressure overload?

Answer 17

hypertrophy

Question 18

What does the acronym MR ASS stand for?

Answer 18

mitral regurgitation/aortic stenosis => systole

Question 19

What does the acronym MS ARD stand for?

Answer 19

mitral stenosis/aortic regurgitation => diastole

Question 20

What is the pathology of aortic stenosis?

Answer 20

LV hypertrophy leads to LV diastolic dysfunction - causes a systolic murmur (greatest risk factor = age)

Question 21

What are the S and S of aortic stenosis?

Answer 21

angina (not enough blood to aorta), syncope, dyspnea, systolic murmur at 2nd intercostal space at right sternal border radiating to neck, S4 commonly heard

Question 22

What is the pathology of mitral regurgitation?

Answer 22

dilated LA leads to dilated LV and decreased LV function - risk for atrial fibrillation (greatest risk factor = infarction/infection)

Question 23

What are the S and S of mitral regurgitation?

Answer 23

dyspnea, systolic murmur at the apex radiating to the axilla (dilation of LA and LV leads to elongation of leaflets - may hear a click followed by murmur)

Question 24

What are the positions of the mitral and aortic valves during diastole (S2) in a normal heart?

Answer 24

mitral open, aortic closed

Question 25

What are the positions of the mitral and aortic valves during systole (S1) in a normal heart?

Answer 25

mitral closed, aortic open

Question 26

What is the pathology of aortic regurgitation?

Answer 26

LV dilation (due to volume overload) leads to LV dysfunction (greatest risk factor = infarction, ischemia, infection)

Question 27

What are the S and S of aortic regurgitation?

Answer 27

dyspnea (CHF), diastolic murmur at the right sternal border), widened pulse pressure, S3 is also commonly heard

Question 28

What is the pathology of mitral stenosis?

Answer 28

hypertrophic LA leads to pulmonary congestion/atrial fibrillation (greatest risk factor = Strep infection, pregnancy - due to volume overload)

Question 29

What are the S and S of mitral stenosis?

Answer 29

dyspnea, palpitations, low pitch diastolic rumble at the apex, atrial fibrillation,

Question 30

How do you distinguish between murmur due to aortic stenosis and that due to hypertrophic obstructive cardiomyopathy?

Answer 30

aortic stenosis:
=> Valsalva/standing (decreased venous return to the heart) - murmurs will be softer
=> squatting/laying down (increased venous return to the heart) - murmurs will be louder
HOCM:
=> Valsalva/standing - murmurs will be louder
=> squatting/laying down - murmurs will be softer

Question 31

What are the S and S of hypertrophic obstructive cardiomyopathy?

Answer 31

syncope during exercise, sudden death, harsh systolic murmur that radiates to carotid artery (best heard at right sternal border), murmur gets louder with Valsalva/standing

Question 32

What are the characteristics of innocent murmurs?

Answer 32

physiologic/flow murmurs; no structural pathology; associated with physical activity, fever (hypermetabolic state), anemia (decreased RBCs means blood is less viscous and moves faster), hyperthyroidism (hypermetabolic state), and pregnancy (volume increase); grade 1-3 (no thrill, always soft); always systolic (never diastolic), softer with standing/Valsalva; no radiation; always asymptomatic; common in children/young adults

Question 33

What are the characteristics of pathological murmurs?

Answer 33

structural pathology (stenosis or radiation); diastolic/holosystolic/continuous; grade > 3; radiate beyond precordium; associated with symptoms

Question 34

What is the approach to assessing murmurs?

Answer 34

=> innocent - observe and re-evaluate
=> pathological - evaluate using transthoracic ECHO first => proceed with trans-esophageal ECHO then cardiac catheterization, if needed

Question 35

What is hypertrophic obstructive cardiomyopathy?

Answer 35

hypertrophy of the septum, not the whole ventricle - blocks blood passage through the aortic valve => no blood flow between the LV and aorta - death due to ischemia-induced ventricular arrhythmia during exertion

Question 36

What is pathway as blood passes through the heart?

Answer 36

superior vena cava => RA => tricuspid valve => RV => pulmonic valve => pulmonary artery => lungs => pulmonary vein => LA => mitral valve => LV => aortic valve => aorta

Question 37

What is the pathophysiology of stenosis and regurgitation ?

Answer 37

stenosis <=> hypertrophy

regurgitation <=> dilation