MIDSYSTOLIC EJECTION MURMURS (MSM)

Question 1

Related to flow of blood across the semilunar valves

MSM begins with ejection (end of isovolumic systole) and termination occurs with the cessation of
forward flow; separated from S1

Crescendo-decrescendo (diamond-shaped) configuration

Answer 1

MIDSYSTOLIC EJECTION MURMURS (MSM)

Question 2

A systolic murmur is present in up to 60% of patients, and 90% are associated with a normal ECHO

The “innocence” of an MSM depends on absence of other abnormal findings, not murmur characteristics

Answer 2

*Innocent or benign flow murmurs

Question 3

Anemia, pregnancy, and thyrotoxicosis

Answer 3

High flow across semilunar valve

Question 4

Midsystolic ejection murmur, generally brief and not very loud; no hemodynamic consequences

Usually best heard over the right 2
nd interspace

Normal carotid pulse and normal S2 confirm the absence of significant aortic valve obstruction

Answer 4

Aortic sclerosis

Question 5

Midsystolic, crescendo-decrescendo; harsh and medium pitch; often loud with thrill

Murmur of AS is usually of maximum intensity over the right 2
nd interspace; radiates up into the neck and over both carotid arteries

If severe AS, weak and delayed carotid pulse (pulsus parvus et tardus)

Answer 5

Aortic outflow obstruction (valvular, subvalvular, or supravalvular, of HCM)

Question 6

Usually due to HCM

Maximum intensity of the murmur is usually located along the lower left sternal border or over the
cardiac apex; radiates poorly to the base and neck.

Ejection-type harsh crescendo-decrescendo midsystolic murmur best heard at 3rd or 4th intercostal
space; can radiate down left sternal border to apex, but not up the neck

Answer 6

Subvalvular outflow obstruction

Question 7

Best heard over the right

2nd interspace with little or no radiation

Answer 7

Bicuspid aortic valve

Question 8

Short systolic murmur is often appreciated in patients with normal functioning bioprosthetic and
mechanical valves due to size of the prosthesis

Answer 8

Prosthetic aortic valve

Question 9

Murmur of valvular pulmonic stenosis is harsh and best heard over the left 2nd interspace

When the murmur loud, it radiates to the left side of the neck and is frequently accompanied by a
palpable thrill

Answer 9

Pulmonic outflow obstruction