Heart Valve Disorders

Stenosis vs Regurgitation · Mitral & Aortic · Cardiovascular Part 2
Think of each valve as a one-way door. It OPENS to let blood through, then SHUTS so blood cannot fall back. Only two things go wrong. The door gets stiff and will not OPEN (stenosis), or it will not latch and leaks backward (regurgitation). The catch is timing. Each door is used during only one part of the heartbeat, so that is when its problem shows up.

Watch the valve through the cardiac cycle

The mitral valve works in diastole, when it fills the LV. The aortic valve works in systole, when it ejects blood to the body. The lesion you pick shows up during that phase.
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Pick a valve and lesion, then press play or scrub the cycle.
Forward flow Stenosis (choked) Regurgitant backflow

Cardiac cycle & murmur timing

S1 = valves close to start systole. S2 = valves close to start diastole. The shaded band is when this murmur is heard.
Normal, no murmur
Select a valve & lesionNormal valves open and close on cue

Controls

Which valve?
Lesion
Severity65%
Speed
Scrub the cyclesystole

This lesion

Normal valve
Blood moves forward only. There is no blockage and no leak.

Systolic vs diastolic: the whole set

Every valve lesion makes either a systolic or a diastolic murmur. Here are all four.

◾ Systolic murmurs

Aortic Stenosis: the LV cannot eject
Mitral Regurgitation: the LV leaks back into the LA

◾ Diastolic murmurs

Aortic Regurgitation: the aorta leaks back into the LV
Mitral Stenosis: the LV cannot fill
Memory hook: a valve makes a murmur when it is supposed to be shut and is not (regurgitation), or supposed to be open and will not open (stenosis). The aortic valve opens in systole, and the mitral valve opens in diastole. So AS & MR are systolic, and AR & MS are diastolic.