Valvular Disease & Murmurs

Question 1

What is the most common congenital abnormality of the heart?

Answer 1

Bicuspid aortic valve

Occurs in 1-2% of the population

Question 2

Complications of bicuspid aortic valve

Answer 2

Valvular - aortic stenosis, aortic insufficiency, endocarditis)

Vascular - proximal aortic dilation, aneurysm, dissection

Question 3

Aortic Sclerosis

Answer 3

Precedes aortic stenosis; valve is sclerotic but no abnormal pressure gradient yet exists between the LA and LV

Question 4

Aortic stenosis - 3 etiologies

Answer 4

Age-related degenerative/calcific changes

Congenitally deformed aortic valve leading to turbulent flow and gradual endothelial damage and calcification

Rheumatic valve disease

Question 5

Complications of aortic stenosis

Answer 5

LV hypertrophy in response to increased pressure; LA hypertrophy in response to LVH

Question 6

Clinical manifestations of aortic stenosis -3

Answer 6

1. Angina, due to increased myocardial oxygen demand
2. Exertional syncope - ventricle cannot increase its CO during exercise + vasodilation of peripheral mucle beds leads to decreased cerebral perfusion
3. Congestive heart failure due to elevation of LA pressure

Question 7

Signs of aortic stenosis

Answer 7

LV hypertrophy
Tall QRS 
Coarse, systolic ejection murmur 
S4 sound due to atrial contraction into stiff LV 
Reduced A2 component of S2

Question 8

Aortic stenosis - treatment

Answer 8

AV valve dilation - mechanical prosthesis, bioprosthesis, or homograph

Question 9

Acute aortic regurgitation

Answer 9

The LV is of normal size and relatively non-compliant; therefore, the volume load of regurgitation causes a substantial increase in LV pressure which is transmitted to the LA and pulmonary vasculature, causing congestion

Question 10

Chronic aortic regurgitation

Answer 10

LV undergoes compensatory eccentric hypertrophy (with dilation) due to volume overload; dilation allows increased compliance of the LV so that it may accomodate a larger regurgitant volume with less pressure increase

Diastolic pressure may decrease; systolic pressure increases due to high LV stroke volume - pulse pressure is high

Question 11

Aortic regurgitation - treatment

Answer 11

Surgical correction - for symptomatic patients or when EF < 50%

Monitoring + possible benefit of afterload reducing vasodilators (Ca2+ channel blockers, ACEIs) in the setting of HTN

Question 12

Pulmonic stenosis

Answer 12

Almost always caused by congenital deformity, diagnosed most often in children/adolescents

Transcatheter balloon valvuloplasty is effective treatment

Question 13

Myxomatous mitral valve disease

Answer 13

Primary mitral valvulopathy associated with connective tissue disease in which normal connective tissue is replaced by mucin

Question 14

Causes of mitral regurgitation - 2 classifications

Answer 14

1. Primary mitral valve disease - myoxomatous, endocarditis, chordae rupture, etc.
2. Functional - ventricular dilation, chordae tethering, etc.

Question 15

What is the major etiolology of mitral stenosis?

Answer 15

Rheumatic Fever - 50%

Question 16

Passive hypertension

Answer 16

Occurs in the setting of increased LA pressure (2/2 mitral stenosis, for example)

High LA pressure is transmitted backward into the pulmonary vasculature; pulmonary hypertension is obligatory in order to preserve forward flow in the setting of increased LA pressure

Question 17

Reactive hypertension

Answer 17

Occurs in the setting of increased LA pressure (2/2 mitral stenosis, for example)

Increased arteriolar resistance impedes blood flow into engorged capillary beds, reducing capillary hydrostatic pressure and further edema; however, contributes to RV heart strain

Question 18

Signs of mitral stenosis

Answer 18

Loud S 1 - caused by mitral valve leaflets slamming shut from a wide position

Diastolic rumble - caused by turbulent flow across the stenotic mitral valve during diastole

Question 19

Treatment of mitral stenosis

Answer 19

Percutaneous balloon valvuloplasty - “cracks open” fused leaflets

Surgical replacement

Medical treatment to slow rapid ventricular rate, improving fill time (B-blockers, Ca2+ channel blockers, Digoxin) + Diuretics

Question 20

Mitral regurgitation - Etiologies

Answer 20

Structural abnormality 
Infective endocarditis
Rheumatic fever
Calcification 
Ischemic heart disease / papillary muscle dysfunction 
LVH

Question 21

Acute mitral regurgitation

Answer 21

Caused by sudden rupture of chordae tendinae, for example

LA is unadjusted and so uncompliant; regurgitant volume causes a substantial increase in LA pressure which is transmitted to pulmonary circulation

LV accomodates increased volume load returning from the LA via Frank-STarling

Question 22

Chronic Mitral Regurgitation

Answer 22

LA undergoes compensatory changes - dilates and increases compliance in order to accomodate larger volume; this decreases pulmonary congestion but compromises forward CO because the compliant LA becomes a low pressure “sink” for LV ejection

LA dilation also predisposes to atrial fibrillation

Question 23

Signs of mitral regurgitation

Answer 23

Apical, systolic murmur
S3 sound - reflects increased volume returning to LV in early diastole
Radiograph shows pulmonary edema in acute MR, more likely to show LV and LA enlargement in chronic MR

Question 24

Tricuspid Regurgitation - Etiology

Answer 24

90% functional problem with right ventricle, most often enlargement (2/2 pulmonary hypertension)

Primary tricuspid valvulopathy is rare - endocarditis, rheumatic

Question 25

Signs of tricuspid regurgitation

Answer 25

Systolic murmur along the left lower sternal border that increases with inspiration

V waves in jugular veins - caused by regurgitation of blood from the RV through the RA and into the jugular

Pulsatile liver - caused by regurgitation of RV blood into systemic veins

Question 26

Physiological split of S2

Answer 26

Audible splitting of A2 and P2 on inspiration

Negative intrathoracic pressure during inspiration induces an increase in venous return from the body into the RA; simultaneously, reduced blood volume returns from the lungs via the LA

Because of increased blood in the RV, the pulmonary valve stays open longer during ventricular systole due to increased emptying time, whereas the aortic valve (A2) closes earlier due to reduction in LV volume and emptying time

Question 27

Murmur of aortic regurgitation

Answer 27

Murmur represents turbulent back flow of blood from the aorta into the LV during diastole

High pitched, decrescendo, diastolic murmur typically heard best with the diaphragm along the left sternal border

Question 28

Murmur of aortic stenosis

Answer 28

Harsh systolic murmur followed by a distinct S2 sound, best heard at the 2nd right intercostal space

Question 29

Murmur of mitral stenosis

Answer 29

Loud S1 due to elevated LA pressure that causes the mitral valve to close under higher pressure

Opening snap after S2 - distinct, crisp sound representing the opening of the stenotic mitral valve

Question 30

S3

Answer 30

S1-S2-S3 (Ten-ne-ssee)

Low pitched sound; occurs during rapid filling of a pressurized ventricle in early diastole

Question 31

S4

Answer 31

Late diastolic sound heard due to atrial ejection into a stiffened ventricle

Normal finding in patients > 55

Question 32

Broadly, what causes systolic murmurs?

Answer 32

Stenosis of the semilunar valves or regurgitation of the atrioventricular valves

Question 33

Broadly, what causes diastolic murmurs?

Answer 33

Stenosis of the AV valves or regurgitation of the semilunar valves