Valvular Disease & Murmurs Flashcards Preview

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Flashcards in Valvular Disease & Murmurs Deck (33):

What is the most common congenital abnormality of the heart?

Bicuspid aortic valve

Occurs in 1-2% of the population


Complications of bicuspid aortic valve

Valvular - aortic stenosis, aortic insufficiency, endocarditis)

Vascular - proximal aortic dilation, aneurysm, dissection


Aortic Sclerosis

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


Aortic stenosis - 3 etiologies

Age-related degenerative/calcific changes

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

Rheumatic valve disease


Complications of aortic stenosis

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


Clinical manifestations of aortic stenosis -3

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


Signs of aortic stenosis

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


Aortic stenosis - treatment

AV valve dilation - mechanical prosthesis, bioprosthesis, or homograph


Acute aortic regurgitation

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


Chronic aortic regurgitation

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


Aortic regurgitation - treatment

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


Pulmonic stenosis

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

Transcatheter balloon valvuloplasty is effective treatment


Myxomatous mitral valve disease

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


Causes of mitral regurgitation - 2 classifications

1. Primary mitral valve disease - myoxomatous, endocarditis, chordae rupture, etc.

2. Functional - ventricular dilation, chordae tethering, etc.


What is the major etiolology of mitral stenosis?

Rheumatic Fever - 50%


Passive hypertension

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


Reactive hypertension

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


Signs of mitral stenosis

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


Treatment of mitral stenosis

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


Mitral regurgitation - Etiologies

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


Acute mitral regurgitation

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


Chronic Mitral Regurgitation

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


Signs of mitral regurgitation

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


Tricuspid Regurgitation - Etiology

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

Primary tricuspid valvulopathy is rare - endocarditis, rheumatic


Signs of tricuspid regurgitation

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


Physiological split of S2

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


Murmur of aortic regurgitation

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


Murmur of aortic stenosis

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


Murmur of mitral stenosis

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



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

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



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

Normal finding in patients > 55


Broadly, what causes systolic murmurs?

Stenosis of the semilunar valves or regurgitation of the atrioventricular valves


Broadly, what causes diastolic murmurs?

Stenosis of the AV valves or regurgitation of the semilunar valves