Valvular Heart Disease Cases - Malmsten Flashcards
Define valvular stenosis
failure of a valve to open completely, usually due to a chronic process involving the valve cusp.
Define valvular insufficiency
failure of a valve to close completely, often due to disease of the valve cusps or disruption of supporting structures
Describe the basic etiologies of aortic stenosis
Which is most likely:
- The patient is <30 years old?
- The patient is <65 years old?
- The patient is >65 years old?
- calcific degeneration
- congenital abnormality
- rheumatic
- congentially abnormal valve
- calcific degeneration, the valve is bicuspid
- calcific degeneration, the valve is tricuspid
Describe the most likely etiology of aortic stenosis if the patient is
In addition to the aortic valve, rheumatic heart disease almost always involves what other valve?
mitral valve
Why might a patient with aortic stenosis still show a normal blood pressure?
Aortic stenosis can show a large LV-Ao pressure gradient due to the resistance of the stenotic valve. Pressure in the aorta (and therefore systemic circulation) may be normal, depite severely (200mmHg or more) increased left ventricular pressure.
How does the left ventricular pressure-volume loop change in response to aortic stenosis?
Increased change in LVP (isovolumetric contraction) with decreased change in left ventricular volume (stroke volume).
Describe the major physical exam findings of aortic stenosis:
- Sustained LV impulse with little/no LV displacement
- Pulsus Parvus et Tardus of the carotid impulse (weakened and late carotid pulse)
- Auscultation: best heard at the base of the heart or the right upper sternal border, possible radiating to the carotid arteries
- Absent or paradoxically split (aortic late) A2 sound
- Systolic crescendo-decrescendo murmur (later peaking = worse stenosis)
In aortic stenosis, approximately what valve area (in cm2) is considered severe?
Mean LV-Ao pressure gradient (mmHg)?
< 1.0 cm2
>40 mmHg
Treatment of aortic stenosis: when is it necessary to intervene?
When symptoms develop
Name the (4) Class-I indications for aortic valve (AV) replacement in patients with aortic stenosis.
- Symptomatic patients with severe AS
- Patients with severe AS undergoing CABG
- Patients with severe AS undergoing surgery on the aorta or other heart valves
- Patients with severe AS with LV systolic dysfunction (ejection fraction < 0.5)
The only life-prolonging treatment for aortic stenosis is what?
Valve replacement
Name some causes of aortic regurgitation:
- Abnormalities of the valve leaflets
- congenital bicuspid valve
- endocarditis
- rheumatic
- Dilation of the aortic root
- aortic anuerysm (examples: inflammation, Marfan’s)
- aortic dissection
- annuloaortic ectasia
- syphilis
Describe the basic patholphysiology of aortic regurgitation:
Part of the blood ejected into the aorta during systole flows back into the left ventricle during diastole across an incompetent valve. This results in volume overload of the left ventricle.
Describe the differences between acute and chronic aortic regurgitation
Acute: surgical emergency
- left ventricle is normal size with low compliance
- the pressure backup during diastole is transferred to the left atrium and pulmonary circulation
- result is pulmonary congestion and/or edema
Chronic:
- Left ventricle slowly undergoes compensatory adaptation (dilation) due to volume overload from chronic regurgitation
- The increased compliance of the left ventricle reduces pressure backup to the left atrium and pulmonary circulation