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
Desribe the major presentations of aortic regurgitation:
- Dyspnea on exertion
- Fatigue
- Decreased exercise tolerance
- Chest pain
Name some key physical exam findings seen with aortic regurgitation:
- Hyperdynamic pulse (head bobbing, water hammer pulse, etc)
- Widened pulse pressure (diastolic < 0.5*systolic)
- Decrescendo diastolic murmur, increased with handgrip or squatting tests, heard best at end-expiration with patient leaning forward
- Austin Flint murmur (diastolic rumble)
What is Quincke’s pulse?
cyclic reddening and blanching of the nail capillaries
What is a ‘Water Hammer’ pulse?
brisk femoral pulsation similar to a water hammer (brisk, ‘slapping’ impact)
Describe the treatment guidelines for aortic regurgitation:
Acute
Chronic
Acute
- emergency surgical valve replacement
Chronic
- Asymptomatic and normal LVEF (>50%) - periodic follow-up with echo, consider calcium channel blocker or ACE-I if patient is hypertensive
- Low LVEF (<50%) - refer to surgery for valve replacement
A holosystolic murmur observed at the apex of the heart is likely indicative of what?
Mitral valve regurgitation
Compare and contrast acute vs. chronic mitral valve regurgitation
Acute = medical emergency
- Backing up blood against normal LA compliance increases LA pressure
- Pressure backs up into pulmonary circulation -> increased pulmonary pressure
- Pulmonary congestion and edema
- prominent V waves on catheterization
Chronic
- increased left atrial size and compliance due to chronic regurgitation -> relatively normal LA and pulmonary pressures
- Lower CO
- increased LV size
- eventual systolic dysfunction
Describe the management strategies for acute and chronic mitral regurgitation
Acute
- stabilize with diuretics and vasodilators
- consider surgical intervention depending on cause/severity
Chronic
- If asymptomatic: monitor
- if symptomatic with severe regurgitation, consider valve replacement surgery
- if severe LV dysfunction -> relatively little to be done at this point…
A 55 year old male presents to the ER Five days after an MI treated with stenting to the right coronary artery he is found nearly unresponsive and brought to the emergency room. His temperature is 95.0, blood pressure 70/30, heart rate 120 beats per minute and respirations 30. No murmur is appreciated and exam otherwise reveals rales throughout both lung fields. Angiography shows a patent stent and hyperdynamic left ventricular systolic function, with large V waves in the pulmonary capillary wedge pressure tracing. Which of the following is the most likely diagnosis?
Acute mitral valve regurgitation
The left ventricle contains how many papillary muscles? Describe the vascular supply of each
(2): anterolateral portion and posteromedial portion
Posteromedial portion: RCA only
Anterolateral portion: dual supply
What is the most common etiology for mitral valve stenosis?
What other etiologies might be seen (albeit rare)?
most common: rheumatic fever
others (rare): congenital stenosis, annular calcification, endocarditis with large obstructive vegetations
Describe some typical symptoms of mitral valve stenosis
- dyspnea and reduced exercise capacity
- symptoms with exertion or increased heart rate (mild stenosis)
- shortness of breath at rest, orthopnea, heart failure symptoms, paroxysmal nocturnal dyspnea (severe stenosis)
- signs of right-sided heart failure - jugular distension, hepatosplenomegaly, ascites, edema
- rare: hoarseness, hemoptysis
What is a normal value for mitral valve area?
What is range of area for mitral valve stenosis (MS)
normal: MVA = 3-4 cm2
MS: MVA < 2 cm2
Describe the criteria for severe mitral stenosis. How are these measured?
Via echocardiogram:
MVA < 1.0 mm2
MVG > 10 mmHg
Describe the typical exam findings in mitral stenosis
- early: opening snap and murmur
- later: opening snap and murmur with RV lift
Describe the treatment approach for mitral stenosis
- Diuretics for Sx of vascular congestion
- Afib: Ca-channel blockers, beta blockers, digoxin
- Afib: chronic anticoagulation
- If refractory to medical management or pulmonary hypertension present: balloon valvuloplasty or valve replacement surgery
A 25 year old 33 weeks pregnant female is becoming increasingly short of breath with some lower extremity edema. She is afebrile, heart rate 110 beats per minute, respirations 20, blood pressure 100/60. Physical examination reveals a II/IV early diastolic decrescendo murmur at the cardiac apex. Which of the following is the likely diagnosis?
mitral valve stenosis
