8/14- Valvular Heart Disease 2 Flashcards
(37 cards)
How to calculate total mitral stroke volume in mitral insufficiency?
SV = Forward (aortic) + regurgitant (mitral)
(then % regurgitation = regurg/total)
Mitral insufficiency causes what type of murmur (diastolic or systolic)?
Systolic
- Pansystolic murmur that coincides with leak across MV
What causes acute mitral insufficiency?
Associated with what?
Caused by: injury to or dysfunction of any valvular component
Often associated with acute heart failure
Broad course in chronic mitral insufficiency?
When does heart failure occur?
- Pathology and insufficiency progress slowly over many years
- Allows for gradual enlargement of the atrium and ventricle
- Heart failure occurs very late
What are the components of the mitral valve?
- Leaflets
- Chordae tendinae (attach to:)
- Papillary muscles
What are the pathologic causes of mitral insufficiency?
Muscular (normal leaflets):
- Acute MI/infarction
- Trauma
Connective tissue:
- Chordal rupture (Marfan’s, prolapse)
- Annular disruption or dilation due to LV dilation (CHF)
Leaflets
- Perforation, vegetations (endocarditis)
- Prolapse (myxomatous degeneration)
- Post inflammatory scarring (rheumatic)
Steps of mitral valve prolapse?
- Valve tissue degenerates
- Leaflets sag into atrium during systole (prolapse), separate from coaptation line: mild MR
- Chordae elongate, fracture, leaflet fragment becomes flail: severe MR
What is myxomatous degeneration?
Aka prolapse aka Barlow’s syndrome
Redundant leaflets cause what kind of murmur?
Mid-to-late systolic murmur
Mitral valve prolapse results in what heart sounds?
- Mid systolic click
- Mid-late systolic murmur
- If severe, holosystolic murmur, S2
How is mitral valve prolapse affected by dynamic auscultation?
MVP results in a systolic murmur at apex
- Louder and longer murmur with maneuvers that decrease EDV or increase systolic function (standing, Valsalva)
- Later and softer murmurs when LVEDV is increased (squat and leg elevation)
Which condition responds like mitral valve prolapse in dynamic auscultation (increase in murmur with Valsalva/standing)?
Hypertrophic cardiomyopathy with dynamic LVOT obstruction
How can HCM and MVP be differentiated (since they return the same dynamic auscultation results)?
Hand grip exercise and the presence of click:
- HCM murmur will become softer
- MVP murmur will become louder
What is the pathophysiology of acute mitral insufficiency?
Sudden LV to LA leak -> acute LV volume overload
- LA and pulmonary venous pressures rise acutely
- Normal size LV
Early short systolic murmur and S3
- Soft S1
- LA pressures rise sharply, equaling LV systolic, terminating murmur
Pathophysiology of chronic mitral insufficiency?
Chronic LV to LA leak -> gradual LV volume overload
- Eccentric LVH with large LV, large LA
Holosystolic murmur and S3 gallop
- Holo (or pan)systolic murmur coincides with actual leak from LV to LA that starts with S1 and ends with S2
What are these?
Left: acute mitral insufficiency murmur
Right: chronic mitral insufficiency murmur
What is the clinical course of chronic mitral insufficiency?
- Progressive leak with minimal symptoms
- Gradual LV volume overload
- Atrial fibrillation due to longstanding LAE
- Progressive CHF in late stages
Compare acute and chronic mitral insufficiency in terms of:
- Onset of symptoms
- Overload and chamber sizes
- Consequences
- Clinical outcomes
Onset of symptoms:
- Acute: acute onset
- Chronic: gradual onset
Overload and chamber sizes
- Acute: LV, LA volume overload but no LV dilation
- Chronic: LV, LA volume overload with dilated LA/LV
Consequences:
- Acute: acute increase in LA pressure
- Chronic: atrial fibrillation
Clinical outcomes
- Acute: acute pulmonary edema
- Chronic: long asymptomatic phase; progressive CHF is a terminal event
What is shown here?
Cardiomegaly and left ventricular enlargement as well as mild pulmonary venous redistribution
- All features of mitral regurgitation
Treatment for mitral insufficiency?
Drugs that reduce CHF symptoms:
- Diuretics
- Vasodilators
Surgery: definitive treatment
- Annuloplasty to reduce annular size
- Leaflet and chordal repair
- Valve replacement if repair not feasible
Earlier surgery leads to better survival!
What is mitral stenosis?
Obstruction to flow from LA to LV due to narrow mitral valve orifice
What causes mitral stenosis?
True valvular stenosis:
- Post-inflammatory “rheumatic”
Pseudo-stenosis*
- Tumors
- Thrombi
- Vegetations
*An obstruction to MV blood flow not caused by intrinsic valvular disease
What is shown here?
Severe mitral stenosis
- Rheumatic fusion of mitral leaflets
Pathophysiology of mitral stenosis?
- Leaflets, chordae, papillary muscles scarred (due to rheumatic heart disease)
- LV preload reduced due to MV obstruction
- Elevated LA pressures causes pulmonary edema: dyspnea, orthopnea and PND
- Atrial fibrillation due to LA enlargement
- Diastolic “rumble” begins when mitral valve opens & coincides with flow through stenotic MV
