ADULT
ECHOCARDIOGRAPHY
Lesson Seven
The Mitral Valve
Harry H. Holdorf PhD, MPA, RDMS, RVT, LRT, N.P.
Mitral Stenosis
• Etiology
– Rheumatic (commissarial
fusion – most common)
– Congenital (rare-Parachute)
– Acquired (mitral annular
calcification (MAC)
– Prosthetic valve dysfunction
Parachute Mitral Valve
(single papillary muscle)
• The insertion of mitral chordae
tendineae into a single papillary
muscle is:
– Parachute mitral valve
Pathophysiology
• Diffuse leaflet thickening,
scarring, contraction,
commissural fusion and chordae
shortening and fusion
• Associated mitral regurgitation
may be present
• Increased left atrial pressure
causes LA dilatation
• Long-standing obstruction leads
to pulmonary hypertension (RV &
RA enlargement)
• Decrease in cardiac output
• Acute rheumatic fever: betahemolytic strep, Polyarthritis,
fever, subcutaneous nodules,
carditis, and a rash (45%
develop MS)
• Increased risk for endocarditis
Physical Signs (MS)
• Diastolic murmur (rumble with
opening snap
• Atrial fibrillation is common
• CHF symptoms (dyspnea,
fatigue, orthopnea, peripheral
edema
• Hemoptysis (bloody sputum)
• ECHO
– Thickened MV leaflets with
decreased mobility
– Tethered MV leaflet tips
(“hockey-stick” presentation)
– Left atrial enlargement
– Signs of pulmonary
hypertension in advanced
cases
– Planimeter valve area in
parasternal SAX view
– RV and RA enlargement
• NOTES:
– Longstanding MS does NOT
lead to: Left ventricular
dilatation
– MS murmur = low frequency
“Diastolic rumble” with an
opening SNAP!!
– Know “hockey-stick”
presentation (goes with
rheumatic MS)
– Patients with mitral stenosis
often develop atrial fibrillation
– Which cardiac valve is the
second most common to be
affected by rheumatic heart
disease? Aortic
• MS patients become very
symptomatic with A-fib.
• Might lose 50% of diastolic filling
since they are very dependent
on atrial contraction.
• AHA/ACC Guidelines for Mitral
Stenosis severity:
MVA (cm sq.)
– Mild >1.5
– Moderate1.0 – 1.5
– Severe <1.0
Supportive findings
– Pulm. Artery pressure (mmHg)
• Mild < 30
• Moderate 30 - 50
• Severe > 50
Mitral Stenosis 2D
Severe doming
• Doppler
– Increased velocity and turbulence
across the mitral valve
– Use pressure half-time for valve
area
– Mitral regurgitation may be present
– Measure
mean
trans-valvular
gradient
Mitral valve area
Normal
4-5 cm sq.
Mild
>1.5 cm sq.
Mod
1.5 – I cm sq.
Sev
<1 cm sq.
NOTE: with atrial fibrillation, mitral
stenosis velocity calculations are best
performed: averaged over 5-10 beats
Mitral pressure half-time
• Mitral valve area:
– To calculate mitral valve area:
• MVA (cm sq.) = 220/pressure
half time
• 220 is the empirical number
– Given a mitral pressure halftime of 400 msec, what would
the area be?
– 220/400 = .5
Mitral valve half-time…
Deceleration time
End of Lesson Seven
NEXT: THE TRICUSPID
VALVE