mitral regurgitation
DESCRIPTION
determining the suitability of the mitral valve for repair most likely in patients with mitral regurgitation due to myxomatous degeneration and is least likely in patients with regurgitation due to endocarditis most likely with posterior prolapse or flail, whereas ileaflet involvement and isolated anterior leaflet prolapse reduce the likelihood of successful repair substantially.TRANSCRIPT
DR.PV.NISHANTH,DM
NIMS,Hyderabad,India.
Dysfunction or altered anatomy of any one of the components of the mitral valve apparatus can result in mitral regurgitation.
• determining the suitability of the mitral valve for repair
• most likely in patients with mitral regurgitation due to myxomatous degeneration and is least likely in patients with regurgitation due to endocarditis
• most likely with posterior prolapse or flail, whereas bileaflet involvement and isolated anterior leaflet prolapse reduce the likelihood of successful repair substantially
thorough examination of the mitral valve and mitral apparatus and to determine the origin and geometry of the regurgitant jet
long-axis imaging planes are best for determining which mitral leaflet is involved
TTE-PLAX/apical long axis/SHORT AXIS/A4C
Long-axis views of the mitral valve are obtained by imaging from midesophageal TEE planes
Typically, when viewing the left ventricle in a longitudinal plane (120 degrees), the imaging plane intersects the A2/P2 boundary
Imaging at a multiplane angle of about 135 degrees cuts perpendicular to this intercommissural line.
short-axis views also are useful for determining which portion of the anterior or posterior leaflet is involved.
approximately 50 to 60 degrees in most patients, the imaging plane parallel to a line between the commissures, is very useful for determining which portion of the anterior or posterior leaflet is involved.
papillary muscles and chordae usually are well visualized from the transgastric long-axis views of the left ventricle
Etiology Presumed Mechanism
Annular dilation Inadequate leaflet coaptation
MAC Increased rigidity of annulus impairing systolic contraction
Myxomatous mitral valve disease Inadequate coaptation and apposition, fail segments
Rheumatic mitral valve disease Increased rigidity of leaflets
Endocarditis Leaflet perforation or deformity
Age-related degenerative leaflet changes
Abnormal coaptation
Hypertrophic cardiomyopathy Abnormal leaflet motion and anatomy
Chordae disruption or elongation Inadequate systolic support of leaflet
Regional left ventricular dysfunction Inadequate systolic support of leaflets
Left ventricular dilation Abnormal papillary muscle orientation
Papillary muscle rupture Inadequate systolic support of leaflets
elongation or disruption of any portion of the mitral valve or of the mitral apparatus, including the papillary muscles and chordae
Myxomatous disease endocarditis papillary muscle infarction
Flail leaflet-not uncommon sequela of a myxomatous mitral valve
anatomic disruption of a portion of the mitral apparatus results in aneccentric direction of the regurgitation jet with an orientation opposite in direction to the leaflet with the anatomic defect
regurgitant jet is directed away from the affected leaflet
chordae to the commissures are ruptured, then a jet originating at the commissures is seen in the transgastric short-axis view.
Jets originating at the commissure also are seen in infarction of a papillary muscle, most commonly the posteromedial one
papillary muscle ruptures in an acute myocardial infarct-differentiated from acute chordal rupture by detecting a mass attached to the flail leaflet that is a portion of the muscle
Postoperative prognosis is best in those with excessive leaflet motion.
rheumatic disease ischemic heart disease the chronic phase oflupus acquired valvular disease caused by
certain drugs such as ergot derivatives and anorexigenic drugs such as the fen-phen
rheumatic, lupus, and drug-induced diseases, the leaflets are thickened
rheumaTIC-pml more affected than AML relatively normal anterior leaflet "over-
rides" the restricted posterior leaflet. The direction of the regurgitant jet in this
situation is posterior, toward the affected leaflet
Echocardiographic findings consistent with rheumatic valve involvement include
(1) leaflet thickening, deformation, and retraction
(2) fusion, shortening, and fibrosis of the subvalvular apparatus
(3) accompanying aortic and/or tricuspid valve involvement
Chordal rupture is mc in chordae to AML in rheumatic while it is MC in chordae to PML in myxomatous valve.
Rheumatic valve is more likely to have IE than spontaneous rupture.
commonly seen in patients with mitral regurgitation secondary to left ventricular dilation of any cause
dilated cardiomyopathy,or severe ischemic cardiomyopathy
Perforation of the valve leaflet causing mitral regurgitation occurs most commonly because of endocarditis or because of a congenital cleft in the valve
Occasionally it is iatrogenic, after attempted repair.
jet origin is eccentric, arising from the midportion of the leaflets rather than from the coaptation line.
Chronic MR, occurring >2 weeks after infarction and in the absence of structural mitral valve disease
disease of abnormal left ventricular (LV) shape and function with a valvular manifestation
Greater degrees of morphologic disturbance are predictive of greater likelihood of persistence of MR following mitral annuloplasty, with the optimal cut-offs for distinguishing patients with persistent MR being a
coaptation distance of .0.6 cm tenting area of >2.5 cm2 posterior leaflet angle >45u. Annular dilatation more than 40 mm
Post annuloplasty PL is relatively fixed ,it is the AL that has to coapt.
So instead of PL angle/AL base angle ,AL tip angle is more determining factor
Evaluation of mechanisms of MR needs a systematic approach utilising both TTE and TEE for visualising all scallops of leaflets.
Excessive leaflet motion has the best chance of surgical correction
Ischemic MR/ventricular annular dilatation is a complex and needs evaluation by multiple variables to predict result of annuloplasty.
3D echo gives excellent visualisation of mitral valve and its structures and provides both aetiological and prognostic information
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