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Valvular Regurgitation. Mitral Regurgitation. Mitral Valve Apparatus. Components Left Atrial wall Mitral annulus Anterior and posterior leaflets. Mitral Valve Apparatus. Chordae tendinae Papillary muscle Left ventricular wall underlying the papillary muscle.
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Valvular Regurgitation Mitral Regurgitation
Mitral Valve Apparatus Components • Left Atrial wall • Mitral annulus • Anterior and posterior leaflets
Mitral Valve Apparatus • Chordae tendinae • Papillary muscle • Left ventricular wall underlying the papillary muscle.
Mechanism of Mitral Regurgitation Papillary Muscle Dysfunction Annular Dilation Underlying LV wall
Mechanism of Mitral Regurgitation Leaflet Coaptation Leaflet Flexibility Leaflet Apposition
Mitral Valve Apparatus • Saddle shaped • Most apical points seen in Apicl 4 chamber view • Most basal points seen in LAX view
Mitral Annular Dilation • Normal mitral leaflets have area of overlap. • Mild degree of dilation may be tolerated without significant regurgitaion
Mitral Annular Dilation Causes • Left atrial dilation • Left ventricular dilation
Mitral Annular Calcification Mitral Annulus • Annulus area smaller in systole than in diastole. • Mitral annular calcification leads to increased rigidity – impairs systolic contraction.
Mitral Annular Calcification • Increased echogenicity on the LV side of the annulus immediately adjacent to the attachment point of the PMVL. • May be focal or extensive involving the entire U-shaped annulus.
Mitral Annular Calcification • The region of AMVL-aortic root continuity is rarely involved. • Seen as incidental findings in the elderly • Premature annular calcification seen in patients with renal failure or hypertension.
Mechanism of Mitral Regurgitation Annular Calcification
Mitral Annular Calcification Annular Calcification
Disease of the Mitral Valve • Myxomatous Disease • Rheumatic Disease • Endocarditis
Disease of the Mitral Valve • Marfan’s Syndrome • Infiltrative diseases • Collagen-vascular disorders
Myxomatous Disease • Thickened, redundant leaflets and chordae • Sagging of portions of the leaftet into the LA in systole • Severity – range from MVP to Flail leaflet segments
Myxomatous Disease Thickened Valve
Myxomatous Disease Sagging Valve
Myxamatous Disease Sagging Leaflet Distance Time Diastole Systole
Rheumatic Heart Disease • Commissural fusion • Thickening of leaflet tips
Endocarditis • Leaflet destruction • Leaftlet perforation • Leaftlet deformity
Marfan Syndrome • Long redundant AMVL • AMLV sags into LA in systole.
Infiltrative Diseases • Amyloidosis • Sarcoidosis • Mucopolysaccaridosis
Infiltrative Disease • Irregular leaflet thickening • Inadequate coaptation
Degenerative Changes • Age-related • Irregular areas of thickening and increased echogenicity. • +/- mitral annular calcification
Hypertrophic Cardiomyopathy • Abnormalities of Leaflet Motion • AMVL obstructs LVOT in systole • Disrupts coaptation of AMVL and PMVL • Posteriorly directed MR jet.
Hypertrophic Cardiomyopathy • Increased SA of MVL • Increased length of MVL especially AMVL • Excessive degree of coaptation
Hypertrophic Cardiomyopathy • Coaptation plane is displaced posteriorly. • 10% of patients have anomalous papillary muscle anatomy with direct insertion of PM into the leaflet.
Chordal Elongation • Inadequate tensile support of the closed leaflet in systole. • Severe bowing of the leaflet/leaflet segment into the LA. • Tip of the leaflet still directed towards the LV apex.
Chordal Rupture • No tensile support of the closed leaflet in systole. • Flail leaflet segment with displacement of leaflet into the LA in systole. • Tip of the leaflet is pointing away from the LV apex.
Regional LV Dysfunction • Abnormal contraction of papillary muscle or underlying LV wall. • Inadequate support of the closed leaflet during systole
Abnormal Papillary Muscle Function • Hypertrophic cardiomyopathy • CAD • LV dilatation • Systolic dysfunction
Partial Papillary Muscle Rupture • Rupture of one of the several heads or • Partial disconnection of the base of the papillary muscle.
Response of the Left Ventricle • Acute/Early stages – hyperdynamic – Increased SV. • Chronic – ventricular dilatation. • Irreversible decline in LV systolic function.
Response of the Left Atrium Chronic MR • Gradual dilation of LA • LA compliance increases • Left atrial pressure- volume relationship is shifted downwards and to the right.
Response of the Left Ventricle Acute MR • Small non- compliant LA • Significant increase in LAP • V-wave in the LA pressure curve.
Response of the PA Chronic • Chronic mildly elevated LAP – passive elevation of PAP Acute • Severe elevation of LAP – passive elevation of PAP
Response of the PA cm/s Chronic
Response of the PA cm/s Acute, V wave
Response of the PA Evaluation of the Pulmonary Artery Pressure • TR jet velocity • Estimation of RAP
M-mode Finding • Increased in aortic root motion in systole.
M-mode Finding Seen in Mitral Regurgitation Exaggerated anterior motion of aortic root
Doppler Flow Mapping • Color flow Doppler • Several tomographic planes • A4C, • A3C, • PLAX, • PSAX.
Volume Flow at Two Intracardiac Sites Mitral Regurgitant SV = Transmitral SV – Transaortic SV