二尖瓣的病理生理学课件.ppt

1、 Alan Sihoe Cardiothoracic Surgery Teaching Round 2nd August 20022020年10月2日1Epidemiology 1998 in the UK:6471 first time valve replacements of which 28%MVR Numbers increasing2020年10月2日2 Mitral Annulus:fibro-muscular skeleton Anchors base of valve leaflets Leaflets:conn tissue+muscle+vessels/nerves An

2、terior(aortic):larger;1/3 of annulus Posterior(mural):2/3 of annulusAnatomy2020年10月2日3Anatomy Papillary muscles:Anterolateral Posteromedial Chordae tendinae 1st,2nd,3rd order Approx 25 major chordal trunks 100 attachments to leaflets No consensus on timing of muscle activity with cardiac cycle2020年1

3、0月2日4Annular dynamics Annular size Increases in late systole(maximum in diastole)Contracts in pre-systole(minimum in midsystole)Annular shape More eccentric in systole Annular position Moves up towards LA in diastole Moves down towards LV apex in systole2020年10月2日5Leaflet dynamics Opening Starts in

4、center,moving to edges Flapping of edges at max.opening Closing(begins in late diastole)Bulging at base/annular attachment Leaflet ascends towards LA Bulging rolls from annulus to edge2020年10月2日6 Aetiology:Rheumatic Male:female ratio is 1:2-3 Acquired early(30mmHg:pulm transudation reduced lung comp

5、liance Pulm art systolic pressure 60mmHg impedes RV emptying right heart failure Ultimately irreversible pulm vascular changes2020年10月2日11MS:Natural historyProgressive life-long diseaseLong latencySymptoms:i.Low cardiac output:dyspnoea,fatigueii.Pulmonary congestion/HT(orthopnea,PND)right heart fail

6、ure hemoptysisiii.Atrial fibrillation/Thromboembolismiv.Cardiac cachexia2020年10月2日12MS:Natural history Onset of symptoms to disability:10 years 10 year survival:Asymptomatic(NYHA class I)80%(progression)Symptomatic(NYHA class III)20%Causes of death:CHF 60-70%Systemic embolism 20-30%Pulmonary embolis

7、m 10%Infection 1-5%2020年10月2日13MS:Investigations CXR:LA enlargement,pulm congestion ECG:LA enlargement(notched P in II,V1)atrial arrhythmias?RVH Echo:valve area,LA/LV dimensions Doppler:measures pressure gradients TOE:better mitral/LA visualization Cardiac catheter:not essential Assocd disease;LV ve

8、ntriculography&pressures2020年10月2日14MS:Medical therapy Pharmacological Tx of mild heart failure,bronchitis,arrhythmias,hemoptysis Endocarditis prophylaxis Anticoagulation:Hx of AF/thromboembolism Balloon(or open)Valvuloplasty2020年10月2日15MS:Indications for surgerySymptomatic(NYHA class III-IV):MVR1.h

9、 long-term survival10 year survival:0-20%90%(89%at 15 yrs)2.h functional capacityValve area 1-1.5cm2 (normal 4-6 cm2)Systemic emboli2020年10月2日16MS:Indications for surgery Class I-II:controversial Risk of SCD if asymptomatic:negligible Survival not improved by MVR?role of valvotomy(pulmonary HT,AF)MV

10、R indicated when:Valve area NYHA class II+2020年10月2日17Aetiology more diverse than MSMyxomatous degenerationLeading cause in West(30-70%)Defective fibroelastic tissue floppy valveMost asymptomaticComplicated by annular dilatation,chordal rupture,endocarditisRheumatic disease next most common2020年10月2

11、日18MR:Carpentier classificationi.Normal leaflet motionAnnular/ventricular dilatationLeaflet disease/perforation2020年10月2日19MR:Carpentier classificationii.Excessive leaflet motion(prolapse)Chordal/papillary muscle elongation or rupture2020年10月2日20MR:Carpentier classificationiii.Restricted leaflet/cho

12、rdal motione.g.fibrosis,calcification,retraction 2020年10月2日21MR:Aetiology1.Mitral AnnulusMyxomatous degenerationSenile calcificationFunctional dilatation(e.g.myocarditis)Ring abscessMarfans2020年10月2日22MR:Aetiology2.Mitral leafletsRheumatic disease,endocarditis(1-30%)Unknown why some develop MS,other

13、s MRFibrocalcific leaflet thickening(without fusion)Chordae shortened,annulus dilatedalso:congenital,connective tissue disease2020年10月2日23MR:Aetiology3.ChordaeIschaemiaMyxomatousInfectiveConnective tissueTraumaIdiopathic2020年10月2日24MR:Aetiology4.Papillary muscle(10-25%)Dysfunction/ruptureIHD/MI:musc

14、le&annular injuryfrank rupture rare,usually fatalesp.Posteromedial muscleAlso:abscess,sarcoid/amyloid,myocarditisMalalignmente.g.LV aneurysm,dilatation,myopathy2020年10月2日25MR:HemodynamicsAcute:J LA pressure,pulm oedemaChronic:LA/PV compliance:i pulm congestnRegurgitant volume depends on:i.Mitral ori

15、fice sizeii.LV-LA pressure gradientiii.Heart rateMedical Tx aims to control above factorsesp.decrease afterload to reduce LV dilatation2020年10月2日26MR:Cardiac adaptations LV:h preload,i afterload LV dilated,more spherical,thinned Increased SV(O2 consumption not markedly h)But decompensation can gradu

16、ally occur LA:h size in chronic MR h compliance Less thromboembloism,AF than MS2020年10月2日27MR:Symptoms Acute:pulmonary congestion&oedema Chronic:may be prolonged asymptomatic phase Risk of endocarditis Congestive heart failure&fatigue Right heart failure2020年10月2日28MR:Investigations CXR:LA/LV enlarg

17、ement ECG:normal;LVH,?AF/arrhythmias Echo:leaflet morphology&function Chamber dimensions,LV function Doppler colour mapping Cardiac catheter:assess coronaries,LV MRI:Dx,LV volumes,regurgitant fraction2020年10月2日29MR:Medical therapy Mainstay:Afterload reduction i regurgitant volume i pulm congestion i

18、 LV volume i mitral orifice but:ongoing LV volume overload 10%class I-II progress to III-IV per year Class II-III survival on medical Mx:5 year:50%10 year:25%2020年10月2日30MR:Natural history Variable aetiology difficult to predict Difficult to identify those progressing to irreversible LV damage Progn

19、ostic indicators:LV function Degree of regurgitation Underlying aetiology(esp.CAD)2020年10月2日31MR:Indications for surgeryAcute:muscle/chordal rupture with shock Immediate MVRChronic,NYHA class II-IV:MVRAim for surgery before irreversible LV changeLV dimension is a predictor of outcome2020年10月2日32演讲完毕，谢谢观看！Thank you for reading!In order to facilitate learning and use,the content of this document can be modified,adjusted and printed at will after downloading.Welcome to download!汇报人：XXX 汇报日期：20XX年10月10日33