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» Case of the week »
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| Role of echocardiography in mitral valve repair due to mitral valve prolapse |
| Author : Rosmarini Hapsari |
| Senin, 07 September 2009 10:59:43 |
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| Dipresentasikan : Jum'at, 28 Agustus 2009 |
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INTRODUCTION
Mitral Valve Prolapse (MVP) is one of the most prevalent cardiac valvular abnormalities. Using standardized echocardiographic criteria, a community based study showed that MVP syndrome occurs in 2,4% percents of the population. Echocardiography plays an essential role in the diagnosis of MVP and has been delineation of this syndrome. To establish the diagnosis, the two dimensional (2D) trans-thoracic echocardiography must show that one of or both mitral valve leaflets billow by at least 2 mm into the left atrium during systole in the long axis view,1
The role of two dimensional (2D) trans-esophageal echocardiography and three dimensional (3D) transesophageal echocardiography provides additional details regarding integrity of the mitral valve apparatus.1
Echocardiography has become a major diagnostic tool in arsenal of clinical cardiology for real time imaging of cardiac dynamics. One of the most significant developments of the last decade was the introduction of three dimensional (3D) imaging and its evolution from slow and labor-intense reconstruction to real time volumetric imaging.2
Most studies using 3D echocardiography have focused on the evaluation of the mitral valve. These studies have played a crucial role in describing and quantifying the geometry of the mitral annulus, leaflet surface, tethering distances, and tenting volume. These studies have also defined and quantified the relationship between the mitral apparatus and the position of the papillary muscles, thus providing insight into the pathophysiology of mitral regurgitation.2
AIM OF PRESENTATION
The aim of this presentation is to understand role of echocardiography in mitral valve repair due to mitral valve prolapse.
CASE ILLUSTRATION
A male patient 51 years old came to National Cardiac Centre Harapan Kita (NCCHK) on May 26th 2009 with chronic heart failure since 1 month before admission. There is no history angina pectoris, syncope, nor fever. His coronary artery disease risk factors are hypertension and ex smoker.
On physical examination during admission the vital signs were about normal. However from cardiac auscultation pan systolic murmur grade 3/6 best heard in apex and radiated to lateral side. There was no gallop, accentuated P2 nor rhales. ECG showed atrial fibrillation with normal ventricular response, normal QRS axis, with ST depression in V5-V6. Chest X-ray revealed slight cardiomegaly (CTR 60%), flattened cardiac waist without any sigh of pulmonary congestion.
The working diagnosis is CHF fc II ec MR. Echocardiography then was planned to confirm the diagnosis. Two dimension (2D) transthoracic echocardiography showed: Dilatation LA, good systolic LV function EF 62%, decrease RV contractility (TAPSE 1,3 cm), global normokinetic. LV EDD 45 mm, LV ESD 30 mm, MR severe ec prolapse of PML (P2,P3) with partially flail of P3, suspect chordal ruptured. TR mild TVG 52 mmHg, (estimated RAP 15 mmHg), mild PR (+), mPAP 50 mmHg. Conclusion: MR severe ec prolapse PML (P2,P3) and partially flail P3, with suspect chordal ruptured, TR mild, PH severe, good systolic LV function EF 62%, decreased RV contractility.
Mitral valve surgery was planned with intra-operative TEE to confirm the valve morphology and the MR mechanism . Before surgery, the patient underwent coronary angiography to evaluate the presence of CAD. The result was : normal LM, LAD stenosis 80% after D1, mid irregular; LCx normal, RCA discrete stenosis 40% proximal, discrete stenosis 80-85% distal. LV graphy : MR grade III-IV MR. Conclusion: CAD 2VD, MR grade III-IV.
The diagnosis of CHF func, III ec MR severe, AFNVR, CAD 2VD was established. The patient was given ascardia 1x80 mg, noperten 1x10 mg, bisoprolol 1x2,5 mg, aldazide 1x25 mg, simarc 1x1 mg, digoxin 1x 0,125 mg, allupurinol 1x300 mg, ISDN 3x5 mg, simvastatin 1x10 mg. The laboratory findings were within normal limits. Then CABG with MV repair was scheduled as suggested by surgical conference.
Surgery was performed at August 4th 2009. Intra-operative TEE (2D and 3D) was performed. The result: MR severe ec flail PML.
Surgery performed CABG 2x LIMA-LAD, SVG-PDA ; MV repair and annuloplasty with ring Physio no.28.
Surgical finding:
• large size cordis, decreased contractility
• relative good native coronary unless small OM, good LIMA and SVG
• mitral valve: thin leaflet, good AML, PML: small P1 and little retraction; redundant P2; redundant P3; dilatation fissure intra scallop; perforation(-); annulus not dilatation but morphology abnormal; rupture chordae(-)
The patient was doing well after surgery with stabil hemodinamic. Problem in
ICU: melena ec GIT bleeding. Patient in stabil condition in ICU and moved to adult ward with treatment thromboaspilet 1x80 mg, lasix 1x40 mg, simvastatin 1x20 mg, bisoprolol 1x2,5 mg, captopril 3x2,5 mg, panadol 3x1 tab.
Post operative trans-thoracal echocardiography was performed to evaluate the result of the surgery (12/8/2009). It showed: LA dilatation, good systolic LV function EF 55%, decreased RV contractility (TAPSE 0,8 cm), uncoordinated/post surgical motion at anteroseptal and septal normokinetic, mitral valve post repair: good opening, residual MR(-), mild MS (MVA 1,6 cm2, mean MVG 5 mmHg), TR mild TVG 27 mmHg. Conclusion: mitral vale post repair good functioning without residual MR; Mild MS, good systolic LV EF 55%; uncoordinated/post surgical motion anteroseptal and septal ; decreased RV contractility, minimal pericardium effusion, pleural effusion (+).
Literature Review
Mitral Valve
Anatomy
The mitral valve is composed of leaflets (valve tissue), mitral annulus, chordae tendinea, papillary muscle and the left ventricle. Anterior and posterior leaflet as well as the commisures (posteromedial and anterolateral) constitute the valvular tissue. They are inserted on the entire circumference of the mitral annulus. Commissures are identified using two anatomical landmarks: the axis of corresponding papillary muscles and the commissural chordae which has a specific configuration. Eight millimeters of valvula tissue separate the free edge of the commisures from the annulus. During the open commissurotomy, the surgical incision should respect this interval. Otherwise, its extension to the annulus may cause mitral regurgitation.3
The mitral valve is separated into eights segmen. Anterolateral and posteromedial commissures are two segments. Two indentations of the posterior leaflet divide this structure into three anatomically individualized scallops. The three scallops of the posterior leaflets are identified as P1 (anterior scallop), P2 (middle scallop), P3 (posterior scallop). The three corresponding segments of the anterior leaflet are A1 (anterior segment), A2 (middle segment), A3 (posterior segment). This anatomical nomenclature is the basis of segmental valve analysis, allowing a precise location of valve pathology (leaflet prolapse or restriction), which is critical importance while performing reconstructive surgery.3
On the atrial surface of the leaflets are two zones, one peripheral smooth zone and one central rough zone. A curved line; called the coaptation line separates these two areas. The rough zone represents the coaptation surface of the valve.This zone is the insertion site of most of the chordae tendinea.3
Mitral Valve Prolapse
Mitral valve prolapse (MVP) is a variable clinical syndrome that results from diverse pathogenic mechanism of one or more portion of the mitral vale apparatus , valve leaflets, chordae tendinea, papillary muscle and valve annulus. The syndrome is twice as frequent in female as in males.
Most frequently, MVP occurs as a primary condition that is not associated with other disease and can be familial or non familial. The characteristic systolic click and mid-to-late systolic murmur is a major diagnostic criteria. 1
The vast majority of patients with MVP are asymptomatic and remain so throughout their lives. Patients may complain syncope,presyncope,palpitation,chest discomfort, and when MR is severe symptoms of diminished cardiac reserve. In patients with MVP and severe MR, the symptoms of the latter (fatigue,dyspnoe and exercise limited) may be present. Patients with MVP may akso develop symptomatic arrhythmia.1
The understanding of valve pathology is facilitated by the use of the “pathophysiological triad” first described by Carpentier. This triad is composed of etiology (cause of the disease), valve lesions (resulting from the disease), and valve dysfunction (resulting from the lesions). These distinctions are relevant because long term prognosis depends on etiology; whereas treatment strategy and surgical techniques depends on valve dysfunction and lesions.3
Carpentier’s functional classification is used to describe the mechanism of mitral regurgitation. This classification is based on the opening and closing motions of the mitral leaflets. Patients type I dysfunction have normal leaflet motion. Mitral regurgitation in this patient to annular dilatation or leaflet perforation. There is an increased leaflet motion in patients with type II dysfunction, with the free edge of the leaflet overriding the plane of the annulus during systole (leaflet prolapse). The most common lesions responsible for typeII dysfunction are chordal elongation or rupture and papillary muscle elongation or rupture. Patients with type IIIA dysfunction have a restricted leaflet motion during both systole and diastole. The most common lesions are leaflet thickening/restraction, chordal thickening/shortening or fusion, and commissural fusion. Mitral regurgitation is most often associated with some degree of mitral stenosis, The mechanism of mitral regurgitation in type IIIB dysfunction is restricted leaflet motion during systole. Left ventricular enlargement with apical papillary muscle displacement causes this type of valve dysfunction.3
Carpentier’s Classification6
Indication of surgery. Several factors such as severity of mitral regurgitation, left ventricular function, symptoms, etiology, overall surgical risk (age,comorbid risk factor) and the likelihood of valve repair should be taken into consideration to surgery. Patients with severe mitral regurgitation, surgical treatment should be considered early even in the absence of symptoms, before left ventricular dysfunction occurred, especially if valve repair is feasible and the patient does not present additional comorbid risk factors.3
ROLE OF ECHOCARDIOGRAPHY IN MITRAL VALVE REPAIR
Two Dimensional (2D)Transthoracal Echocardiography
Two dimensional (2D) transthoracal echocardiography can confirm diagnostic, examine dimension of cardiac chamber and also provide valuable information regarding LV function and size. Two dimensional (2D) transthoracal echocardiography has also revealed prolapse of the tricuspis an aortic valves in approximately 20% patient with MVP. Sign of mitral valve prolapse: valve prolapse of 2 mm or above the mitral annulus in the long axis parasternal view and other views.7 Prolapse is associated with annular dilatation, leaflet thickening or elongation. Regurgitation usually directed away from the prolapsing leaflet7
Colour Doppler imaging is the primary echocardiography tool for detection and quantitation of mitral regurgitation. The characteristic of a true mitral regurgitation jet are as follow 1). There is evedende of proximal flow acceleration (proximal isovelocity surface area (PISA)),2) the flow confirms to the appearance of a true jet or ejection flow with a vena contracta, 3). The downstream (left atrial) appearance is consistent with a volume of blood being ejected through a relatively constraining orifice, 4) the flow signal is appropriately confined to systolic and 5). The Color Doppler signal are appropriate in color for the anticipated direction and/reveal the appropriate variance of turbulence.5
Semiquantitative and quantitative Doppler methods of regurgitant volume using maximal jet length, area, ratio of jet to left atria and also calculation of regurgitant volume has been used to assess the severity of mitral regurgitation.3
The jet of mitral regurgitation may be either central, peripheral, single or multiple and may be eccentric within the left atrium and impinge on the wall. The direction taken by the mitral regurgitation jet provides valuable clues as to the etiology of mitral regurgitation. An eccentric jet suggest an anatomic abnormality resulting in flail or partial flail of one leaflet. As such a posterior flail leaflet generally results in an anteriorly directed jet, whereas the converse is true for an anterior flail leaflet.5
From two dimensional (2D) transthoracal echocardiography we could defined timing operation for patient with MR (based on EF and LV ESD). Factors influencing timing of surgery for MR include symptoms, LV ejection fraction, LV ESD, atrial fibrillation, and pulmonary hypertension).8 In most cases, mitral valve repair is the operation of choice for those with suitable valvular anatomy and when appropriate surgical skill and expertise are available. In an asymptomatic patient with severe MR and normal LV function, mitral valve repair may be contemplated to preserve LV size and function and prevent the sequelae of chronic MR. 9
Recommendations for Mitral Valve Surgery in Nonischemic Severe Mitral Regurgitation9
Class I
1. Acute symptomatic MR for which repair is likely.
2. Patients with NYHA functional class II, III, or IV symptoms with normal LV function defined as EF >0.60 and ESD <45 mm.
3. Symptomatic or asymptomatic patients with mild LV dysfunction, EF 0.50 to 0.60, and ESD 45 to 50 mm.
4. Symptomatic or asymptomatic patients with moderate LV dysfunction, EF 0.30 to 0.50, and/or ESD 50 to 55 mm.
Class IIa
1. Asymptomatic patients with preserved LVfunction and atrial fibrillation.
2. Asymptomatic patients with preserved LVfunction and pulmonary hypertension (PA systolic pressure >50 mm Hg at rest or >60 mm Hg with exercise).
3. Asymptomatic patients with EF 0.50 to 0.60and ESD <45 mm and those with EF >0.60 and ESD 45 to 55 mm.
4. Patients with severe LV dysfunction (EF <0.30 and/or ESD >55 mm) in whom chordal preservation is highly likely.
Class IIb
1. Asymptomatic patients with chronic MR with preserved LV function for whom mitral valve epair is highly likely.
2. Patients with MVP and preserved LV function who have recurrent ventricular arrhythmias despite medical therapy.
Class III
Asymptomatic patients with preserved LV functionfor whom significant doubt exists about the feasibility of repair.
Two Dimensional (2D) and Three Dimensional (3D) Tranesophageal Echocardiography
Two dimensional (2D) transesophageal echocardiography and three dimensional (3D) transesophageal echocardiography provides additional details regarding integrity of the mitral valve apparatus.
Two dimensional (2D) transesophageal echocardiography could increase the understanding of more complex abnormalities of MV apparatus an individual scallop identification assessment of mitral valve but demands specialist skill and experience.10
Three dimensional echocardiography play a role in the determination of the mechanism and severity of mitral regurgitation.3 Three dimension visualization of the mitral valve used a wide-frame display which eas instrumental in decribing the saddle shape of the mitral annulus and redefining the diagnostic criteria for mitral valve prolapse.2
Three-dimensional (3D) transesophageal echocardiograph is feasible and provides a detailed anatomic depiction of the mitral valve. In patients with severe mitral regurgitation due to mitral valve prolapse, it allowed to precisely locate the diseased portion of the leaflets, visualize its extension and appreciate its relations to important anatomic landmarks like the valve commissures. Moreover, in patients with mitral valve repair, the technique allowed measurements of the volume of prolapsing tissue that corresponded well to the volume of resected tissue by the surgeon.This approach should be of value in the preoperative assessment of patients with severe mitral insufficiency due to mitral valve prolapse, providinga a complete visualization of the valve before he intervention and possibly a better prediction of the feasibility of valve repair.11
DISCUSSION
A male patient 51 years old was diagnose as CHF fc II ec MR severe ec MVP and CAD (2 VD). The diagnosis of MR due to MVP was confirmed by echo.
From two dimensional (2D) transthoracal echocardiography we found MR severe prolapse PML (P2,P3) and partially flail P3, with suspect chordal ruptured based on: displacement of posterior mitral valve >2 mm from parasternal long axis, Scallop P2P3 from parasternal short axis, dilatation LA, jet to LA > 50%, density of mitral Doppler look dense. The direction jet of mitral regurgitation eccentric within the left atrium and impinge on the wall give the prediction of the etiology of mitral regurgitation. From the echo we found an eccentric jet to anteriot suggest a partially flail P3.
From two dimesional (2D) transthoracal echocardiography we can classified the mitral abnormality into type II dysfunction based on Carpentier’s classification. There is an increased leaflet motion in patients with type II dysfunction, with the free edge of the leaflet overriding the plane of the annulus during systole (leaflet prolapse).
The role of echocardiography in mitral valve repair to make diagnose about abnormality mitral valve and also determining the mechanism and severity of mitral regurgitation. Carpentier’s functional classification can be used to exactly describe the underlying mechanism of mitral regurgitation.
From two dimensional (2D) transesophageal echocardiography intraoperative we found the precise location of valve dysfunction using segmental valve analysis. In this patient we found mitral valve prolapse in posterior mitral leaflet (Scallop P2-P3). From three dimensional (3D) transesophageal echocardiography intraoperative we found more clearly location of prolaps in posterior mitral leaflet (Scallop P3), flail in posterior mitral leaflet (Scallop P2 more severe than P3) due to surgeon view (from LA). The superior usefull of three dimensional (3D) tranesophageal echocardiography is better orientation of abnormality of mitral leaflet from surgical view due to abnormality structure mitral valve on operation table compare to two dimensional (2D) transesophageal echocardiography.
From surgical finding, it was reported that the mitral valve thin leaflet, good AML. PML: small P1 and little retraction; redundant P2; redundant P3; dilatation fissure intra scallop. The finding similar to the result of three dimensional transesophageal echocardiography intraoperative showed that role of echocardiography in mitral valve repair.
SUMMARY
Echocardiography examination plays a very important role in mitral valve repair due to mitral valve prolapse. Each modalities have its role in gaining information used for the management of MVP. The 2 D TTE is used to provide precise information regarding MV anatomy. While TEE (2D) has the advantage of increasing the understanding of more complex abnormalities of MV apparatus and individual scallop identification. Hence, with three dimensional (3D) transesophageal echocardiography we found better orientation of abnormality of mitral leaflet from surgical view (from LA) due to abnormality structure mitral valve on operation table compare to two dimensional (2D) transesophageal echocardiography. This approach should be of value in the preoperative
assessment of patients with severe mitral insufficiency due to mitral valve prolapse, providing a complete visualization of the valve before the intervention and possibly a better prediction of the feasibility of valve repair.
The echocardiography result ( TTE, 2D TEE, and 3D TEE) have a good correlation with the surgical findings
REFERENCES
1. Libby P, Bonow RO, Mann DL. Brauwald’s Heart Disease. In: Textbook of Cardiovascular Medicine, 8th Edition. 2007. Saunders & Elsevier. 1657-77
2. Robert M.Lang, Victor MA, Petra SN. Three Dimensional Echocardiography. JACC 2006;48:2053-69
3. Sellke FW, Nido PJ, Swanson SJ. Sabiston and Spencer.In Textbook of surgery of the chest, 7th Edition. 2005.Saunders and Elsevier. 1299-3352006
4. Marshall S, Runge S. Netter’s Cardiology ,6th edition.2005. Saunders.283-90
5. Harley F, Armstrong WF, Ryan T. Feigenbaums’s Echocardiography. 6th Edition. 2005. Philadelphia:Lippincott Williams & Wilkins. 308-20
6. Fedak PW, McCarthy PM, Bonow RO. Evolving Concepts and Technologies in Mitral Valve Repair. Circulation 2008;117:963-74
7. Solomon DS, Bulwer B, Libby P. Essential Echocardiography. 2007.Human Press. 255-85 Armstrong WF, Aurigemma GP, Beller GA. ACC/AHA/ASE 2003 Guidelines Update for the Clinical Application of Echocardiography. A report of the American College of Cardiology/ American Heart Association Task Force on Practice Guidelines
8. Armstrong WF, Aurigemma GP, Beller GA. ACC/AHA 2000 Guidelines Management of Patients With Valvular Heart Disease.A report of the American College of Cardiology/ American Heart Association Task Force on Practice Guidelines
9. Bonow RO, Carabello B, Leon AC, Edmunds LH. Armstrong WF, Aurigemma GP, Beller GA. ACC/AHA/ASE 2003 Guidelines Update for the Clinical Application of Echocardiography. A report of the American College of Cardiology/ American Heart Association Task Force on Practice Guidelines
10. Delabays A, Jeanrenaud X, Chassot PG, Segesser LK. Localization and quantification of mitral valve prolapse using three dimensional echocardiography. Eur J Echocardiography 2004;5:422-29
11. Macnab A, Jenkins NP, Bridgewater BJ, Hooper TL. Three dimensional echocardiography is superior to multiplane trans esophageal echo in the asseament of regurgitant mitral valve morphology. Eur J Echocardiography 2004;5;212-22
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