TEE assessment of massive left atrial thrombus due to mitral stenosis and atrial fibrillationJurnalul Român de Anestezie Terapie Intensivă 2013 Vol.20 Nr.2, 131-133

CAZURI CLINICE

Transesophageal echocardiography assessment of massive leftatrial thrombus due to mitral stenosis and atrial fibrillation

J. Barack1, P.E.F. Roman1, A.S. Grewal1, Inna Shats2, M. Dawood3, Alina M. Grigore1

1 Division of Cardiothoracic Anesthesiology, University of Maryland School of Medicine, Baltimore, Maryland, USA2 Department of Anesthesiology, Intraoperative Cardiac Sonographer, University of Maryland School of Medicine, Baltimore, Maryland, USA3 Department of Cardiac Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA

AbstractMitral stenosis, usually caused by rheumatic fever, contributes to significant worldwide morbidity and

mortality. Late intervention is associated with worse outcome, with complications including pulmonaryhypertension, atrial fibrillation and left atrial thrombus. We present the case of an elderly patient withmassive left atrial thrombus due to rheumatic mitral stenosis and discuss the assessment of mitral stenosiswith transesophageal echocardiography.

Keywords: mitral stenosis, transesophageal echocardiography, atrial thrombus

J Rom Anest Terap Int 2013; 20: 131-133

IntroductionRheumatic heart disease remains the most common

world-wide cause of mitral stenosis (MS). Significantreduction in mitral-valve area requires an increase inthe atrioventricular pressure gradient for maintenanceof cardiac output. Chronic increased left atrial pressureresults in atrial enlargement and dysrhythmias such asatrial fibrillation. Decreased atrial outflow and stagnantblood increases the risk of left atrial thrombus formationand embolic events. The gold standard assessment ofmitral stenosis is echocardiography, with particularattention on exclusion of thrombi [1].

Adresa pentru corespondenţă: Philip E.F. Roman, MD, MPHUniversity of Maryland Schoolof Medicine22 S Greene Street S11C03Baltimore, Maryland, USA 21201E-mail: proman@anes.umm.edu

Case reportA 72-year old Nigerian female, with a history of

rheumatic fever, cryptogenic stroke at 19 years oldand hypothyroidism, presented to an outside hospitalafter being found unresponsive. She was noted to bein atrial fibrillation and developed respiratory distressrequiring non-invasive ventilation. Transthoracicechocardiography (TTE) revealed severe MS and alarge left atrial thrombus. After transfer to our facility,transesophageal echocardiography (TEE) confirmedsevere MS with a valve area of 0.9 cm2 by pressurehalf-time, a 3.7 × 4 cm left atrial thrombus and severepulmonary hypertension. Cardiac catheterization de-monstrated non-occlusive disease, however thepatient’s respiratory status deteriorated and sherequired intubation and mechanical ventilation. She wasurgently taken to the operating room.

After placement of pre-induction radial arterial andpulmonary artery catheters, the patient was placed inTrendelenburg position to minimize the potential of thethrombus causing a ball-valve effect. With the surgeonspresent, anesthesia was induced uneventfully with eto-midate, fentanyl and rocuronium.

Roman et al.132

DiscussionRheumatic fever is caused by infection with group

A streptococci and is most frequently observed inchildren and adolescents. An autoimmune reaction,called molecular mimicry, against valvular proteins andcardiac myosin peptides causes the inflammation andscarring that is characteristic of rheumatic heartdisease. In its chronic form, the mitral valve is mostcommonly affected although valves may be involved[1].

Although the prevalence of rheumatic fever hasgreatly diminished in developed countries, the incidenceof rheumatic MS is still a common finding in the elderlyand foreign-born. The Euro Heart Survey found MSaccounts for 9.5% of native valve disease [2]. MSremains a significant cause of morbidity and mortalityand the prognosis is exceptionally poor in advancedcases without surgical intervention.

Echocardiographic evaluation of mitral stenosis isthe cornerstone of operative decision-making. Rheu-

Intraoperative TEE demonstrated an 8 cm leftatrium with giant thrombus (Fig. 1, Movie 1* – can beseen on www.jurnalul-anestezie.ro). Severe MSwas confirmed with a mean pressure gradient of 22mmHg, MVA of 0.59 cm2 by continuity equation and0.65 cm2 by pressure half-time (Fig. 2).

* First loop demonstrates severely enlarged left atrium, stenoticmitral valve and large thrombus in LA. Second loop is a modifiedright ventricle inflow-outflow view showing bowing of the intraatrialseptum and thrombus adherent to lateral and posterior walls ofLA. Third loop is a bicaval view again demonstrating thrombusadherent to majority of left atrium.

Fig. 1. Mid-esophageal view of bilateral atria demonstrates largethrombus (arrow) in left atrium (LA). Thrombus measures 4 cmin this view. Bowing of the intraatrial septum toward the rightatrium (RA) noted consistent with increased left atrial pressure

Fig. 2. Continuous Wave Doppler through mitral valve andcalculation of pressure half-time. Severe mitral stenosis with

Mitral Valve Area (MVA) of 0.65 cm2

A standard median sternotomy was performed andcardiopulmonary bypass (CPB) was initiated via asingle 25-French dual-stage venous cannula and a 19-French aortic cannula. After diastolic arrest, the leftatrium was exposed through the interatrial groove. The

left atrial wall was heavily calcified and a small segmentof non-calcified tissue was available for atriotomy. Asseen on preoperative echocardiography, the left atriumwas filled with organized thrombus. The thrombus wasextracted (Fig. 3) and the mitral valve was replacedwith a 27-mm bovine pericardial bioprosthesis. Thepatient was successfully weaned from CPB on lowdose epinephrine and vasopressin infusions.

Fig. 3. Surgeon’s view of left atrium after atriotomy performed.Large, organized thrombus noted in left atrium

The patient was extubated on postoperative day 1and discharged to a rehabilitation hospital on day 15.Due to the raw surface area resulting from the throm-bus extraction, she was anticoagulated with warfarinwith a goal INR of 2 for 6-months. The patient con-tinues to do well at time of publication.

TEE assessment of massive left atrial thrombus due to mitral stenosis and atrial fibrillation 133

References1. Fuster V, Rydén LE, Cannom DS, et al; American College of

Cardiology Foundation/American Heart Association Task Force.2011 ACCF/AHA/HRS focused updates incorporated into theACC/AHA/ESC 2006 guidelines for the management of patientswith atrial fibrillation: a report of the American College ofCardiology Foundation/American Heart Association Task Forceon practice guidelines. Circulation 2011; 123: e269-367

2. Iung B, Baron G, Butchart EG, et al. A prospective survey ofpatients with valvular heart disease in Europe: The Euro HeartSurvey on Valvular Heart Disease. Eur Heart J 2003; 24: 1231-1243

3. Baumgartner H, Hung J, Bermejo J, et al. Echocardiographicassessment of valve stenosis: EAE/ASE recommendations forclinical practice. J Am Soc Echocardiogr 2009; 22: 1-23

4. Manjunath CN, Srinivasa KH, Panneerselvam A, et al. Incidenceand predictors of left atrial thrombus in patients with rheumaticmitral stenosis and sinus rhythm: a transesophagealechocardiographyc study. Echocardiography 2011; 28: 457-460

5. Srimannarayana J, Varma RS, Satheesh S, Anilkumar R,Balachander J. Prevalence of left atrial thrombus in rheumaticmitral stenosis with atrial fibrillation and its response toanticoagulation: a transesophageal echocardiographic study.Indian Heart J 2003; 55: 358-361

Conflict of interestNothing to declare

Evaluarea ecocardiograficătransesofagiană a unui tromb masiv alatriului stâng datorat stenozei mitraleşi fibrilaţiei atriale

RezumatStenoza mitrală este cauzată cel mai adesea de

reumatismul articular acut şi contribuie semnificativ lamorbiditatea şi mortalitatea generală. Intervenţiaterapeutică tardivă este asociată cu un prognostic mairezervat şi cu complicaţii care includ hipertensiuneapulmonară, fibrilaţia atrială şi formarea trombilor înatriul stâng. Prezentăm cazul unui pacient vârstnic cuun tromb masiv al atriului stâng datorat stenozei mitralereumatismale şi discuţia legată de evaluarea pacienţilorcu stenoză mitrală prin intermediul ecocardiografieitransesofagiene.

Cuvinte cheie: stenoză mitrală, ecocardiografietransesofagiană, tromb atrial

matic mitral stenosis results from commissural fusion,chordal shortening and leaflet thickening and calcifi-cation. Symptoms due to MS typically occur when theMVA decreases to < 1.5 cm2 from 4-5 cm2 as cardiacoutput falls. American Society of EchocardiographyLevel 1 recommended assessment of MS severityincludes the estimation of the diastolic transmitralpressure gradient with the simplified Bernoulli equation(p1-p2 = 4V2), 2 dimensional basal short-axis planimetryand calculation of the pressure half-time (MVA = 220/PHT ½). Level 2 recommendations include the conti-nuity equation and proximal isovelocity surface area(PISA) method [3]. Associated findings, such as leftatrial enlargement, left atrial spontaneous contrast andpulmonary hypertension also assist with grading mitralstenosis.

Mitral stenosis and resultant low flow state predis-posed to left atrial thrombus formation, and thromboem-bolic complications are frequently seen. This risk issignificantly increased with atrial fibrillation (AF) [1].Thrombus formation is seen in 33% of rheumatic MSpatients with AF compared to 2.4-13.5% with sinusrhythm. [4]. Advanced age, LA enlargement, meanMV gradient and dense SEC are predictors of throm-bus among those remaining in SR [5]. Intracardiacthrombus is most commonly found in the left atrialappendage. Thrombus may also be seen in the left atriumwith severely stenotic valves as seen in this case.

Transesophageal echocardiography is highly sen-sitive for detection of atrial chamber thrombus. TTEmay be limited in obtaining optimal imaging windows,particularly in patients who are intubated. The diffe-rence between the thrombus size measurementsbetween the two TEE may have been due to difficultyperforming a detailed exam in a sedated, non-intubatedpatient. The more representative TEE study wasperformed in the Operating Room under general anes-thesia. Imaging of the mitral valve with TEE is fre-quently superior due to proximity of the probe to thevalve, resulting in higher temporal resolution. This caseillustrates the importance of TEE in evaluation of mitralstenosis and intracardiac masses.