Left ventricular pseudoaneurysm is a rare
complication of myocardial infarction.
Differentiation between true and false aneurysms,
although difficult, is crucial, because of the
different treatment options they entail.
We present a rare case of a giant pseudoaneurysm
of the left ventricle related with a previous
myocardial infarction. The present case highlights
the pivotal role of magnetic resonance imaging
for differential diagnosis between these entities

Andrade, LC

Caseiro-Alves, F

Donato, P

Ferreira, MJ

CHUC Institutional Repository

Left ventricular false aneurysm characterized by cardiovascular magnetic resonance and late enhancement technique

Name not available

Repositório Institucional dos Hospitais da Universidade de Coimbra

  35Caso Clínico / Radiological Case ReportCorrespondênciaLuísa Costa AndradeMedical Imaging Department and Faculty ofMedicine, University Hospital of  Coimbra.Praceta Mota Pinto,3000-075 Coimbra, PortugalEmail: isa.c.andrade@hotmail.com1Radiology Resident - Medical ImagingDepartment and Faculty of  Medicine,University Hospital of  Coimbra.2Radiologist - Medical Imaging Department andFaculty of  Medicine, University Hospital ofCoimbra.3Cardiologist - Cardiology Department andFaculty of  Medicine, University Hospital ofCoimbra.4Radiologist (Head of  Department) - MedicalImaging Department and Faculty of  Medicine,University Hospital of  Coimbra.ResumoO pseudoaneurisma do ventrículo esquerdo é umacomplicação rara do enfarte do miocárdio. Adistinção entre os aneurismas verdadeiros e falsos,apesar de difícil, é crucial devido às diferentesopções de tratamento que eles acarretam.Apresentamos um caso raro de umpseudoaneurisma de grandes dimensões doventrículo esquerdo, relacionado com um enfartedo miocárdio antigo. O presente caso destaca opapel fundamental da ressonância magnética parao diagnóstico diferencial entre estas duasentidades.Palavras-chaveVentrículo esquerdo, ressonância magnética,enfarte do miocárdio, pericárdio,pseudoaneurisma.AbstractLeft ventricular pseudoaneurysm is a rarecomplication of  myocardial infarction.Differentiation between true and false aneurysms,although difficult, is crucial, because of  thedifferent treatment options they entail.We present a rare case of  a giant pseudoaneurysmof  the left ventricle related with a previousmyocardial infarction. The present case highlightsthe pivotal role of  magnetic resonance imagingfor differential diagnosis between these entities.Key-wordsLeft ventricle, magnetic resonance imaging,myocardial infarction, pericardium,pseudoaneurysm.LEFT VENTRICULAR FALSE ANEURYSM CHARACTERIZEDBY CARDIOVASCULAR MAGNETIC RESONANCE AND LATEENHANCEMENT TECHNIQUECARACTERIZAÇÃO POR RESSONÂNCIA MAGNÉTICA CARDÍACA ETÉCNICA DE REALCE TARDIO DE UM PSEUDOANEURISMA DOVENTRÍCULO ESQUERDOLuísa Costa Andrade1, Paulo Donato2, Maria João Ferreira3, Filipe Caseiro Alves4IntroductionRupture of  the left ventricular free wall is a catastrophiccomplication occurring in 4% of  patients after acutemyocardial infarction. Though rare, the rupture may becontained by adherent pericardium or scar tissue, giving riseto a pseudoaneurysm.Differentiation between true and false aneurysms, althoughdifficult, is crucial, because true aneurysms tend to be managedconservatively whereas false aneurysms, because of  the riskof  rupture, are usually treated with urgent surgery.Distinguishing these two subtypes is therefore critical andcardiovascular magnetic resonance has a major role. Thepresent case highlights the pivotal role of  non-invasive imagingmodalities, mainly magnetic resonance (MR) and pericardialdelayed enhancement technique, for differential diagnosisbetween these entities in order to ensure appropriatemanagement of  these patients.Recebido a 20/01/2014Aceite a 25/05/2014Case ReportA 78 year-old man with a history of  myocardial infarction (8years before) was admitted to our hospital with dyspnea(NYHA III), without angina. He had a mechanical aortic valveprosthesis since 2001. Routine transthoracicechocardiography showed a saccular extra-cardiac structure.A multidetector computed tomography (MDCT) waspreformed and showed an aneurysmatic enlargement of  theanterior-inferior left ventricular wall measuring about 10cm.After administration of contrast material the lesion filledintensely, allowing us to exclude a pericardial cyst. We werenot able to see the communication with the left ventricle andwe were unable to distinguish a true aneurysm from apseudoaneurysm (figure 1).Cardiac MR imaging was performed and showed a largenarrow-necked aneurysmal dilatation, arising from the infero-lateral wall of  the left ventricle (LV) It was clearlydemonstrated the communication of  the dilatation with theleft ventricle (figure 2).ACTA RADIOLÓGICA PORTUGUESAJaneiro-Abril 2014   nº 101 Volume XXVI   35-3836The lesions are usually first identified with echocardiographyor catheter angiography, but with the widespread availabilityof  MDCT, some of  these aneurysms are now being detectedon routine CT.Regarding catheter angiography, left ventriculography isconsidered the gold standard imaging modality, with diagnosticaccuracy of  around 85% (1). However, it is an invasivetechnique that also exposes the patient to ionizing radiationand presents a risk of possible embolization. On the otherhand, transthoracic echocardiography is usually the first non-invasive imaging technique used for the assessment of  patientswith myocardial infarction due to its accessibility andrepeatability, but the differential diagnosis between ventricularpseudoaneurysms and true aneurysms based onechocardiographic findings is sometimes difficult mainly dueto the limited narrow echo window. Another importantlimitation of  echocardiography is the inferior rate of  detectionof  left ventricular thrombi comparing to cardiovascular MRimaging (2). MDCT is usually a second-line option in thiscontext because it requires the use of iodinated contrast andexposes the patient to ionizing radiation. The advantage ofthis technique over MR imaging is the higher spatial resolutionwhich enables accurate assessment of  the coronary arterysystem.Nevertheless, cardiovascular MR imaging is the most preciseimaging tool that enables correct characterization anddistinction between true and false LV aneurysms and enablestissue characterization.True LV aneurysms occur most commonly in the setting of  atransmural myocardial infarction and are defined as an areaof  bulging of  the thinned and scarred myocardium which isdyskinetic, but involve the full thickness of  the wall (3). Earlyfocal ventricular expansion has been reported within 48h inapproximately 50% of  patients who develop aneurysms, whilethe remaining patients have evidence of  aneurysm formationat 2 weeks (4).They are more commonly found in the anteroapical wallfollowing occlusion of  the left anterior descending coronaryartery. Less common causes include trauma, Chagas diseaseand sarcoidosis (4).Rupture of  the LV free wall is a catastrophic complicationoccurring in 4% of  patients after acute myocardial infarctionand in 23% of  those who die of  myocardial infarction (5).Though rare, the rupture of  the ventricular free wall may becontained by adherent pericardium or scar tissue, giving riseFig. 1 - Axial unenhanced CT scan (A) shows a homogeneous mass withdense fluid attenuation, adjacent to infero-lateral left ventricular wall limitedby pericardium with small calcifications. Axial contrast-enhanced CT scan(B and C) shows intense partial filling of  the lesion with contrast material. Dand E images show coronal and sagittal reformations, respectively.Fig. 2 - T2-w black-blood half-Fourier turbo spin-echo (HASTE) MR images- transverse (A) and sagittal (B) views show wall rupture of  the left ventricularinfero-lateral wall, resulting in a large left ventricular pseudoaneurysm withthrombus. Vertical long-axis view (C) and short-axis view (D) through theplane of  the neck of  the pseudoaneurysm, obtained with a fast steady-statecine MR imaging sequence, show a narrow interruption (arrows) of  the infero-lateral left ventricular wall and formation of  a bulging cavity. Note that themaximal width of  the orifice is shorter than the maximal parallel internaldiameter, a typical feature of  false aneurysm. Oblique vertical long-axis view(E and F) and short-axis view (G) steady-state free precession MR images,through the plane of  the neck of  the pseudoaneurysm, clearly demonstratethe pseudoaneurysm and its communication with the left ventricle. There isa signal void jet flow (arrows) through the aneurysmal sac during the systoleand another during diastole into the left ventricle.Fig. 3 - Vertical long-axis (A) and horizontal long-axis (B) views obtainedwith inversion-recovery-prepared breath-hold cine gradient-echo sequence,10 minutes after injection of  gadolinium, show delayed enhancement of  thepericardium that forms the wall (large arrows) of  the false aneurysm, as wellas hypointense thrombus (small arrows) that abuts the false aneurysm wall.The pericardium that was adherent to the wall of  thispseudoaneurysm demonstrated late gadolinium enhancement(LGE) with associated mural thrombus, while the adjacentmyocardium in the remaining wall returned a normal nulledsignal (figure 3).After extensive discussion of  the potential risks and benefitsof the surgical treatment, the patient refused this option.DiscussionLeft ventricular aneurysms can be subdivided into true andfalse aneurysms and both are complications of  myocardialinfarction. They are occurring much less frequent aftermyocardial infarction due to implementation of  effective earlyrevascularization strategies.  37to a saccular formation with no myocardial fibers, which istermed a pseudoaneurysm. This usually occur 5-10 days postmyocardial infarction (1,6) and if  untreated has a risk ofrupture of  30-45% (7).Usually, myocardial rupture produces haemopericardium,tamponade and death. Occasionally, an organizing thrombusand hematoma, together with the pericardium andinflammatory tissue, seal the rupture of  the LV, producing acavity that lacks any elements of  the original myocardial walland communicates with the LV cavity through the point ofrupture. Transmural myocardial infarction is the commonestcause of  LV pseudoaneurysm, but it may result from cardiacsurgery, trauma and endocarditis (1). False aneurysms arisemore commonly from the base of the inferior and inferolateralwall (1), secondary to inferior wall myocardial infarction. Thereason for this uneven distribution is explained by the factthat anterior wall rupture is more fatal and there is no chanceof  forming a pseudoaneurysm compared to an inferior orposterior wall rupture (5).From a clinical standpoint, patients may be asymptomatic (upto 48% of  cases), hence the diagnosis may be delayed as inthis case (6), or present with recurrent chest pain, signs ofheart failure, syncope or thromboembolic phenomena (1,8).Sudden death is the form of  presentation of  ventricularpseudoaneurysm in only 3% of  cases (8).Differentiation between true and false aneurysms can bedifficult, but is of  major importance distinguish the twobecause of the different treatment methods recommended.True aneurysms are unlikely to rupture following the earlypost-infarction period and are often managed medically unlessthey cause symptoms related to congestive heart failure orarrhythmia unresponsive to medical treatment. On the otherhand, since untreated LV pseudoaneurysm has a greatertendency to rupture compared to LV true aneurysm, earlysurgical intervention is recommended (9). However,management of  chronic LV pseudoaneurysms is controversial,and risk of  rupture and embolism should be weighed againstthe estimated risk of  surgery (10).Cardiovascular MR imaging has been used since 1991 toimprove diagnosis of  ventricular pseudoaneurysms (8,11) andis now considered to be the most powerful tool for detectingand characterizing ventricular aneurysms (12-15).Besides providing information on overall morphology and leftventricular wall motion and function, particularly ventricularvolumes and systolic and valve function, cardiovascular MRimaging provides better morphological definition of  apseudoaneurysm’s location, extension, its relations to adjacentstructures and the presence of  thrombi. Moreover, LGEsequences enable accurate assessment of the location andextent of  the infarcted area and of  viable myocardium, thuscontributing to pre-operative planning. This cardiovascular MRstudy involve an inversion recovery sequence performed at10–15 min post iv injection of  gadolinium. On the imagesobtained, normal myocardium is nulled to produce a low signalwhile areas of fibrosis demonstrate significant increased signalowing to local gadolinium accumulation.Although both types of  aneurysms show late enhancement inthe wall of  the aneurysm sac, enhancement of  the pericardiumhas been shown more frequently in patients with falseaneurysms and is thought to represent the effects of  seepageof  blood into the pericardial space at the time of  rupture,with subsequent pericardial inflammation and fibrosis (13).Pericardial delayed enhancement (not only bordering the falsecavity but in areas surrounding normal myocardium) has thenbeen proposed as a useful method of  distinguishing betweenpseudoaneurysm and true ventricular aneurysm, with asensitivity of  100% and specificity of  83% (8,13).Given its many advantages, cardiovascular MR imaging hasan enormous potential to differentiate between ventricularaneurysms and pseudoaneurysms.Certain cardiovascular MR imaging features are moresuggestive of  a false aneurysm: narrow neck in relation to theaneurysm sac (orifice to aneurysm diameter ratio < 1), originof  the inferior-lateral wall, discontinuity of  the myocardiumat the neck of  the aneurysm, absence of  coronary arteriesoverlying the aneurysm and delayed pericardial enhancementin the wall of  the pseudoaneurysm (table I).As in this case, the MR findings can provide accurateinformation to distinguish true from false aneurysms and toguide subsequent surgical intervention.ConclusionDifferentiation between true and false LV aneurysms, althoughdifficult, is of  major importance because of  the differenttreatment methods recommended: true aneurysms are oftenmanaged medically and false aneurysm requires an earlysurgical intervention because of  their greater tendency torupture.There are cardiovascular MR imaging features suggestive of  afalse aneurysm: narrow neck in relation to the aneurysm sac(orifice to aneurysm diameter ratio < 1), origin of  the inferior-lateral wall, discontinuity of  the myocardium at the neck ofthe aneurysm, absence of  coronary arteries overlying theaneurysm and delayed pericardial enhancement in the wall ofthe pseudoaneurysm.References1 - Frances, C.; Romero, A.; Grady, D. - Left ventricular pseudoaneurysm.J Am Coll Cardiol, 1998, 32: 557-561.2 - Oliveira, S. M.; Dias, P.; Pinho, T. et al. - Giant left ventricularpseudoaneurysm: The diagnostic contribution of  different non-invasive imagingmodalities. Rev Port Cardiol., 2012 Jun, 31(6):439-44.3 - Brown, S. L.; Gropler, R. J.; Harris, K. M. - Distinguishing left ventricularaneurysm from pseudoaneurysm: A review of  the literature. Chest, 1997,111:1403-1409.4 - Shambrook, J. S.; Chowdhury, R.; Brown, I. W.; Peebles, C. R.;arden, S. P. - Cross-sectional imaging appearances of  cardiac aneurysms. ClinRadiol., 2010 May, 65(5):349-57.5 - Pollak, H.; Nobis, H.; Miczoc, J. - Frequency of  left ventricular free wallruptures complicating acute myocardial infarction since the advent of  thrombolysis.Am J Cardiol, 1994, 74:184-186.Table I - Differences between left ventricular aneurysms andpseudoaneurysms.386 - Yeo, T. C.; Malouf, J. F.; Oh, J. K.; Seward, J. B. - Clinical profile andoutcome in 52 patients with cardiac pseudoaneurysm. Ann Intern Med, 1998,128:299-305.7 - Catherwood, E.; Mintz, G. S.; Kotler, M. N. et al. - Two-dimensionalechocardiographic recognition of  left ventricular pseudoaneurysm. Circulation,1980, 62:294-303.8 - Gill, S.; Rakhit, D. J.; Ohri, S. K. et al. - Left ventricular true and falseaneurysms identified by cardiovascular magnetic resonance. Br J Radiol., 2011,84:e35-7.9 - Vlodaver, Z.; Coe, J. I.; Edwards, J. E. - True and false left ventricularaneurysms: Propensity for the latter to rupture. Circulation, 1975, 51:567-572.10 - Moreno, R.; Gordillo, E.; Zamorano, J. et al. - Long term outcome ofpatients with postinfarction left ventricular pseudoaneurysm. Heart, 2003,89:11441146.11 - Harrity, P.; Patel, A.; Bianco, J. et al. - Improved diagnosis andcharacterization of  postinfarction left ventricular pseudoaneurysm by cardiacmagnetic resonance imaging. Clin Cardiol., 1991, 14:603-6.12 - Baks, T.; Cademartiri, F.; Spierenburg, H. A.; de Feyter, P. J. -Chronic pseudoaneurysm of  the left ventricle. Int J Cardiovasc Imaging,2006, 22:497-499.13 - Konen, E.; Merchant, N.; Gutierrez, C. et al. - True versus false leftventricular aneurysm: differentiation with MR imaging¯initial experience.Radiology, 2005, 236:65-70.14 - Heatlie, G. J., Mohiaddin, R. - Left ventricular aneurysm: comprehensiveassessment of  morphology, structure and thrombus using cardiovascular magneticresonance. Clin Radiol., 2005, 60:687-692.15 - Tran, T.; Ross, B. D.; Colletti, P.; Ching, R. E. - Gd-enhancedcardiovascular MR imaging to identify left ventricular pseudoaneurysm. JCardiovasc Magn Reson, 2005, 7:717-721.

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Left ventricular false aneurysm characterized by cardiovascular magnetic resonance and late enhancement technique

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