Overview of cardiac and paracardiac aneurysms/pseudoaneurysms: Radiologist`s perspective. Presenting Authors. Ameya J Baxi, MD Carlos Restrepo, MD

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1 Overview of cardiac and paracardiac aneurysms/pseudoaneurysms: Radiologist`s perspective Presenting Authors Ameya J Baxi, MD Carlos Restrepo, MD Co-authors S. Martinez Jiminez, MD Disclaimer: We do not have any conflict of interest or financial gain to disclose

2 Introduction Cardiac chamber aneurysm is a defect usually in the left (or right) ventricle, produced by transmural infarction, there by interfering with ventricular performance by diminishing contractile function Coronary artery aneurysms are as such rare; however, they are now more frequently seen on MDCT as incidental findings in many conditions Echocardiography is still the initial imaging modality of choice, however, it has many limitations & may not be sufficient in evaluating aneurysms Cross sectional imaging (MDCT/MRI) offers excellent noninvasive assessment in accurately diagnosing and guiding treatment In this exhibit, we discuss the characteristic multimodality imaging findings and differential diagnosis of cardiac and paracardiac aneurysms and pseudoaneurysms

3 Teaching points: 1. To study pathophysiology of cardiac and paracardiac aneurysms/pseudoaneurysms 2. To study the role of imaging in the diagnosis and evaluation of aneurysms/pseudoaneurysms 3. To discuss pathology based pertinent imaging findings helpful in preoperative planning 4. To discuss imaging based differential diagnosis Increased awareness of such entities will contribute to optimized care of patients

4 Cardiac Aneurysms and Pseudoaneurysms True ventricular aneurysm False ventricular aneurysm Ventricular diverticulum Interatrial septum aneurysm Atrial aneurysms and diverticula Coronary sinus aneurysm Coronary artery aneurysm Coronary artery bypass graft aneurysm Sinus of Valsalva aneurysm Aneurysm can be True: large, localized to the apical and anterolateral aspects of the LV wall, and made up of damaged myocardial wall False: small, usually occur along the posterolateral wall of the LV, and represents localized myocardial rupture covered by pericardial adhesions which shows delayed pericardial)

5 Distinguishing between true vs. pseudo LV-aneurysm is important because the clinical management and complication risks are different True aneurysm False aneurysm Neck Pathology Wide neck and contain all 3 layers of the cardiac wall Progressive thinning of infarcted myocardium leads to aneurysmal dilatation Location Apex Free lateral wall Delayed enhancement Rupture risk Usually not seen (Infarcted myocardium enhances) Low Small neck and consists of ½ layers Free wall rupture of the LV that is contained by the pericardium Usually seen (Pericardium enhances) High Treatment Medical management Surgery Br J Radiol Feb; 84(998) Radiology 2005;236:65 70 Courtesy : H Murillo, M.D. Sacramento, Ca.

6 True aneurysm: CT & MR Imaging Findings LV aneurysm secondary to a large myocardial infarction (arrows). Cardiac gated CT shows abnormal thinning and bulging of the mid and distal left ventricle, as well as low density wall LV aneurysm secondary to a large myocardial infarction (arrows). Cardiac MRI shows abnormal thinning and bulging of the left ventricle apex and delayed transmural enhancement

7 True aneurysm: CT Imaging Findings LV aneurysm secondary to a large myocardial infarction (arrows). Radiograph showing dilated LV with a curvilinear calcification. Cardiac gated CT shows abnormal thinning and bulging of the distal septum and apex of the left ventricle with calcification Teaching point: The infarcted myocardium may develop thinning, fatty replacement and calcification. The poorly contracting infarcted ventricle is also prone to the development of intraluminal thrombus Diagram and CCTA demonstrating a calcified LV aneurysm with thrombus formation (arrow).

8 Pseudo-aneurysm: CT Imaging Findings * * * * 84 year old female presenting with back pain and history of remote MI. CTA axial images, coronal and volume rendering reconstructions demonstrate a large, apical false aneurysm (*) with organized mural thrombus and wall calcification.

9 Pseudo-aneurysm: CT Imaging Findings Cardiac gated CT shows LV apical pseodoaneurysm with a small neck (arrows) 50 year old female with history of chest pain, hyperlipidemia and cigarrette smoking Cardiac gated CT shows LV apical pseodoaneurysm with a small neck (arrows)

10 Traumatic pseudoaneurysm (arrows): GSW to the chest with RV injury

11 Ventricular Diverticulum Congenital diverticula more commonly occur in the LV It is a pouch or saclike projection from the cardiac lumen Muscular: contains all layers of normal ventricular myocardium and shows synchronous contraction Fibrous forms often show akinetic or dyskinetic contractile function with the ventricle Prevalence: 0.04%-2.2% When large, may predispose to thrombus formation and peripheral embolization Most are small (<1.5 cm) AJR 2007; 189:

12 Two diverticular formations within the septum in the same patient. Contrast enhanced CT shows projection of contrast at the basal (white arrows) and mid ventricular septum (black arrows) Left ventricular diverticula in two different patients. CCTA images illustrate the different shapes and locations of these diverticular formations my have (arrows) Teaching point: Ventricular diverticula are commonly found in the apex and perivalvular area, however, any segment can be involved. Apical diverticula have a high association (> 70%) with other congenital abnormalities, including septal defects, pulmonary stenosis, and dextrocardia. AJR 2007; 189:

13 Interventricular Septum Aneurysm Rare Congenital, mostly involves membranous IV septum (arrows) Associated with transposition of great arteries & VSD (20%) Often asymptomatic Complications - Rupture (intracardiac shunt) - Tricuspid regurgitation and aortic insufficiency - Endocarditis - Thrombus, embolism, - Subpulmonic stenosis - Arrhythmia Insights Imaging Feb; 7(1): Teaching point: The detection of the interventricular membranous septum has clinical significance due to thrombogenic and arrythmogenic predisposition, as well as a role in obstructing the pulmonary flow

14 Right Atrial Aneurysm Rare, probably congenital Intrapericardial Mostly symptomatic Can present with arrhythmias, palpitations, chest pain, shortness of breath, and fatigue and had findings of paradoxical and pulmonary emboli ASD Complications - Slow flow leads to thrombus formation - Stroke (paradoxical embolism) - Pulmonary embolism RadioGraphics 2015; 35:14 31

15 Chest radiographs and Black blood MR images demonstrating right atrial aneurysm (white arrows)

16 Left Atrial Diverticula and Accessory Appendages Left atrial diverticula and left atrial accessory appendage are common anatomic variants. Prevalence: left atrial diverticula: 20% accessory appendage: 8% Most common location of left atrial diverticula is on the anterior and superior aspect of the left atrium. Most accessory appendages have a left lateral inferior location Uncertain pathologic value remains Abbara S, et al. AJR 2009;193:807

17 Left atrial diverticula in different patients. CCTA, axial images and sagittal reconstruction. Images show saccular collection of contrast communicating with the atrial lumen arising from the anterior and superior left atrial wall (arrows).

18 Interatrial septal aneurysm (IASA) Abnormal protrusion of the interatrial septum towards the right or left atrium Prevalence: 2% - 5% in TEE series Probably congenital Mobile, thin wall (<2 mm), commonly involves the fossa ovalis 90% protrude into the right atrium Association with interatrial shunting is common (PFO or ASD) Other associations: MV prolapse and aneurysm of the sinus of Valsalva Heart Views Apr-Jun; 14(2): 88 89

19 Interatrial septum aneurysm (red arrow) with ASD (blue arrow) Teaching point: Cardiac septal aneurysms mimicking cardiac masses have been detected with echocardiography. Recognition of such an entity with cardiac CT and MRI is important to avoid confusion with tumors and unnecessary additional investigation. When echocardiographic evaluation is suboptimal, cardiac MRI and CT are useful alternatives and provide excellent depiction of cardiac septal aneurysms. It is important for radiologists to recognize such entities because of their association with intracardiac shunting and thromboembolic complications and to avoid misdiagnosis of an aneurysm as a cardiac tumor Interatrial septum aneurysm (red arrows) AJR 2007; 188:W550 W553

20 Coronary Sinus Aneurysm and Diverticula Congenital outpouching of the CS, typically with a distinct neck that extends behind the left ventricle Close proximity to the posteroseptal and left posterior accessory conduction pathways and thus predisposes to cardiac arrhythmias and sudden cardiac death Often diagnosed incidentally In patients with CS atresia, blood from the coronary sinus drain into the atria by way of enlarged thebesian veins Mantini E et al. Circulation1966;33:317 Insights Imaging (2014) 5:

21 21 y/o F, super-obese with Wolff-Parkinson-White syndrome Failed attempt to canalize the coronary sinus (twice) MDCT: Two aneurysmal dilations of the coronary sinus (red arrows) Dx: Coronary sinus atresia

22 Coronary artery aneurysm (CAA) Incidence of CAA during catheter angiography is <1% CAA is diagnosed when the vessel diameter is >1.5 times the diameter of the normal vessel Right CAA account for 50% of coronary artery aneurysms In the adult, atherosclerosis is the most common etiology, followed by collagen vascular diseases In children, Kawasaki disease is the most common cause Teaching Point: First described by Morgagni in 1761 in a patient with coronary artery dilatation and syphilitic aortitis. Munkner et al reported the first case of antemortem diagnosis of a coronary artery in CAA are classified as true aneurysms (composed of three layers) & pseudoaneurysms (composed of single/double layer due to disruption of external elastic membrane). Pseudoaneurysms are frequently a result of blunt chest trauma or catheter-based coronary interventions RadioGraphics 2009; 29:

23 Multiple coronary artery aneurysms in a 31 y/o female patient with Wegener s granulomatosis. CCTA demonstrates aneurysmal dilation of the left main, LAD and LCX coronary arteries (red arrows) Teaching point: The aim of imaging is to evaluate (a) the distribution, (b) maximal diameter, (c) presence or absence of intraluminal thrombi, (d) number, (e) extension, and (f) associated complications such as myocardial infarction. RadioGraphics 2009; 29:

24 Kawasaki disease: Catheter angiography in two different infants demonstrates multiple coronary artery aneurysms (red arrows) Atherosclerotic aneurysms of the LAD (red arrow) in a 45 y/o male patient with long history of cigarette smoking and cocaine abuse

25 Coronary artery aneurysms in a 35 y/o male. Sequela of Kawasaki s disease Atherosclerotic coronary Artery Aneurysm

26 Saphenous Vein Graft Aneurysm (SVGA) SVG >1.5 times the expected diameter of the vessel True aneurysm: all layers of the vessel wall are involved False pseudoaneurysm: Disruption of the vessel wall False aneurysms are more common and develop earlier, usually at a suture line More common location is at an SVG graft to the LAD, followed to an SVG graft to the RCA Complications include rupture, thrombosis, embolization and infarction RadioGraphics 2005; 25:

27 50 y/o M, status post CABG presents with chest pain. New MI. Pseudoanerysm SVG graft to RCA (red arrows) SVG-RCA graft pseudoaneurysm Teaching Point: True aneurysms typically arise > 5 years after bypass, occur in the body of the graft and are related to accelerated atherosclerosis. Pseudoaneurysms more commonly occur within 6 months after surgery & arise at either proximal or distal anastomotic sites. RadioGraphics 2005; 25:

28 SVG graft aneurysm Partially thrombosed SVG graft aneurysm

29 Sinus of Valsalva (SoV) Aneurysm Can be congenital or acquired Congenital most often arise from right SoV Acquired, is usually secondary to AV endocarditis or Marfan disease. When large, may bulge, protruding out from the cardiac contour Congenital SoV aneurysms most commonly arise from right coronary SoV (R-SoV) and the non-coronary SoV (N-SoV) because of incomplete fusion (or weakness) of 2 halves of distal bulbar septum Congenital left SoV are rare White CS, et al. Radiology 2001;219:82 RV L A Aorta LA Bacterial endocarditis and acquired L-SoV aneurysm (arrows)

30 Pathophysiology of Congenital SoV Aneurysms Typical SoV aneurysm progression R-SoV R-SoV aneurysm R-SoV aneurysm defect thickened AV leaflets Courtesy Horacio Murillo, M.D. Sacramento, Ca. Teaching point: Congenital SoVA may also be associated with VSD (50 %), Aortic insufficiency (20-30 %), Bicuspid aortic valve (10%), pulmonary stenosis, coarctation, & ASD

31 Clinical Presentation of SoV Aneurysms Unruptured SoV aneurysms are asymptomatic Unless large enough to cause: Obstruction of the rvot Tricuspid stenosis and insufficiency due to prolapse of aneurysm through tricuspid valve Conduction abnormalities due to mass-effect on bundle of his or its fascicles Compression of the RCA (R-SOVA) Ruptured SoV aneurysms present with sudden onset of severe chest pain and dyspnea

32 Diagnostic Imaging Cardiac CTA, aortography, and magnetic resonance imaging may also be used. a. b c MPA RA LA CCTA volume rendered 3D reconstruction (a) of an unruptured SoV aneurysm (white arrow). Catheter angiography (b) demonstrating an unruptured N-SoV aneurysm. Magnetic resonance imaging (c) demonstrating an unruptured N-SoV aneurysm.

33 Ruptured SoVA Rupture can occur spontaneously, following trauma, strenuous exertion or bacterial endocarditis. When ruptured, produces an intracardiac fistula (L R shunt). When a SoVA from the left coronary sinus ruptures, may bleed into the pericardium. Association with ventricular septal defect (VSD) (59%) and aortic regurgitation (25%) is common. 56 yo female with fatal rupture of R-SoV into the RV. Morgan JR, et al. Chest 1972;61:640 J Thorac Cardiov Surg 1990;99: yo female with fatal rupture of R-SoV aneurysm into RA

34 Rupture SoVA into the RA Rupture SoVA into the RV MPA LA RV RA Previously healthy, 40 y.o. athletic male with one week of severe chest pain, shortness of breath,and orthopnea Courtesy Horacio Murillo, M.D. Sacramento, Ca.

35 Summary Several types of aneurysms & pseudoaneurysms may arise from the different anatomic structures within the heart Pathophysiology, morphology and clinical significance of these different anomalies vary greatly Imaging plays a crucial role in the identification and appropriate management of these conditions Recognizing typical imaging manifestations using MDCT/MRI with adequate clinical correlation is essential for timely and accurate diagnosis, classification, pathogenesis, & treatment Presenting author contact information: Dr Ameya J Baxi baxi@uthscsa.edu