CASE REPORT Calcified mitral subannular left ventricular aneurysm I rma van de Werke FRCR Zarina Loekhat FFRad(D) SA Betsie van der Walt FCRad(Diagnostic) SA Rowaida Abdullah MBChB Radi%gy Department, Ka/afong Hospita/, University of Pretoria Abstract Mitral subannular left ventricular aneurysms are not frequently seen, and those described have occurred mostly in Africa and India. This con- dition is rare in the Caucasian popula- tion. in this case report we describe a mitral subannular left ventricular aneurysm which was calcified, in a pregnant, HIV-positive African woman. This condition should be suspect- ed in patients of African or Indian descent presenting with mitral incom- petence and a localised bulge and ring calcification on the left cardiac border on a chest radiograph. Case report A 33-year-old African woman pre- sented with pain in the left arm, dysp- noea, and chest pain. She was 24 weeks pregnant and was sent for a chest X-ray by the antenatal clinic, with the history of cardiac disease in pregnancy. The chest X-ray (Figs la + b) showed an enlarged heart with a mitralised configuration as well as a large left atrium extending past the right cardiac border on the PA view. A calcified ring (AP 4 cm x TV 5 em x HT 4 em) suggestive of an aneurysm of the left ventricle in the region of the mitral valvewas also pre- sent. The left main bronchus was dis- placed posteriorly due to the enlarged left atrium. The lung fields showed early pul- monary venous congestion. Fig. 1A. PA view of the chest. 33 SA JOURNAL OF RADIOLOGY • March 2002 Fig. 1B. Lateral view of the chest. The patient then had a cardiac sonar (Fig. 2) which showed severe left atrial dilatation and mitral imcompe- tence. The left ventricular walls were normal but the left ventricular func- tion was low. The right atrium and right ventri- cle were normal and a small tricuspid incompetence was present. There was a 4 x 3 em well-outlined hypoechoic area protruding into the left atrium just below the posterior mitral leaflet. There was a connection between this area and the left ventri- cle. Fig. 2. Cardiac sonar demonstrating the relationship of the aneurysm arising just be/ow the posterior mitral valve leaflet. CASE REPORT This was considered to be a mitral subvalvular LV aneurysm protruding into the left atrium. The walls of the aneurysm were calcified. Laboratory investigations Laboratory investigations includ- ed the following: (i) serology for syphilis (negative) (ii) blood culture for anaerobic organisms (negative); (iii) rheumatoid factor 10.6 (normal 0.0 - 15.0 IU/ml); (iv) ASO titre 184.0 (0.0 - 200 IU/ml); (v) an HIV test (positive); and (vi) a sputum investi- gation, which showed no growth. The patient was referred to the cardiothoracic surgeons whose pre- operative diagnosis was chronic rheumatic endocarditis with mitral stenosis/incompetence and pul- monary hypertension. At operation the mitral valve was replaced by a Sorin prosthesis, and the mitral valve aneurysm was repaired. Pathological report The pathological specimen included the anterior leaflet of the mitral valve and a single calcified nod- ule measuring 8 x 5 x 2 mm as well as multiple calcified fragments of the mitral valve and mitral valve ring tis- sue. Histological examination showed multiple valve leaflet fragments with areas of nodular fibrosis, dystrophic calcification, as well as focal neovascu- larisation. There were areas of ossification with marrow elements present. The aneurysm as such could not be identified with certainty, but frag- ments probably of the wall of the aneurysm were present. The final pathological diagnosis was late-phase rheumatic valvulitis. Postoperative follow-up Five days after operation the patient delivered a premature baby who died 9 days later. The patient was dyspnoeic and received Lasix. Chest X-ray (Fig. 3) still showed cardiomegaly, residual calcified aneurysm and the prosthetic mitral valve. Fig. 3. Immediate postoperative supine view of the chest. Relationship of mitral valve prosthesis to residual calcified aneurysm. Postoperative lung changes present. Seven weeks later the patient was seen in casualty with cardiovascular collapse and a GCS of 3/15. A heart sonar was done which showed no life- threatening abnormality. The inter- national normalised ratio (INR) was 15 (therapeutic range 2 - 4.5) and as she was on anticoagulant therapy a cerebral haemorrhage w~s suspected. However the patient di~d before a brain scan could be done in spite of intensive resuscitation. Discussion Ventricular aneurysms can be clas- sified as congenital or acquired. The congenital type, seldom with any 34 SA JOURNAL OF RADIOLOGY • March 2002 obvious aetiology, may affect any part of the heart. The acquired type may result from myocardial infarction, TB, syphilis, rheumatic fever,collagen vascular dis- ease, Takayasu's arteritis, mycotic emboli, myocarditis or trauma. The majority of ventricular aneurysms occur secondary to ather- osclerosis of the coronary arteries. When the aneurysm is not attrib- uted to ischaemie heart disease, syphilis has been noted as the next most common cause. In our case the cause was rheumatic fever. One previous case seen last year by the sonar department was due to syphilis. The clinical presentation varies. Heart failure may present as acute pulmonary oedema or when murmurs of MI are present it may mimic heart failure seen in chronic rheumatic heart disease. Chest pain may be due to stretching of the peri- cardium or coronary insufficiency. Left ventricular aneurysms of the annular subvalvular type were described in the literature before 1962, when Abrahams introduced the term 'annular subvalvular left ventricular aneurysm' for this unusual type aris- ing in the fibrous rings below the mitral or aortic valves. The submitral type is more com- mon than the subaortic type. Submitral aneurysms occur in the epicardium related to the base of the left ventricle. They have ovoid ostia which are frequently multiple and located under the posterior leaflet of the mitral valve. The aneurysms are of the false type and may frequently reach enor- mous proportions. They may be calcified or contain CASE REPORT mural thrombus. When the aneurysm walls are thin, rupture may occur. In contrast to the anterior leaflet of the mitral valve, which has fibrous continuity with the aortic root, the posterior mitral leaflet is attached to the myocardium of the left ventricle by the fibrous tissue of the mitral ring. It is this region where the ostia of sub- mitral aneurysms occur, and here the mitral ring is directly related to the epicardium of the atrioventricular groove. Sections through this leaflet and the ring reveal that the epicardium in this region contains abundant fat as well as the circumflex coronary artery and the coronary sinus. Imaging 1. A chest radiograph may suggest the diagnosis of the submitral type. Characteristically there is a bulge on the left cardiac border, the size and shape depending on the size and posi- tion of the aneurysm. It may also show partial or total calcification. 2. On fluoroscopy it can be seen to pulsate. 3. Cardiac sonography is used for the detection, confirmation and assessment of the submitral type. 4. Cardiac catheterisation helps to confirm the diagnosis and locate the origin of the aneurysm and assess the severity of the haemodynarnic distur- bance. 5. Recently three cases were described in India, using MR! as a modality for diagnosis. MR! has the unique capability of multiplanar imaging with multiple imaging parameters. The exact dimensions and extent of the lesion, especially the neck of the aneurysm and the degree of mitral regurgitation, were well seen on gradi- ent echo cine images. Complications Complications include myocardial ischaemia and infarction, systemic embolisation, congestive cardiac fail- ure and infective endocarditis as well as rupture of the aneurysm. Treatment Surgical resection of the aneurysm with or without valve replacement is indicated in severe valvular regurgita- tion or cardiac failure resistant to medical therapy. Summary Calcified mitral subannular left ventricular aneurysm can be suspect- ed on a chest radiograph when there is a high index of suspicion of this con- dition in a relevant clinical setting. The purpose of this case report is to familiarise general radiologists with this rare condition which is more known to cardiologists, cardiotho- racic surgeons and echocardiogra- phers. Therefore as we say in radiolo- gy: 'You only see what you look for and you only recognise what you know.' Acknowledgement We would like to thank Annelize Gates for her help in the preparation of this case report. References 1. Edelstein CL, Blake RS, Klopper JF. Mitral sub- annular left ventricular aneurysm. 5 Afr Med J 1987; 71: 114-ll5. 2. Chesler E, Joffe N, Schamroth L, Meyers A. Annular subvalvular left ventricular aneurysms in the South African Bantu. Circulation 1965; XXXII: 43-51. 3. Edington GM, Williams AO. Left atrial aneurysms associated with annular subvalvular left ventricular aneurysms. JOl/mal of Pathology and Bacteriology 1968; 96: 273-283. 4. Chesler E. Aneurysms of the left ventricle. Cardiovascular Clinics 1972; 4: 187-217. 5. Taneja K, Mathur A, Sharma S, Rajani M, Das B, Venugopal P. Magnetic resonance imaging fea- tures of submitral left ventricular aneurysm. Indian Heart J 1998; 50: 453-455. 35 SAJOURNAL OF RADIOLOGY • March 2002