Submitral aneurysm of varied aetiologies: a case series

Abstract

Background: Submitral aneurysm is a rare disease initially described in the African population. It is usually considered congenital in origin, due to a defect in the posterior portion of the mitral annulus. However, it can be seen in other diseases like ischaemic heart disease, rheumatic heart disease, infective endocarditis, tuberculosis, and syphilis.

Case presentation: Case 1 was a 29-year-old female, hypertensive undergoing maintenance haemodialysis for chronic kidney disease and on anti-tubercular therapy. She was found to have a large submitral aneurysm with severe mitral regurgitation, moderate left ventricular dysfunction, and pericardial effusion on echocardiogram. Case 2 was a 58-year-old gentleman presented with inferior wall ST-elevation myocardial infarction and was thrombolyzed with streptokinase for the same. Echocardiogram done 6 months later for evaluation of dyspnoea showed a large inferobasal aneurysm. Case 3 was a 56-year-old hypertensive presented with dyspnoea on exertion and echocardiogram showed a large posterolateral region with transmural late gadolinium enhancement. Case 4 was a 13-year-old boy presented with fever and cerebrovascular accident. Echocardiogram revealed vegetation in the mitral valve and a small submitral aneurysm with vegetation inside it.

Discussion: Submitral aneurysm is usually considered congenital in origin. However, it can be due to ischaemic heart disease, rheumatic heart disease, Takayasu arteritis, and tuberculosis. Top dimensional echocardiogram is the investigation of choice. Cardiac magentic resonance imaging helps in identifying the underlying aetiology and delineating the surrounding structures.

Keywords: Case series; Coronary artery disease; Infective endocarditis; Submitral aneurysms; Tuberculosis.

Figure 1

Echocardiogram showing large submitral aneurysm (SA) measuring approximately (A) in A4C view 3.8 cm × 3.6 cm with a neck diameter of 3.5 cm. (B) in PLAX view 5 cm × 4 cm with a wide neck of size 3.67 cm. (C) Echocardiogram showing pericardial effusion with multiple thick strands and organized fluid at some places. (D and E) Computed tomography coronary angiogram showing no obstructive lesions in right coronary artery (D) and left anterior descending artery (E). (F) Cardiac magnetic resonance (CMR) bright blood image [frame from cine steady state free precession (SSFP) sequence] in 4Ch-view showing the large submitral aneurysm.

Figure 2

(A and B) Echocardiogram showing large submitral aneurysm (SA) (4.5 cm × 4.3 cm) with a wide neck (3.1 cm) underneath the posterior mitral leaflet with thrombus.

Figure 3

(A) Cardiac magnetic resonance bright blood image (frame from Cine SSFP sequence) in four-chamber view showing large aneurysm arising from the basal inferolateral wall of LV with large eccentric hypointense thrombus. (B) Corresponding late gadolinium-enhanced image showing enhancement of the thinned out aneurysmal wall with large internal non-enhancing thrombus. (C) Echocardiogram showing large submitral aneurysm (SA) (7.7 cm × 6.6 cm) with wide neck and organized thrombus. (D) Colour Doppler across mitral valve (MV) showing moderate MR.

Figure 4

(A) Echocardiogram showing submitral aneurysm (SA) under the posterior mitral leaflet communicating with the left ventricle with vegetation inside the aneurysm. Colour Doppler showing blood in and out of the aneurysm. (B) Transoesophageal echocardiogram (TOE) showing vegetation over the posterior mitral leaflet and also in the aneurysm. (C) Cardiac magnetic resonance black blood image [frame from half-Fourier single-shot turbo spin-echo (HASTE) axial sequence]. (D) Bright blood image (frame from SSFP sequence) showing small submitral aneurysm.