Idiopathic subvalvular aortic aneurysm masquerading as acute coronary syndrome

Abstract

Subvalvular aneurysms are the least common type of left ventricular (LV) aneurysms and can be fatal. Subaortic LV aneurysms are much rarer than submitral LV aneurysms and mostly reported in infancy. They can be congenital or acquired secondary to infections, cardiac surgery or trauma. Here, we report a unique presentation of a large, idiopathic subaortic aneurysm in an adult masquerading as an acute coronary syndrome. Diagnosis was made with the help of a CT aortography. Aneurysm was surgically resected with good results. This case highlights the clinical presentation and management of subaortic aneurysms, an important differential for congenital aortic malformations.

Figure 1

Chest X-ray taken at presentation showing cardiomegaly and widened mediastinum.

Figure 2

2D echo colour flow image showing three flows: (1) aortic regurgitation due to distortion of aortic valve by the aneurysm; (2) large flow into Aneurysm 1 between left atrium and ascending aorta; (3) smaller jet into Aneurysm 2.

Figure 3

CT aortography image showing a large trilobed subaortic aneurysm (1) in relation to the non-coronary cusp and a smaller subaortic aneurysm (2) in relation to the left cusp of the aortic valve.

Figure 4

(A) Coronary angiography image showing external compression of the RCA by Aneurysm 1. (B) External compression of the LCA by Aneurysm 2. LCA, left coronary artery; RCA, right coronary artery.

Figure 5

(A) Intraoperative appearance of the trilobed subaortic aneurysm after releasing pericardial adhesions. (B) The mouth of a smaller second aneurysm opening into the aorta below the left cusp of the aortic valve, closed with sutures. (C) Normal-appearing tricuspid aortic valve.

Figure 6

Histology slide of the aneurysm wall showing (A) the absence of elastic fibres on Verhoeff's stain and (B) showing blue staining of collagen fibres with Masson trichome stain.