Spontaneous dissecting aneurysm of the left atrium complicated by cerebral embolism: A report of two cases with review of literature

Abstract

Left atrial dissection is a very uncommon complication of cardiac surgery and usually causes significant hemodynamic compromise. Little is known about spontaneous dissection of the left atrium. Two patients, one middle-aged man and another elderly woman were evaluated following stroke. Routine trans-thoracic echocardiogram showed vertical division of the left atrium with both chambers communicating with each other through an orifice. Detailed trans-oesophageal echocardiographic study revealed dissection of the left atrium producing an additional false chamber (pseudo-aneurysm) placed posterior to the left atrial appendage and above the postero-lateral aspect of mitral annulus. Spontaneous dissection of the left atrium is extremely rare, and there is no report of cerebral embolism associated with it. Review of literature reveals interesting facets of this rare entity.

Keywords: Dissecting aneurysm; Left atrial dissection; Mitral annulus; Pseudoaneurysm.

Fig. 1

Trans-thoracic echocardiographic 4-chamber and 5-chamber views showing an additional chamber within the left atrium just above posterolateral mitral annulus (arrows). Yellow arrow in right image points toward the communicating channel.

Fig. 2

Multiple trans-esophageal views showing the pseudo-aneurysm (A, green arrows), separate left atrial appendage (red arrow) and communication between the true left atrial chamber and the false chamber on color flow mapping (D).

Fig. 3

Multiplanar 3D TEE views showing the dissection flap in two different views (long axis and short axis). Yellow arrow points at the communicating orifice. A is the false chamber. MV – mitral valve.

Fig. 4

(Case #2): Multiple apical trans-thoracic echocardiographic views showing vertically split left atrium in 4-chamber views (X is the false chamber). In 5-chamber view, the false chamber or pseudo-aneurysm appears like a cystic mass (yellow solid arrows). (B, C) Communication between the two chambers situated above the posterior and lateral edge of the mitral annulus.

Fig. 5

Multiple 2D TEE views showing a cystic mass with some echogenic structure in the lower part (X) lateral to the left atrial appendage (C). (D) Two secundum atrial septal defects.

Fig. 6

Trans-esophageal two-chamber view showing the false chamber (X) communicating with the true chamber (yellow arrow). (B) The false chamber with low velocity swirling flow.