Europace (2008) 10, 120
doi:10.1093/europace/eum275
IMAGES IN ELECTROPHYSIOLOGY/PACING
The small diverticulum in the right anterior wall
of the left atrium
Osamu Igawa*, Junichiro Miake, and Masamitsu Adachi
Department of Cardiovascular Medicine, Tottori University Hospital, 36-1 Nishimachi, Yonago, 683-8504, Japan
Received 11 October 2007; accepted after revision 21 November 2007; online publish-ahead-of-print 17 December 2007
KEYWORDS
Catheter ablation;
Left atrium;
Diverticulum;
Atrial fibrillation;
Trabeculation
A small recess in the right anterior wall of the left atrium
(LA) can sometimes be seen on the endocardial side when
viewing the examination results of a multidetector computed tomography. Radiologically, it is very hard to differentiate whether the recess indicates the image of the orifice of
a vein or a diverticulum. And furthermore, the anatomical
details of this structure remain unknown.
A recess, as shown in Figure 1A and B, was found by
chance in an autopsied heart of a 53-year-old female, who
died due to breast cancer. Macroscopically, this recess was
5 mm in depth and 6 3 mm2 in diameter. It was located
in the right anterior wall of the LA and near the atrial
septum. It protruded into the pericardial transverse sinus.
The endocardial surface shared the same aspects as that
of the tissue around the recess. The trabeculated myocardium could be observed in it. Histologically, the recess had
the same construction as that of the normal LA wall, as
shown in Figure 1C. Judging from these results, we could
diagnose that it was a small diverticulum. As far as we
have investigated, a diverticulum, like one observed in
this case, has not been reported in autopsied hearts. The
application of high energy in the LA diverticulum may have
potential complications such as a catheter trap, a steam
pop, and a wall penetration. It seems important to take
this anatomical information to avoid these complications
associated with LA anterior wall ablation.
Figure 1 (A) An endocardial view of the LA. We could easily notice
the orifice of the recess in the LA (arrow). The recess was located in
the right anterior wall of the LA. (B) A detailed view of the LA recess
after the fixation by 10% formalin. (C) A histological section of the
LA recess along the dotted line in (B) stained with Masson trichrome.
The recess has the same construction as that of the normal LA wall,
but we can observe the prominent trabeculation in the recess. LSPV,
left superior pulmonary vein; RSPV, right superior pulmonary vein;
LAA, left atrial appendage; MV, anterior cusp of mitral valve.
* Corresponding author. Tel: þ81 859 386517; fax: þ81-859-386519.
E-mail address: [email protected]
Published on behalf of the European Society of Cardiology. All rights reserved. & The Author 2007.
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