l;PP4 Mera et al.

Fernando Mera, MD, Jerry Patt, MD, Warren Israel, MD, and Jonathan D. Dubin, MD Baltimorb, Md.

In recent ye’ars echocardiogxaphy has shown the intexatrial septum to be an important location of cardiac pathology. Abnormalities of the interatrial septum include atrial sep- tal aneurysm, atria1 septal defect, and patent foxamen ovale. Also, the interatrial septum is the most common lo- cation of cardiac myxomas. Numerous studies have shown that transesophageal echocardiography (TEE) provides excellent high-resolution imaging of the interatrial septum and is markedly superior to transthoracic echocardiogra- phy (TTE) in this regard. r* s In this case report we descrgbe a patient who on TTE appeared to have a mass attached to the left atria1 side of the interatrial septum. TEE defi-

From the Division of Cardiology, Departments of Medicine and Radiology of Sinai Hospital of Baltimore. Reprint requests: Jonathan D. Dubin, MD, Division of Cardiology, Depart- ment of Medicine, Sinai Hospital of Baltimore, 2401 W. Belvedere Ave., Baltimore, Maryland 21215-5271.

AM H~~~~J1993;126:1224-5. Copyright @ 1993 by Mosby-Year Book, Inc. 0002.8703/93/$1.00 t .lO 4/4/48905

November 1893

American Heart Journal

nitely and dramatically revealed the correct atrial septal anatomy and pathology in this case.

A 62-year-old man with a medical history of diabetes mellitus and hypertension was seen in the emergency de- partment with prolonged retrosternal chest pain. An elec- trocardiogram showed ST-segment elevation in the pre- cordial leads consistent with an acute anterior myocaxdial infarction (MI). The patient was admitted to the coronary care unit and received thrombolytic therapy. His post-MI course was uncomplicated. As part of his post-MI cardiac evaluation, a TTE was performed. The study suggested a mobile, irregularly shaped echogenic mass on the left atria1 side of the interatrial septum (Fig. 1). Cardiac magnetic resonance imaging (MRI) was obtained in an attempt to evaluate this mass noninvasively. The study was inter- preted as being normal. In particular, no cardiac masses or abnormalities of the interatrial septum were seen. TEE clearly revealed a large atria1 septal aneurysm. The inter- atrial septum was so elongated that it occasionally folded over on itself, forming loops (Fig. 2), thus accounting fur the appearance of a mass on the TTE. In addition, bubble- contrast echocardiography showed right to left shunt flow across the interatrial septum within two cardiac cycles of bubble injection consistent with a patent foramen ovale or a small atria1 septal defect. No intracavitary masses were seen in the atria or on the interatrial septum.

Atria1 septal aneurysm is a congenital elongation of the septum primum layer of the interatrial septum.3 Atria1 septal aneurysm was initially thought to be a rare congen- ital abnormality. However, new imaging techniques have identified atrial septal aneurysm with increasing frequen-

Fig. 1. Transthoracic echocardiogram, apical four-chamber view. Arrows, Irregularly shaped echogenic mass on left atrial side of interatrial septum; LA, left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle.

Volume 126, Number 6 American Heart Journal Takahashi et al. 1225

Fig. 2. Transesophageal echocardiogram, basal short-axis view. Large atrial septal aneurysm. Arrows, Loops formed by markedly elongated interatrial septum; LA, left atrium; RA, right atrium; AV, aortic valve.

CY.~,~ At least two previous reports have identified large atria1 septal aneurysms mimicking right atrial masses.2+ 5 In a report by Smith et a1.5 MRI was used to define an atria1 septal aneurysm that had appeared to be a cystic right atria1 mass with TTE. In our patient, TTE suggested a mobile echogenic mass in the left atrium. MRI was not helpful in defining this abnormality. This may have been because the interatrial septum was excessively mobile and thin. The MRI technology1 has difficulty imaging highly mobile structures. Also, the image volume sample size may have been inadequate to detect this structure. TEE pro- vided cle’ar, high-resolution images of the interatrial sep- tum armatria. A large atria1 septal aneurysm that folded into multiple loops was clearly revealed, and a cardiac mass was convincingly ruled out. This distinction had obvious important clinical and therapeutic implications. In addi- tion, right,to left shunting across the interatrial septum was documented with bubble-contrast echocardiography. TEE should~be the imaging technique of choice in the complete evaluation of the linteratrial septum.

REFERENCES

1. Schneider B, Hanrath P, Vogel P, Meinertz T. Improved mor- phologic characterization of atrial septal aneurysm by trans- esophageal echocardiography: relation to cerebrovascular events. J Am Co11 Cardiol 1990;16:1000-9.

2. Yeoh JK, Applebe AF, Martin RP. Atrial septal aneurysm mimicking a right atria1 mass on transesophageal echocardi- osranhv. Am J Cardiol 1991:68:827-8.

3. B%l&kN, Kisslo J. Atrial septal aneurysm: recognition and clinical relevanc’e. AM HEART J 1990;120:948-57.

4. Hanley PC, Tajik AJ, Hines JK, Edwards WD, Reeder GS, Hagler DJ, Seward JB. Diagnosis and classification of atria1 septal aneurysm by two-dimensional echocardiography: re- port of 8’7 consecutive cases. J Am Co11 Cardiol1985;6:1370-82.

5. Smith AJ, Panidis IP, Berger S, Gonzales R. Large atrial sep- tal aneurysm mimicking a cystic right atria1 mass. AM HEART J 1990;120:714-6.

Unilateral pulmonary edema related to pulmonary artery compression resulting from acute dissecting aortic aneurysm

Masafumi Takahashi, MD,% b Uichi Ikeda, MD,b Kazuyuki Shimada, MD,” and Hisanao Takeda, MDa Miyagi and Tochigi, Japan

Unilateral pulmonary edema is uncommon. Kagele and Charanl recently described a case of unilateral pulmonary edem.a related to pulmonary venous compression caused by a large thoracic aortic aneurysm. We observed a rare case in whom an acute dissecting aortic aneurysm caused right pulmonary artery occlusion, resulting in contralateral (left- sided) pulmonary edema.

A 69-year-old man with a history of mild hypertension was admitted to our hospital because of the sudden onset

From the Departments of Cardiology,%emine Hospital, Miyagi, and bJichi Medical School, Tochigi.

Reprint requests: Masafumi Takahashi, MD, Department of Cardiology, Jichi Medical School, Minamikawachi-machi, Tochigi 329-04, Japan.

AM HEART J 1993;126:1225-7.

Copyright @ 1993 by Mosby-Year Book, Inc. 0002~8703/93/$1.00 +.10 4/4/48911