西 功¹, 神谷 英樹^{1, 2}, 石光 敏行^{1, 2}, 森山 直子^{1, 2}, 瀬尾 由広^{1, 2}, 石川 公人¹, 武安 法之¹, 野口 祐一^{1, 2}, 山口 巖^{1, 2}, 杉下 靖郎^{1, 2}

Isao NISHI¹, Hideki KAMIYA^{1, 2}, Toshiyuki ISHIMITSU^{1, 2}, Naoko MORIYAMA^{1, 2}, Yoshihiro SEO^{1, 2}, Kimito ISHIKAWA¹, Noriyuki TAKEYASU¹, Yuichi NOGUCHI^{1, 2}, Iwao YAMAGUCHI^{1, 2}, Yasuro SUGISHITA^{1, 2}

¹筑波メディカルセンター病院内科, ²筑波大学臨床医学系内科

¹Department of Internal Medicine, Tsukuba Medical Center Hospital, ²Institute of Clinical Medicine, University of Tsukuba, Tsukuba Medical Center Hospital

キーワード : Atrial septal aneurysm , Contrast echocardiography , Transesophageal echocardiography , Transthoracic echocardiography, Ultrasound

We studied the echocardiographic findings of 4847 consecutive patients undergoing transthoracic echocardiography (TTE) to estimate the incidence and to clarify the clinical characteristics and significance of atrial septal aneurysm (ASA). Our TTE diagnostic criteria included large aneurysm (basal diameter greater than 15 mm) and prominent protrusion or excursion (greater than 10 mm) in the parasternal, apical, and subcostal views. ASA is classified as right atrial type, left atrial type, or bilateral type, based on site of protrusion. In this series containing 2857 males and 1990 females, ASA was identified in 24 (0.50%) patients, 8 (0.28%) males and 16 (0.80%) females. ASA was depicted with a significantly higher frequency in females (0.80%) than in males (0.28%) (χ², p=0.01). Right atrial type was found in 8 patients, left atrial type in 6 patients, and bilateral type in 10 patients. Mean ages of the patients with and without ASA, 63.4±12.1 years and 56.4±17.8 years, respectively, did not differ significantly. Nine (38%) of 24 patients with ASA had abnormal findings in a health check program: abnormal ECG, 7 cases; cardiomegaly, 1 case; and heart murmur, 1 case. Transesophageal echocardiography (TEE) was performed on 6 patients, none of whom had a thrombus inside the ASA, and Doppler color flow imaging disclosed no atrial shunt. Intravenous contrast TEE revealed atrial shunt during Valsalva's maneuver in 2 patients, however. One patient had an atrial septal defect, 1 had patent foramen ovale, 1 had both patent foramen ovale and cerebrovascular embolism, 1 had cerebrovascular embolism, and 2 had supraventricular arrhythmia. ASA was found in 1.24% (9/727) of all subjects undergoing TTE for further evaluation of abnormal signs in the healthcheck program. ASA was detected with a significantly higher frequency (1.24%) in patients undergoing TTE who showed abnormal signs on health check program than in patients undergoing TTE for evaluation of heart disease (0.36%) (χ², p