矢北 夢夏¹, 西野 峻², 西野 千春², 矢野 光洋³, 浅田 祐士郎⁴, 有馬 美樹¹, 髙原 智幸¹, 柴田 剛徳²

Yumeka YAKITA¹, Shun NISHINO², Chiharu NISHINO², Mitsuhiro YANO³, Yujiro ASADA⁴, Miki ARIMA¹, Tomoyuki TAKAHARA¹, Yoshisato SHIBATA²

¹宮崎市郡医師会病院心臓病センター検査科, ²宮崎市郡医師会病院心臓病センター循環器内科, ³宮崎市郡医師会病院心臓病センター心臓血管外科, ⁴宮崎市郡医師会病院心臓病センター病理診断科

¹Department of Clinical Laboratory, Miyazaki Medical Association Hospital Cardiovascular Center, ²Department of Cardiology, Miyazaki Medical Association Hospital Cardiovascular Center, ³Department of Cardiothoracic Surgery, Miyazaki Medical Association Hospital Cardiovascular Center, ⁴Department of Diagnostic Pathology, Miyazaki Medical Association Hospital Cardiovascular Center

キーワード : transthoracic echocardiography, emergency echocardiography, acute chest pain, left atrial myxoma, takotsubo syndrome

急性冠症候群患者における救急初療時の経胸壁心エコー図検査は，診断および治療方針の決定に極めて重要な役割を果たす．当院では，心臓超音波検査士が24時間常駐しており，常時心エコー図検査が施行可能な体制を整えている．今回，我々はST上昇型急性心筋梗塞（STEMI）が疑われ救急搬送された患者に対し，初療時の心エコー図所見が診断の決め手となり，左房粘液腫にたこつぼ症候群を合併した比較的稀な病態を的確に診断し得た症例を経験した．症例は50代女性．土曜夕方に自転車走行中，持続する胸痛を自覚し，休日当番医を受診した後，STEMI疑いで当院へ救急搬送された．救急外来における心エコー図検査にて，心房中隔に茎を有し可動性に富む辺縁整な多形性腫瘍を左房内に認め，左房粘液腫が強く疑われた．同時に，左室心尖部の高度壁運動低下と心基部の過収縮を認め，たこつぼ症候群または腫瘍塞栓による急性心筋梗塞が鑑別に挙げられた．緊急冠動脈造影では有意狭窄や閉塞は認められず，翌日に緊急腫瘍摘出術が施行され，病理診断にて左房粘液腫と確定された．後日施行したMRIおよび核医学検査により，最終的にたこつぼ症候群と診断された．本症例は，救急初療という限られた時間と体位制限下においても，経胸壁心エコー図検査により診断の決め手となる画像情報が得られ，迅速かつ適切な治療へと結びついた点で，非常に意義深い症例である．

Transthoracic echocardiography （TTE） in the emergency room during initial evaluation plays a crucial role in the diagnosis and therapeutic decision-making for patients with acute coronary syndrome （ACS）. At our institution, certified cardiac sonographers are available 24 hours a day, including nights, allowing for full TTE studies to be performed promptly in the emergency setting. Here, we present a rare case in which an initial TTE performed in the emergency room was pivotal in diagnosing a left atrial myxoma complicated by takotsubo syndrome in a patient initially suspected of having ST-elevation myocardial infarction （STEMI）. The patient was a woman in her 50s who developed persistent chest pain while riding a bicycle on a Saturday evening. She was referred to our hospital by a duty physician with a presumptive diagnosis of STEMI. Initial TTE in the emergency room revealed a well-defined, highly mobile, multilobulated mass with a stalk arising from the interatrial septum, strongly suggestive of a left atrial myxoma. Additionally, severe regional wall motion abnormalities were noted in the left ventricular apex and hypercontractility in the basal portion of the left ventricle, prompting consideration of takotsubo syndrome or myocardial infarction secondary to tumor embolism. Emergency coronary angiography revealed no significant coronary stenosis or occlusion. The following day, urgent surgical resection of the tumor was performed, and histopathology confirmed the diagnosis of a left atrial myxoma. Subsequent cardiac magnetic resonance imaging and nuclear imaging studies led to a final diagnosis of takotsubo syndrome. This case underscores the critical importance of high-quality TTE imaging, even under time constraints and limited patient positioning during initial emergency evaluation. The diagnostic clarity provided by early echocardiographic assessment was instrumental in guiding appropriate and timely therapeutic intervention.