急性心筋炎が原因と思われる，いわゆる“たこつぼ”型心筋症の1例

A Case of “Takotsubo” like Cardiomyopathy due to Acute Myocarditis

　急性心筋炎が原因と思われる，いわゆる“たこつぼ”型心筋症の1例を経験した．患者は感冒様症状に続く呼吸困難と心電図EST上昇を認めたため入院した．冠動脈造影で冠動脈に有意狭窄を認めず，左室造影で心尖部を中心に高度の壁運動低下を認め，いわゆる“たこつぼ”型心筋症と診断した．慢性期左室造影では左室壁運動異常は正常化していた．アセチルコリン冠注後の冠動脈造影では有意な冠攣縮は誘発されなかった．^99mTc-PYPと²⁰¹T1によるDual SPECTでは，²⁰¹T1の欠損部位と^99mTc-PYPの集積部位の不一致を認めた．Gd-DTPA造影MRIで心尖部を中心に冠動脈の支配に一致しない広範かつまだら状の造影効果を認めた．以上より，本症例の“たこつぼ”型心筋症の原因は急性心筋炎と思われ，その原因の把握に^99mTc-PYPと²⁰¹TlによるDual SPECTとGd-DTPA造影MRIが有用であった．

An 81-year-old woman without chest pain admitted because of suspicion of acute myocardial infarction. Marked ST segment elevation at I, II, aV _L, aV_F and V₃ from V₆ were evident by electrocardiography. To clarify the culprit coronary arteries, emergency cardiac catheterization was performed. Although no significant coronary artery stenosis was detected by coronary angiography, a broad akinesis area of the left ventricle excluding the basal area was demonstrated by left ventriculography. The shape of her end-systolic left ventriculography was like a “Takotsubo”. In order to clarify the cause of left ventricular dysfunction, weperformed Dual SPECT (²⁰¹T1 & ^99mTc-pyrophosphate scintigraphy) and Gd-DTPA enhanced MRI. Dual SPECT demonstrated the mismatch of the defect area of ²⁰¹T1 and the uptake area of ^99mTc-pyrophosphate. Gd -DTPA enhanced MRI demonstrated diffuse and patchy enhancement of left ventricular myocardium and the enhanced area did not match the region of the coronary arteries. The normalization of the patient's abnormal left ventricular wall motion was observed within ten days by echocardiography. To exclude the possibility of stunned myocardium due to coronary vasospasm, we performed an acetylcholine provocated coronary angio-gram 3 weeks after admission. Coronary vasospasm was not provocated. These date indicated that one of the causes of “Takotsubo” like cardiomyopathy seems to be acute myocarditis.