ミトコンドリア脳筋症・乳酸アシドーシス・脳卒中様発作症候群成人例における心エコー図所見の特徴  [in Japanese] The Echocardiographic Characteristics of Cardiac Involvement of Adult Mitochondrial Encephalomyopathy, Lactic Acidosis and Stroke-like Episodes Syndrome  [in Japanese]

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Abstract

<p><b>はじめに</b>:ミトコンドリア脳筋症・乳酸アシドーシス・脳卒中様発作症候群MELASは軽症の成人例では診断は困難である.心筋はミトコンドリア遺伝子異常の影響を受けやすく,心エコーによる早期診断が期待されるが,その心エコー図所見の詳細は未だ十分に検討されていない.本研究の目的はMELAS成人例における心エコー図の特徴を明らかにすることである.</p><p><b>対象と方法</b>:MELAS成人8症例において臨床症状,血液検査所見および心エコー図の特徴的所見について検討した.</p><p><b>結果と考察</b>:臨床所見では神経筋症状6例,糖尿病6例,難聴全例,低身長4例を認めた.乳酸値は7例,乳酸・ピルビン酸比は全例,BNPは6例で異常高値を認めた.心電図では左室高電位を4例に認め,低電位は認めなかった.全例左室駆出率は保たれ,求心性左室肥大を6例,拡張早期僧帽弁輪速度e′低下を5例,左室長軸方向ストレイン値低下を6例に認めた.また,肥大心筋のエコー性状として糖原病やアミロイドーシスなど蓄積性心筋症類似の細かな高輝度エコー像を5例に認めた.このような心エコー所見を認める症例において,神経筋症状,糖尿病,難聴,低身長を伴っている場合,積極的にMELASを念頭に置き,ミトコンドリアDNA遺伝子変異を含めた特異的検査を行うことが早期診断の一助となると考えられた.</p><p><b>結論</b>:MELASの心エコー図所見としては輝度の高い細かな異常エコーを伴う求心性左室肥大,左室弛緩遅延,左室長軸方向機能障害が特徴的であった.</p>

<p><b>Purpose</b>: Diagnosis of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is often difficult in adult patients, especially those with mild clinical manifestations. The myocardium is susceptible to mitochondrial abnormalities, and therefore, echocardiography might play a role in the early diagnosis of MELAS. However, details of the echocardiographic findings have not yet been fully investigated. Accordingly, the aim of this study was to clarify the characteristic echocardiographic findings in adult patients with MELAS.</p><p><b>Subjects and Methods</b>: Eight patients with MELAS who were undergoing echocardiography were included. Clinical symptoms, laboratory test results, and echocardiographic findings were investigated.</p><p><b>Results and Discussion</b>: Among the 8 patients, neuromuscular symptoms were present in 6, hearing loss in all, diabetes in 6, and short stature in 4 patients Additionally, abnormalities were observed in lactic acid level in 7, lactic acid to pyruvic acid ratio in all, and BNP in 6 patients. Echocardiographic findings showed preserved left ventricular ejection fraction in all patients, apparent left ventricular hypertrophy and abnormal global longitudinal strain in 6, and impaired diastolic function in 5 patients. A fine-particle bright-echo ultrasonic appearance in the hypertrophied myocardium, so-called "granular sparkling echo", which is seen in glycogen storage disease or amyloidosis, was subjectively observed in 5 patients. Accordingly, in patients with left ventricular hypertrophy with abnormally bright echo accompanied by deafness, diabetes, or short stature, it is important that mitochondrial disease be considered in the differential diagnosis.</p><p><b>Conclusion</b>: Echocardiographic findings of adult patients with MELAS were characterized by apparent left ventricular hypertrophy with fine-particle bright-echo appearance accompanied by left ventricular global longitudinal strain dysfunction and relaxation delay.</p>

Journal

  • Japanese Journal of Medical Ultrasound Technology

    Japanese Journal of Medical Ultrasound Technology 41(6), 634-641, 2016

    Japanese Society of Sonographers

Codes

  • NII Article ID (NAID)
    130005331215
  • Text Lang
    JPN
  • ISSN
    1881-4506
  • Data Source
    J-STAGE 
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