運動誘発性血管痙攣性狭心症と顕著なST上昇を呈した1例

Exercise-induced vasospastic angina with prominent ST elevation: a case report.

• Akinori Tamura
• Kazuya Nagao
• Tsukasa Inada
• Masaru Tanaka

抄録

背景:

運動誘発性血管痙攣性狭心症（VSA）は比較的まれな臨床シナリオであるが、適切な管理を行わなければ致死的になる可能性がある。

Background: Exercise-induced vasospastic angina (VSA) is a relatively uncommon clinical scenario but may be fatal if not appropriately managed.

ケースサマリー:

56歳の男性患者が2週間にわたり労作時の胸部圧迫を訴えて当院を受診した。症状は午前中に自転車走行中に出現したが，午後には安静時や労作時には出現しなかった．喫煙者であり，高血圧症の既往歴があり，家族に突然死の既往歴があった．安静時心電図（ECG）は正常であり，心エコー図では壁運動異常は認められなかった．冠動脈CT（コンピュータ断層撮影）血管造影では円周枝に狭窄性病変の可能性を指摘した。このため，入院を手配し，経カテーテル冠動脈造影（CAG）を行った．CAGでは，鈍側周縁枝の灌流面積が小さく，軽度の狭窄のみであった．翌日にトレッドミル運動試験を行い，労作時の胸部症状に対する心筋虚血の寄与を評価した．10代謝当量で突然胸痛を発症し，心電図上ではII，III，aVF，V2-5リードで顕著なST上昇が認められた。直ちに検査を中止し、硝酸塩を投与した。症状は消失し，心電図は正常化し，運動誘発性VSAの診断が確定した。血管拡張薬投与開始から6日後に再度トレッドミル運動試験を行った。最大運動強度でも胸部症状や虚血性変化は認められなかった。患者は退院したが、胸部症状は再発していない。

Case summary: A 56-year-old male patient presented to our hospital for chest oppression on exertion for a 2-week duration. The symptom arose while he was riding a bicycle in the morning but did not arise at rest or on exertion in the afternoon. He was an ex-smoker with a history of hypertension and a family history of sudden death. A resting electrocardiogram (ECG) was normal, and echocardiogram revealed no wall motion abnormalities. Coronary computed tomography angiography indicated a possible stenotic lesion in the circumflex branch. Thus, hospitalization was arranged, and transcatheter coronary angiography (CAG) was performed. In CAG, there was only mild stenosis with small perfusion area in the obtuse marginal branch. A treadmill exercise test was performed the following day to assess the contribution of cardiac ischaemia to his chest symptom on exertion. At 10 metabolic equivalents, he suddenly developed chest pain and prominent ST elevation in leads II, III, aVF, and V2-5 was noted on ECG. The test was immediately terminated, and nitrates were administered. The symptom disappeared, and the patient's ECG normalized, confirming the diagnosis of exercise-induced VSA. Another treadmill exercise test was performed 6 days after vasodilators were started. Even at maximum exercise intensity, neither chest symptoms nor ischaemic changes occurred. The patient was discharged, and the chest symptoms have not returned.

考察:

本症例は、運動誘発性血管痙攣狭心症の適切な診断と管理の重要性を強調している。

Discussion: This case highlights the importance of appropriate diagnosis and management of exercise-induced VSA.