Yamaguchi Syndrome: A Difficult Diagnosis in the Differential Diagnosis of Acute Coronary Syndrome

Apical hypertrophic cardiomyopathy (ApHCM) (Yamaguchi Syndrome) with hypertrophy of the ventricular apex constitutes 8% of the hypertrophic cardiomyopathies (HCMs). ApHCM can cause ventricular malignant dysrhythmias, atrial fibrillation, and ischemic chest pain. Definitive diagnosis is made by electrocardiography (ECG) and transthoracic echocardiography. A 73-year-old male patient was admitted to the emergency department with chest pain. The patient's vital signs were within the normal range. In the ECG, there were giant negative T wave in leads V4-5-6, 0.5 mm ST segment depression, and left ventricular hypertrophy in the inferior derivations. The left ventricular apex thickness was measured as 14 mm (reference range: 6-11). Although the HEART score was 4, the preliminary diagnosis of the patient was determined as ApHCM. Beta-blocker and antiplatelet therapy were started. The mortality and morbidity rates of ApHCM are higher among HCMs. Clinicians should be aware of such ECG and echocardiography findings to prevent possible morbidity and mortality.