A 73-year-old woman was admitted to the hospital because of recent onset of progressive dyspnea, fatigue, and malaise. On physical examination, an ejective systolic murmur (grade 2-3/6) split from S1 was audible at the base of the heart and S4 tone was also present. Lungs were clear and no increased venous jugular pressure was evident. She had well-controlled blood pressure under medications, no history of diabetes, coronary heart disease and of familial hypertrophic cardiomyopathy (HCM). On 12-lead ECG, only leftward electrical cardiac axis deviation and minor abnormalities of the repolarization phase were present. On transthoracic echocardiography a significant asymmetric hypertrophy of basal anterior septum was described with systolic anterior motion of anterior mitral leaflet causing a peak dynamic gradient of 35 mmHg at rest. The patient was referred for cardiac magnetic resonance imaging (MRI).