Introduction: Sudden death – non-traumatic, unex-pected fatal event occurring within 1 hour of the onset of symptoms in an apparently healthy subject. It is a major problem of public health, represents 25% of all cardiovascular deaths, among the young people with an incidence of 0.46-3.7 cases / 100000 persons / year, gaining a dramatic psychological and social burden. As a second etiology, after coronary artery disease, is cardiomyopathy. HCM – the disease is an autosomal dominant trait caused by mutations in cardiac sarco-mere protein genes, consequently appear structural and functional abnormalities of the ventricular myo-cardium.

Methods: We present the case of a 43-year-old patient, apparently without cardiovascular risk factors, witho-ut a heredocolateral and personal pathological cardiac history, extremely anxious, who presented for fatigability to sustained efforts and an episode of fast-paced palpitations.

Results: Objective exam, laboratory tests, ECG, echo-cardiography, within normal limits, but a 24-hour ECG Holter monitoring revealed a NSVT episode, at the second thorough echocardiography, made during the internment, were detected small myocardial velo-cities, diastolic dysfunction, posterior SIV hypertrophy with the maximum thickness at the level of the pillars approximate 26 mm, without intraventricular gradient at rest, but the Valsalva maneuver showed a gradient of 64 mmHg, and on the stress test >92 mmHg.

Conclusions: The peculiarity of the case is, lack of ECG changes described in very rare HCM forms with this location, the difficulty of identifying the hypertrophy with this location, sometimes framing the patient in the anxiety pattern, can superficially medical exami-nation, often small and usual maneuvers can help us make difficult diagnosis. Cardiac MRI was performed for a detailed description of myocardial morphology, genetic tests and family screening were performed.