A 7 months-old child affected of West syndrome presented a cardiac hypertrophy with subaortic obstruction induced by adrenocorticotropic hormone treatment. The administration of this hormone may induce a Cushing syndrome; at high doses has chronotropic and inotropic positive effects and may produce arterial hypertension and cardiac hypertrophy. We pointed out the importance of the echocardiography-Doppler in the diagnosis and follow-up of the cardiac hypertrophy with subaortic obstruction as well as the reversibility of the cardiac involvement when the drug is suppressed.