Deep recessus of the muscular interventricular septum documented with echocardiography and magnetic resonance imaging

We describe a case of a male patient in whom a routine transthoracic echocardiography reveals a deep recessus of the muscular interventricular septum, without evidence of left-to-right shunt. The helical myocardial band, a new concept of myocardial architecture, could help in the interpretation of the genesis of this anatomic finding.