Subdivision of the left ventricle by a discrete ridge and anomalous papillary muscle causing mid-ventricular obstruction: A case report.

A 16-year-old healthy boy visited our department because of a heart murmur. A 12-lead electrocardiogram showed left QRS axis deviation and repolarization abnormalities. Transthoracic echocardiography and a computed tomographic scan revealed a hypertrophied papillary muscle and a discrete ridge arising from the septal wall, causing mid-ventricular obstruction. Doppler echocardiography revealed that the pressure gradient at the obstruction was mild. The patient will be followed up annually, without medication or physical restriction.