A method is disclosed for automatically determining the position and orientation of the left ventricle and/or adjacent regions in 3D image data records of the heart that have been recorded with the aid of an imaging, tomographic method after injection of contrast agent. In the method, the left ventricle is firstly coarsely segmented, and the long main axis is determined from the segmented image data. Starting from this long main axis, end points of a boundary line of the septum are determined in a plane by using search beams. The segmented image data, the long main axis and the end points fix the position and orientation of the left ventricle in the image data record.