Mahaim type preexcitation

Mahaim type pre-excitation is a form of ventricular pre-excitation characterized by a normal PR interval and a long QRS interval with initial slurring of or slow deflection of the QRS complex (a delta wave is present).

In Mahaim type pre-excitation, the atrial impulse travel to the ventricle via the Mahaim fibers which connect atrioventricular node directly to the right ventricular wall (nodoventricular pathway) or to the right bundle branch of His (nodofascicular pathway)