PEFA is a technique for the prediction of sudden cardiac death.  

PEFA is based on the premise that disorganised heart muscle (myocardium) will create the substrate for lethal arrhythmias.  The patient is investigated by insertion of temporary catheters, containing electrodes, into the heart (See diagram).  These catheters are then connected to proprietary instrumentation.

The substrate may be detected by pacing the heart at one site and recording the response at other sites.  The recorded signals "electrograms" are analysed to look for small potentials that show conduction is slowed and through multiple, disorganised pathways, known as "Fractionation".

The study is easily performed, has been done in more than 600 patients, takes 30 minutes and is completely safe.