Late potentials are thought to be caused by early afterdepolarizations of cells in the right ventricle (in ARVD). Their amplitude is often too small to show up on a normal ECG. However, when multiple QRS recordings (typically 250 consecutive QRS complexes) are averaged, random noise is filtered out and late potentials can show up.
|Criteria for late potentials on a signal averaged ECG|
|* filtered QRS duration > 114ms