This section under development.
Reentry Arrhythmias

There must be two conductive pathways that are joined by conductive tissue at both the proximal and distal ends.
One of the pathways must conduct slower than the other.
The slower conducting pathway must have a shorter refractory period than the faster pathway. ie, the pathway that conducts slower must recover faster than the pathway that conducts faster. When these three conditions are met, reentry becomes a possability. For a tachycardia to be initiated at this point requires a unidirectional block. This can occur when a premature beat is blocked by the normal refractory periods of one of the pathways.