It occurs because the duration of the refractory period of the myocardium is proportional to the R-R interval of the preceding cycle. A short R-R interval is associated with a shorter duration of action potential and vice versa. A long R-R cycle will prolong the ensuing intractable period, and if a shorter cycle follows, the beat terminating the cycle is likely to be conducted aberrantly. Because the refractory period of the right bundle branch is longer than the left, the right bundle will stil
First described by Gouaux and Ashman in 1947, Ashman phenomenon, also known as Ashman beats, describes a particular type of wide complex tachycardia (fast rhythm of the heart) that is often seen in atrial fibrillation. It is more often misinterpreted as a premature ventricular complex.