Ashman phenomenon

Ashman phenomenon, also known as Ashman beats, describes a particular type of wide QRS complex, often seen isolated that is typically seen in

It is named for Richard Ashman (of New Orleans) (1890 –1969),^[1] after first being described by Gouaux and Ashman in 1947.^[2]

Presentation

Ashman beats are described as wide complex QRS complexes that follow a short R-R interval preceded by a long R-R interval.

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 refractory 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 still be in the refractory period when the supraventricular impulse reaches the His-Purkinje system, resulting in a complex with right bundle branch block morphology.^[citation needed]

Prognosis

Clinically, it is often asymptomatic by itself and considered benign in nature.^{[citation needed]}

See also

• Atrial fibrillation
• Electrocardiogram

References