Concealed extrasystolic ventricular bigeminy with interpolation.

The first reported case of concealed extrasystolic ventricular bigeminy with interpolation is described. This arrhythmia is characterized by the presence of both interpolated ventricular extrasystolic beats and a presumed persistent and continuous bigeminal ectopic rhythm with exit block. The distributional pattern of sinus conducted beats in the present case conforms to a formula defining this unusual disorder of rhythm, while the appearance of manifest ectopic beats follows the rule of bigeminy.