The tachycardia which presents with regularly irregular rhythm consists of a broad set of differential diagnoses. We present a case of cycle length alternans tachycardia in a patient, with Ebstein's anomaly and describe how a diagnosis was arrived at after careful analysis of electrocardiogram and EGMs.
Keywords: congenital heart disease; electrophysiology study; supraventricular tachycardia.
© 2024 The Author(s). Journal of Arrhythmia published by John Wiley & Sons Australia, Ltd on behalf of Japanese Heart Rhythm Society.