This case report provides electrophysiological evidence supporting a fascicular origin for reentrant tachycardia presenting with cycle length alternans.
This report details the electrophysiology of a unique case of reentrant fascicular tachycardia in a patient without structural heart disease. Persistent cycle length alternans, with constant fluctuation in alternate RR intervals, occurred during tachycardia. A distinct mode of spontaneous termination of tachycardia was observed. The findings were consistent with the presence of decremental conduction properties in the tachycardia circuit or decremental dual functional pathways within one limb of the circuit. These observations provide further evidence in support of a fascicular origin of the tachycardia.
Tai et al. (Sun,) studied this question.