Dual antegrade response tachycardia induced cardiomyopathy

GABA, D., ET AL.: Dual Antegrade Response Tachycardia Induced Cardiomyopathy. We report a rare case of tachycardia induced cordiomyoputhy resulting from nearly incessant dual antegrade response tachy-cardia. Criteria necessary for sustaining dual antegrade responses are discussed, including: (1) sufficient antegrade dissociation of the AV node; (2) absence of retrograde conduction over each AV nodal pathway following antegrade conduction over its counterpart; (3) difference between fast and slow pathway conduction times exceeding His-Purkinje refractoriness; and (4) critical timing of sinus impulses relative to preceding AV nodal conduction. Both the arrhythmia and cardiomyopothy were successfully treated by slow pathway oblation.