Reentrant fascicular tachycardia with cycle length alternans: insights into the tachycardia mechanism and origin.
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
Y T
YT
University Department of Medicine, Queen Mary Hospital, Hong Kong.
Fong
P C
PC
Lau
C P
CP
Chow
W H
WH
Cheng
C H
CH
D002036:Bundle of His / Q000187:drug effects / Q000503:physiopathology; D002037:Bundle-Branch Block / Q000503:physiopathology; D002304:Cardiac Pacing, Artificial / Q000379:methods; D004110:Diltiazem / Q000627:therapeutic use; D004562:Electrocardiography; D015716:Electrocardiography, Ambulatory; D006801:Humans; D008297:Male; D008875:Middle Aged; D011690:Purkinje Fibers / Q000187:drug effects / Q000503:physiopathology; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology*; D013617:Tachycardia, Supraventricular / Q000503:physiopathology*; D013997:Time Factors; D014700:Verapamil / Q000627:therapeutic use
D014700:Verapamil; D004110:Diltiazem