Unifying mechanism of sustained idiopathic atrial and ventricular annular tachycardia.
BACKGROUND
Based on the current understanding of cardiac conduction system development and the observation that arrhythmogenic foci can originate in areas near the atrioventricular annuli, we hypothesized that focal annular tachycardias, whether atrial or ventricular, share a common mechanism. We, therefore, prospectively evaluated this hypothesis in patients with sustained atrial and ventricular tachycardia originating from the peri-tricuspid and mitral annuli.


RESULTS
Forty-nine consecutive patients with sustained, focal annular tachycardia comprised the study group. All underwent electrophysiological evaluation and the mode of tachycardia initiation, termination, sensitivity to catecholamine infusion, and response to adenosine/verapamil were evaluated. Electroanatomical activation maps identified the sites of arrhythmia origin. Tachycardias could be initiated or terminated or both with programmed stimulation in 46 of 46 patients and most (70%) were catecholamine facilitated. Of the 9 patients with sustained annular ventricular tachycardia, 3 were localized to the tricuspid annulus, and 6 to the mitral annulus. All the 9 ventricular tachycardias (100%) terminated with adenosine, 2 of 2 terminated with verapamil, and 2 of 2 terminated with Valsalva. Of the 40 patients with annular atrial tachycardia, 4 tachycardias were localized to the mitral annulus and 37 to the tricuspid annulus (including 9 para-Hisian), and all were adenosine sensitive.


CONCLUSIONS
Peri-annular atrial and ventricular tissue correspond to a region enriched with arrhythmogenic foci, which may reflect a common developmental origin. Furthermore, the sensitivity of these tachycardias to adenosine provides evidence for a shared arrhythmia mechanism, consistent with intracellular calcium overload and triggered activity.
From the Department of Medicine, Division of Cardiology, Cornell University Medical Center, New York, NY.
James E
JE
Ip
From the Department of Medicine, Division of Cardiology, Cornell University Medical Center, New York, NY.
Christopher F
CF
Liu
From the Department of Medicine, Division of Cardiology, Cornell University Medical Center, New York, NY.
George
G
Thomas
From the Department of Medicine, Division of Cardiology, Cornell University Medical Center, New York, NY.
Jim W
JW
Cheung
From the Department of Medicine, Division of Cardiology, Cornell University Medical Center, New York, NY.
Steven M
SM
Markowitz
From the Department of Medicine, Division of Cardiology, Cornell University Medical Center, New York, NY. blerman@med.cornell.edu.
Bruce B
BB
Lerman
D000241:Adenosine / Q000008:administration & dosage; D000328:Adult; D000368:Aged; D015331:Cohort Studies; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000187:drug effects / Q000503:physiopathology*; D011446:Prospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013612:Tachycardia, Ectopic Atrial / Q000175:diagnosis* / Q000188:drug therapy; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000188:drug therapy; D014261:Tricuspid Valve / Q000187:drug effects / Q000503:physiopathology*; D014700:Verapamil / Q000008:administration & dosage
D014700:Verapamil; D000241:Adenosine
adenosine; mitral valve; tachycardia, ectopic atrial; tachycardia, ventricular; tricuspid valve