Paradoxical undersensing during atrial flutter: what is the mechanism?
A patient with congenital complete heart block underwent implantation of a dual-chamber pacemaker. He presented to the emergency room with fatigue and was found to be in atrial flutter. Device interrogation revealed undersensing of 5 mV flutter waves at a programmed sensitivity of 0.5 mV. Due to undersensing, mode switch did not occur. This case illustrates apparently paradoxical undersensing of atrial flutter waves by a dual-chamber pacemaker and can be explained by a phenomenon known as "quiet timer blanking."
Kalahasty
Gautham
G
From the Virginia Commonwealth University Medical Center, Richmond, VA 23298-0053, USA.
Kenigsberg
David N
DN
Wood
Mark A
MA
Ellenbogen
Kenneth A
KA
D000328:Adult; D001282:Atrial Flutter / Q000175:diagnosis* / Q000503:physiopathology* / Q000628:therapy; D004868:Equipment Failure; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial / Q000592:standards*