Split atrial activity in a man with brady-tachy syndrome.
A 74-year-old man with brady-tachy syndrome showed split atrial activities in electrophysiologic studies. The split intervals of atrial activities varied spontaneously or in response to electric stimulations. The shorter were the coupling intervals of atrial extrastimuli, the longer the split intervals of captured atrial activities. At a critical timing of atrial extrastimuli, atrial flutter-fibrillation was initiated reproducibly. During atrial flutter-fibrillation, the split activities showed Wenckebach-like phenomenon. These findings seem to result from depressed conductivity. The split atrial activity may reflect a diseased state of the atrium which predisposes to atrial arrhythmias.
D000368:Aged; D001919:Bradycardia / Q000503:physiopathology*; D004558:Electric Stimulation; D004562:Electrocardiography; D004594:Electrophysiology; D006325:Heart Atria / Q000503:physiopathology; D006801:Humans; D008297:Male; D013577:Syndrome; D013610:Tachycardia / Q000503:physiopathology*