A case of non-conducted atrial bigeminy simulating a second-degree atrioventricular block. A holter ECG diagnosis.
A 82-years-old man, symptomatic for fatigue and lypothymia, was referred to our centre in order to evaluate the opportunity of a permanent pacemaker insertion. A 12-lead ECG was described as a Mobitz type II second-degree atrioventricular block with 2:1 conduction. This surface ECG revealed some sinus beats with normal AV conduction, everyone followed by a bizarre, non-conducted P' wave, inscripted in the previous T wave. The Holter ECG showed a sinus rhythm with a mean rate of 70 beats/minute: during the night and at 06:39 pm of the following day, ECG strip showed some sinus beats, everyone followed by an atrial non-conducted ectopic beat, characterized by prematurity and abnormal shape (P' wave), that appears as a small deformation on the preceding T wave. At the beginning and the end of the strip we can estimate respectively 9 and 4 sinus beats, that represent the normal rhythm of this patient. So, it is possible to compare the normal P-P interval (P-P = 0.84 sec) to the shorter P-P' interval (P-P = 0.40 sec) and make the correct diagnosis of non-conducted atrial bigeminy simulating a second-degree AV block with 2:1 conduction.
Gaudio
C
C
Department of Cardiology, University La Sapienza - Rome (Italy).
Di Michele
S
S
Ferri
F M
FM
Mirabelli
F
F
Franchitto
S
S
Alessandri
N
N
D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000503:physiopathology; D003937:Diagnosis, Differential; D015716:Electrocardiography, Ambulatory; D006325:Heart Atria / Q000503:physiopathology; D006327:Heart Block / Q000175:diagnosis*; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial