Wide Complexes Intervening Regular Sinus Rhythm - 3

Author(s) A.A.M. Wilde
NHJ edition: 2009:03,102
These Rhythm Puzzles have been published in the Netherlands Heart Journal and are reproduced here under the prevailing creative commons license with permission from the publisher, Bohn Stafleu Van Loghum.
The ECG can be enlarged twice by clicking on the image and it's first enlargement

A 73-year-old man presents with palpitations (irregular heartbeat). There is no medical history. Physical examination reveals no abnormalities. A baseline ECG is presented in figures 1A and 1B, which together show a 12-lead ECG (extremity leads in figure 1A and precordial leads in figure 1B).

Figure 1A
Figure 1B

What is your diagnosis?

Answer