Rarely reported case of non-conducted focal atrial tachycardia

The techs this week showed me an atrial tachyarrhythmia which did not conduct to the ventricle. The rate was about 300 bpm and was slightly irregular. The pattern was repeated many many times.

Those, who report lots of Holters, see this about once a month and this is a focal atrial tachycardia with block, although the third beat probably conducts. This is rarely reported in the literature.In the next example from the same patient, there is again one conducted beat. The focal atrial tachycardia is irregular and the last atrial complex occurs earlier and then blocks. The ladder diagram, demonstrates that this is a “Wenckebach block at the ectopic-myocardial junction”.There is also a suggestion of Wenckebach AV block as well.

I reported this recently in Heart Lung and Circulation. The examples are below and a reprint enclosed.

Assoc Prof Harry Mond