Left Atrial Abnormality

Report:

Sinus rhythm 74/min

Left atrial abnormality

Second degree AV block, Möbitz 2 (Wenckebach) type

4:3 conduction, with trigeminy

Horizontal heart position

Nonspecific ST/T changes

Comment:

The P wave is 3 mm broad, with a 1 mm notch; in V1 the PTF is just over 1 x 1 mm. It isn’t the most striking or obvious LAA in this collection, but is typical enough to be noticed and reported (the computer got it, too, but most computers appear to overdiagnose it). Another typical feature is that it is combined with other conduction defects, in this case the Wenckebach AV block.

An interesting thing about LAA is that, among its other implications, it is now recognised as a risk marker for embolic stroke214.

The AV Wenckebach here should be compared to its SA counterpart in Case 283: the QRS rate fails to accelerate.

Below (Fig 288a) is the same patient’s DDDR paced rhythm, showing a sinus capture beat. Why he needed permanent pacing is unclear (the low-grade Wenckebach would not be an indication per se – not if he was on verapamil). Maybe he was privately insured.

288a. 289. 65 year old lady with ruptured diverticulum and no cardiac history, diagnosed on this postoperative ECG

If you have any suggestions for or feedback on this report, please let us know.