ECG puzzle: Appearances Can be Deceiving

Author(s)	T.A. Simmers
NHJ edition:	2005:1,23
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

Figure 1

Case

A 61-year-old male was referred with symtoms of exertional dyspnoea and palpitations. He had suffered an anterior myocardial infarction two years previously, but had well preserved systolic left ventricular function. Diastolic function was, however, impaired due to hypertrophic cardiomyopathy which had been diagnosed many years ago. His ECG is shown in figure 1. Serial antiarrhythmic drugs and cardioversions had failed to restore sinus rhythm.

What is the diagnosis? And treatment?

Answer