case_images: PMC3714094_01
case_images: Alternating QRS amplitude and axis.
case_images: JCHIMP-2-17610-g001.jpg
case_images: PMC3714094_01_JCHIMP-2-17610-g001.jpg
case_images: F0001
case_images: Electrocardiography (Fig. 1) revealed a beat-to-beat shift in the QRS axis and amplitude. Fig. 1 does suggest the presence of a delta wave and a short PR interval in lead V2, although this configuration may also occur with a fusion beat.