High-density versus point-by-point electroanatomical activation mapping of a cranial vena cava tachycardia in a dog.

A seven-year-old, male intact Newfoundland was referred for catheter ablation of supraventricular tachycardia. Activation mapping was performed using an electroanatomical mapping system to visualize the activation wavefront in a color-coded fashion on an anatomical shell. Atrial flutter with an early-meets-late signal (i.e. suspected isthmus) at the cranial vena cava was most suspected, but could not be targeted due to overlap with the phrenic nerve. On follow-up, a more complete high-density map better outlined the suspected circuit and substrate of cranial vena cava flutter. Compared to point-by-point catheters, high-density mapping catheters enhance identification and annotation of low-amplitude electrogram signals.