Table 2.

Practical considerations for avoiding map shifts in device procedures

Access site	Avoid mapping from the femoral approach (map shift and increased procedure duration). Consider percutaneous access before incision, especially in upgrade procedures (we observed no map shift before pocket opening).
Tools	Avoid as far as possible metallic instruments in the field during mapping. Especially removing or exchanging during mapping. Consider using coated wires.
Reference electrodes	System reference can be used, but use of another implanted lead as reference can reduce the risk of map shifts.
Tagging	Tagging of other implanted lead tips and mapping of coronary sinus can be useful for correcting map shifts.
Connections	Consider use of best possible insulated connection lead for the implanted lead when mapping, to avoid map shifts (insulated “alligator clips”).