The author’s approach is to attempt

The author’s approach is to attempt a second puncture if the puncture for the first wire was easy and switch to double wiring if the second puncture proves to be difficult. Double wiring is also preferred in patients who are at higher risk of a pneumothroax. A second puncture is preferred if the initial guide-wire is appears “tight” and not supporting of two closely spaced leads. For dual chamber ICDs and CRTs separate punctures are preferred as lead thicknesses and sheaths vary.