Tip surface changes in endocardial stimulation electrode, visualised by scanning electron microscopy.

The authors have been probably the first investigators who applied scanning electron microscopy to studies of the changes occurring in the surface of the metalic tip of an endocardial stimulating electrode. They found a lowered conductivity for secondary electron emission, and describe the surface changes in a platiniridium-tipped electrode which had been used for almost four years, in comparison with an unused electrode.