Cardiac Pacing: An Unusual Complication

To the Editor.— Recently, in converting a bipolar endocardiac transvenous pacing system to a unipolar epicardial one, we encountered an unusual complication we had not seen previously. After placing a single epicardial lead (Medtronic model 6919), the original left infraclavicular pocket was again used for the generator together with an immediately adjacent subcutaneous pocket for the new indifferent lead. Pacing was established at a low threshold and with good R wave sensing. Six hours later, pacing was lost. On inspection of the wound, an air pocket could be felt over the indifferent lead. This was aspirated and a pressure dressing applied, with immediate recapture of the rhythm. Cardiac pacing has continued without incident since that time. Suction drainage may have obviated this potentially dangerous complication.