Myocardial perforation by flexible Elema endocardial pacing catheters.

, , 678-684. Myocardial perforation as a complication of permanent endocardial pacing with flexible Elema catheters is described in nine patients. In eight patients pacing failed, but there were no other serious ill-effects. Diaphragmatic pacing occurred in five patients. Radiological evidence of movement, either posteriorly and/or laterally, of the electrode tip was detected in five patients. In only two of them was the electrode seen to be definitely extracardiac in position. A change in the pacing wave form aided the diagnosis in two patients. In a further two patients electrode tip electrocardiograms helped to confirm the diagnosis where, upon withdrawal of the perforating electrode, small Q waves disappeared, RS complexes enlarged, and the ST segments became more elevated, with deeply inverted T waves. Withdrawal and repositioning of the electrode catheters was performed in seven patients. In one, a new catheter was inserted, and in another, where uninterrupted cardiac pacing was accompanied by intermittent diaphragmatic pacing, the pacing system was left unaltered. The follow-up is from six months to four and a half years with one late death apparently unrelated to pacing failure.