Experience with 407 transvenous, finned pacing leads with a sintered porous-surfaced electrode

Experience with 407 transvenous ventricular finned pacing leads with a sintered porous-surfaced electrode is reported. A low complication rate was encountered: 97% of patients were free from lead-related complications. Four patients (1%) required re-operation: two for lead displacement, one for failure to sense spontaneous ventricular activity and one for exit block. A further patient developed exit block which resolved spontaneously. The vast majority of patients had low chronic stimulation thresholds; for example at six months after implantation, the mean threshold for a group of pacemakers with a pulse duration of 0.5 ms was 1.4 +/- 0.7 V and for another group with a pulse duration of 0.8 ms it was 1.9 +/- 0.7 mA. However, six patients developed a transient high stimulation threshold during the month after implantation, and a high threshold developed in another patient at five months and persisted. Mean acute stimulation and sensing thresholds were satisfactory: 0.7 +/- 0.2 V at 0.5 ms pulse duration and 7.6 +/- 2.4 mV, respectively.