The intraoperative and early postoperative mechanical complications of a procedure combining an atrial screw-in lead and a ventricular screw-in lead insertion were prospectively evaluated. The procedure was performed in 119 consecutive patients (mean age 69 +/- 8 years), at first implant in 100 patients and at reoperation in 19. Nine patients had previously undergone cardiac surgery and three underwent transvenous ventricular defibrillator implantation. The double sets of leads were introduced through 2 separate veins in 5 cases, through a single venous route in 114 cases, using a percutaneous approach in 75 cases and a venous cutdown in 49, and a guidewire procedure following the venotomy in 19. The screw was mannitol coated in 102 cases, exposed in 111, and extendable/retractable in 25. The fixation of the ventricular lead was performed at the apex in 108 cases, at the outflow tract in 11, and was followed by the fixation of the atrial lead at the appendage in 112 cases and at the lateral wall in 7 cases. The lead positioning and fixation were successful at first attempt in 103 cases and after repeated lead manipulation in 19 cases. The rotational torque could be transferred to the helix in all cases except in one patient who required a second vein puncture. Unintentional fixation in the ventricular chamber with subsequent failure to remove the lead occurred in one patient. Reoperation for lead dislodgment was required in two patients. In one patient, symptomatic pericarditis with pericardial effusion was observed 1 day after the procedure and resolved spontaneously. Dual active fixation is feasible with a low incidence of mechanical complications.

The overall incidence of interaction by a magnetic field was low in patients tested with a wide variety of conventionally programmed pacemaker models. A magnetic field pulsed at power frequency can cause a mode switch and pacing inhibition in patients with devices programmed in the unipolar sensing configuration. The risk of interference appears negligible in patients with bipolar sensing programming.

A number of experimental and clinical studies have documented the risk potential of interference with implanted pacemakers by various types of cellular phones. Radiofrequency susceptibility of external medical equipment has also been reported in experimental studies. The purpose of this experimental study was to evaluate electromagnetic interference of external pacemakers by walkie-talkies and digital cellular telephones. External bipolar pacing was monitored using a digital oscilloscope to record pacemaker pulses and electromagnetic interference separately. Tests with the walkie-talkie, Private Mobile Radio (PMR) (160 MHz, 2.5 W) were conducted during the calling phase. Tests with the cellular phones, global system for mobile communications (GSM) (900 MHz, 2 W) and Digital Cellular System (DCS) (1,800 MHz, 1 W) were conducted in the test mode. Nine widely used external pacemakers from four manufacturers were tested. Various disturbances including pacing inhibition and asynchronous pacing were observed in eight pacemakers by the PMR, in four by the GSM phone, and in two by the DCS phone. The maximum distance that interference persisted ranged from 10-200 cm. This experimental study shows a potential risk of interference of external pacemakers by walkie-talkies and cellular digital phones. Appropriate warnings should be issued against the potentially serious risks of using communication devices in the vicinity of acutely ill patients treated with temporary transvenous cardiac pacemakers.

This report describes the case of a patient in whom atrial perforation with penetration of the thoracic wall was diagnosed 2 years after the implantation of an Accufix lead. Despite this complication, atrial detection in the bipolar mode and ventricular pacing were normal. Digital fluoroscopy detected a fracture with extrusion of a short segment of the retention wire. The rupture of the retention wire might have been the result, but was not the cause of the perforation.

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This experiment shows the sensibility of modern pacemakers to neutron-induced soft errors and effectiveness of backup reversion in response to irradiation. The lower neutron fluence associated with a positive test was used to propose the calculation of the very low soft error rate for the tested devices in real-life atmospheric radiation.

We report the observation of interference between an implanted loop recorder and a cellular telephone when the latter was placed over the subcutaneous pocket. The artifact produced during the ringing of the telephone was automatically recorded and stored in the device memory. A similar interference was documented during ex vivo testing.