RESUMO
BACKGROUND: The performance of temporary pacing wires is still limited by capture and sensing problems. Fractal coating can enhance electrical properties and reliability. We therefore investigated fractal-laminated wires in comparison with conventional wires. METHODS: In 21 patients two unipolar, fractal-coated pacing wires (fe) and one conventional bipolar electrode (se) were implanted in ventricular position. Afterward pacing threshold (V), R-wave sensing (mV), lead impedance (ohm), and slew-rate (mV/s) were measured. Loss of capture or sensing and dislocation was documented. fe wires were examined with energy dispersive x-ray diffraction (EDX)-analysis and scanning electrode microscopy (SEM). RESULTS: Failure in pacing was less frequent in fe wires. Also fe leads had lower pacing thresholds at implantation (0.76 +/- 0.15 V vs 1.51 +/- 0.95 V, P< 0.0001) and afterward. Furthermore fe wires showed lower increase of pacing threshold/time (0.25 V/day vs 0.42 V/day). R-wave sensing and slew-rate values in the fe group on day of operation (5.81 +/- 4.80 mV; 0.63 +/- 0.71 V/s) were lower than in the se group (10.37 +/- 6.89 mV; 1.85 +/- 1.71 V/s P< 0.0001) and afterward. Nevertheless, decrease of amplitude/time was lower in fe wires (0.17mV/day vs 0.46 mV/day). fe wires always had lower impedance values. CONCLUSIONS: Lower pacing threshold and increase of threshold/time in fe wires indicate more reliable function. Initial lower sensitivity values are still not understandable and must be investigated. However, fe wires, constancy of sensing and impedance values was more stable, so fe epicardial wires can be recommended for safe and feasible use.
