Breivik K, Engedal H, Resch F, Segadal L, Ohm O J
Pacing Clin Electrophysiol. 1982 Jul;5(4):600-6. doi: 10.1111/j.1540-8159.1982.tb02286.x.
A new temporary pacemaker lead, Medtronic 6400, with a solid defined electrode surface area of 7.5 mm2, has been implanted in 50 patients after open-heart surgery. One electrode was inserted intramyocardially on the right ventricle, while another was placed extracardially and served as a reference lead. Forty-six of the patients were followed postoperatively with measurements of myocardial stimulation threshold and resistance. In 25 of the patients, electrograms were recorded on magnetic tape for further computer analysis of amplitudes, slew rates, and signal source impedance. During constant current pacing, myocardial stimulation threshold increased from a median of 0.4 mA one hour postoperatively to a maximum value of 2.3 mA. In two patients (4.3%) intermittent pacing failure was seen. Stimulation resistance fell from a median of 875 omega to a minimum of 487 omega, with a subsequent increase of 598 omega before electrode removal. Both mean electrogram amplitude (7.35 mV) and slew rate (0.82 V/s) had their minimum values on the sixth postoperative day. Intermittent sensing failure was observed in 2/25 patients (8%). Signal source impedance was of a magnitude not likely to contribute to sensing failure. No complications were seen from the use of this lead. The new electrode is an important improvement in temporary pacemaker lead design.
一种新型临时起搏器导线美敦力6400，其固体限定电极表面积为7.5平方毫米，已在50例心脏直视手术后的患者体内植入。一根电极经心内膜插入右心室，另一根置于心外膜作为参考导线。46例患者术后接受了心肌刺激阈值和电阻的测量。25例患者的心电图被记录在磁带上，以便进一步对振幅、上升速率和信号源阻抗进行计算机分析。在恒流起搏期间，心肌刺激阈值从术后1小时的中位数0.4毫安增加到最大值2.3毫安。2例患者（4.3%）出现间歇性起搏失败。刺激电阻从中位数875欧姆降至最小值487欧姆，在电极移除前随后又增加到598欧姆。平均心电图振幅（7.35毫伏）和上升速率（0.82伏/秒）均在术后第6天达到最小值。25例患者中有2例（8%）出现间歇性感知失败。信号源阻抗的大小不太可能导致感知失败。使用这种导线未观察到并发症。这种新型电极是临时起搏器导线设计的一项重要改进。
