Cardiac pacing is a medical device to help human to overcome arrhythmia and to recover the regular beats of heart. A helical configuration of electrode tip is a new type of cardiac pacing lead distal tip. The helical ...Cardiac pacing is a medical device to help human to overcome arrhythmia and to recover the regular beats of heart. A helical configuration of electrode tip is a new type of cardiac pacing lead distal tip. The helical electrode attaches itself to the desired site of heart by screwing its helical tip into the myocardium. In vivo experiments on anesthetized dogs were carried out to measure the acute interactions between helical electrode and myocardium during screw-in and pull-out processes. These data would be helpful for electrode tip design and electrode/myocardium adherence safety evaluation. They also provide reliability data for clinical site choice of human heart to implant and to fix the pacing lead. A special design of the helical tip using strain gauges is instrumented for the measurement of the screw-in and pull-out forces. We obtained the data of screw-in torques and pull-out forces for five different types of helical electrodes at nine designed sites on ten canine hearts. The results indicate that the screw-in torques increased steplike while the torque-time curves presente saw-tooth fashion. The maximum torque has a range of 0.3-1.9 Nmm. Obvious differences are observed for different types of helical tips and for different test sites. Large pull-out forces are frequently obtained at epicardium of left ventricle and right ventricle lateral wall, and the forces obtained at right ventricle apex and outflow tract of right ventricle are normally small. The differences in pull-out forces are dictated by the geometrical configuration of helix and regional structures of heart muscle.展开更多
Objective To evaluate the safety and possibility of transesophageal emergency ventricular pacing with esophageal balloonelectrode catheter.Methods Sixty four patients with critical bradyarrhythmias were divided random...Objective To evaluate the safety and possibility of transesophageal emergency ventricular pacing with esophageal balloonelectrode catheter.Methods Sixty four patients with critical bradyarrhythmias were divided randomly to receive either transesophagealventricular pacing with esophageal balloon electrode catheter(balloon.catheter group,n=32),or transesophageai ventricular pacing withnormal esophageal electrode catheter(normal catheter group,n=32).Pulse width(ms),current output(mA),and the success rate werecompared between the 2 groups.Results Success rate in the balloon catheter group was 87.5%,which was significantly higher thanthat in the nodal catheter group(18.7%,X2=27.7,P＜0.01).The success rate oftransesophageal ventricular pacing with esophagealballoon electrode catheter was 87.5%.The average current output(mA)was significantly lower in the balloon catheter group than thatin the normal catheter group (24.5+2.5 mA VS 53±3.4mA,P＜0.05).Conclusions Esophageal balloon electrode catheter pacing couldbecome an available teclmiqBe for transesophageal emergency ventricular pacing.展开更多
文摘Cardiac pacing is a medical device to help human to overcome arrhythmia and to recover the regular beats of heart. A helical configuration of electrode tip is a new type of cardiac pacing lead distal tip. The helical electrode attaches itself to the desired site of heart by screwing its helical tip into the myocardium. In vivo experiments on anesthetized dogs were carried out to measure the acute interactions between helical electrode and myocardium during screw-in and pull-out processes. These data would be helpful for electrode tip design and electrode/myocardium adherence safety evaluation. They also provide reliability data for clinical site choice of human heart to implant and to fix the pacing lead. A special design of the helical tip using strain gauges is instrumented for the measurement of the screw-in and pull-out forces. We obtained the data of screw-in torques and pull-out forces for five different types of helical electrodes at nine designed sites on ten canine hearts. The results indicate that the screw-in torques increased steplike while the torque-time curves presente saw-tooth fashion. The maximum torque has a range of 0.3-1.9 Nmm. Obvious differences are observed for different types of helical tips and for different test sites. Large pull-out forces are frequently obtained at epicardium of left ventricle and right ventricle lateral wall, and the forces obtained at right ventricle apex and outflow tract of right ventricle are normally small. The differences in pull-out forces are dictated by the geometrical configuration of helix and regional structures of heart muscle.
文摘Objective To evaluate the safety and possibility of transesophageal emergency ventricular pacing with esophageal balloonelectrode catheter.Methods Sixty four patients with critical bradyarrhythmias were divided randomly to receive either transesophagealventricular pacing with esophageal balloon electrode catheter(balloon.catheter group,n=32),or transesophageai ventricular pacing withnormal esophageal electrode catheter(normal catheter group,n=32).Pulse width(ms),current output(mA),and the success rate werecompared between the 2 groups.Results Success rate in the balloon catheter group was 87.5%,which was significantly higher thanthat in the nodal catheter group(18.7%,X2=27.7,P＜0.01).The success rate oftransesophageal ventricular pacing with esophagealballoon electrode catheter was 87.5%.The average current output(mA)was significantly lower in the balloon catheter group than thatin the normal catheter group (24.5+2.5 mA VS 53±3.4mA,P＜0.05).Conclusions Esophageal balloon electrode catheter pacing couldbecome an available teclmiqBe for transesophageal emergency ventricular pacing.
