Pacemaker is an electronic therapeutic instrument implanted in the body, which sends out electric pulses powered by batteries through a pulse generator, stimulates the myocardium contacted by the lead electrodes through conduction, and makes the heart excited and contract, thus achieving the purpose of treating some cardiac dysfunction caused by arrhythmia. The pulse generator regularly sends out a pulse current with a certain frequency, which is transmitted to the myocardium contacted by the electrode through wires and electrodes, so that local myocardial cells are excited by external electrical stimulation, and then transmitted to the surrounding myocardium through the gap connection or intercalated disc connection between cells, which leads to the excitation of the whole atrium or ventricle, and then produces contraction activity.

It should be emphasized that the myocardium must have the functions of excitation, conduction and contraction, and cardiac pacing can play its role. Artificial heart pacing system mainly includes two parts: pulse generator and electrode lead. Pulse generators are often called pacemakers alone. The electrode lead is a conductive metal wire covered with insulation layer, and its function is to transmit the electrical pulse of the pacemaker to the heart and the electrocardiogram in the heart to the sensing circuit of the pacemaker. Pacing electrode leads are usually placed for no more than 2 weeks. Pacemaker is placed outside the body. After diagnosis, treatment and prevention, the pacing electrode leads are withdrawn immediately.

If pacing therapy is still needed, a permanent pacemaker should be considered. Any patient with symptomatic bradycardia or hemodynamic changes caused by bradycardia is the object of temporary cardiac pacing. The purpose of temporary cardiac pacing is usually divided into treatment, diagnosis and prevention. Femoral vein, subclavian vein or internal jugular vein are usually used to puncture and send temporary pacing electrode leads.

Electrode lead displacement is more common than permanent cardiac pacing. Postoperative ECG monitoring should be strengthened, including early increase of pacing threshold, change of sensing sensitivity and dislocation of electrode lead, especially for pacemaker dependent patients. In addition, because the electrode leads communicate with the outside world through the puncture point, it is necessary to pay attention to local cleaning to avoid infection, especially for those who have been placed for a long time. In addition, after temporary pacing through femoral vein, the patient should stay in supine position, and the lower limbs on the venipuncture side should be braked. ?