Pacemakers wires

Complications related to the thermal ablation itself include unintentional thermal harm to non-targeted areas including burns at the grounding pads and interference with metallic implants such as pacemaker wires and cardioverter defibrillators. 

Used to assess QRS-complex arrhythmias, monitor premature ventricular beats and P-wave changes, distinguish different types of tachycardia (ventricular, supraventricular) and bundle-branch defects, and confirm pacemaker wire placement. 

Instruct him not to manipulate the pacemaker wires or pulse generator. 

Platiaum and its alloys are also used as biomedical electrodes, eg, platiaum—indium wires for permanent and temporary pacemaker leads and defibrillator leads. Electrophysiology catheters, which contain platinum electrodes and marker bands, have been used to map the electrical pathways of the heart so that appropriate treatment, such as a pacemaker, can be prescribed. 

The pacemaker device is surgically placed in a pocket of tissue near the patient s collarbone. One or more wires, called leads, are connected to the pacemaker and threaded down through a major vein to the patient s heart. By sending electrical impulses along the leads to the heart, the pacemaker can induce a heartbeat. 

The most widely studied synthetic polymers for blood contact applications are polyether urethane ureas ( Biomer (Ethicon)). These materials have been used in artificial hearts, as coatings for lead wires in pacemakers, have been used and are being considered for blood vessel prostheses. The success of these materials is believed to be due to preferential adsorption of albumin rather than globulin or fibrinogen which promote a clotting response. However, these materials are hydrophobic and questions of long-term effectiveness are unresolved. Particularly, these materials may shed emboli or may be susceptible to surface calcification. Thus, it may be desirable to have synthetic polymers which are hydrophilic and better resemble blood vessels [475]. 

Following septal ablation, patients should be monitored in a coronary care unit for 24 to 48 hours and the temporary pacing wire should be removed at the end of this period in the absence of atrioventricular block. Patients may then be transferred to a telemetry unit for monitoring of arrhythmias. Total hospitalization is usually for three to five days to monitor for occurrence of complete heart block that would require a permanent pacemaker. A sizeable infarction is induced with alcohol ablation and causes creatinine phosphokinase to peak at 1000 to 1500 one day after the ablation. Patients should be maintained on aspirin indefinitely. 

To correct problems of rhythm disturbance or SA node malfunction, cardiologists often use a pacemaker, an electrical device implanted in the shoulder or abdomen of the patierrt with a wire leadir to the heart. This mecharrical pacemaker generates the electrical signal which regulates the heart s functions. The rate of heartbeat, which is set when the pacemaker is implanted, can be changed if necessary without surgery. Modem... 

Pacemakers like these are usually implanted under the skin below the clavicle and connected to the heart by a wire inserted into a major vein in the neck and guided down into the heart. Photograph byEamonn McNulty National Audubon Soa-ety Collectionff boto Researcbers, Inc. Reproduced by permission. 

The first pacemaker, the result of lor, arduous research, was used in a patient in 1958. The pacemaker device was not implanted, but its wire was connected to the patient s heart. The pacemaker itself was so large that it had to be carted around in a grocery store cart. While it was a sduHcn to the patient s arrhythmia, it was hardly practical. Fortunately, pacemakers were socn miniaturized. 

Surgeons prefer to implant pacemakers in the shoulder because the procedure can be carried out under local anesthetic. The wire from the pacemaker is inserted into one of the large veins in the shoulder and fed down into the heart, through the right atrium and into the ventricle where it is attached to the heart muscle. If the wire cannot be fed through veins that are too small or diseased, the pacemaker can be implanted in the abdomen. 

The use of permanent pacemakers is beyond the scope of this book. In an emergency, AV conduction may be improved by atropine (antimuscarinic vagal block) (0.6 mg i.v.) or by isoprenaline (p-adrenoceptor agonist) (0.5-10 micrograms/min, i.v.). Temporary pacing wires may be needed prior to referral for pacemaker implantation. 

Heart Valves and Pacemakers. Pacemakers, which regulate the heart beat by electrical stimulation, have been used on humans since 1952, and implantable models have been used since 1958. The wires and electrodes are usually plastic coated for purposes of insulation, and the entire device is usually embedded in a plastic for protection from the body fluids. Over 60,000 of these pacemakers are placed in people each year. 

W Leads Insulated wires called leads carry electric signals between the heart and the pacemaker. A lead Is implanted into a blood vessel and then into a chamber of the heart. Pacemakers might use one, two, or three leads, each in a different chamber. 

Other cardiovascular uses have included coatings on pacemakers and pacemaker lead-wires for purposes of insulation and for achieving biocompatibility. Medical grade silicone elastomer has been widely used as a material of construction in experimental artificial hearts and heart assist devices. Silicone tubing is often preferred for use in roller-type blood pumps during cardiopulmonary bypass. Medical grade silicone elastomer contains no leachable or organic plasticizers and thus contributes minimal contamination in blood contact applications. 

Kawanishi DT, Brinker JA, Reeves R et al (1998) Kaplan-Meier analysis of freedom from extraction or death in patients with an Accufix J retention wire atrial permanent pacemaker lead a potential management tool. Pacing Clin Electrophysiol 21 2318-2321... 

Lead clippers these are used to separate the connector from pacemaker or defibrillator lead wire. They cleanly cut the lead so that the inner coil is exposed. 

Noble mebds such as platinum-iridium are also utilized in pacemaker electrodes. In addition to the noble metals, stainless steel and tantalum can also be used in sensing (nonpacing) electrodes. Stainless steel has also been used as wire braids and reinforcements in catheters, particularly in high-pressure catheters, such as those used for radiopaque dye injection. 

A polycarbonate TPE polyurethane that claims biostability is achieved through its replacement of virtually all ether or ester linkages with carbonate groups. The soft segment is composed of a polycarbonate diol formed by the condensation reaction of 1,6-hexanediol with ethylene carbonate. The polycarbonate diol is converted to a high molecular weight polyurethane by the reaction with 1,4-methylene bisphenyl diisocyanate (MDI) and 1,4-butanediol. It is reported to be resistant to environmental stress cracking as experienced with insulation on pacemaker lead wires. The polymer can be extruded, injection molded or compression-molded, and can be bonded with conventional urethane adhesives and solvents (Tables 4.4, 4.12, 4.13, and 4.14). 

Silicone elastomers have a long history of use in the medical field. They have been applied to cannulas, catheters, drainage tubes, balloon catheters, finger and toe joints, pacemaker lead wire insulation, components of artificial heart valves, breast implants, intraocular lenses, contraceptive devices, burn dressings and a variety of associated medical devices. A silicone reference material has been made available by the National Institutes of Health to equate the blood compatibility of different surfaces for vascular applications. This material is available as a silica-free sheet. Contact the Artificial Heart Program, NHBLI, NIH, Bethesda, Md. for further information. 

Electrosurgical cutting and coagulation device Nonpowered suction apparatus Hydraulic/mechanical impotence device Implantable pacemaker Peritoneal dialysate delivery system Catheter introducer Catheter guide wire... 

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