Defibrillator

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. 

External defibrillation was first performed in 1952 and continues as a routine procedure in hospitals and ambulances. The problem of external defibrillation has not been a technological one, but rather a legal one. Only in the 1990s have laws been passed to permit people other than doctors and paramedics to operate semiautomatic defibrillators to provide help when it is needed. New and better defibrillation devices continue to come to market and are easier and safer to use. 

Clinical evaluation is underway to test transvenous electrodes. Transvenous leads permit pacemakers to be implanted under local anesthesia while the patient is awake, greatly reducing recovery time and risk. As of 1996, the generation of implantable defibrillators requires a thoracotomy, a surgical opening of the chest, in order to attach electrodes to the outside of the heart. Transvenous electrodes would allow cardiologists to perform pacemaker procedures without a hospital or the use of general anesthesia. 

Devices for the 1990s. The 1990s may turn out to be the decade of active arrhythmia-control devices. Implantable devices to pace, cardiovert, and defibrillate the heart without the need for open-heart surgery should become widely accepted before the year 2000. Dramatic developments and... 

Ventricular fibrillation should be terminated by electrical defibrillation. Alternatively, lidocaine can be injected intravenously. In cases with lower frequency, ventricular tachyarrhythmia class I diugs such as aj marine, flecainide or propafenone are more effective as a result of the use-dependence of lidocaine. For prophylaxis treatment, amiodarone or sotalol may be helpful or the implantation of a cardioverter-defibrillator system. Acute amiodarone (i.v. in higher doses) can also terminate ventricular tachyarrhythmias. This action, however, seems to be mediated by its INa-blocking side effects and not (or less) by its class III like effects. 

Larsen GC, Manolis AS, Sonnenberg FA, et al. Cost-effectiveness of the implantable cardioverter-defibrillator effect of improved battery life and comparison with amiodarone therapy. J Am Coll Cardiol 1992 19 1323-34. 

In addition, electrochemical methods and instruments based on electrochemical phenomena may find direct nses in healing various diseases. The most significant example of a direct dealing metfiod relying on an electrocfiemical phenomenon is defibrillation, a techniqne nsed in reanimation where contraction of the heart muscle is provoked by an electrical pnlse. 

Press the sync control button to synchronize the defibrillator o Look for markers on R waves indicating synchronized mode o If needed, adjust monitor gain until synchronized markers... 

Announce to team members Charging defibrillator—stand cleaf ... 

When the defibrillator is charged announce to team members o I am going to shock on three. ... 

Implantable cardioverter-defibrillators are more effective than antiarrhythmic drugs for reduction in the risk of sudden cardiac death due to VT or VF. 

The purpose of drug therapy for VF is facilitation of electrical defibrillation in the absence of electrical defibrillation, drug therapy alone will not terminate VF. 

Termination of VT Hemodynamically unstable VT should be terminated immediately using synchronized DCC beginning with 100 J and increasing subsequent shocks to 200, 300, and 360 J.14 In the event that VT is present but the patient has no pulse (and therefore no blood pressure), asynchronous defibrillation should be performed, starting with 200 J and increasing to 300 and 360 J.14... 

In patients who have experienced VT and are at risk for sudden cardiac death, implantation of an implantable cardioverter-defibrillator (ICD) is the treatment of choice.44 An ICD is a device that provides internal electrical cardioversion of VT or defibril -lation of VF the ICD does not prevent the patient from developing the arrhythmia, but it reduces the risk that the patient will die of sudden cardiac death as a result of the arrhythmia. Whereas in the past ICD implantation required a thoracotomy, these devices now may be implanted transvenously, similarly to pacemakers, markedly reducing the complication rate. 

TABLE 6-12. Drugs for Facilitation of Defibrillation in Patients with Ventricular Fibrillation... 

A defibrillation attempt should be made after every dose of drug. 

GFR Glomerular filtration rate ICD Implantable cardioverter defibrillator... 

Implantable cardioverter-defibrillator (ICD) A device implanted into the heart transvenously with a generator implanted subcutaneously in the pectoral area that provides internal electrical cardioversion of ventricular tachycardia or defibriUation of ventricular fibrillation. 

The precise effects obtained are dependent on the fabric quality, the type of cellulase enzyme and the application conditions, but no mechanical forces are involved in removal of the fibrils. The process has attracted considerable attention and is now one of the main methods of defibrillating lyocell fabrics [94,101-114]. Simultaneous treatment with cellulase and protease enzymes has been applied to the biofinishing of wool/cotton blends [115]. 

The use of antiarrhythmic drugs in the United States is declining because of major trials that showed increased mortality with their use in several clinical situations, the realization of proarrhythmia as a significant side effect, and the advancing technology of nondrug therapies such as ablation and the implantable cardioverter-defibrillator (ICD). 

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