Cardiac pacemaker cardioverter-defibrillator

Thus far, batteries for general medical applications have been described. Now low-power batteries for specialized medical fields and special medical applications will be described with a particular emphasis on cardiac rhythm management (CRM) systems [7]. Studies performed by medical experts reveal that three distinct types of devices are capable of treating cardiac diseases pacemakers, cardioverter defibrillators, and left-ventricular assist devices [7]. Batteries also have been developed to meet the power requirements of an artificial heart. 

According to heart specialists, four distinct types of medical devices can be used to treat cardiac diseases, namely pacemakers, cardioverters, defibrillators, and left-ventricular assist devices. In addition, the total artificial or mechanical heart needs to be powered by batteries with an emphasis on reliability, safety, and OCV with no electrical surges and voltage fluctuations. Generally, cardiac pacemakers are prescribed by heart specialists when the cardiac rhythm is too slow or when the patient has an abnormal heart beat. This device is implanted in the patient s chest. The implanted pacemaker detects the slow heart rate and sends electrical impulses to stimulate the heart muscle. An electrical signal from the muscle is fed back to the device to make appropriate corrections in the stimulation parameters, which will normalize the heart rate within a hundred microseconds or so. 

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. 

However, the long-term effects of cardiac resynchronization therapy (CRT) on morbidity and mortality were not known. Two clinical trials have established the morbidity and mortality effects of CRT. The COMPANION trial was a three armed trial, testing optimal medical therapy (OPT) against OPT plus CRT by a pacemaker or a OPT plus CRT by an implantable cardioverter-defibrillator (CRT-D) [118]. In this study, patients were enrolled prior to... 

Recent studies demonstrate that cardiac resynchronization therapy (CRT) offers a promising approach to selected patients with chronic heart failure. Delayed electrical activation of the left ventricle, characterized on the ECG by a QRS duration that exceeds 120 ms, occurs in approximately one-third of patients with moderate to severe systolic heart failure. Since the left and right ventricles normally activate simultaneously, this delay results in asynchronous contraction of the left and right ventricles, which contributes to the hemodynamic abnormalities of this disorder. Implantation of a speciahzed biventricular pacemaker to restore synchronous activation of the ventricles can improve ventricular contraction and hemodynamics. Recent trials show improvements in exercise capacity, NYHA classification, quality of life, hemodynamic function, and hospitalizations. A device that combined CRT with an implantable cardioverter-defibrillator (ICD) improved survival in addition to functional status. CRT is currently indicated only in NYHA class ni-IV patients receiving optimal medical therapy (ACE inhibitors, diuretics, -blockers, and digoxin) and... 

There are three implantable devices used today to treat cardiac arrhythmias - the pacemaker, the implantable cardioverter defibrillator (ICD), and the cardiac resynchronization therapy (CRT) devices for heart failure patients. 

The implantable cardioverter defibrillator (ICD) is a cardiac pacemaker. It can be used to pace one or both chambers on the right side of the heart It has an additional feature, though. ICDs can also impart powerful shocks to the heart if it is beating too fast (tachycardia) or goes into ventricular fibrillation. Either condition means that blood cannot be pumped very efficiently, if at all. A number of major clinical studies were done that identified various categories of heart patients who could benefit from the therapies delivered by devices like the ICD. 

Takeuchi ES, Leising RA, Spillman DM, Rubino R, Gan H, Takeuchi KJ, Marschilok AC (2004) Lithium batteries for medical applications, hi Nazii G-A, Pistoia G (eds) Lithium batteries science and technology. BQuwer, Boston, pp 686-700 Untereker DF, Crespi AM, Rorvick A, Schmidt CL, Skarstad PM (2007) Power systems for implantable pacemakers, cardioverters, and defibrillators. In Ellenbogtai KA, Kay GN, Lau C-P, Wilkoff BL (eds) Clinical cardiac pacing and defibrillation, 3rd edn. Saunders, Philadelphia, pp 235-259... 

Fig. 4.2 Detailed anatomy of the anterolateral chest, demonstrating the axillary vein with the pectoralis major and minor muscles removed. (From Belott PH, Reynolds DW. Permanent pacemaker and cardioverter defibrillation implantation. In Ellenbogen KA, Kay N, Wilkoff BL, eds. Clinical cardiac pacing and defibriUation, 2nd ed. Philadelphia WB Saunders, 2000, with permission.)...

Nazarian S, Roguin A, Zviman MM, et al. Clinical utility and safety of a protocol for noncardiac and cardiac magnetic resonance imaging of patients with permanent pacemakers and implantable-cardioverter defibrillators at 1.5 Tesia. Circulation 2006 114 1277-1284. 

Shellock EG, O Neil M, Ivans V, Kelly D, O Connor M, Toay L, Crues JV. Cardiac pacemakers and implantable cardioverter defibrillators are unaffected by operation of an extremity MR imaging system. Am J Roentgenol 1999 172 165-170. 

Wolber T, Ryf S, Binggeli C, Holzmeister J, Brunkhorst C, Luechinger R, Duru F. Potential interference of small neodymium magnets with cardiac pacemakers and implantable cardioverter-defibrillators. Heart Rhythm 2007 4 1-4. 

Fig. 18.3 Abdominal scout CT image in a patient with a malfunctioning implantable cardioverter-defibrillator. Inspection demonstrated a tight twisting of the lead, which resulted in device malfunction. The most likely diagnosis was twiddler syndrome. (From Hayes DL. Complications and Lloyd MA, Hayes DL. Pacemaker and ICD radiography. In Hayes DL, Lloyd MA, Friedman PA, editors. Cardiac pacing and defibrillation a clinical approach. Armonk [NY] Futura Publishing, 2000 453-84, 485-517. Used with permission of Mayo Foundation for Medical Education and Research.)...

Even more severe than the diseases leading to cardiac pacemaker implantation is the sudden cardiac death (SCO). It is the most often reason for death in western industrial countries and accounts for 1200 deaths per day in the USA. SCD is caused by ventricular tachycardia or fibrillation and death occurs within minutes. The only possibility to overcome the tachycardia and to induce a regular heart beat is to delibrillate the heart. In these cases, instead of a normal cardiac pacemaker, a different implant has to be applied. Implantable cardioverter-defibrillators (ICD) have been developed in the 1980s and more than 25 000 devices have been implanted worldwide up to the mid... 

A CVC used just to bridge the time for creation and/or maturation of a subcutaneous VA should be placed on the contralateral side. Safe CVC insertion by translumbal access into inferior vena cava with long-term patency in patients with no other options has also been described [8]. In patients with a cardiac pacemaker or implantable cardioverter-defibrillator placed under their clavicle, the contralateral approach should be preferred to avoid damage to the implanted device. Presence of such a device also hampers creation of a good subcutaneous tunnel. 

Electromagnetic interference (EMI) can wreak havoc on patients who have pacemakers or implanted cardioverter-defibrillators (ICE)s). For someone wHh a pacemaker, EMI may inhibit pacing, cause asynchronous or unnecessary pacing, or mimic intnnsic cardiac activily. For someone with an ICD, EMI may mimic ventricular fibnilab on, or it may prevent detection of a problem that needs treatment... 

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