Permanent Pacemaker system

Septal ablation related mortality at experienced centers is currently 1% to 2%, similar to that of surgical myectomy (Table 4). Conduction system abnormalities are relatively common complications of septal ablation, Permanent right bundle branch block occurs in about 50% of patients and transitory complete heart block in 60% and permanent pacemakers required for high grade atrioventricular block in about 5% to 20%, Concerns of late occurrence of complete heart block following septal ablation mandates in-patient monitoring for 4 to 5 days,... 

A 64-year-old woman with systemic lupus erythematosus took chloroquine for 7 years (cumulative dose 1000 g). She developed sjmcope, and the electrocardiogram showed complete heart block a permanent pacemaker was inserted. The next year she presented with biventricular cardiac failure, skin hyperpigmentation, proximal muscle weakness, and chloroquine retinopathy. Coronary angiography was normal. An echocardiogram showed a restrictive cardiomyopathy. A skeletal muscle biopsy was characteristic of chloroquine myopathy. Chloroquine was withdrawn and she improved rapidly with diuretic therapy. 

The jugular vein has been used for permanent pacemaker implantation as an alternate cutdown site (81). As a rule, the jugular vein has not been utilized for nonthoracotomy lead systems. This is a large venous structure that lies in the cervical triangle defined by the lateral border of the omohyoid muscle, inferior... 

Fig. 4.30 A Pacemaker system upgrade using contralateral subclavian vein. The pacemaker pocket is opened and the old pulse generator and lead and dissected free, externalized and disconnected. B A second lead is inserted via the contralateral vein using the percutaneous technique. C The second lead is tunneled back to the initial pocket. The chronic ventricular and new atrial electrodes are connected to the pulse generator. (From Belott PH. Unusual access sites for Permanent Cardiac Pacing. In Barold SS, Mugica J, eds. Recent advances in cardiac pacing Goals for the 21st century. Armonk, NY Futura Publishing, 1997, with permission.)...

Fig. 4.41 Location of surgical incisions for placement of epicardial systems. The common median sternotomy is not shown. (From Belott PH, Reynolds DW. Permanent pacemaker implantation. In Ellenbogen KA, Kay N, Wilkoff BL, eds. Clinical cardiac pacing. Philadelphia WB Saunders, 1995, with permission.)...

Implantation of transvenous ICD systems employs techniques similar to those used for permanent pacemaker implantations, and is discussed in detail in a separate chapter in this book. Connecting ICD leads to the device is slightly different than connecting pacemaker leads to pacemaker generators. All ICD pulse generators have at least three ports for single chamber devices (four ports for dual chamber devices, and five ports for CRT-D). One LV port is for the pace/sense IS-1 terminal pin, and two are for the defibrillation coil (usually DF+ and DF-). The second DF port may be capped if a single coil... 

Type I second-degree AV block with bundle branch block (which is far less common than narrow QRS type I block) must not be automatically labeled as AV nodal. Outside of acute myocardial infarction, type I block and bundle branch block (QRS > 0.12 s) occur in the His-Purkinje system in 60-70% of the cases (10) (Fig. 10.5). In such cases exercise is likely to aggravate the degree of AV block. Yet, many still believe that type I blocks are all AV nodal and therefore basically benign. It is believed that the prognosis of infranodal type I block is as serious as that of type II block and a permanent pacemaker... 

Fig. 10.14 Very long HV interval representing severe disease of the His-Purkinje system. His bnndle recording in a patient with right bundle branch block and syncope. Left ventricular ejection fraction was normal. There was no documentation of seconder third-degree AV block before the electrophysiological study. Note the very long HV interval of 124ms measured from the His bundle potential to the earliest ventricular activation either in the surface or intracardiac leads, (normal = 35-55 ms) responsible for the first-degree AV block. Time fines = 10ms. A = low atrial depolarization, H = His bundle potential, V = Activation of high ventricular septum. Syncope disappeared after implantation of a permanent pacemaker.

Chronotropic Support. Temporary pacing should be considered in patients who demonstrate hemodynamic compromise due to bradycardia. Unstable bradycardia is usually caused by either severe sinus node dysfunction or complete AV conduction block, but even mild sinus bradycardia or second-degree AV block can result in instability if there are underlying conditions such as severe dilated cardiomyopathy or critical aortic stenosis. In some patients, the bradycardia is due to intrinsic conduction system disease and temporary pacing is merely a bridge to permanent pacemaker insertion. In others, a... 

Waller D, Calhes E, Langenfeld H. Adverse effects of direct current cardioversion on cardiac pacemakers and electrodes. Is external cardioversion contraindicated in patients with permanent pacing systems Europace 2004 6 165-168. 

Lucas E, Johnson D, McEhoy BP. The effects of electronic article surveillance systems on permanent pacemakers an in vitro study. Pacing Clin Electrophysiol 1994 17(PtII) 2021-2026. 

Anatomic variations can alter the placement of the pacing system and therefore the radiographic appearance. It is not possible to discuss all potential anatomic variations. However, one anatomic variation does merit discussion - a persistent left superior vena cava. A permanent pacing system can be implanted via a persistent left superior vena cava (Fig.18.21). (If this anatomic variation is noted before pacemaker implantation, it is easier to implant the system via the right side if the patient has a normal right superior vena cava.) If pacing leads are implanted through a persistent left superior vena cava, the lead in the PA projection descends within the left side of the cardiac shadow and enters the atrium and then the ventricle by communication of the left superior vena cava and the coronary sinus. On the lateral projection, the ventricular lead is seen on the posterior cardiac wall within the coronary sinus. 

Patients may require temporary pacing. If however the block is permanent a Permanent Pacemaker (PPM) system may be required. 

Sometimes due to damage to the conduction system, or to manage certain types of heart block, it becomes necessary to insert a Permanent Pacemaker (PPM) system. The PPM system consists of one or more electrodes (leads) and a battery (pulse generator). The pulse generator can detect the patient s rhythm and emit an... 

The incidence of permanent pacemaker implantation varies between 6% and 23% (Melton et al. 1999) using the biatrial technique. If necessary a rate-responsive pacing system should be implanted as chronotropic incompetence is the rule. With the use of the bicaval anastomosis technique, the incidence of permanent pacemaker implantation diminished to less than 5%. 

Alternatives of non-invasive rejection monitoring have been developed to supplement or replace EMB and are now established in some transplant units monitoring and recording of intramyocardial electrogram (IMEG) amplitude with telemetry function (monitoring) using a permanent, implanted pacemaker system (Iberer et al. 1998 Warnecke et al. 1992). With this tool it will be possible to abandon EMB, which is important for infants or children, in whom routine EMB cannot be performed (Muller et al. 1993). 

The capabilities of permanent pacemakers can be described by a five-letter coding system. Typically, only the first three letters are used. ... 

Vulnerability to ventricular arrhythmias. There is the theoretical risk of ventricular fibrillation whenever a pacemaker stimulus is delivered into the vulnerable period of the ventricle. Experimentally, the ventricular fibrillation threshold is lower with bipolar stimulation than with conventional unipolar cathodal stimulation. Despite these laboratory observations, no clinical differences between permanent unipolar and bipolar systems have been reported with respect to the risk of inducing ventricular arrhythmias. 

It is now appreciated that when approaching a patient for a permanent transvenous pacemaker or modem AICD system, every effort should be made to preserve atrial and ventricular relationships.(In addition there are patients... 

Shonld a complete obstrnction between the superior vena cava and right atrium be documented, it is likely that the only reasonable approach for pacing will be an epicardial system, although there is at least one report of the use of the transhepatic approach for placement of a permanent pacing lead in such a patient (43). However, if there is stenosis without complete obstruction, one may consider balloon dilation with or without placement of an expandable stent (44). If a stent is placed, one should not cross the site immediately with a pacemaker lead becanse of the chance of dislodging the stent. If a stent is not placed, one shonld still wait nntil the area has healed to avoid the possibility of disrnpting an area with a fresh intimal tear. 

Implantable devices are man-made implants partly or totally introduced into the hnman body and intended to remain after the procedure. These devices reside within the hnman body either temporarily or permanently, for diagnostic, monitoring, or ther-apentic pnrposes. Examples include catheters, stents, drug delivery systems, pacemakers, implantable cardiac defibrillators, and neurostimulators. Currently more than 25 million US citizens rely on them for life-critical functions (Daniel, 2008). The market was valued at 43.1 billion in 2011 and is expected to increase 8% annually over 7 years to be worth 73.9billion by 2018 (Implantable Medical, 2013). 

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