Permanent Pacemaker and Implantable Cardioverter-Defibrillator Implantation

21 Permanent Pacemaker and Implantable Cardioverter-Defibrillator Implantation



The approach to cardiac pacemaker implantation has evolved during the past half century.1 From the initial epicardial implants of Senning2 and transvenous implantation by Furman and Schwedel,3 cardiac pacemaker implantation has undergone radical changes not only in the implanted hardware but also in the preoperative planning, anatomic approach, personnel, and implantation facilities. The early trend from the epicardial approach to the simpler transvenous cutdown led to the percutaneous technique developed by Littleford and Spector.4 Previously simple preoperative planning, in particular device selection, has become complex. The pacemaker system, both device and electrodes, must be individualized to the patient’s particular clinical and anatomic situation. The implantation procedure, previously the exclusive domain of the cardiovascular surgeon, has also become the purview of the invasive cardiologist. Similarly, the procedure has undergone a transition from the operating room to the cardiac catheterization laboratory or special procedures room. Except in special instances, the luxury of an anesthesiologist has disappeared, with the implanting physician assuming additional responsibilities. Finally, because of concerns about cost containment, the usual in-hospital postoperative observation period has been dramatically reduced or replaced by an ambulatory approach to pacemaker implantation.


Similarly, since Mirowski et al.5 implanted the first implantable cardioverter-defibrillator (ICD) in 1980, its evolution has been comparable with that of the cardiac pacemaker. The initial epicardial ICD placement with an abdominal pocket has given way to a transvenous approach and a pectoral pocket. The surgery initially performed in the operating room exclusively by a cardiovascular surgeon is now carried out by nonsurgeons in the catheterization or electrophysiology laboratory. Also, protracted hospital stays have been replaced by much shorter hospital stays, even outpatient situations. The once-simple ICD device is now much more complex, offering total arrhythmia control as well as backup dual-chamber rate-adaptive pacing.


The advent of cardiac resynchronization therapy (CRT) has added a new level of complexity to pacemaker and defibrillator implantation. Not only is a third lead required, but reliable left ventricular stimulation also is essential for positive clinical results. CRT has brought new challenges to device implantation with respect to venous access, coronary sinus cannulation, lead positioning, effective stimulation, and new complications. Further, the new popularity of selective or alternative-site pacing for optimal hemodynamics and arrhythmia management has challenged the traditional sites of lead placement. All these changes have had a price: new techniques have created new challenges as well as new problems. This chapter explores all aspects of modern pacemaker and ICD implantations from a practical point of view as it addresses these new challenges and concerns.



image Pacemaker Implantation



Personnel



Implanting Physician or Surgeon


Traditionally, pacemaker implantation procedures were performed exclusively by a thoracic or cardiac surgeon. The skills were acquired during a residency or fellowship. Early pacemaker implantations involved more extensive surgery and, at times, an open-chest procedure for placement of epicardial electrodes. The pulse generator and electrodes were large, requiring considerable dissection and surgical skill. Since 1980, diminishing pacemaker size has limited the more extensive surgery previously required. At present, the knowledge and skills required for dual-chamber pacing are well suited for the physician trained in cardiac catheterization.


It is generally accepted that the pacemaker-implanting physician may be either a thoracic surgeon or an invasive cardiologist.6 At times, the two may even act as a team, with the surgeon isolating the vein and the cardiologist positioning the electrodes. With the current reimbursement structure and the changing economic environment, however, this team approach is rapidly becoming burdensome; in any event, it is frequently unnecessary. Currently, the credentialing for pacemaker implantation procedures poses a dilemma. The trainee in thoracic surgery has ever-diminishing exposure to pacemaker implantation as the procedure becomes more the responsibility of the cardiologist. At the same time, the cardiologist has little or no exposure to proper surgical technique, the use of surgical instruments, and preoperative and postoperative care. Although controversy surrounds the appropriate implantation experience and its length, physicians with limited training and ongoing experience apparently have higher complication rates.7 To remain proficient, the physician should perform a minimum of 12 procedures per year.


In a single-center study of more than 1300 permanent pacemaker implants, Tobin et al.8 reported complications in 4.2% of patients. The economic impact was substantial. Most importantly, there was an inverse relationship between the incidence of acute complication and implanter experience and case volume. Similarly, complications associated with elective generator replacements, revisions, and upgrades have been directly related to operator experience. Harcombe et al.9 found a higher rate of late complications after elective replacements (6.5%) compared with initial implants (1.4%). This higher rate was clearly related to operator inexperience.


There is a definite need for formal training programs specifically designed to teach cardiac pacing.1012 Such programs should be offered to both cardiologists and surgeons interested in cardiac pacing. The ideal program should be comprehensive and integrated, involving not only all implantations but also follow-up and troubleshooting. To be an effective implanter, the physician must understand the problems of follow-up and troubleshooting. Formal didactic experience and hands-on exposure are necessary. Although a formal, year-long, comprehensive, integrated training program is ideal, consideration of physicians who are out of formal training programs sometimes requires combining more intensive didactic programs with extended, supervised hands-on experience. Training is important for the implantation and nonimplantation aspects of pacing. We see substantially less enthusiasm for the presurgical and postsurgical aspects of pacing. We ardently believe such mastery is crucial to becoming an effective implanter.


Regardless of how physicians have been trained to implant pacemakers, careful review of their training and experience by those granting privileges at the institution will help prevent inadequately trained individuals from performing independent, unsupervised pacemaker implantation. Criteria for adequate training and experience should involve a minimum number of pacemaker procedures, including single-chamber and dual-chamber implantations, lead replacements, pulse generator replacements, and upgrades to dual-chamber from single-chamber systems. Also, some documentable experience in an active pacemaker service clinic should be required.13 An electrophysiology (EP) fellowship is one way of obtaining these skills, and physicians trained as surgeons, pediatricians, radiologists, and cardiologists have access to this training. Credentials can include the EP boards under the jurisdiction of the American Board of Internal Medicine, the Certified Cardiac Device Specialist examination by the International Board of Heart Rhythm Examiners, and cardiothoracic (CT) surgical boards, but only for pacemakers, not ICDs.



Support Personnel


Support personnel are crucial to the success and safety of any pacemaker procedure. Historically, whether in a large medical center or a small community hospital, the procedure was performed in the operating room (OR). This had its drawbacks because each case could be a first-time experience for the OR staff. Pacemaker procedures were often added at the end of a busy OR schedule and were assigned to the first available room with support personnel, who changed from procedure to procedure. Personnel not familiar with the procedure can interrupt the flow of the case. Even with the transition to the cardiac catheterization laboratory (CCL) for pacing procedures, the same problems can apply. Conversely, depending on the volume of procedures in the OR and CCL, there may be more opportunity for consistent, recurrent availability of cardiovascular technicians, nurses, and radiography personnel in the CCL. These more focused staff members tend to have a certain appreciation for the procedure and are better equipped to deal with the unique problems that may be encountered during pacemaker implantation.


Whether implantation takes place in the OR or CCL, the minimal personnel required are the same, as follows:





It is also useful to have access to an experienced cardiovascular radiology technician, which generally is more easily accomplished in the CCL than the OR.


The presence of an anesthesiologist or nurse anesthetist (CRNA) is inconsistent. Initially an essential member of the implantation team, an anesthesiologist in many centers is now involved only in special situations requiring airway support in an unstable or otherwise problematic patient. As ICDs, biventricular devices, extraction procedures, and other patients with unstable hemodynamics have become more common, each patient should be assessed for the need for support before the procedure. Anesthesiology staff should always be available for emergency situations and consulted if problems are anticipated.


The participation of the manufacturer’s representative as support personnel has always been a subject of debate. This person’s role varies from center to center.14 At one extreme, the representative merely delivers the device and leads to the hospital. At the other extreme, the person is a vital member of the support team, retrieving threshold data, filling out registration forms, and at times, offering technical advice. The latter extreme is particularly true in smaller institutions with less pacemaker activity and in-house support of ICD implantation. A well-trained manufacturer’s representative can be an important member of the support team. An experienced representative dedicated to cardiac pacing and ICD implantation typically has broad experience and a knowledge base in problems unique to the company’s products. Although such a representative of industry can be helpful, this person, no matter how experienced or knowledgeable, should not be considered an acceptable alternative to a knowledgeable, skilled, and experienced physician implanter. If an industrial representative is to be used during implantations for support, hospital approval is advisable.


Comparing OR and CCL support personnel requirements, besides the CCL’s previously noted general advantages, another important concern is sterile technique. The regular OR personnel tend to be more keenly aware of sterile technique and are scrupulous in this regard. In contrast, CCL personnel are not routinely trained in OR and sterile techniques, and if not strongly reinforced, these procedures can be disastrously neglected.



Implantation Facility and Equipment


The cardiac catheterization laboratory and special procedures room appear well suited for permanent pacemaker and ICD procedures.15,16 Early concerns about safety and sterility were unfounded, if these issues are appropriately addressed prospectively. Radiologic capabilities are invaluable; high-resolution images, unlimited projections, and angiographic capabilities assist in venous access and electrode placement, as well as in variable image magnification, digital image acquisition, and image imposition techniques and storage. In addition, these facilities tend to be equipped for ready access with all the catheters, guidewires, sheaths, and angiographic materials for special situations. The implantation facility also typically has the most sophisticated physiologic monitoring and recording equipment (Fig. 21-1), offering continuous, surface and endocardial electrical recordings, as well as extensive hemodynamic monitoring capabilities. Again, staffing with qualified cardiovascular nurses and technologists is essential.



Concerns about the potential for infection must be addressed. These facilities are designated as intermediate-sterile areas. The sterile precautions tend to be less rigid than in the OR. The CCL also tends to be a high-traffic area. A rigid protocol for sterile technique must be established, and the room sealed from traffic after cleaning for the surgical procedure. Everyone entering this area must wear scrub clothing, a hat, and a mask. The ventilation system should also meet the standards for an intermediate-sterile area.


The CCL and special procedures room generally have another drawback. Many do not allow the patient to be placed in the Trendelenburg position, which can be important in the percutaneous approach to pacemaker implantation. However, using a wedge under the legs early in the procedure can obviate this problem.


The ideal room or suite would be dedicated to pacemaker and ICD procedures, with all the capabilities and skilled staffing previously described, although this is clearly the exception at present. As the number of transvenously implanted defibrillators, biventricular systems, and extraction procedures increases, however, more rooms will likely be dedicated to pacemaker and ICD implantation.


The strongest arguments for implanting a pacemaker in the operating from are sterility and patient control. The OR is typically the area of best sterility and sterile technique. A pacemaker represents a foreign body, so a prime concern is infection. An OR procedure generally offers the maximum protection against infection. Also, patient control is better because policy in most ORs requires that an anesthesiologist be available for any procedure. Presence of the anesthesiologist allows for more effective airway control and ventilation in the unstable or uncooperative patient. The anesthesiologist is available to intubate the patient and even administer general anesthesia, if necessary. The OR has a wide range of available surgical instruments and supplies and arguably is better than the CCL should a catastrophe occur requiring more extensive surgery, such as an open-chest procedure, although this rarely occurs and the advantage is usually theoretical.


The main pitfall of the OR is the inconsistent quality of the fluoroscopy equipment. It is usually of lesser quality and of limited capability compared with that available in the CCL. In addition, the OR equipment is frequently shared with other services, such as orthopedics, and scheduling conflicts can arise. The lack of immediate access to angiographic materials and catheterization equipment is another drawback to using the OR for pacemaker procedures. Unless device implantation is given special consideration and is performed in a specific OR with equipment and supplies under the control of a device physician and staff, there is a tendency for lack of technical preparation, which disrupts the procedural flow and can adversely affect the outcome. However, this same caveat holds for a busy CCL.


The monitoring equipment used for the device procedure is variable. A multichannel electrocardiographic (ECG) recording system is frequently recommended; such systems are able to monitor and record a minimum of three surface electrocardiograms and one intracardiac electrocardiogram.17 From a more practical view, the only requirement is continuous ECG monitoring on an oscilloscope. The ECG pattern need only be clear. Selection of ECG leads should demonstrate adequate atrial and ventricular morphology for defining underlying rhythm, arrhythmias, and atrial and ventricular capture. However, multiple and particularly orthogonal ECG leads are useful to confirm the lead position by ECG morphology.


Threshold information can be obtained from the combined use of a pacing system analyzer (see later) and the recording system. Sensing data can be obtained from a reliable analyzer alone. Multichannel recorders provide more thorough evaluation and documentation and occasionally are extremely valuable in discerning arrhythmias, capture, capture morphology, timing, and so on. The multichannel recorder also allows retrieval of intracardiac signals, precise waveform analysis, and assessment of ventriculoatrial (VA) conduction. High-quality hard copy for analysis is also generally available with these more sophisticated recording devices, which tend to be ubiquitous in the CCL but uncommon in the OR.


Patient monitoring should also include reliable blood pressure and arterial oxygen saturation (Sao2) determinations, usually obtained with an automatic noninvasive blood pressure cuff and a transcutaneous Sao2 monitor. Arterial catheter pressure monitoring is rarely required; it is useful for patients with potential hemodynamic instability but can also be associated with morbidity. These devices are of particular value when an anesthesiologist is not in attendance. Continuous Sao2 monitoring can detect hypoventilation from sedation, pneumothorax, and air embolization. A direct current (DC) biphasic defibrillator and complete emergency cart should be in the room where the pacemaker procedure is performed. The cart must include an Ambu bag and intubation equipment.


The surgical instruments for a pacemaker procedure are usually found in a “minor surgical” setup (Fig. 21-2). Depending on the institution, the contents of a minor surgery setup can be overwhelming, particularly for the nonsurgeon implanting physician. The rows of unnamed clamps and retractors would suggest the need to enter a major body cavity. Actually, a pacemaker procedure can be performed efficiently with only a few, well-selected instruments,18 and there are many acceptable variations and personal preferences. Problems can occur, however, with the nonsurgeon implanting physician who is unfamiliar with the instruments and their appropriate use.



Box 21-1 lists the contents of an acceptable basic surgical tray for pacemaker implantations. The Gelpi and Weitlaner retractors can be used throughout the procedure for improved visual exposure (see Fig. 21-2). The Senn retractor is used for more delicate retraction of tissue edges; one end is L shaped, and the other has tiny claws. Another useful retractor, the Goulet retractor (see Fig. 21-2), can be replaced with a Richardson retractor and is extremely helpful in retraction when creating the pacemaker pocket. Unlike other large retractors, the smooth, scalloped ends of these retractors are gentle to the tissues while affording a generous area of exposure. Army-Navy retractors can also be helpful for this purpose. Other instruments, such as forceps (with or without “teeth”), hemostats, scissors (tissue and other), needle holders, and clamps, are necessary, but their use does not require explanation here. Proper use and care of the instruments are crucial, and replacement of worn-out instruments is mandatory for avoiding frustration, delays, and suboptimal work.



Device procedures performed in the OR typically benefit from excellent lighting. Multiple high-intensity lamps light the surgical field. However, this is not the case for procedures in the CCL or special procedures room, where lighting is frequently marginal. One solution is a high-intensity headlamp, which is extremely useful when creating the pocket and inspecting for bleeders, particularly when one’s head blocks out other light (Fig. 21-3). Using the headlamp can initially be frustrating and requires practice, but once facile, it will become the major light source for creating the pocket. Even in the OR, despite all the lighting, the headlamp can be very helpful.



The electrocautery device can be useful, and some experienced implanters consider it essential to any pacemaker procedure. Its use, however, is controversial.1921 Historically, using electrocautery equipment for cutting or coagulation during a pacemaker procedure was taboo, with concerns about causing burns at the myocardium-electrode interface, destroying the pulse generator, and damaging the pacemaker leads. The general consensus, however, is that an appropriately grounded electrocautery device is safe when two precautions are taken: (1) active cautery should never touch the exposed proximal pin of the electrode, and (2) use of all electrocautery should cease when the pulse generator is in the surgical field. Cutting with electrocautery expedites pulse generator changes while avoiding the risk of cutting the lead. At times, even in the most experienced hands, a tedious dissection ends with the scalpel or scissors nicking or cutting the electrode insulation. Use of rapid strokes with cautery avoids the buildup of heat, preventing injury to leads. Although experience indicates no important untoward effects on the myocardium if the cautery touches the pulse generator, there is a risk of causing a permanent no-output situation by destroying the pulse generator. This appears particularly true in certain pulse generators or when the battery voltage is well below the replacement indicator. The risk to the patient of a sudden lack of output can be eliminated by placing a temporary pacemaker in pacemaker-dependent patients; this consideration is fundamental to all pacemaker procedures whether or not electrocautery is used.


The pacing system analyzer (PSA) is extremely valuable during pacemaker procedures. PSA circuitry (especially sensing) mimics that of the planned pulse generator and more accurately predicts the performance of the pulse generator, even when stimulators and recorders are available. The early PSAs were simple and designed to measure the pacing and sensing thresholds for single-chamber ventricular pacing. PSAs were unable to perform (or cumbersome performing) the tasks required for atrial and dual-chamber pacing.22 Previously, PSA devices were designed to test both the lead function and the pulse generator. Currently, PSAs can test lead function and usually can adjust the pacing mode so that both the atrial and the ventricular leads can be tested without risking asystole. Modern PSAs can function in any mode and should measure from either chamber, offering a clear digital display as well as extensive programmability. PSAs provide emergency capabilities, including high output, high rate, and often antitachycardia pacing. In addition, hard copy and electronic transfer of data is useful for documentation. An example of a PSA is the Medtronic model 2090 (Fig. 21-4); Table 21-1 summarizes its desirable features. Some of the pacemakers driven by sensors, (e.g., temperature, oxygen) require special additional sensor analysis by a specialized PSA tool. Whether supplied by the institution or the manufacturer, a good PSA is essential.



TABLE 21-1 Operating Features of the Medtronic CareLink Programmer 2090 Pacing System Analyzer (Medtronic)
























































































































Parameter Range
Models VOO, VVI, AOO, AAI, DOO, DDD, VDD, ODO
Lower rate:  
AOO, AAI, VOO, VVI, DOO 30-220
DDD, VDD 30-110
Upper rate 80-220
Amplitudes (A and V) 0.1-10.0 V
Pulse width (A and V) 0.02-1.5 msec
AV interval:  
Sensed 20-350 msec
Paced 20-350 msec
Rapid atrial stimulation 200-800 min. (ppm)
Atrial refractory 200-500 msec
Ventricular refractory 250 msec
Atrial sensitivity 0.25-20 mV
Ventricular sensitivity 0.5-20 mV
Polarity (A and V) Unipolar/bipolar
Atrial Blanking  
After atrial pace 160-300 msec
After atrial sense 160-300 msec
After ventricular pace:  
VVI/VOO 150-350 msec
DDD/VDD 200-220 msec
After ventricular sense 150 msec
Ventricular Blanking  
After atrial pace 40 msec
After ventricular sense 125 msec
After ventricular pace 200 msec
Measurement Parameters  
P-wave amplitude 0.3-30 mV
R-wave amplitude 0.6-30 mV
Impedance (A and V) 200-2499
  2500-4000
Slew rate 0.1-4.0 V/s
Pacing current 0.1-25 Max
Special Features  
Rapid stimulation AOO, VOO, DOO modes
Rates 180-800 ppm
Emergency pacing VVI rate at 70 at 10 V and 1.5 msec

A, Atrium/atrial; AV, atrioventricular; V, ventricle/ventricular.


There never seem to be enough spare parts during a pacemaker procedure. Most manufacturers offer service kits containing splice kits, stylets, lead adapters, wrenches, lubricant, lead caps, wire cutters, and so on (Box 21-2). It is advisable to set up a pacemaker cart stocked with all the supplies likely to be needed. This cart should hold (1) a temporary pacemaker tray that contains the materials for venous insertion, as well as the temporary pulse generator and leads, (2) an assortment of sheath sets, dilators, and guidewires, (3) the service kits from the manufacturers of the most commonly used pacemakers, (4) the equipment for lead retrieval, and (5) if they are used, a supply of polyester (Parsonnet; C. R. Bard) pouches (Fig. 21-5). A designated person should make sure supplies are reordered and up to date. Other, lesser used supplies can be obtained from the OR or central supply facility, such as a Jackson-Pratt drain for managing hematomas (Fig. 21-6) and various-sized Penrose drains for tunneling.






Preoperative Planning


Planning a pacemaker procedure is important if the case is to proceed smoothly, starting with patient evaluation, including symptoms, medications, and associated conditions. The physical examination may demonstrate the effects of bradycardia, including altered vital signs, evidence of cardiac decompensation, and neurologic deficits. Anatomic issues potentially affecting the implant can also be uncovered. A key preoperative consideration is documentation of the bradyarrhythmia, through 12-lead electrocardiogram (ECG), Holter monitor, event recordings, or inhospital critical care unit or telemetry unit monitoring. Supporting laboratory data, such as digitalis levels, thyroid parameters, and blood chemical analysis, provide documentation that the bradycardia is not secondary to another condition. The patient evaluation should substantiate the indications outlined by the American College of Cardiology (ACC), American Heart Association (AHA), and North American Society of Pacing and Electrophysiology (NASPE) joint task force.23 The documentation should be readily available and is usually affixed to the patient’s chart.



Inpatient Versus Outpatient Procedure


With all documentation obtained and indications met, the next step is scheduling the procedure. Pacemaker and ICD surgery can be performed on either an inpatient or an outpatient basis. Traditionally, even pacemaker procedures were done on an inpatient basis, which involves formal admission of the patient to the hospital for the procedure. The preoperative evaluation (in most cases), the device procedure, and early postoperative care are carried out in the hospital. Generally, the patient has already been admitted to the hospital because of symptoms (e.g., syncope) and the diagnosis of a bradyarrhythmia subsequently established. The device procedure is then scheduled. Alternatively, the evaluation is mostly or partly completed before admission; after the need for a pacemaker is determined, the patient is admitted for the pacemaker procedure and postoperative care. In some cases, this inpatient approach is inefficient and not cost-effective.


The early pacing systems were large, had brief longevity, and were prone to catastrophic complications, such as lead dislodgement, perforation, and wound infection. Postoperatively, therefore, patients were managed with extreme caution; an abbreviated hospital stay seemed radical, and an ambulatory procedure was unthinkable. Currently, complications are rare; pacemakers and even ICDs are small; venous access is easy and quick with the introducer technique; and the procedure is relatively minor. Refinements of the electrode systems with active and passive fixation have reduced the dislodgement rate to near zero. In addition, the indications have been expanded to include more patients who are less pacemaker dependent and for prophylactic purposes. Lastly, and perhaps most directly, there is a growing mandate for cost containment. The very technologies that have made cardiac pacing and ICDs physiologic, reliable, and safe have resulted in higher cost. For all these reasons, it seems logical that an ambulatory approach for device procedures could be safe and effective as well as less expensive.


There is a trend toward performing pacemaker procedures on an ambulatory basis. The experiences at several centers, in both Europe and the United States, have clearly supported the safety and efficacy of this approach.24,25 Concerns about potential complications continue to be expressed.2628 Questions about lead selection, the timing of discharge, and the intensity of follow-up are frequently raised. In addition, the economic impact has yet to be fully appreciated. Although more ambulatory pacemaker procedures are being performed, this has not been reflected well in the pacing literature. Since the original reports of Zegelman et al.24 and Belott,25 Haywood et al.29 have reported a randomized controlled study of the feasibility and safety of ambulatory pacemaker procedures. Although the study group was small (50 patients), the results were similar to those of one of the authors (PHB). There was good patient acceptance, no evidence of a higher complication rate, and cost savings of £540 (at that time, about $810 U.S.).


Since the initial report of 181 new pacemaker implants in 1987, our own ambulatory experience continues to be gratifying. During a 13-year span reported in 1996, that experience comprised 1474 pacemaker procedures, 1043 (69%) of which were performed on an ambulatory basis.30 The experience also included pulse generator changes, all of which we have performed on an outpatient basis since 1987. Our experience indicates that 60% to 75% of new pacemaker implantations can be successfully performed as ambulatory procedures (Table 21-2). There have been no additional ambulatory failures, pacemaker-related emergencies, or deaths in the ambulatory procedures. (An ambulatory failure is an implantation that is initiated as an ambulatory procedure, but for which the hospital stay is extended to admitting the patient because of a complication.) The complications encountered in ambulatory cases included one hemothorax detected 2 weeks after discharge, successfully managed by hospitalization and chest tube drainage. Three hematomas were managed on an ambulatory basis with reoperation, control of bleeding, and drain placement. Two small pneumothoraces that did not require chest tubes occurred fortuitously in hospitalized patients who had no planned ambulatory procedure.



These experiences underscore the safety of the ambulatory approach. At present, almost all elective pacemaker procedures (new implantations, electrode repositioning, upgrade procedures, electrode extractions, and pulse generator changes) are done on an ambulatory basis. A simple protocol is used, and the patients often go home 1 to 2 hours after the procedure. They are seen the following day in the pacemaker clinic. Box 21-3 outlines a simple outpatient protocol.



In most institutions, patients can remain in the hospital overnight and still be considered outpatients. This practice conforms to the present U.S. Health Care Financing Administration (HCFA) definition of ambulatory surgery for reimbursement in the United States, as follows: “When a patient with a known diagnosis enters a hospital for a specific minor surgical procedure or treatment that is expected to keep him or her in a hospital for only a few hours (less than 24) and this expectation is realized, he or she will be considered an outpatient regardless of the hour of admission, whether or not he or she occupied a bed, and whether or not he or she remained in the hospital past midnight.”31 An important caveat of ambulatory pacemaker procedures is that if there is any doubt or concern about the patient’s well-being, the hospital stay can be extended.


In the United States, the primary instrument for reimbursement is Medicare, administered by the Centers for Medicare and Medicaid Services. To limit fraud and abuse, a recovery system of private contractors was implemented, called the Medicare Recovery Audit program. With respect to pacemakers and defibrillators, the program has brought pressure to bear on hospitals to perform these procedures on an outpatient basis. Hospitals have been denied reimbursement on the basis of insufficient and inaccurate documentation of medical necessity as well as incomplete and improper coding. The denial of reimbursement has been challenged and reversed on a number of occasions. The fundamental issue is documentation. For this purpose and for all other regulatory and reimbursement purposes, clear documentation of indications for the device and the need for inpatient or outpatient procedures is essential.



Preoperative Patient Assessment


The preoperative patient assessment consists of the synthesis of all patient information, including history, physical findings, old records, cardiac rhythm strips, and laboratory data. With this information, appropriate decisions can be made about the pacemaker mode, leads, and general approach.


The first such decision is whether the patient requires a single-chamber or dual-chamber pacemaker. With the expansion of options in devices, physicians also need to consider whether the patient’s condition would be better served with an ICD or a cardiac resynchronization device. As a rule, if the patient has intact atrial function, every effort is made to preserve atrial and ventricular relationships. Single-chamber ventricular pacing is usually reserved for the patient with chronic atrial fibrillation or atrial paralysis. A device is selected with appropriate size, longevity, and programmability. If the heart is chronotropically incompetent, a device that offers some form of rate adaptation is considered.


Lead selection is equally important. One necessary decision is whether to use passive-fixation or active-fixation leads. Generally, an active-fixation electrode is selected when problems of dislodgement are expected, such as in the patient with a dilated right ventricle or amputated atrial appendage. Active-fixation leads are one of several factors that enhance removability of the lead, if it is necessary in the future. Also important is the pacing configuration (unipolar vs. bipolar). This decision relates to both electrodes and the pulse generator. Although the use of bipolar pacing and sensing has definite advantages, bipolar leads have historically been more complicated and prone to more problems. Bipolar leads are also larger in diameter. The compatibility of electrodes and the pulse generator is extremely important, particularly when using an original electrode with a modern pulse generator. If these are incompatible, an appropriate adapter must be obtained. Directly related to the device selection process is whether an ICD or CRT system should be placed. These decisions also affect the type of device selected and the lead systems employed.


If an ambulatory approach is being considered, the patient is assessed with respect to the risk of this approach. An unstable patient should always be admitted to the hospital. If the patient is critically ill, pacemaker dependent, or unstable, a temporary pacemaker is considered. It is usually better to take the few extra minutes and place a temporary pacemaker. Doing so can avoid moments of “terror” during the procedure if asystole occurs. This statement is particularly true in patients with complete atrioventricular block, in whom an apparently stable escape rhythm can suddenly disappear, a common situation after initial pacing has been established.


The timing of the procedure usually relates to the stability of the patient. In the critically ill patient in whom there are concerns about the stability of the cardiac rhythm or temporary pacemaker, an early permanent procedure is in order. Conversely, in a patient whose survival is in doubt, the clinician may appropriately decide to wait for stabilization. At times, the procedure is delayed because of systemic infection or sepsis. A permanent pacemaker implantation performed in a septic patient may lead to the seeding of bacteria on the pacemaker or electrode. If there is active infection, our approach is to defer the procedure until the patient is afebrile and no longer septic, to reduce the risk of pacemaker system infection.


Decisions with regard to the implantation site are not as important at present as when only large pulse generators were available. The currently available devices, weighing less than 30 grams, make the site, in most situations, moot. Devices tend to be tolerated well in almost any location. However, special circumstances deserve mention, including hobbies, recreational/occupational activities, cosmetic issues, and previous medical conditions. In the patient who hunts, for example, the pacemaker should be placed on the side opposite that of the rifle butt. Similar considerations are appropriate for the tennis enthusiast or golfer (although our experience with golfers indicates that placing the pacemaker on the backswing or follow-through side varies). In a young person, placement of the pacemaker under the breast (women) or in the axilla may be more desirable from a cosmetic point of view. Medical conditions, such as previous surgery, radiation therapy, and skeletal or other anatomic abnormalities, should also be considered. In the patient who is small with little subcutaneous tissue, a subpectoralis muscle (subpectoral) implantation may be required. This calls for the use of a bipolar system to avoid stimulation of skeletal muscles.



Preoperative Orders


The preoperative orders for pacemaker implantation are generally simple. The patient fasts for at least 6 hours before the procedure. If the implantation is an ambulatory procedure, the patient reports to the hospital on the day of the procedure, with enough time to obtain the necessary preoperative testing, generally 2 hours. The preoperative procedures consist of posteroanterior (PA) and lateral chest radiographs, an ECG, a complete blood count (CBC), prothrombin time (PT), partial thromboplastin time (PTT), and measurements of serum electrolytes, blood urea nitrogen (BUN), and serum creatinine. Because the patient is fasting, adequate hydration is maintained with a stable intravenous (IV) line. Hydration is extremely important for subsequent venous access and prevention of air embolization during the procedure. It can be frustrating and dangerous to try to gain venous access in a patient who is dehydrated after prolonged fasting without IV hydration. We generally request that the IV line be started on the side of the planned procedure, so as to facilitate venography during attempts at venous access if this becomes a problem.


The management of pacemaker surgery in the patient taking anticoagulants is controversial. Little information is available regarding management of a patient who requires anticoagulation. Clearly, however, the patient receiving anticoagulants, including heparin and platelet antagonists, is at risk for hematoma formation. It is generally held that in patients who require oral anticoagulants, PT should be normalized before implantation. Anticoagulant therapy can be resumed between 24 and 48 hours after pacemaker implantation. Reducing the PT to normal in a patient requiring anticoagulants (e.g., with artificial heart valve) creates a serious risk for thromboembolic complications. To address this issue, many operators choose to admit the patient to the hospital and start IV heparin while the warfarin is withheld and PT normalized. This process, called bridging, often takes several days. When the PT has reached the control value, the patient is scheduled for surgery. On the day of surgery, the heparin is stopped, and in some situations, the anticoagulation is reversed and the procedure carried out. Several hours postoperatively, the heparin is resumed. After 24 to 48 hours with no evidence of significant hematoma, the warfarin is then resumed; when therapeutic levels are reached, the heparin is stopped, and the patient is discharged with oral warfarin therapy.


In 2008 the American College of Chest Physicians (ACCP) published evidence-based practice guidelines for the perioperative management of patients receiving antithrombotic therapy,32 including vitamin K antagonists (VKAs) and antiplatelet drugs. ACCP recommends temporary cessation of VKAs and use of perioperative bridging anticoagulation with low-molecular-weight heparin (LMWH) and unfractionated heparin (UFH) for patients at moderate to high risk for thromboembolism and for those with a mechanical heart valve, atrial fibrillation, or venous thrombosis. There is no mention of uninterrupted VKA therapy. For the patient taking antiplatelet drugs who has bare-metal or drug-eluting stents and requires surgery within 6 weeks of stent placement, uninterrupted antiplatelet therapy is recommended. In patients who require temporary interruption of antiplatelets, treatment is stopped 7 to 10 days before surgery. It is recommended that antiplatelet drugs be resumed approximately 24 hours postoperatively. Frequently with pacemaker and ICD procedures, however, antiplatelet therapy cannot be suspended.


Cost controls and managed care can make this process problematic. In addition, despite vigorous attempts at hemostasis, significant hematomas have resulted from the use of heparin. This problem is anecdotal, but in our general experience, the greatest risks for bleeding complications, hemorrhage, and hematoma occur with the use of heparin or platelet antagonists such as aspirin. Having encountered a patient with a devastating thromboembolic complication caused by withdrawal of warfarin, as well as multiple large hematomas from the use of heparin, one of us (PHB) has chosen to perform pacemaker and ICD procedures with the patient still undergoing anticoagulation with oral warfarin. As a rule, patients taking oral anticoagulants have their international normalized ratio (INR) reduced to about 2. With this policy in effect more than 22 years, there have been no devastating hematomas or thromboembolic events. In a recent 13-year retrospective review of 458 device procedures on patients receiving continuous uninterrupted VKA therapy, there were only eight hematomas and no catastrophic hemorrhages or VKA-related deaths.33 This gratifying experience underscores the safety and cost-effectiveness of continuous uninterrupted VKA therapy, which unfortunately remains unaddressed by current guidelines for cardiac implantable electronic device (CIED) procedures.


We believe that pacemaker and ICD procedures can be performed safely with the patient anticoagulated as previously described. Supporting this approach in a 4-year experience, Goldstein et al.34 found no difference in incidental bleeding complications between patients receiving warfarin and those without anticoagulation. No wound hematomas, blood transfusions, or clinically significant bleeding occurred in any patients receiving warfarin. In a later, large series of patients, Giudici et al.35 further substantiated the safety and efficacy of CIEDs without reversing warfarin therapy.


More recently, Ahmed et al.36 demonstrated that interrupting anticoagulation is associated with increased thromboembolic events, and cessation of VKAs with bridging was associated with a higher rate of pocket hematoma and prolonged hospital stays. The authors concluded that continuous uninterrupted VKA therapy with a therapeutic INR was safe and cost-effective. Thal et al.37 compared the incidence of hematoma formation among patients receiving continuous warfarin, aspirin, and clopidogrel therapy. Hematoma formation was rare, even among anticoagulated patients, although an increased incidence was seen in patients receiving dual-antiplatelet therapy. Dreger et al.38 found CIED procedures to be safe in patients on dual-antiplatelet therapy but recommended the use of a drainage system. In patients requiring CRT, Ghanbari et al.39 found uninterrupted warfarin therapy to be a safe alternative to routine bridging therapy, reducing risk of bleeding and shortening hospital stay. More recently, continuing warfarin in patients with a therapeutic INR was shown to be a safe, cost-effective approach compared with cessation of warfarin and bridging anticoagulation.


A new strategy is developing with the release of dabigatran in the United States. This direct thrombin inhibitor has the advantage of a short half-life and obviates the need for INR tracking. The RE-LY study demonstrated its efficacy and safety for patients with atrial fibrillation in comparison to warfarin.40 At this time, no data are available on the impact of dabigatran on perioperative hematomas or the most appropriate perioperative management. However, witholding the medication for 24 hours before the procedure and restarting 24 hours later seems a reasonable initial approach.


The risks of interrupting continuous anticoagulant therapy with a resultant thromboembolic event can be substantial. Although hemorrhage is possible during and after pacemaker procedures in patients with therapeutic levels of anticoagulation, the risk seems minimal. The bleeding can generally be treated with local measures, such as the placement of drains or reoperation. Risk of bleeding is greatly outweighed by risk of thromboembolism after withdrawal of anticoagulant therapy. Pacemaker and ICD surgery in the patient receiving anticoagulant therapy is becoming more prevalent as more patients are prescribed these therapies for atrial fibrillation. The patient is instructed to continue maintenance oral medications, which may be taken with small sips of water. Patients taking a hypoglycemic agent are instructed to reduce the preoperative dose by 50%.


The administration of prophylactic antibiotics is controversial. We prefer intraoperative administration of a broad-spectrum cephalosporin (e.g., cefazolin). Others use vancomycin, which covers all gram-positive organisms. Approximately 50% of device infections are caused by methicillin-resistant staphylococci. Screening for Staphylococcus aureus nasal colonization helps in identifying patients at highest risk. The patient should scrub the chest, neck, shoulders, and supraclavicular fossae with a povidone-iodine (Betadine) sponge the evening and the morning before the procedure; the surgical area usually is shaved in the procedure room. Also, the patient should empty the bladder before coming to the procedure room.



Pacemaker Implantation: General Information


On arrival at the procedure room, the patient is transferred to a radiography table. In the catheterization laboratory or special procedures area, the table’s radiolucent properties are standard. In the operating room, prior arrangements are made for a special radiolucent operating table; it is advisable to test the fluoroscopy equipment’s ability to penetrate the table. It is also helpful to establish proper x-ray tube orientation. Attention to these details can avoid later problems, when it is discovered that the patient is on the wrong table, the radiographic equipment is inoperative, or the image is upside down, backward, or both.


Almost immediately, the patient is connected to physiologic monitoring (ECG, pulse oximetry, blood pressure cuff). If not already done, a reliable venous line is established, preferably on the side of the operative site. The circulating nurse must have easy access to the IV line for drug administration and introduction of radiographic materials. Oxygen can be administered by nasal cannula or mask. With a temporary pacemaker, the appropriate site is shaved and prepared, and the temporary pacemaker is placed using the Seldinger technique. It is important to secure the lead and sheath adequately to maintain accessibility and allow easy removal at the end of the procedure.



Site Preparation and Draping


When effective patient support has been established, focus turns to the operative site. If not already accomplished, shaving and skin cleansing should include the neck, supraventricular fossae, shoulders, and chest. The operative site, shaved and cleansed, is now formally prepared and draped. A povidone-iodine (Betadine) scrub may be followed by alcohol, then povidone-iodine solution, with skin drying before applying the final povidone-iodine solution. Alternately, povidone-iodine gel is spread liberally over the operative site. Within 30 seconds, an optimal bactericidal effect is achieved. With this approach, scrubbing the area is not required. For patients allergic to povidone-iodine, a chlorhexidine (Hibiclens) or hexachlorophene (pHisoHex) scrub can be used.


Currently, many traditional scrubs have been replaced by either a povidone-iodine or a chlorhexidine and alcohol combination. These preoperative skin preparations have the benefit of a single, rapid application. DuraPrep is iodine povacrylex and isopropyl alcohol; ChloraPrep is 2% chlorhexidine and 70% isopropyl alcohol; both offer rapid-acting broad-spectrum protection. Because alcohol-based antiseptic solutions can act as fuel for surgical fires, the skin preparation must be allowed to dry, strictly observing recommended drying times. In addition, it is important to remove the fuel; surgical fires in the OR can result in patient burns and even death.41


The draping process is a matter of personal preference. One of the authors (DWR) applies a sterile, see-through plastic adhesive drape (impregnated with an iodoform solution) over the entire operative area. The other (PHB) uses one or more sterile plastic drapes with adhesive along one side (Fig. 21-7); the adhesive surface is applied from shoulder to shoulder at the level of the clavicle, which serves to create a sterile barrier from the shoulder level down. Depending on the situation, other barriers can be created. In both cases, the plastic drape is used to optimize sterility.



After some form of sterile barrier is established, the operative site is draped with sterile towels, and one or more large, sterile surgical sheets are applied. Care is taken to avoid smothering the patient and causing claustrophobia, best achieved by keeping the drapes off the patient’s face and maintaining the cephalic aspect of the main drape perpendicular to the patient’s neck. This arrangement allows unrestricted access to the patient’s head and neck. The main drape is clipped to some form of support on both sides of the patient. The support can consist of IV poles placed on each side of the patient.


Such an arrangement may not be possible in laboratories, where it interferes with radiographic equipment. Alternatively, the drape may be fixed to the C-arm or image intensifier. This solution is less than optimal; the drapes pull away whenever the C-arm or radiographic table is repositioned, increasing the risks of contamination and breaks in sterile technique. A simple, cost-effective solution consists of a length of common house wire (8/3-gauge Romex) shaped into an arc over the patient’s neck. The ends of the wire are bent at right angles to the arc and tucked under the x-ray table padding at the level of the patient’s shoulders (Fig. 21-8). The weight of the patient’s shoulders supports the wire arc. The wire positioned under the shoulder is checked with fluoroscopy to avoid interference with the radiographic field of view. The house wire is strong enough to keep its shape under the weight of the surgical drape, offering optimal patient comfort and a reliable sterile barrier. There is no interference with the C-arm, and claustrophobia is avoided. The traditional use of a Mayo stand over the patient’s face is problematic because it can cause claustrophobia, makes access to the patient’s airway difficult in an emergency, and may interfere with the x-ray equipment.



From the moment the catheterization laboratory or special studies room is cleaned, it must be treated as a surgical suite. All personnel must wear surgical clothing, hats, and masks. There should be an attempt to seal the room, limiting traffic and restricting access to personnel participating in the procedure.



Anesthesia, Sedation, and Pain Relief


Most pacemaker procedures are performed with local anesthesia and some form of sedation and pain reliever.42 Local anesthesia alone is inadequate for optimal patient comfort; its effect does not prevent the discomfort associated with creation of the pacemaker pocket. Therefore, the additional combination of a narcotic and sedative is recommended; use of sedation alone is frequently inadequate. The challenge to the physician in charge is to achieve patient comfort without risking oversedation or respiratory depression. If an anesthesiologist or nurse anesthetist is part of the implantation team, patient comfort is usually achieved easily and safely. In this situation, if respiratory depression occurs, the patient can easily be ventilated. When the implanting physician orders the sedation and narcotics, however, the patient must be carefully monitored by the circulating nurse. The medications should be administered slowly.


The selection and dose of local anesthetic are also important considerations. A local agent in therapeutic concentration that provides rapid onset of action and sustained duration is desirable. Local agents can be used in combination to achieve the desired effect, such as lidocaine for its rapid onset and bupivacaine for its sustained action. Also, the upper limit of total local anesthetic dose should not be exceeded. Toxic blood levels of local anesthetics can result in profound neurologic abnormalities, including obtundation and seizures. Table 21-3 lists the pharmacologic properties of common local anesthetic agents.



The selection of sedative and narcotic depends on personal preference. We use midazolam and fentanyl. The operator should become familiar with one or more sedative agents as well as an analgesic, preferably a narcotic. Many newer agents are available. The selection of a benzodiazepine in combination with a semisynthetic narcotic can achieve ideal sedation, amnesia, and analgesia. A cooperative, relaxed, and pain-free patient is fundamental to the success of the procedure and the avoidance of complications. Pentothal and nitrous oxide have been used to effect brief periods of complete sedation at times of anticipated maximum discomfort, but the use of these drugs requires the expertise of an anesthetist because temporary respiratory support is frequently needed.


The U.S. Joint Commission on Accreditation of Healthcare Organizations mandates that institutions establish a policy and protocol for patients receiving IV sedation, which would include pacemaker procedures. In essence, the protocol requires formal patient assessment before sedation. Resuscitation equipment must be present at all times in the sedation and recovery areas, and patients undergoing IV sedation must be monitored with pulse oximetry, continuous ECG rhythm monitoring, and automatic blood pressure recordings. Monitoring of the patient should continue for at least 30 minutes after the last IV sedative dose and for at least 90 minutes after intramuscular (IM) sedative administration. There are also strict discharge criteria. Table 21-4 lists common intravenous sedation drug protocols. A North American Society of Pacing and Electrophysiology (NASPE; now Heart Rhythm Society) Expert Consensus developed recommendations and specified minimum training requirements on the use of IV sedation/analgesia by nonanesthesia personnel in patients undergoing arrhythmia-specific diagnostic, therapeutic, and surgical procedures.43




Antibiotic Prophylaxis and Wound Irrigation


The use of prophylactic antibiotics to reduce the incidence of postoperative wound infection in a pacemaker procedure is controversial.44 Importantly, antibiotics are not a substitute for good infection control practices, an adequate surgical environment, and good surgical technique. The use of antibiotics in a pacemaker procedure follows the principle of prophylaxis, in which the risk for infection is low but the morbidity is high.4547

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Jun 4, 2016 | Posted by in CARDIAC SURGERY | Comments Off on Permanent Pacemaker and Implantable Cardioverter-Defibrillator Implantation

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