Permanent pacemaker infections: characterization and management

Bridge pacemaker with an externalized active fixation lead for pacemaker-dependent patients with device infection

BACKGROUND

The risk of Cardiac Implantable Electronic Device (CIED) infection has been increasing in recent years. For pacemaker-dependent patients, a temporary pacemaker is needed before a new device can be implanted. The aim of this study is to evaluate the safety and efficacy of using a temporary pacing device with an externalized active fixation lead (bridge pacemaker) before a new device can be implanted in pacemaker-dependent patients with device infection.

METHODS

All patients who were admitted to our cardiac center with CIED infection and in need of bridge pacemaker implantation from April 2013 to August 2020 were prospectively enrolled in this observational study. The medical records of all patients were collected and evaluated. All procedure-related complications were also collected. Long-term outcomes, including reinfection and death within one year after hospital discharge, were collected through telephone follow-ups.

RESULTS

During the study period, 1,050 patients underwent CIED extraction, of which 312 pacemaker-dependent patients underwent bridge pacemaker implantation. The mean age of the extracted leads was 44±38.7 months. The bridge pacemakers were in use for a mean duration of six days. Nine patients developed procedure-related complications including pericardial tamponade, pneumothorax, peripheral venous thrombosis, and pulmonary embolism. Three patients developed complications that were related to their bridge pacemakers, including lead dislodgement, over-sensing and elevated pacing threshold. During the 1-year follow-up, it was found that four patients had developed CIED reinfection and three patients had died due to cardiac-related reasons.

CONCLUSIONS

A bridge pacemaker with an externalized active fixation lead is safe and efficacious for pacemaker-dependent patients with device infection. This article is protected by copyright. All rights reserved.

Fully implantable and bioresorbable cardiac pacemakers without leads or batteries

Temporary cardiac pacemakers used in periods of need during surgical recovery involve percutaneous leads and externalized hardware that carry risks of infection, constrain patient mobility and may damage the heart during lead removal. Here we report a leadless, battery-free, fully implantable cardiac pacemaker for postoperative control of cardiac rate and rhythm that undergoes complete dissolution and clearance by natural biological processes after a defined operating timeframe. We show that these devices provide effective pacing of hearts of various sizes in mouse, rat, rabbit, canine and human cardiac models, with tailored geometries and operation timescales, powered by wireless energy transfer. This approach overcomes key disadvantages of traditional temporary pacing devices and may serve as the basis for the next generation of postoperative temporary pacing technology.

A Review of Cardiac Implantable Electronic Device Infections for the Practicing Electrophysiologist

Cardiovascular implantable electronic device (CIED) infections are morbid, costly, and difficult to manage. This review explores the pathophysiology, diagnosis, and management of CIED infections. Diagnostic accuracy has been improved through increased awareness and improved imaging strategies. Pocket or bloodstream infection with virulent organisms often requires complete system extraction. Emerging prophylactic interventions and novel devices have expanded preventative strategies and options for re-implantation. A clear and nuanced understanding of CIED infection is important to the practicing electrophysiologist.

A prospective comparison of four methods for preventing pacemaker pocket infections

This study aims to evaluate four pacemaker pocket cleaning methods for preventing implantation-related infections. This single-center trial prospectively randomized 910 patients undergoing first-time pacemaker implantation or replacement into four pocket cleaning methods: hemocoagulase (group A, n = 228), gentamicin (group B, n = 228), hemocoagulase plus gentamicin (group C, n = 227), and normal saline (group D, n = 227). Before implanting the pacemaker battery, the pockets were cleaned with gauze presoaked in the respective cleaning solutions. Then, these patients were followed up to monitor the occurrence of infections for 1 month after implantation. Twelve implantation-related infections occurred in 910 patients (1.32%): four patients from group A (1.75%), three patients from group B (1.32%), two patients from group C (0.88%), and three patients from group D (1.32%) (P > .05). Furthermore, two patients developed bloodstream infections (0.22%), and both of these patients were associated with pocket infection (one patient was from group A, while the other patient was from group C, respectively). No cases of infective endocarditis occurred. The differences in the number of infections in these study groups were not statistically significant. The application of hemocoagulase, gentamicin, hemocoagulase plus gentamicin, or normal saline on the presoaked gauze before implantation was equally effective in preventing pocket-associated infections.

Complications of retained cardiac defibrillator coil left in situ

A 42-year-old man presented to a regional hospital emergency department with a 4-day history of haemoptysis, shortness of breath, pleuritic chest pain, productive cough and subjective fevers. This episode was the third similar presentation in a 2-month period. The patient was known to have dilated cardiomyopathy secondary to amphetamine use and had previously required insertion of automated implantable cardiac defibrillator (AICD). Due to recurrent complications, the AICD had been replaced on two occasions and a superior vena cava (SVC) lead left in situ on its final removal. Clinical examination and investigations revealed lower respiratory tract infection and transthoracic echocardiogram revealed severe left ventricular failure with an ejection fraction of 16%. The patient was admitted under the general medical team for treatment and investigation of suspected bacteraemia and septicaemia secondary to colonisation of the retained AICD lead. He spent 6 days as an in-patient and was discharged on home where he was to be followed up by the advanced heart failure team in a tertiary centre for consideration of new AICD insertion and to explore possibility of retained coil removal. This case report discusses the concerns surrounding retained SVC leads and potential clinical sequalae. As this patient presented three times within a period of 2 months, it was suspected retained SVC lead was a predisposing factor for recurrent lower respiratory infection.

Candida parapsilosis: An Unusual Cause of Infective Endocarditis

Fungal endocarditis (FE) is a rare form of infectious endocarditis caused by fungi. Herein, we report a case of fungal pacemaker lead endocarditis. FE, especially in the setting of in-vivo cardiac devices, is on the rise. A high index of suspicion is required for its management that involves a combination of medical and surgical therapy.

Septic Pulmonary Embolism Caused by Infected Pacemaker Leads After Replacement of a Cardiac Resynchronization Therapy Device

BACKGROUND Cardiac resynchronization therapy (CRT) has been demonstrated to reduce morbidity and mortality in patients with advanced, drug-refractory heart failure. Procedure-related mortality is less than 1% in larger studies. Approximately10% of CRT patients have to undergo surgical revision because of infections, dislocations, or unacceptable electrical behavior manifested as high threshold, unstable sensing, or unwanted phrenic nerve stimulation. CASE REPORT A 70-year-old man with symptomatic congestive heart failure underwent implantation of a biventricular pacemaker on the left anterior chest wall in 2003 and pulse generator exchange in August 2009. The patient responded well to CRT. At follow-up, the pacing system functioned normally. In September 2009, in the context of a predialysis program, an abdominal computed tomography (CT) scan was performed in another hospital for assessment and evaluation of chronic kidney disease. This procedure was complicated with peripheral thrombophlebitis that was managed appropriately with complete recovery. Eight months later (May 2010), the patient was admitted to our hospital with fever, anemia, and elevated infection parameters. During admission, blood cultures grew Staphylococcus epidermidis. The chest X-ray, lung perfusion scintigraphy, and CT scan depicted pulmonary embolism and infarction. The right ventricular lead threshold was found to be increased to 7 volts with unsuccessful capture. Echocardiography demonstrated vegetations on leads. The entire pacing system was explanted, but the patient expired few days later following percutaneous removal due to multiorgan failure. CONCLUSIONS In heart failure, replacement of the CRT device may be complicated by bacterial endocarditis. As noted from this case report, sudden elevation of the pacing lead threshold should prompt thorough and immediate investigation to unravel its causes, not only the electrical characteristics but also the anatomical features.

Iatrogenic Cardiovascular Disease Secondary to Diagnostic and Therapeutic Procedures

The number of diagnostic and therapeutic procedures performed in cardiology continues to grow. These pro cedures are generally considered safe or of minimal risk to the patient. However, it is important to remember that significant complications may occur, and in each patient the risk: benefit ratio must be carefully weighed. In this review, the complications documented in the medical literature resulting from the use of cardiologic interventions and procedures are discussed. A thorough knowledge of these complications and their precipitat ing factors can help minimize the risk to the patient.

Infection and readmission rate of cardiac implantable electronic device insertions: An observational single center study

BACKGROUND

Infection is one of the most serious complications following surgical placement of cardiac implantable electronic devices (CIEDs). Infection prevention efforts are necessary in reducing CIED infectious outcomes. These devices, however, are commonly inserted in higher risk patients, which may explain the ongoing risk of surgical site infection (SSI) in this population. The rates of CIED infection and utilization vary widely in the literature. The definitions of infection may also vary between clinical definitions and the National Healthcare Safety Network (NHSN) criteria.

METHODS

The primary objective of this study was to review patient data to identify risk factors for infection and readmission after CIED placement at an academic medical center. The secondary objectives were to compare the rates of SSI identified by NHSN criteria compared to that obtained by applying clinical infection definitions.

RESULTS

The overall rate of infection (SSI) was 1.9%, which was identical in both the clinical definition and NHSN reported data. The 30 day readmission rate and the 90 day readmission rate were 12.7% and 25.6% respectively with the most readmissions related to the patients' underlying medical conditions. A lower ejection fraction (EF) was identified as an independent risk factor for readmission, inpatient procedures, smoking and device infection were also significantly associated with readmission after CIED insertion.

Complications of cardiac implants: handling device infections

Managing patients with cardiac implantable electrophysiological devices (CIED) infections can be challenging. The first step should be prevention, which involves patient selection, timing of implantation, and the procedure itself. After implantation, a high degree of suspicion should be applied in order to correctly diagnose patients with infected implanted devices. It is necessary to recognize that patients can present with a wide variety of signs and symptoms. Once diagnosed, the next step is determining if it is a local pocket infection or system infection. In almost every patient, in addition to antibiotics, complete removal of ALL hardware is required. Transvenous lead extraction is now safe and effective, but should only be performed at experienced centres with a practiced extraction team, all possible needed equipment, and cardiothoracic surgical backup. After extraction, the indication for CIED therapy should be re-evaluated to determine re-implantation is warranted. Timing of re-implantation depends on a variety of factors such as type of infection or valvular involvement and should be made in concordance with an infectious disease specialist. This review is aimed at introducing the steps needed to manage patients with infected cardiac devices.

Microbiology of cardiac implantable electronic device infections

AIMS

The aim of the study was to describe the microbiological findings of cardiac implantable electronic devices (CIEDs) infection in the 2000-2011 period at the Cardiology Unit of New Santa Chiara Hospital in Pisa (Italy).

METHODS AND RESULTS

Removed CIED leads and pocket material were seeded on solid media and isolates tested for antimicrobial susceptibility with the Kirby Bauer method. Electrodes from 1204 patients were analysed and 854 (70.9%) tested positive. In 663 (77.6%) cases only one species was isolated, in 175 (20.5%) two species, and in 14 (1.8%) >2 species. In 116 cases material from the pocket was also cultured. The result was consistent with that from the electrodes in 69 (59%) cases. In 359 cases a blood sample was also obtained for culture. The result was consistent with that from the leads in 124 (35%) cases. A total of 1068 strains were isolated from electrodes. Gram-positive organisms were most frequently isolated (92.5% of isolates); particularly, coagulase-negative staphylococci (CoNS), mainly Staphylococcus epidermidis, in 69% of cases and Staphylococcus aureus in 13.8%, Gram-negative rods in 6.1%, yeasts in 1% and molds in 0.4%. Overall, Oxacillin resistance was 30%, in particular 33% among CoNS and 13% among S. aureus. Oxacillin resistance and quinolones resistance have increased in the period 2006-2011 with respect to the 5 years before. Seventeen percent of Enterobacteriaceae strains had a phenotype compatible with extended spectrum beta-lactamase expression.

CONCLUSIONS

Culture of the leads offers the possibility of an aetiological diagnosis in the majority of cases. When material from the pocket can be obtained, the microbiological result is often consistent with that from the electrodes, while species isolated from blood cultures are often different and more likely to be the result of contamination. Cardiac implantable electronic device infection is more often monomicrobial, CoNS are most frequently isolated and S. epidermidis is largely the main single agent. Very early infections were associated with S. aureus infection. The pattern of susceptibility to antimicrobials is in general that of community-acquired infections, although oxacillin resistance and quinolones resistance has increased in the last 5 years.

Cardiac device-related endocarditis: Epidemiology, pathogenesis, diagnosis and treatment - a review

Cardiac device-related endocarditis (CDE) is a phenomenon for which incidence is on the rise; it presents difficult management problems to the clinician. On one hand, there is the patient who needs the implanted device, and the potential morbidity and mortality associated with its removal. On the other hand, there is the problem of a persistent infection - usually acquired during insertion of an electrical device - that is resistant to many antibiotics, has a high recurrence rate, and necessitates an extensive operation to remove the device if removal is delayed. Most studies recommend device and metal lead replacement if CDE occurs. The aim of the present review is to raise awareness of CDE among clinicians, and to provide an appropriate approach to its management.

[Efficacy and safety of non-permanent transvenous pacemaker implantation in an intensive care unit]

OBJECTIVE

To analyze the clinical indications for use, morbidity and mortality associated with a non-permanent transvenous pacemaker.

DESIGN

Prospective and observational study.

SETTING

Cardiac intensive care unit.

METHOD

One hundred and eighty-two patients with non-permanent pacemakers implanted consecutively over a period of four years.

DATA COLLECTED

Main variables of interest were demographic data, clinical indications, access route, length of stay and complications.

RESULTS

A total of 63% were men, with a median age of 78 ± 9.5 years and with symptomatic third-degree atrioventricular block in 76.9% of the cases. Femoral vein access was preferred in 92.3% of the cases. Complications appeared in 40.11% of the patients, the most frequent being hematoma at the site of vascular access (13.19%). Restlessness was associated to the need for repositioning the pacemaker due to a shift in the electrode (p=0.059) and to hematoma (p=0.07). Subclavian or jugular vein lead insertion (p=0.012; OR=0.16; 95%CI, 0.04-0.66), restlessness during admission to ICU (p=0.006; OR=3.2; 95%CI, 1.4-7.3), and the presence of cardiovascular risk factors (p=0.042; OR=5; 95%CI, 1.06-14.2) were identified by multivariate analysis as being predictors of complications. Length of stay in ICU was significantly longer when lead insertion was carried out by specialized staff (p=0.0001), and in the presence of complications (p=0.05).

CONCLUSIONS

Predictfurors of complications were restlessness, cardiovascular risk factors, and insertion through the jugular or subclavian vein. Complications prolonged ICU stay and were not related to the professionals involved.

Peri-procedural anticoagulation and the incidence of haematoma formation after permanent pacemaker implantation in the elderly

BACKGROUND

Haematoma formation is a recognised complication after permanent pacemaker (PPM) implantation. The contribution of peri-procedural anticoagulation to the risk of haematoma formation is unclear.

METHOD

The records of 518 consecutive patients, mean age 76.9±9.8 years, receiving their first PPM (2004-2007) in a single tertiary referral centre were reviewed. Follow-up was complete for 506 patients (97.7%) up to six weeks. Haematomas were diagnosed clinically, and further subdivided according to the need for evacuation.

RESULTS

There were 27 instances of haematoma formation in 25 patients (4.9%) with 19 requiring drainage or evacuation. Twenty-one of the 25 patients who developed a haematoma had stopped warfarin and received bridging therapeutic anticoagulation pre- and post-PPM. The incidence of haematoma was significantly greater in those receiving peri-operative therapeutic anticoagulation (26.9% vs 0.9%, p<0.001), but was unaffected by the use of anti-platelet therapy. Most haematomas developed in patients whose heparin was recommenced within 24 hours of implantation. The development of haematoma post-PPM increased median hospital stay significantly (p<0.001). The main indication for anticoagulation in these patients was atrial fibrillation (79.5%) and most of these patients had a low to intermediate risk of peri-procedural thromboembolic events.

CONCLUSION

Peri-operative therapeutic anticoagulation is associated with more than 25-fold increase in haematoma formation post-pacemaker implantation. The risk-benefit ratio of therapeutic anticoagulation should be carefully considered, particularly in patients with a low risk of thromboembolic events.

Maintained deep brain stimulation for severe dystonia despite infection by using externalized electrodes and an extracorporeal pulse generator

Infection in the context of implant surgery is a dreaded complication, usually necessitating the removal of all affected hardware. Severe dystonia is a debilitating condition that can present as an emergency and can occasionally be life threatening. The authors present 2 cases of severe dystonia in which deep brain stimulation was maintained despite the presence of infection, using ongoing stimulation by externalization of electrode wires and an extracorporeal pulse generator. This allowed the infection to clear and wounds to heal while maintaining stimulation. This strategy is similar to that used in the management of infected cardiac pacemakers. The authors suggest that this prolonged extracorporeal stimulation should be considered by neurosurgeons in the face of this difficult clinical situation.

Pacemaker endocarditis: an important clinical entity

Pacemaker endocarditis remains a rare but potentially life threatening complication of pacemaker implantation. This case illustrates a rare cause of pacemaker endocarditis, Serratia marcescens, the management difficulties that can be faced with such organisms, and the potential indolent nature of pacemaker lead associated endocarditis. A review of the current data for pacemaker endocarditis management suggests that treatment with antimicrobials alone is unlikely to be curative and explantation of the device is recommended in all cases of confirmed pacemaker endocarditis (by echocardiography, in correlation with the patient's clinical condition and inflammatory markers).

Aspergillus infection of implantable cardioverter-defibrillators and pacemakers: case report and literature review

Presented here is a case of implantable-cardioverter-defibrillator infection caused by Aspergillus flavus and a review of 14 previously reported Aspergillus infections of pacemakers or implantable cardioverter-defibrillators. Among all 15 cases, fever was the most common presenting feature (11 patients). Three patients presented with generator-pocket inflammation. Transthoracic echocardiography was performed on eight of 13 patients with endocarditis, revealing vegetations in only one. Transesophageal echocardiography demonstrated the presence of vegetations in all eight of the patients on whom it was performed (p < 0.01). Death was due to the Aspergillus infection in five cases. Patients who presented with unexplained fever had a higher mortality rate (60%) than patients with other clinical presentations (20%, p = 0.166).

Complications of Pacemakers and Defibrillators in the Elderly

Within the United States, the elderly population is projected to increase 126% by 2050, making those over the age of 65 the most rapidly growing segment in the population. Permanent pacemakers and defibrillators are important therapies with expanding indications for their use, and older persons constitute the majority of recipients of these devices. Recognizing complications associated with these cardiac devices is essential in caring for patients with them. Complications can be related to the implantation procedure and are most commonly lead dislodgement, pneumothorax, lead perforation, hematoma, and infection. Intrinsic device programming can also result in complications such as pacemaker syndrome, pacemaker-mediated tachycardia, and inappropriate shocks. Extrinsic factors, such as electromagnetic interference and physically manipulating the device, can also result in problems. Recent work suggests that older age, by itself, is not associated with a significant increase in the complication rates from these devices and should not preclude their use.

Frequency of Permanent Pacemaker or Implantable Cardioverter-Defibrillator Infection in Patients with Gram-Negative Bacteremia

BACKGROUND

Despite the frequent occurrence of bacteremia due to gram-negative organisms in patients with underlying permanent pacemakers (PPMs) or implantable cardioverter defibrillators (ICDs), the outcome and treatment of these patients has received scant attention. In patients with PPMs or ICDs who have Staphylococcus aureus bacteremia, 45% have PPM/ICD infection.

METHODS

We conducted a retrospective cohort study over a 7-year period to assess the clinical features and frequency of PPM/ICD infection in patients with gram-negative bacteremia, as well as the incidence of relapse in patients for whom the device was not removed.

RESULTS

Forty-nine patients were included in the study; 3 (6%) had either definite (2 patients) or possible (1 patient) PPM/ICD infection. Both patients with definite PPM/ICD infection had clear infection of the generator pocket. None of the other patients with alternate sources of bacteremia developed PPM/ICD infection. Thirty-four patients with retained PPM/ICD were observed for >12 weeks (median time, 759 days), and 2 (6%) developed relapsing bacteremia, although they each had alternative sources of relapse.

CONCLUSIONS

In sharp contrast to S. aureus infection, PPM/ICD infection in patients with gram-negative bacteremia was rare, and no patients appeared to have secondary PPM/ICD infection due to hematogenous seeding of the system. Despite infrequent system removal in these patients, relapsing bacteremia among patients who survived initial bacteremia was rarely seen. If secondary PPM/ICD infection occurs in patients with gram-negative bacteremia, it is either uncommon or it is cured with antimicrobial therapy despite device retention.

Klebsiella Pneumoniae: A Rare Cause of Device-Associated Endocarditis

Intravascular infections involving implanted pacemakers and defibrillators are being seen with increasing frequency. This report describes a case of intravascular infection of an implanted defibrillator with Klebsiella pneumoniae, an unusual pathogen for pacemaker or defibrillator infection.

One Stage Side-to-Side Replacement of Infected Pulse Generators and Leads

Infected and contaminated cardiac pulse generators and leads must be removed entirely in order to effect a cure. We have shown through our experience with 68 consecutive cases that explantation of the offending system and replacement of a new device on the opposite side can be safely accomplished in one sitting--a side-to-side replacement--as long as there is appropriate case selection. There were no early or late infections of the new operative site.

Transvenous pacemaker lead removal is safe and effective even in large vegetations: an analysis of 53 cases of pacemaker lead endocarditis

BACKGROUND

The aim of this study was to investigate whether transvenous lead removal is safe and effective in patients with lead vegetations greater than 1 cm in size.

METHODS

From 1991 to 2005, a total of 53 patients underwent pacemaker or ICD lead removal for vegetations. Transvenous lead removal using locking stylets and sheaths was performed in 30 patients (56.6%) and was found to be effective in 29 of those patients. In 1 patient, due to rupture of the lead, open heart removal of the ventricular lead remnant and tricuspid valve repair had to be performed due to persistent infection. In 23 of these patients, transesophageal echocardiography (TEE) verified vegetations greater than 1 cm in size. The remaining patients underwent primary lead removal using sternotomy and extracorporeal circulation (ECC). Pacemaker pocket infection was found in 16 patients (55.2%) of the transvenous study group and in 11 patients (45.8%) of the ECC group (P = 0.72).

RESULTS

Perioperative mortality was 5.7% (3 patients); all of them underwent primary ECC removal and had severe endocarditis of the tricuspid valve. None of the patients who underwent transvenous lead removal died and there were no further complications such as pericardial tamponade or major pulmonary embolism requiring further interventions, even in patients demonstrating large vegetations.

CONCLUSIONS

This study demonstrates that transvenous lead removal is a safe and highly effective procedure for the removal of infected pacemaker and ICD leads, even in patients with large vegetations. Embolism to the lung proceeds mainly without further complications; however, patients with vegetations that might obstruct a main stem of the pulmonary artery should undergo ECC removal.

The Impact of Povidone-Iodine Pocket Irrigation Use on Pacemaker and Defibrillator Infections

BACKGROUND

Infection is a devastating complication of permanent pacemakers (PMs) implantable cardioverter defibrillators (ICDs). Many implanting physicians commonly use povidone-iodine solution to irrigate the device pocket before implanting the device. We sought to assess if such a measure would alter the rate of infection.

METHODS

A total of 2,564 consecutive patients who received implantable PM or ICD devices between 1994 and 2002 were studied. Povidone-iodine was used for pocket irrigation in 53% and saline in 47%. A total of 18 (0.7%) patients developed pocket infections with 0.7% (10/1,359) in povidone-iodine (group I) and 0.6% (8/1,205) in saline (group II) pocket irrigation (p = ns). Groups I and II were studied for various clinical and demographic variables described in the results section.

RESULTS

There was no statistical difference in the baseline demographic and clinical characteristics between groups I and II, respectively. ICDs were most frequently infected than PMs (56% vs 44%). Most (83%) of the devices were dual chamber. Reopening of the pocket for either lead or generator replacement had a higher incidence of infection than new implants (61% vs 39%). There was no difference in the use of preimplantation antibiotic prophylaxis. Late (61%) and deep pocket infections (78%) were more common than early (39%) and superficial infections (22%). Blood cultures were positive in 67% and Staphylococcus aureus was the common most pathogen (50%). The mean duration of antibiotics use after the diagnosis of device infection was 35 +/- 23 days with 72% requiring device explantation. The device was reimplanted on the contralateral side in 56% cases. One patient in each group died due to device infection and related complications. No significant allergy to iodine was seen in either group.

CONCLUSION

Povidone-iodine irrigation of the subcutaneous pocket did not alter the rates of pocket infection after pacemaker/defibrillator implantation.

Haemophilus parainfluenzae mitral prosthetic valve endocarditis in an intravenous drug abuser

Haemophilus species are an infrequent cause of subacute bacterial endocarditis. Of the Haemophilus species causing endocarditis, H. aphrophilus and H. parainfluenzae are more frequent causes of subacute bacterial endocarditis than H. influenzae. H. parainfluenzae requires growth factor V (nicotinamide adenine dinucleotide) and grows very slowly on routine culture media. H. parainfluenzae is a rare cause of "culture negative" endocarditis because it is a slow-growing organism. We present a case of a 42-year-old intravenous drug abuser with H. parainfluenzae mitral prosthetic valve endocarditis. To the best of our knowledge, this is the first case of mitral prosthetic valve endocarditis caused by H. parainfluenzae in an intravenous drug abuser.

Pacemaker lead infection secondary to Haemophilus parainfluenzae

Cardiac device infections are a rare complication of pacing and defibrillator therapy. The number of implanted devices will likely continue to rise with increasing implantation of the cardioverter defibrillator and cardiac resynchronization devices. This report describes a case of an uncommon pathogen for device-associated endocarditis.

Local symptoms at the site of pacemaker implantation indicate latent systemic infection

BACKGROUND

To determine whether local complications at the site of pacemaker implantation indicate infection of the intravascular part of the lead as well as of the pacemaker pocket.

METHODS

105 patients admitted for local inflammatory findings, impending pacemaker or lead exteriorisation, frank pacemaker or lead exteriorisation, or overt infection were studied prospectively. After systematic lead extraction, the initial clinical presentation was related to the results of lead cultures.

RESULTS

Regardless of the initial presentation, the intravascular parts of the leads gave positive cultures in 79.3% of patients. Additionally, 91.6% of the cultures of the extravascular lead segments were positive, in contrast to 38.1% positivity for wound swab cultures. No clinical observations or laboratory investigations permitted identification of patients with negative lead cultures. In a subgroup of 50 patients with manifestations strictly limited to the pacemaker implantation site, cultures of intravascular lead segments were positive in 72%. Infection recurred in 4/8 patients without complete lead body extraction (50%) v 1/97 patients (1.0%) whose leads were totally extracted (p < 0.001).

CONCLUSIONS

Local complications at the site of pacemaker implantation are usually associated with infection of the intravascular part of the leads, with a risk of progressing to systemic infection. Such local symptoms should prompt the extraction of leads even in the absence of other infectious manifestations.

Surgical treatment of pacemaker and defibrillator lead endocarditis: the impact of electrode lead extraction on outcome

BACKGROUND

Cardiac device (CD) endocarditis is an infrequent but potentially lethal infectious complication of permanent pacemakers or implantable cardioverter-defibrillators (ICDs), and mortality rates of 30 to 35% have been reported. Medical treatment has been suggested for the treatment of CD endocarditis, but there is increasing evidence that surgical treatment is to be preferred as the best approach to achieve eradication of the infection and reduce mortality.

OBJECTIVE

To evaluate the following: (1) the clinical and echocardiographic characteristics of patients with pacemaker or ICD endocarditis, (2) the outcome of this population depending on the mode of treatment (medical vs surgical treatment), and (3) the clinical, microbiological, echocardiographic, and therapeutic variables associated with patient outcome.

DESIGN

Prospective cohort study.

SETTING

Tertiary referral center in Barcelona, Spain.

PATIENTS

All consecutive patients with infectious endocarditis (IE) admitted to the study institution between 1990 and 2001 were prospectively evaluated by a multidisciplinary treatment team, and a definite diagnosis of CD endocarditis was established when cases met pathologic or clinical criteria according to the Duke criteria.

RESULTS

A total of 31 patients, 25 men and 6 women aged 61 +/- 15 years (mean +/- SD), with pacemaker or ICD endocarditis were identified among 669 consecutive patients (4.6%) with IE. During the study period, a total of 3,768 pacemakers and 460 ICDs were implanted in the study institution. In 22 cases of pacemaker endocarditis, the pacemaker was implanted in our institution, and 9 cases were referred from other institutions (incidences of endocarditis on pacemaker and ICD implanted in our institution of 0.58% and 0.65%, respectively). Medical treatment without removal of the pacing system was initially performed on seven patients; all of them (100%) had relapses of endocarditis, and one patient died. The remaining 24 patients underwent surgical removal of the pacing system; 1 patient had one relapse, 3 patients died after surgical treatment, and the others were successfully cured with no relapses after a mean follow-up of 38 +/- 9 months. Clinical, echocardiographic, microbiological, and therapeutic variables were evaluated in association with prognosis. The only prognostic factor for failure of treatment or mortality was the absence of surgical treatment (p < 0.0001).

CONCLUSIONS

Electrode lead endocarditis occurred in < 1% of pacemaker and ICD implants. Conservative treatment without explantation of all hardware failed in all patients, and surgical treatment during antibiotic therapy was effective in eradication of infection but was associated with a 12.5% mortality. The only patient characteristic associated with treatment failure or death was the absence of surgical removal of all infected hardware. Complete extraction of the pacemaker or ICD should be considered as standard therapy for most patients with CD endocarditis.

Pacemaker lead infection in young patients

Transvenous pacing has become widespread in the pediatric population, but related pacemaker lead infection in young patients has rarely been reported. To determine prevalence and optimal management of pacemaker lead infection in children and young adults, the authors reviewed their pacing database including 4476 patients who previously had pacemaker implantations from 1975 to 2001. A pacemaker was implanted in 304 patients under the age of 40. Of these patients 217 of them had congenital heart disease: 108 with structural defect, 109 without (mainly complete AV blocks). Among patients with congenital heart disease, 12 developed a pacemaker lead infection (5.5%, 6 patients with structural defect, 6 without). This incidence was significantly higher than in patients < 40 years at first implantation without congenital heart disease (2.3%) and in > 40-year-old patients(1.2%, P < 0.001). However, the number of reinterventions at the pulse generator site was higher in patients having had their first implantation before the age of 40. In patients with structural cardiac defect: two died after surgical lead extraction and one died before the scheduled lead extraction. The three remaining patients had successful surgical (n = 1) or percutaneous (n = 2) lead extractions. In patients without structural cardiac defect successful percutaneous extraction (5/6) or surgical extraction (1/6 with vegetation > 25 mm) was performed. One patient with percutaneous extraction developed chronic cor pulmonale during follow-up. One infection recurred in one patient with structural cardiac defect although complete removal of the pacing material had been performed. The prevalence of pacemaker lead infection is higher in younger patients, perhaps in part due to a higher number of procedures at the pacemaker site than in the general population of patients with a pacemaker. Patients with structural cardiac defect who underwent surgical lead removal were at high risk for death. Patients with percutaneous lead extraction may develop cor pulmonale.

The challenge of staphylococcal pacemaker endocarditis in a patient with transposition of the great arteries endocarditis in congenital heart disease

Staphylococcus aureus is a leading cause of septicaemia and infective endocarditis. The overall incidence of staphylococcal bacteraemia is increasing, contributing to 16% of all hospital-acquired bacteraemias. The use of cardiac pacemakers has revolutionized the management of rhythm disturbances, yet this has also resulted in a group of patients at risk of pacemaker lead endocarditis and seeding in the range of 1% to 7%. We describe a 26-year-old man with transposition of the great arteries who had a pacemaker implanted and presented with S. aureus septicaemia 2 years postpacemaker implantation and went on to develop pacemaker lead endocarditis. This report illustrates the risk of endocarditis in the population with congenital heart disease and an intracardiac device.

Surgical lead-preserving procedures for pacemaker pocket infection

BACKGROUND

In the treatment of pacemaker pocket infection, removal of the entire pacing system has been considered necessary to avoid recurrent infection. We report a series of patients treated surgically by our lead-preserving procedures.

METHODS

Between 1990 and 2001, a total of 18 patients underwent one of two types of lead-preserving procedures. Procedure 1 preserves the full length of the lead, and procedure 2 preserves only the distal part of the lead. Signs of bacteremia, endocarditis, or purulent material within the lead insulation preclude application of these procedures in patients with potential or definite pacemaker pocket infection.

RESULTS

Seventeen patients who met the indications for our procedures were discharged 7 to 14 days (8.9 +/- 2.4 days, mean +/- SD) postoperatively without signs of infection and were followed up for a total of 987 patient-months until the close of the study or death without recurrent infection. The remaining 1 patient, who did not meet the indications, suffered reinfection soon after the operation.

CONCLUSIONS

The follow-up data suggest that our lead-preserving procedures should be considered as alternatives to conventional removal of the entire pacing system in cases of pocket infection that meet specific criteria.

Pediatric pacemaker infections: twenty years of experience

OBJECTIVE

We sought to evaluate possible predictors of early and late pacemaker infections in children.

METHODS

A review was performed of all pacemakers implanted in children at The Children's Hospital of Philadelphia between 1982 and 2001. Infections were classified as superficial cellulitus, deep pacemaker pocket infection necessitating removal, or positive blood culture without an identifiable source.

RESULTS

A total of 385 pacemakers (224 epicardial and 161 endocardial) were implanted in 267 patients at 8.4 +/- 6.2 years. All 2141 outpatient visits were reviewed (median follow-up, 29.4 months; range, 2-232 months). There were 30 (7.8%) pacemaker infections: 19 (4.9%) superficial infections; 9 (2.3%) pocket infections; and 2 (0.5%) isolated positive blood cultures. All superficial infections resolved with intravenous antibiotics. The median time from implantation to infection was 16 days (range, 2 days-5 years). Only 1 deep infection occurred after primary pacemaker implantation. Six patients with deep infections were pacemaker dependent and were successfully managed with intravenous antibiotics, followed by lead-generator removal and implantation of a new pacemaker in a remote location. In univariate analyses trisomy 21 (relative risk, 3.9; P <.01), pacemaker revisions (relative risk, 2.5; P <.01), and single-chamber devices (relative risk, 2.4; P <.05) were identified as predictors of infection. However, in multivariate analyses only trisomy 21 and pacemaker revisions were predictors.

CONCLUSIONS

The incidences of superficial and deep pacemaker infections were 4.9% and 2.3%, respectively. Trisomy 21 and pacemaker revisions were significant risk factors in the development of infection after pacemaker implantation. For primary pacemaker implantation, the risk of infection requiring system removal is low (0.3%).

Pacemaker related endocarditis: analysis of seven cases

Vegetative electrode infection following permanent pacemaker implantation is a rare and serious complication. Among 1920 patients who underwent permanent pacemaker implantation in our institute between 1980 and 2000, 7 patients aged 65 to 78 years were diagnosed to have pacemaker related endocarditis. In this study, the clinical course and management strategies for these patients are reviewed. The most frequently encountered factors contributing to development of pacemaker infection were local complications such as postoperative hematoma and inflammation, and recurrent surgical interventions on the pacemaker system. In blood cultures S. aureus was the most common causative microorganism. Echocardiography could be performed in 5 patients. Three patients were referred to open-heart surgery for total removal of the pacemaker system, and one patient had his pacemaker system removed percutaneously. The remaining 3 patients did not agree to either surgical or percutaneous removal. These patients have been under antibiotic therapy for approximately 3 years and they still do not have any signs of a serious infection. Consequently, in patients with permanent pacemakers, infective endocarditis should be considered in the presence of fever and local symptoms. Blood cultures should be obtained and echocardiography should be performed. Complete removal of the pacemaker system with intensive antibiotic treatment is necessary for complete eradication of the infection. However, if percutaneous or surgical removal of the electrodes cannot be done because of high perioperative risk or the patient does not agree to undergo either method, medical treatment with long term antibiotic use may be considered as an alternative.

Staphylococcus aureus bacteremia in patients with permanent pacemakers or implantable cardioverter-defibrillators

BACKGROUND

Although cardiac device infections (CDIs) are a devastating complication of permanent pacemakers or implantable cardioverter-defibrillators, the incidence of CDI in patients with bacteremia is not well defined. The objective of this study was to determine the incidence of CDI among patients with permanent pacemakers or implantable cardioverter-defibrillators who develop Staphylococcus aureus bacteremia (SAB).

METHODS AND RESULTS

A cohort of all adult patients with SAB and permanent pacemakers or implantable cardioverter-defibrillators over a 6-year period was evaluated prospectively. The overall incidence of confirmed CDI was 15 of 33 (45.4%). Confirmed CDI occurred in 9 of the 12 patients (75%) with early SAB (<1 year after device placement). Fifteen of 21 patients (71.5%) with late SAB (>/=1 year after device placement) had either confirmed (6 of 21, 28.5%) or possible (9 of 21, 43%) CDI. In 60% of the patients (9 of 15) with confirmed CDI, no local signs or symptoms suggesting generator pocket infection were noted.

CONCLUSIONS

The incidence of CDI among patients with SAB and cardiac devices is high. Neither physical examination nor echocardiography can exclude the possibility of CDI. In patients with early SAB, the device is usually involved, and approximately 40% of these patients have obvious clinical signs of cardiac device involvement. Conversely, in patients with late SAB, the cardiac device is rarely the initial source of bacteremia, and there is a paucity of local signs of device involvement. The cardiac device is involved, however, in >/=28% of these patients.

Subpectoral cardioverter-defibrillator implantation using a lateral approach

INTRODUCTION

Third-generation cardioverter-defibrillators have revolutionized management of ventricular tachyarrhythmias. Implantation can be performed in the electro-physiology laboratory, with minimal morbidity. Generator size has shrunk to the point that subcutaneous implantation is feasible and safe, even under local anesthesia. The prepectoral technique, however, is associated with increased mechanical stress to the subcutaneous tissue and can predispose to device erosion or infection. These complications may be avoided by submuscular placement. Among subpectoral techniques, the lateral approach offers unrestricted ability to deploy patches or array electrodes, should the need arise, and may represent the optimal implant technique under some circumstances.

METHODS

We studied 29 male patients, aged 29-78 years, who presented with syncope or sustained ventricular tachycardia, and underwent subpectoral defibrillator implantation under general anesthesia or conscious sedation. All devices were third-generation active can systems with biphasic shock capability. Six dual-chamber defibrillators were used.

RESULTS

Subpectoral implantation was successful in all cases, with an estimated blood loss of 28+/-17 mL and no immediate complications. Except for one patient who developed twiddler's syndrome and ultimately required revision to a subcutaneous pocket, the implant site was tolerated well, and no limitation in the range of motion of the upper limb was observed during 20 months of follow-up.

CONCLUSIONS

Subpectoral implantation using a lateral approach is technically straightforward and can be applied globally, with modest additional resource and equipment requirements. Familiarity with this approach can maximize the likelihood of successful defibrillator implantation in the electrophysiology laboratory.

Is there an adverse outcome from abandoned pacing leads?

BACKGROUND

Indications for extraction of an abandoned pacemaker lead (APL) are controversial. The purpose of this study was to determine whether or not APLs should be extracted in the absence of pacemaker-related problems.

METHODS AND RESULTS

We retrospectively reviewed, from 1977 through 1998, all patients with retained, non-functional leads and identified 433-266 males and 167 females. Mean age at initial pacemaker implantation was 68[emsp4 ]years. These patients received a total of 259 atrial and 948 ventricular leads. Of the total of 1,207 leads, 611 became non-functional. A total of 531 non-functional leads were abandoned, of which 18 were later extracted: one APL in 345 patients, two in 78, and three in 10. Indications for new lead placement when non-functional leads were abandoned included capture and/or sensing failure (243), lead recall (177), lead fracture (86), pacing system replacement to the contralateral side (11), accommodating patient growth (5), pacemaker function upgrade (5), replacement with implantable cardioverter defibrillator (ICD, 2), interference with ICD (1), and unknown (1). Complications that were associated with pacemakers were found in 24 patients (5.5%)-pacemaker system infection (8 patients) and venous occlusion at the time of a subsequent procedure of new lead placement when APLs had already been in place (16) which resulted in APL extraction (7) or transfer of the pacemaker system to the contralateral side (9). Neither venous thrombosis nor other complications were found in the remaining 409 patients (94.5%). The incidence of complications was higher in patients with three APLs than in patients with two or fewer APLs (40% vs. 4.7%, P=1x10(-6)), in patients with four or more total lead implantations than in patients with three or fewer total lead implantations (26.2% vs. 0. 6%, P<1x10(-10)), and in patients with three or more procedures of new lead placements than in patients with two or fewer procedures of new lead placements (36.4% vs. 3.9%, P=1x10(-10)). Patients with complications were younger than those without complications both at the time of initial pacemaker implantation (59+/-16 vs. 68+/-17 y, P=0.01) and when non-functional leads were abandoned (63+/-15 vs. 71+/-16 y, P=0.04). Mean numbers of APLs, total leads implanted, and procedures of new lead placement were significantly larger in patients with complications than in those without complications (1.58+/-0.78 vs. 1.2+/-0.44, 4.96+/-1.23 vs. 2.66+/-0.8, and 2.13+/-0.85 vs. 1.25+/-0.53, P=0.03, 4x10(-9) and 4x10(-5), respectively).

CONCLUSIONS

1. With only 5.5% of patients having had pacemaker-related complications, the adverse outcome of APL is small. 2. Clinical clues to the possible occasion for pacemaker-related complications include three or more APLs, four or more total leads, three or more procedures of new lead placement, and a younger age at initial pacemaker implantation. 3. Patients with a large number of APLs, total lead implantations, and procedures of new lead placement should be carefully observed to detect possible pacemaker-associated complications.

Successful laser-assisted percutaneous extraction of four pacemaker leads associated with large vegetations

A man with four endocardial pacemaker leads and two vegetations (1.5 cm and 1 cm) underwent successful percutaneous laser-assisted lead extraction. Although this procedure was complicated by embolization to a left pulmonary arterial branch, the patient recovered without sequelae. This article reviews the literature on lead extraction associated with large vegetations.

Permanent pacemaker therapy before and after the reunification of Germany: 16 years of experience at an East German regional pacing center

The reunification of Germany had a significant influence on the management of patients with bradyarrhythmias. The current study was performed in a regional pacing center located in the former German Democratic Republic. It compares the situation of patients with critical bradyarrhythmias before and after the reunification of Germany in 1990 focusing on (1) indication for pacemaker implantation, (2) pacemaker modalities and function, (3) type of leads, (4) frequency of reintervention, and (5) early and late complications. The study covers 9 years before and 7 years after the reunification. A total of 1,125 patients were included, and the database was formed by the patients' files and the protocols of implantation. The situation before reunification was characterized by a nonavailability of modern physiological pacing devices and insufficient diagnostic equipment. Between 1981 and 1990, 384 patients underwent pacemaker implantation solely receiving single chamber devices with no or only minimal feasibility of programming. Between 1990 and 1996, 741 patients were treated, and they all received modern pacemakers having the capability of multiprogramming and telemetry. Regarding complications of pacemaker therapy, lead related problems significantly decreased after the reunification (dislocation, 5.3% vs 1.7%, P < 0.05; exit block, 6.7% vs 1.4%, P < 0.05) opposite to pacemaker infections, which significantly increasing after dual chamber pacemakers were implanted (2.2% vs 6.0%, P < 0.05). The reunification of Germany dramatically improved the situation of patients with critical bradyarrhythmias leading to free access to high-tech pacing equipment within a few months. However, the abrupt change from antiquated to modern pacemaker therapy created some new problems, especially regarding application and handling of modern physiological pacing devices.

Analysis of charges and complications of permanent pacemaker implantation in the cardiac catheterization laboratory versus the operating room

During the last two decades, an increasing number of permanent pacemakers have been implanted outside of the operating room (OR) by nonsurgeons. Previous investigators have demonstrated that pacemakers can be safely implanted in the cardiac catheterization laboratory with no increase in complications or infections. This is the first study of its kind to simultaneously evaluate cost, length of hospitalization, and complications between pacemakers implanted in the OR by surgeons with those implanted in the catheterization laboratory by an electrophysiologist. A total of 254 consecutive pacemaker implants were analyzed over a 2-year period. The OR group consisted of 122 patients with a mean age of 64 +/- 21 years versus 132 patients in the catheterization laboratory group with a mean age of 65 +/- 17 years. The indication and type of pacemaker implanted were similar among both groups with 78% of OR patients and 73% of catheterization laboratory patients receiving dual chamber devices. The average cost for pacemaker implantation in our study was significantly higher in the OR group $5,464 +/- $1,670 versus $2,682 +/- $8 for the catheterization laboratory group (P < 0.001). There was a reduction in preimplant days in the catheterization laboratory group 3.16 +/- 12.40 days versus 5.65 +/- 9.54 days in the OR group (P < 0.05). Complications were minimal and there were no significant differences between the two groups. This study confirms that pacemakers can be safely implanted in the catheterization laboratory by nonsurgeons with no increase in complications and a significant reduction in hospital costs.