Cardiac Pacemaker Infection: Surgical Management With and Without Extracorporeal Circulation

Background. Pacemaker infections are rare, but serious complications of pacemaker therapy. The generator pocket, the pacing leads, or both may be involved.

Methods. We report on 12 patients with infected pacemaker systems. Four patients suffered from localized generator pocket infections, 6 had infected leads, and 2 patients had both. Pacemaker systems were completely removed in all patients. When the infection was limited to the generator pocket, the pacemaker system was removed at the original implantation site. Extracorporeal circulation was employed for the explantation of infected pacing leads.

Results. No complications occurred in patients with localized generator pocket infections. One patient with infected leads who was preoperatively already in a serious clinical condition died of septic shock in the early postoperative period; another patient died of pulmonary complications after tricuspid valve replacement 14 months after pacemaker explantation. No recurrent infections were observed.

Conclusions. Explantation of the complete pacemaker system has proved a reliable method to eradicate infection. Complications have been rare, except in patients in a critically ill state who undergo cardiopulmonary bypass.     

VATS-guided epicardial pacemaker implantation

Background: In neonates and infants epicardial stimulation may be preferred to endocardial stimulation because of growth-associated lead problems and the risk of vascular complications associated with transvenous electrodes. This study analyzes the feasibility of atrioventricular implantation of a new epicardial lead using the video-assisted thoracic surgical (VATS) technique in an animal model. Methods: Bipolar steroid-eluting epicardial leads were implanted in seven young white pigs. In five animals bipolar atrial and ventricular pacing leads (n= 10) were inserted and fixed by the VATS technique, while two animals served as controls and underwent implantation through anterolateral thoracotomy. Surgical feasibility, pacing, and sensing thresholds of the leads as well as hemodynamic parameters during pacing were studied. Histological changes beneath the electrodes were evaluated 1 week after the implantation. Results: All animals survived the pacemaker lead implantation. One animal which underwent thoracotomy died because of irreversible ventricular fibrillation induced by rapid ventricular pacing. One animal in the VATS group exhibited intraoperative herniation of the heart through the pericardial window. All animals with left-sided VATS implantations demonstrated good individual pacing and sensing threshold values. The mean cardiac output was 1.6 times higher during AAI-mode pacing as compared to VVI-mode pacing at a heart rate of 140/min. One animal died postoperatively due to respiratory failure. No displacements of the pacemaker leads were observed in the survivors. Conclusion: While VATS-guided implantation of epicardial, atrial, and ventricular leads is feasible, technical improvements of the system are mandatory for safe clinical application. Received: 14 October 1996/Accepted: 14 April 1997     

Removal of methicillin-resistant staphylococcus aureus infected pacemaker leads under cardiopulmonary bypass: report of a case

A 71-year-old man, who underwent an intravenous pacemaker implantation previously, suffered from fever and local infection of the generator pocket. A blood culture showed positive for methicillin-resistant staphylococcus aureus (MRSA). He underwent removal of total pacemaker system under cardiopulmonary bypass support successfully. Two leads were tightly adhered to the right atrial free wall, tricuspid valve and right ventricular trabeculation. Postoperative course was uneventful with administration of antibiotics for 5 weeks. Removal under cardiopulmonary bypass is considered to be an effective procedure for treatment of patients with infected pacemaker lead.     

Load dependence of cardiac output in biventricular pacing: right ventricular volume overload in pigs

BACKGROUND: Previous work from our laboratory has demonstrated that optimization of biventricular pacing is load dependent. During acute pulmonary stenosis and right ventricular pressure overload in swine, cardiac output was maximized by pacing the right ventricle 40 ms before the left ventricle. To extend those studies, this experiment examined biventricular pacing optimization during right ventricular volume overload. METHODS: After median sternotomy in 6 anesthetized domestic pigs, complete heart block was induced by ethanol ablation. A conduit was grafted from the right ventricle to the right atrium to simulate tricuspid insufficiency. During epicardial, atrial tracking DDD biventricular pacing, atrioventricular delay was varied between 60 and 180 ms in 30-ms increments. Right ventricular-left ventricular delay was varied at each atrioventricular delay from +80 ms (right ventricle first) to -80 ms (left ventricle first) in 20-ms increments. Aortic flow, right ventricular pressure, and electrocardiogram were measured at each pacemaker setting with the graft clamped and unclamped. RESULTS: Atrioventricular and right ventricular-left ventricular delays had no significant effect on cardiac output with the graft clamped. With the graft unclamped, however, there was a statistically significant (P =.003 by mixed modeling repeated measures analysis of variance) trend toward higher cardiac output with left ventricle-first pacing. CONCLUSION: Left ventricle-first biventricular pacing in swine significantly increased cardiac output during acute tricuspid insufficiency but not during the control state. Trials are warranted to develop clinical biventricular pacing for treatment of perioperative right ventricular dysfunction.     

Institution of Physiological Pacing Utilizing Preexisting Hardware

Six patients with ventricular inhibited pacemakers, who experienced adverse effects from loss of atrial contribution to cardiac output and loss of atrioventricular synchrony, were successfully converted to atrial demand (3 patients) and atrioventricular sequential systems (3 patients). The preexisting ventricular pulse generator was used for atrial pacing in 3 patients, and the preexisting ventricular leads were employed for atrioventricular sequential pacing in 3 patients. The advantages and potential risks of utilizing preexisting hardware for conversion of ventricular pacing into physiological pacing are discussed.     

Cardiac Pacing in Japan

A general update on pacemakers and cardiac pacing in Japan in 1981 is presented, including costs, prepacing studies, follow-up, pacing center activity, average number of first implants per million inhabitants, age of patients at first implantation, clinical indications for pacing, etiology, prepacing electrocardiogram, pacemaker hardware, electrode leads, electrocardiogram indications for pacing, indications for generator or electrode changes, and extended application of pacing. The author's data are compared with those obtained by the survey of the Seventh World Symposium on Cardiac Pacing.     

Simplified physiological pacing after cardiac surgery

Temporary pacing wires are routinely placed at the end of cardiac surgery. These pacing wires are helpful in maintaining patients with postoperative bradycardias, and physiological pacing is also more desirable in critically ill patients. We herein report our simplified procedure for atrial pacing. This technique uses commercially available intravenous pacing catheters. The catheter is passed through the skin, and its tip is placed at the pericardial oblique sinus just between the right and left pulmonary veins. Atrial pacing is then initiated with a temporary pulse generator. This procedure is simple and effective for patients undergoing cardiac surgery. We also report two clinical cases that satisfactorily underwent atrial pacing using this procedure.     

Pacemaker dependent patients with device infection—a modified approach

A modified surgical concept for temporary cardiac pacing in pacemaker dependent patients requiring total removal of infected devices is presented. Proximal to the infected pocket a permanent bipolar pacing lead is placed transcutaneously into the ipsilateral subclavian or jugular vein. The lead is placed in the right ventricle and fixed into the skin using the suture sleeve. Pacing is established by connecting an external pacing generator. Subsequently the infected device can be removed completely. After wound dressing the externalized lead is connected to a permanent VVI-pacemaker allowing for prolonged temporary pacing.     

Clinical Experience with Permanent Atrioventricular Sequential Pacing

In a 23-month period, we implanted 26 permanent atrioventricular (AV) sequential pacing units in 11 women and 15 men ranging from 37 to 85 years old (mean, 68 years). Indications for pacing were complete heart block in 12 patients and sick sinus syndrome in 14 patients.Cardiac index, using standard thermodilution techniques, was determined in 9 patients during ventricular pacing and AV sequential pacing at constant heart rate. Atrioventricular sequential pacing was superior in all patients, with a mean increase in cardiac index of 22% (p < 0.01). Complications of AV sequential pacing included the need to revise two pulse generator pockets due to the large size of the pulse generator. One transvenous atrial lead displacement occurred in a patient who had previously undergone right atrial appendage ligation at open-heart operation. No failures of pacing or sensing occurred during 279 patient-paced months.The theoretical hemodynamic advantage of AV sequential pacing has been confirmed in this clinical trial. Experience with electrode placement and improvements in pulse generator design should aid in eliminating complications with this pacing modality.     

Permanent cardiac pacing after the Fontan procedure

Permanent cardiac pacing after a Fontan procedure is complicated by complex cardiovascular anatomy. Of 332 patients undergoing the Fontan procedure at the Mayo Clinic, we evaluated 15 who postoperatively required permanent pacing (mean age 16.5 years, range 4 to 31 years). Underlying congenital cardiac defects included univentricular heart in nine patients, double-outlet right ventricle in three, and tricuspid atresia in three. The indication for pacing was postoperative heart block in seven patients, congenital heart block in five, postoperative sick sinus syndrome in two, and heart block because of previous operation in one. Pacemakers were implanted immediately postoperatively in 11 patients and 12 to 57 months later in four patients. VVI systems were used in nine patients, DDD in four, AAI in one, and a Medtronic Activitrax VVI in one. All ventricular leads were epicardial. Four atrial leads were transvenous endocardial and one was epicardial. Three patients died 4, 9, and 69 months later of causes unrelated to pacing. Among the 12 survivors, mean follow-up was 34 months (range 1 to 107 months). Two patients had a total of three episodes of loss of ventricular capture because of increased chronic thresholds. Our current approach to pacing after a Fontan procedure includes (1) intraoperative placement of temporary atrial and ventricular electrodes, (2) intraoperative attachment of a permanent ventricular epicardial lead for congenital or surgically induced high-grade atrioventricular block, (3) postoperative insertion of transvenous atrial leads if dual-chamber pacing is indicated, and (4) use of programmable pulse generators with high output capability.     

Tempor?re Schrittmachertherapie bei herzchirurgischen Operationen

Bradycardia during and after cardiac surgery requiring temporary pacing is observed in roughly 50% of patients. Complete heart block as well as bradycardia associated with a sinus node dysfunction or permanent atrial fibrillation are the most common types of perioperative bradycardia; however, in some cases even a heart rate below 80 beats/min can be associated with hemodynamic problems. Finally, the occurrence of bradycardia in the immediate postoperative period after cardiac surgery cannot be predicted with reasonable accuracy. Thus, implantation of temporary epimyocardial stimulation leads in every patient undergoing cardiac surgery is common practice. The versatility of temporary pacing in cardiac surgery is unique, as all parts of the heart can be accessed during the operation. Thereby it allows temporary atrial, AV-sequential, P-wave synchronized or biventricular pacing in addition to ventricular pacing, the only pacing mode available for temporary pacing outside cardiac surgery. This results in desirable and substantial hemodynamic advantages compared to single chamber ventricular pacing for cardiac surgery patients in the perioperative period. This article summarizes the key elements of temporary pacing after cardiac surgery and adds some practical points.     

Long-term epicardial ventricular pacing from endocardial bipolar pacemaker lead: perforation of right atrial wall.

One of the hazards of endocardial cardiac pacing is that the pacemaker lead may perforate the myocardial wall or interventricular septum although the incidence of such perforations is believed to be small. This paper describes what is believed to be a unique case in which a pacemaker lead perforated the atrial wall at implantation (or possibly shortly afterwards) and yet gave satisfactory right ventricular epicardial pacing for more than five years. The perforation was discovered during a routine postmortem examination but earlier lateral x-ray examinations would probably have identified the abnormal position of the electrodes. Moreover, the present implantation technique would not have allowed perforation of the atrial wall at implantation to go undetected.     

Cardiac pacing.

The basic electrophysiology of temporary and permanent cardiac pacing is reviewed, as are the indications, the types of pacing systems, and the methods of implantation. Recent developments in power sources and leads are described. The mercury-zinc battery is now obsolete and is being replaced by lithium, rechargeable, and isotopic power systems. While ventricular pacing continues to be the standard, a brief review of atrial programmed systems is given, including atrial pacing and atrioventricular synchronized and atrioventricular sequential pacing. Conventional pacing is aimed at the control of symptomatic bradycardia. Brief reference is made to experimental pacing systems designed to control ventricular or supraventricular tachyarrhythmias.     

New site for pacemaker generators in children

Bipolar pacemaker implantation was performed in three children, aged 5, 6 and 9 years. The two epimyocardial fishhook pacing electrodes were inserted through different incisions. After resection of the anterior part of the 5th and 6th rib, the generator was placed into a pocket with the posterior wall resulting from the remaining periostium/perichondrium and the anterior wall consisting of the isolated intercostal and pectoral muscle. The leads were brought in extrapleurally and connected to the generator. The operations were conducted without perioperative and late postoperative complications.     

Right ventricular outflow tract pacing: an alternative, safe, and effective pacing site

The right ventricular apex (RVA) has traditionally been preferred for the insertion of permanent cardiac pacemaker leads because of vast experience with their use, their ease of implantation, and the stability of passive fixation leads in the RVA trabeculae. However, prolonged RVA pacing is associated with progressive left ventricular dysfunction due to dysynchronous ventricular activation, and often results in substantial functional, hemodynamic, electrical, and structural changes, as previously demonstrated in many studies. Only in recent years has interest in the use of alternate pacing sites developed. The right ventricular outflow tract (RVOT) is now the preferred site of pacing because of potential advantages such as ease of application, better hemodynamics, synchronous activation, fewer myocardial perfusion defects, and a narrower QRS complex compared with RVA pacing. This review article comprehensively discusses this novel technique in terms of its beneficial effects, long-term safety, and performance measures compared with RVA pacing, and as an alternative method for biventricular pacing.     

Optimal positioning of temporary epicardial atrial pacing leads after cardiac surgery

OBJECTIVES: Atrial pacing plays an important role in preventing low output syndrome and arrhythmia after cardiac surgery. We studied the optimal positioning for temporary epicardiac atrial pacing. METHODS: The performance of temporary epicardiac atrial pacing leads was examined after 13 cases of elective coronary artery bypass grafting between October 1999 and January 2000. Two bipolar electrode leads were used--1 on the cephalic atrial wall between the left and right atrial appendages, where the Bachmann bundle indwells (site A), and the other on the interatrial groove (site B). To assess pacing performance on postoperative days 1, 2, and 7, we measured 3 pacing patterns--bipolar use of sites A and B leads, and combined use of the 2 with the site A lead acting as the negative electrode and the site B lead as the ground. The pacing threshold was measured at a 0.5 ms pulse width, using the P wave amplitude and slew rate as indicators of sensing performance. RESULTS: Bipolar pacing both at sites A and A-B was superior to that at site B in pacing threshold and sensing parameters. CONCLUSIONS: The negative electrode at site A is mandatory for high atrial pacing and sensing performance.     

Load dependence of cardiac output in biventricular pacing: right ventricular pressure overload in pigs

BACKGROUND: The effect of biventricular pacing on stroke volume is believed to be dependent on right ventricular/left ventricular delay, but effects in individual patients are unpredictable. This variability may reflect relative right and left ventricular volume and/or pressure overloads. Accordingly, we tested the hypothesis that the relation of cardiac output to right ventricular/left ventricular delay is load dependent in a pig model of pulmonary stenosis. METHODS: After median sternotomy in 6 anesthetized, domestic pigs, complete heart block was induced by ethanol ablation. During epicardial, atrial tracking DDD biventricular pacing, atrioventricular delay was varied between 60 and 180 ms in 30-ms increments. Right ventricular/left ventricular delay was varied at each atrioventricular delay from +80 ms (right ventricle first) to -80 ms (left ventricle first) in 20-ms increments. Aortic flow, right ventricular pressure, peripheral arterial pressure, and electrocardiogram were measured in the control state and during pulmonary stenosis, created by tightening a snare around the pulmonary artery until cardiac output decreased by 50%. RESULTS: Atrioventricular and right ventricular/left ventricular delay had no effect on cardiac output during the control state, but during pulmonary stenosis there was a statistically significant (P =.0001, repeated-measures analysis of variance) right ventricular/left ventricular delay-related trend toward higher cardiac output with right ventricular pacing first. This effect was more pronounced when the optimal atrioventricular delay was determined first, resulting in a 20% increase in cardiac output when the optimal right ventricular/left ventricular delay was compared with simultaneous biventricular pacing. CONCLUSIONS: Optimized biventricular pacing in swine is associated with increased cardiac output during acute pulmonary stenosis, but not during the control state. Further studies are needed to determine whether specific types of right ventricular and left ventricular overload predictably affect the relation between right ventricular/left ventricular delay and cardiac output.     

Forceps extraction of permanent pacing leads

With the advent of tined transvenous cardiac pacing leads, the complete extraction of pacing leads in the treatment of an infected cardiac pacing system has become increasingly difficult. A method is described for the extraction of permanent pacing leads from the heart using alligator forceps inserted transvenously through the right internal jugular vein, grasping the lead near its insertion point in the cardiac muscle.     

Management of the infected pacemaker: explantation, sterilization, and reimplantation

From January, 1970, through December, 1984, nineteen infected or eroded pacemaker units were reimplanted in 17 patients. Characteristics of the patients, types of infecting organisms, surgical management, and complications are described. Optimal treatment of the infected generator pocket requires explantation of the generator unit with utilization of the in situ leads for pacing by an external-demand pacemaker unit. The generator unit is sterilized, and new leads are placed with relocation of the pocket. The old leads are then removed. This technique has been used safely and with excellent results for the past fourteen years.     

Robotic-enhanced biventricular resynchronization: an alternative to endovenous cardiac resynchronization therapy in chronic heart failure

BACKGROUND: Cardiac resynchronization therapy (CRT) by pacing the left and right ventricles is an emerging option for treatment of severe heart failure with ventricular conduction disturbances. Stimulation through a coronary vein is currently the technique of choice to achieve left ventricular (LV) pacing. Unfortunately, this approach carries significant limitations and drawbacks. Therefore we explored robotic-enhanced thoracoscopic implantation of an epicardial lead as an alternative technique to stimulate the LV in cardiac resynchronization therapy. METHODS: A total of 15 patients were included in this study. Right (atrial and ventricular) leads were implanted classically through the left subclavian vein. Robotic-enhanced thoracoscopy was then performed to implant the LV epicardial lead. RESULTS: Of the 15 patients, 13 underwent successful endoscopic robotic cardiac resynchronization therapy. Two patients underwent conversion to a small thoracotomy. No perioperative complication occurred in the patients who did not undergo conversion. Acute and chronic LV lead thresholds were satisfactory in all patients, improving over time. All were subjectively and objectively improved at 4 months. As compared with conventional methods, the procedural cost was not significantly affected. CONCLUSIONS: Based on this feasibility study, we believe that robotic LV epicardial lead implantation is a valuable option to achieve biventricular resynchronization therapy. It allows for more reproducible acute thresholds for LV pacing and sensing than does the percutaneous approach; enables fine tuning of the LV lead position, thus potentially providing optimal hemodynamic benefit; and avoids the pitfalls and limitations of the endovenous approach. Therefore it deserves further prospective studies to assess its place in the therapeutic armamentarium against heart failure.