Entrapment of an Atrial Tined Pacemaker Electrode in the Tricuspid Valve—A Case Report

A rare complication is described in which an atrial tined pacemaker electrode was trapped in the chordae of the tricuspid valve and could not be removed. A possible method for avoiding this complication is discussed.     

Inadvertent Transarterial Pacemaker Insertion: An Unusual Complication

We describe an unusual complication of pacemaker treatment in a patient who died after a replacement operation. In a difficult situation in which a functioning pacemaker was highly desirable and in which most of the available veins had already been used, the pacemaker electrode was inserted, by mistake, through a small artery. This was not detected by fluoroscopy during surgery. The postoperative X-ray examination seemed to indicate that the electrode tip was located in the coronary sinus, but the subsequent autopsy revealed it to be located in the left ventricle.     

Lead Dislodgment of a Permanent Pacemaker Due to Removal of a Temporary Pacing Electrode

A 63-year-old male received a transvenous temporary pacemaker for bradyarrhythmia following mitral valve replacement and tricuspid valve annuloplasty. A transvenous permanent pacemaker was implanted the following day due to persistence of the bradyarrythmia and pacemaker dependency of the patient. Later the same day during removal of the temporary pacing electrode the permanent pacing lead was dislodged and had to be operatively repositioned. To avoid this complication, the position of pacemaker leads should be checked postoperatively with a frontal and lateral chest radiograph, and fluoroscopy should be used during removal of a temporary lead.     

Candida Albicans Pacemaker Site Infection

A 69-year-old man with a history of diabetes and episodic lymphocytopenia underwent pacemaker implantation for complete heart block. Despite prophylactic antibiotics, pocket irrigation, and strict sterile technique, a fungal (Candida albi-cans) pacemaker site infection developed that required pacemaker explantation and systemic ampho-tericin B therapy. After 3 days of temporary pacing, a second pulse generator was implanted on the opposite side. At 2-year follow-up, he has had no recurrence of pacemaker infection. This report underscores the predilection of diabetics for infections, and in particular, their susceptibility to Candida albicans.     

永久性心脏起搏器安置术后并发症的护理

随着我国心律失常介入治疗的迅速开展,心脏起搏器的临床应用日益广泛,安置心脏起搏器是治疗不可逆性心脏传导功能障碍的安全有效的方法,特别是治疗因“窦房结病变”和“心脏传导系统病变”引起的重症缓慢心律失常。2009年1—12月,我院心内科安置永久性心脏起搏器患者141例,     

Pacemaker Electrode Repositioning Using the Loop-Snare Technique

Using a percutaneous femoral vein approach under fluoroscopic control, a malpositioned ventricular pacemaker electrode was released from the right ventricular wall by hooking the lead with a deflecting wire inserted into a RIM catheter. A closed loop was formed by tightening the handle of the wire allowing the electrode to be dislodged and pulled into the inferior vena cava. The electrode was then snared using a loop formed by an exchange wire advanced through an 8 French catheter with a J-curve steamed at its tip. The electrode was advanced to the right ventricular apex and released by advancing one end of the snare wire while pulling the other end to open the loop.     

Removal of Fractured Pacemaker Electrode Tip Using Dotter Basket

During attempted removal of an infected permanent pacemaker system, the electrode fractured, leaving the tined tip embedded in the wall of the left subclavian vein. The electrode tip was successfully removed using a Dotter basket retrieval kit.     

Detachment of Pacemaker Active Fixation Helix

The introduction of active fixation electrodes has been a major advance in permanent atrial and ventricular endocardial pacing. We report here an important complication in the use of one such device, the Medtronic transvenous unipolar screw-in ventricular lead (Model 6959).     

Electrical Alternans of Pacemaker Spike Amplitude: an Unusual Manifestation of Permanent Pacemaker Generator Malfunction

A case of electrical alternans of pacemaker stimulus amplitude is presented, with constant alternation of large and small amplitude pacemaker spikes without loss of ventricular capture, due to a defect in the oscillator hybrid of a rate programmable Medtronic unit. This represents an unusual electrocardiographic manifestation of pacemaker generator malfunction which, to our knowledge, has not been reported previously.     

High Rate of Late Dislodgements of an Active Fixation Atrial Lead

Between May 1985 and May 1991 we implanted 115 DFH-leads as unipolar atrial leads. The active fixation mechanism of this electrode consists of two sickle-shaped anchoring hooks which are placed at a distance of 0.9 mm parallel to the distal flat end of the electrode. All leads were affixed to the free wall of the right atrium. One hundred eight leads (93.9%) were implanted for dual chamber pacing and seven leads (6.1%) for single chamber atrial pacing. Parameters measured at implantation were (mean values): stimulation threshold 1.06 ± 0.42 V at 0.5 msec pulse width, P wave amplitude 5.12 ± 2.04 mV, and lead impedance 560 ± 76.1 Ohms. Within the first week after implantation, three early dislodgements occurred (2.6%). The follow-up period averaged 30.4 ± 16.2 months (range 2–76 months). During this time, 14 late macrodislodgements (12.2%) occurred after a mean period of 18.4 months (range 2–59 months). All of them required reoperation. The active fixation mechanism of the DEH-lead appears to be unreliable, if implanted in the free wall of the right atrium for dual chamber pacing.     

Suppression of an External Demand Pacemaker by Diaphragmatic Myopotentials: A Sign of Electrode Perforation?

Transient pacemaker inhibition was observed in a patient with an external bipolar demand pulse generator. Recordings of the proximal, distal and bipolar electrograms showed extracardiac myopotentials only in the unipolar distal and bipolar configuration. These myopotentials which caused inhibition of the pulse generator were related to respiration and other maneuvers that resulted in active contraction of the diaphragm, thus proving their diaphragmatic origin.     

Acute Pericarditis Resulting From an Endocardial Active Fixation Screw-In Atrial Lead

We examined the occurrence of acute pericarditis after pacemaker implantation in 123 consecutive patients (61 males, 62 females, ages 17–87 years) in whom a newer atrial active fixation bipolar lead was inserted endocardially in the right atrium for dual chamber pacing. The atrial leads were positioned to obtain the best possible pacing and sensing thresholds, after an initial attempt was made for insertion into the right atrial appendage or medially into the right atrial septum. Six patients (4.9%) developed acute symptomatic pericarditis with effusion within 24 hours of implantation. Of these six patients, four had leads screwed into the lateral waH. and the other two had leads placed in the anterolateral wall. The lead implantation parameters between patients with pericarditis and those without did not show any significant difference in the atrial P wave amplitude (2.3 ± 0.4 vs 2.9 ± 0.9 mV), pacing threshold (1.1 ± 0.2 vs 1.1 ± 0.4 V), or resistance (524 ± 112 vs 480 ± 94 ohms). All symptomatic patients were treated with nonsteroidal anti-inflammatory drugs with symptoms resolving in 1–2 weeks. We condude that: (1) a significant number of patients (4.9%) developed acute symptomatic pericarditis after insertion of this type of atrial fixation lead: (2) because of the lead design, the implantation parameters coud not be taken to predict the occurrence of pericarditis: and (3) caution should be taken for the insertion of this lead into the thin atrial wall.     

Programming Eccentricities of an Activity Sensing Pacemaker

The Activitrax rate responsive pacemaker system has enjoyed wide popularity but minor engineering eccentricities have occurred and have been reported. We report another unusual feature seen in Activitrax models 8400, 8402, and 8403. This feature consists of continuing in a temporary mode while a different permanent mode was programmed. These eccentricities of the programming features are not very commonly seen, however, they can be somewhat perplexing to the physician following the patient. These unusual features are no longer present in the newer models being manufactured.     

Pacemaker lead extraction with the needle's eye snare for countertraction via a femoral approach

Femoral approach pacemaker lead extraction is described as a safe and efficacious procedure. When the lead can not be removed from its myocardial insertion, the "Needle's eye snare" has become available, and it allows a femoral approach traction associated with a countertraction. Between May 1998 and May 2000, 222 lead extraction procedures were performed in 99 patients using the femoral approach. This article reports the results of the 70 lead extractions requiring the use of the Needle's eye snare for femoral approach countertraction in 39 patients with a total of 82 leads. The indications were infection, accufix leads and lead dysfunction in 56, 1 and 6 leads, respectively. The age of the leads was 113 +/- 56 months. Sixty-one (87.2%) leads were successfully extracted, the extraction was incomplete in 3 (4.3%) cases and failed in 6 (8.5%) cases. The failures were due to leads totally excluded from the venous flow for four leads, the impossibility of advancing the 16 Fr long sheath through the right and left iliac veins for one lead and one traction induced a nontolerated ventricular arrhythmia. In these cases, an extraction by a simple upper traction had been attempted in another center several months before. The complications included two deaths and one transient ischemia of the right inferior limb. Despite the selection of a series of leads for which an extraction by a simple traction on the proximal end of the lead was impossible or unsuccessful, femoral countertraction seems to be a safe and efficacious procedure. The failure of this technique occurred in patients with damaged leads due to a previous extraction procedure performed in centers with limited experience in lead extraction.     

Serial Lead Impedance Measurements Confirm Fixation of Helical Screw Electrodes During Pacemaker Implantation

The purpose of this study was to determine whether serial measurements of helical screw pacemaker lead impedance could reliably confirm electrode fixation in the right atrium and right ventricle. Fixation is generally assessed fluoroscopically, which can be misleading because the myocardium is radio lucent. Alternatively, because the electrical conductivity of blood is greater than that of myocardium, serial measurements of the lead impedance might be expected to show an impedance increase with appropriate fixation of the pacemaker electrode when the electrode becomes embedded in myocardial tissue. Impedance measurements were made during the placement of 23 atrial and 28 ventricular active fixation electrodes in 31 consecutive patients. Impedance measurements were recorded in unipolar and bipolar electrode configurations with the electrode free floating in the chamber, unfixed (with exposed screws) but touching the endocardial surface, and after fixation. No significant impedance differences were found between free-floating and unfixed electrode positions. With fixation, the lead impedance increased significantly in the ventricle (P = 0.0001, unipolar and bipolar) and the atrium (P = 0.0069 unipolar and 0.0052 bipolar). Typical increases, reflected by median values, were 197 ohms unipolar and 203 ohms bipolar in the ventricle and 47 ohms unipolar and 53 ohms bipolar in the atrium for electrodes with permanently exposed or retractable screw designs. Comparing serial measurements of lead impedance before and after electrode fixation is a valid electrical method of confirming appropriate fixation of helical screw electrodes.     

Pneumopericardium With Cardiac Tamponade as a Complication of Cardiac Pacemaker Insertion One Year After Procedure

Background: Lead dislodgement has been shown to be the most common complication in the first 30 days after pacemaker insertion. Although it is rare, pneumopericardium with tamponade can also result. Objectives: We present a case of an extremely rare delay from cardiac pacemaker insertion to lead migration with resulting pneumopericardium and cardiac tamponade. Case Report: A 65-year-old woman with a past medical history significant for congestive heart failure, chronic obstructive pulmonary disease, and third-degree heart block, requiring pacemaker insertion 2 years prior with a revision 1 year prior, presented to the Emergency Department complaining of sudden-onset pleuritic chest pain. Her work-up revealed a pneumopericardium with atrial pacemaker lead migration into the right middle lobe of the lung. She suddenly developed hypotension and respiratory distress and required pericardiocentesis and, ultimately, surgical repair for a perforated right atrium. Conclusion: Pacemaker migration can lead to pneumopericardium and tamponade, even up to 1 year after placement.     

Pulmonary Emboli from a Platelet-rich Thrombus Attached to a Pacemaker Electrode

A patient with recurrent, fatal pulmonary emboli originating from thrombus attached to a permanently-implanted pacemaker electrode is described. While most throm-boemboli are composed predominantly of fibrin and erythrocytes. histologic and immunologic studies showed this thrombus to be rich in platelets. A possible therapeutic approach to this rare situation is discussed.     

Migration of an Epicardial Pacemaker to the Pericardial Space in an Infant

We report the case of a 4-month-old infant who was implanted with an epicardial ventricular pacing system at 6 days of age for the prolonged QT syndrome, who subsequently developed migration of the pulse generator to the pericardial space. Tracking of the pulse generator through the diaphragm and into the pericardium followed the route of the myocardial lead. The possibility of pulse generator migration, as well as disruption of the diaphragm and pericardium, should be considered by those who care for infants with implanted pacemakers.     

False-Positive Behavior with the dP/dt Sensing Pacemaker: A Rare Complication of a Physiological Sensor

As with "nonphysiological" devices, sensors that directly measure physiological variables bave the potential to measure unexpected signals and for the physiological parameter being measured to respond in an unexpected manner. We present tbe case of a dP/dt sensing pacing system that functioned normally for 2 months and then developed upper rate behavior due to the sensing of a high frequency artifact on the pressure recording. Our case and others cited reinforce the need for future physiological rate responsive pacemakers to incorporate a second sensor to provide for backup rate response in cases of inappropriate rate response.     

Pacemaker Upgrade for Recurrent Pacemaker Syndrome Using a Redundant Contralateral Electrode in a Patient with Bilateral Venous Stenoses

Following His-bundle ablation and VVIR pacemaker implantation, severe pacemaker syndrome developed and was treated with DDDR pacing, in a 70-year-old woman. Due to bilateral subclavian vein stenoses, DDDR pacing could not be maintained and an unusual method of restoring atrioventricular synchrony is described using the contraiateral redundant atrial electrode connected to the ipsilateral dual chamber pacemaker and ventricular electrode.