Endocardial Pacemaker Research Articles

First Case Report in Japan of Left Ventricular Pacing via a Coronary Vein in a Patient With a Mechanical Tricuspid Valve

Transvenous endocardial pacemaker implantation is contraindicated in patients after prosthetic tricuspid valve replacement. A 65-year-old woman underwent both replacement of the mitral and tricuspid valves and pacemaker implantation with epicardial lead for bradycardia with chronic atrial fibrillation. At 2 years after this operation, the pacemaker's battery became low, and she was admitted for a battery exchange. To avoid frequent battery exchanges because of high stimulation thresholds, a left ventricular pacing lead was implanted via a coronary vein. There were no complications and the stimulation thresholds were stable. Coronary vein leads enable a minimally invasive approach, improve safety, and give effective stimulation for patients with a prosthetic tricuspid valve. This is the first case report in Japan of left ventricular pacing in such a patient.

Two Cases of an Implantation of a Permanent Pacemaker Using a Transaxillary Incision

In surgeries that require the implantation of a pacemaker, the endocardial pacemaker leads are introduced into the cardiac chambers through subclavian or axillary venous catheterization or cephalic vein cutdown. The drawback of this type of surgery is scarring of the pectoral area, which can be a serious cosmetic problem especially for young women. In this study, we report on 2 cases where a permanent pacemaker in two young women with symptomatic bradycardia was implanted using a transaxillary incision. Both patients successfully recovered with no complications and were asymptomatic for more than 17 months after the procedure. Therefore, we found that implantation of a pacemaker via transaxillary incision provided excellent cosmetic results and should be considered in young women that require this type of surgery. (Korean Circ J 2008;38:500-504)

Celebrating 50 years of electrical therapies for the heart

Fifty years ago, on 8 October 1958, Elmqvist and Senning, at the Karolinska Hospital in Stockholm, implanted the first endocardial pacemaker to treat a patient with recurrent Adam–Stokes episodes.1 Since this pioneering experience, arrhythmia management has evolved enormously in the last 50 years, with electrophysiology being one of the areas of medicine where technology has had the strongest impact.2 The technologically driven evolution of devices and tools has been complemented by the acquisition of important scientific evidence of benefit in specific patient settings. Accumulation of hard evidence has … *Corresponding author. Tel: +39 051 349858; fax: +39 051 344859. E-mail address : giuseppe.boriani{at}unibo.it

Intracardiac Masses Associated With Permanent Endocardial Pacemaker Lead Erosion Through the Skin

A 72-YEAR-OLD, 178-cm, 57-kg man presented to the authors' institution with an exposed permanent endocardial pacemaker lead adjacent to an old left subclavian pacing generator pocket. The patient reported that a “cystic” swelling began over the old generator site approximately 4 months before admission. The pacemaker lead eroded through the skin 2 months later, but the patient had only recently sought medical attention for an unrelated problem. He denied fevers, chills, or drainage at the wire-erosion site.

Tricuspid valve stenosis caused by fibrous adhesions to an endocardial pacemaker lead in a dog

Acquired tricuspid valve stenosis (TVS) is a rare complication of endocardial lead placement in humans that has not been described in the veterinary literature. We describe a 6.5-year-old Border terrier that was presented with right-sided congestive heart failure 5.5 years after placement of a transvenous pacemaker. Severe TVS was confirmed by cardiac ultrasonography and appeared to be secondary to excessive endocardial pacemaker lead within the right atrium. Repositioning of the lead proved impossible and subsequent postmortem examination demonstrated fusion of the tricuspid valve (TV) leaflets around the endocardial lead with associated narrowing of the tricuspid valve orifice. In addition, the loop of the endocardial lead was anchored by thick fibrous tissue to the right atrial wall. This case report suggests that if sufficient endocardial lead is left inside the heart, in dogs undergoing transvenous pacemaker therapy, the redundant lead can become adherent to the tricuspid valve apparatus and cause valvular stenosis.

A rare cause of abdominal pain

Pacemaker migration is a rare, but important, complication of pacemaker insertion mainly documented in children. We report the case of a 60-year-old woman who was admitted with right iliac fossa pain thought to be caused by appendicitis. She was noted to have both an epicardial and endocardial pacemaker in situ. Imaging and laparoscopy revealed migration of the epicardial pacemaker to the right iliac fossa. We describe the possible mechanisms of pacemaker migration.

Superior Vena Cava Syndrome Induced by Endocardial Defibrillator and Pacemaker Leads

Two cases of superior vena cava syndrome induced by endocardial defibrillator and pacemaker leads are described. The 2 patients had histories of multiple endocardial leads and device upgrades and venous thrombosis. The first patient was treated with laser lead extraction followed by percutaneous venoplasty and stenting. The second patient was treated conservatively with long-term anticoagulation. The 2 patients had symptomatic reduction. In conclusion, superior vena cava syndrome induced by transvenous leads is an uncommon but serious complication. Anticoagulation can be effective in select patients, but in severe cases, thrombolytic therapy or surgical or percutaneous intervention may be required.

Single-centre experience on endocardial and epicardial pacemaker system function in neonates and infants

Endocardial (ENDO) or epicardial (EPI) pacing systems are implanted in infants but it remains unclear which system should be preferred. We evaluated the results of children <or=1 year who underwent pacemaker (PM) implantation at our centre with a retrospective analysis. Between 1992 and 2004, 56 patients, 37 of whom had other congenital heart defects (CHDs), received a PM at 4.4 +/- 3.8 months of age for atrioventricular block (n = 52) and sinus node dysfunction. Rate-responsive ventricular demand pacing (VVIR) PMs were implanted in 25 patients (19 ENDO), dual-chamber demand pacing (DDD) in 29, and rate-responsive atrial demand pacing (AAIR) in 2 (all EPI). Follow-up (FU) was 4.5 +/- 3.5 (range 0.3-13) years: 15 pacing system failures occurred among the 56 patients (26%) after 4.5 +/- 3.2 years, with a significantly reduced success rate for EPI (21-fold increase of the risk of failure) and complex CHD. Also in patients without surgery for CHD, EPI showed a worse outcome. Among the 91 leads implanted, failures occurred more significantly in EPI (18% of atrial, 24% of ventricular leads) than in ENDO (5% of ventricular leads). No venous occlusion was found at FU. Single-lead, VVIR ENDO pacing had higher efficiency and safety than EPI, and it might be the best choice for PM implantation in infants. However, because of small patient numbers and lack of longer FU, these findings should be treated with caution.

Tricuspid Ring Valve Abscess in an AICD implanted patient

A 73 year old Caucasian male with dilated cardiomyopathy, atrial fibrillation, and an automated implantable cardioverter defibrillator (AICD) placed 1 year ago presented with implant side soreness and methicillin resistant staphylococcus aureus (MRSA) bacteremia. EKG showed multiple runs of nonsustained ventricular tachycardia (NSVT). Transesophageal echocardiogram revealed a 4.2 cm size abscess on tricuspid valve ring at the site of electrode implantation. CASE REPORT A 73 year old Caucasian male with dilated cardiomyopathy, atrial fibrillation, and an automated implantable cardioverter defibrillator (AICD) placed 1 year ago presented with implant side soreness and methicillin resistant staphylococcus aureus (MRSA) bacteremia. EKG showed multiple runs of nonsustained ventricular tachycardia (NSVT). Transesophageal echocardiogram revealed a 4.2 cm size abscess on tricuspid valve ring at the site of electrode implantation (Figure ). Treatment of this abscess would have required surgical removal of leads during extracorporeal circulation. During the course of his hospitalization the patient developed lower gastrointestinal bleed and was found to be having a colonic carcinoma. The patient's general condition precluded anesthesia and surgery and he was treated with vancomycin and was planned for hospice care. Unfortunately the patient expired before hospice was set up. The incidence of infective endocarditis after permanent endocardial pacemaker (PM) implantation varies 0.13% to 7% in the reported literature 1 . Staphylococcus aureus, and Staphylococci epidermis account for upto 80% of the acute cases 2 This patient had his AICD placed more than 1 year ago. The high rate of relapse associated with PM - related

Novel Approach to Obtaining Vascular Access in Patients with Abandoned Endocardial Pacemaker and ICD Leads

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The Incidence of Reoperations in Pacemaker Recipients

To evaluate the incidence of reoperation due to complications or battery depletion in patients who underwent endocardial permanent pacemaker implantation during an 8-year period. All pacemaker implantation and related procedures from January 1996 to June 2003 were retrospectively collected and entered into a database. During this time period a total number of 3856 operations with 2242 primary implantations and 1614 redo operations were performed at our department. As 809 patients were referred from another hospital, where the primary operation was done, these patients were excluded from further analysis. The mean follow-up time was 48 months, ranging from 6 to 96 months. A total of 547 patients underwent 805 reoperations during this 8-year period. The most common cause for reoperation was lead malfunction, which occurred in 326 patients (8.4%). Atrial leads were affected more commonly (206 patients, 63%) than ventricular leads (120 patients, 37%). Eighty percent of lead failure occurred during the first 3 months after implantation and was due to dislocation of the lead, whereas the remaining 20% occurred more than 3 months after implantation and were caused by lead fracture, insulation failure, and exit block. Elective replacement indication of a pacemaker was necessary in 312 patients (8%), and pacemaker pocket erosion or infection required reoperation in 167 patients (4%). Permanent pacemaker implantation is now accepted as a highly effective and safe procedure. However, cost effectiveness and the relatively simple procedure have to be weighed against the need of reoperations due to system malfunction or replacement indication.

Applications, Complications, and Outcomes of Transvenous Pacemaker Implantation in 105 Dogs (1997–2002)

We reviewed the indications for age and breeds of dogs who received transvenous endocardial artificial pacemaker (AP) implantation (n = 105) and complications and survival thereafter at a single institution over a 6‐year period. A third‐degree atrioventricular (AV) block (59%) and sick sinus syndrome (SSS; 27%) were the most common indications, along with a high‐grade second‐degree AV block (9%) and atrial standstill (5%). The most common breeds identified were Labrador Retriever (n = 16; 11 with a third‐degree AV block), American Cocker Spaniel (n = 14; 10 with SSS), and Miniature Schnauzer (n = 13; all with SSS). Common presenting complaints were syncope (n = 66) and exercise intolerance or lethargy (n = 25). Half of the dogs (n = 52) had a history of acute onset of clinical signs (&lt; 2 weeks). Mean survival time for the 60 dogs who died during the study period was 2.2 years (range, 0.1–5.8 years). Major complications occurred in 13% of dogs and included lead displacement (n = 7), sensing problems that led to syncope (n = 3), infection at the pacemaker site (n = 1), bleeding (n = 1), and ventricular fibrillation during implantation (n = 1; successfully defibrillated). Minor complications occurred in 11 dogs (11%). The success rate of transvenous AP implantation was comparatively high (all dogs survived the first 48 hours), and the complication rate was comparatively low when compared with a previous multicenter study, most likely because of how commonly the procedure was performed and supervisory experience.

Late complete atriovenous block after percutaneous closure of a perimembranous ventricular septal defect

Percutaneous closure of a perimembranous ventricular septal defect (VSD) is an alternative to surgical closure. Complications include arrhythmias and in particular early postoperative complete atrioventricular (AV) block. We report the cases of two patients, aged 2.5 and 4 years, treated with an eccentric VSD occluder device whom developed complete AV block 4 and 12 months after the procedure. The first patient experienced syncope, while the second one was completely asymptomatic. Both subjects underwent endocardial ventricular pacemaker implantation.

An unexpected finding during gastroscopy

At the age of 3 years, the patient had undergone surgery for repair of an atrial septal defect and had an epicardial pacing system placed for congenital atrioventricular block. This was replaced with an endocardial dual chamber pacemaker at the age of 15 years. The epicardial pulse generator and leads were left in situ. Now aged 23 years old, the patient presented with a 48-hour history of right shoulder tip pain, palpitations, rigors and subsequent melaena. On examination she was pyrexic (40°C) with vague upper abdominal tenderness. She had no overt features of bacterial endocarditis. Her chest X-ray shows both the endocardial and epicardial pacing system in situ (Figure 1). Preliminary haematological investigations revealed a microcytic hypochromic anaemia (7.4 g/dl), neutrophilia (25x109/ml), an erythrocyte sedimentation rate of 121 mm/hr and a C-reactive protein of 272 mg/litre. Repeated blood cultures were negative. Transoesophageal echocardiography showed no evidence of valvular or pacemaker lead vegetations. Gastroscopy revealed the redundant epicardial pacemaker generator inside the stomach with evidence of gastric ulceration (Figure 2). After initial resuscitation with blood products and parenteral antibiotics she underwent surgery where through a gastrostomy the pulse generator was retrieved. At laparotomy the left lobe of the liver appeared unhealthy and subsequent computed tomography scan of the abdomen confirmed the presence of multiple intrahepatic abscesses (Figure 3). It was decided that the hepatic abscess were not suitable for percutaneous drainage as they were multiple and predominantly in the left lobe of the liver. She continued on a protracted course of intravenous antibiotics and made a full recovery thereafter.

Applications, Complications, and Outcomes of Transvenous Pacemaker Implantation in 105 Dogs (1997–2002)

We reviewed the indications for age and breeds of dogs who received transvenous endocardial artificial pacemaker (AP) implantation (n = 105) and complications and survival thereafter at a single institution over a 6-year period. A third-degree atrioventricular (AV) block (59%) and sick sinus syndrome (SSS; 27%) were the most common indications, along with a high-grade second-degree AV block (9%) and atrial standstill (5%). The most common breeds identified were Labrador Retriever (n = 16; 11 with a third-degree AV block), American Cocker Spaniel (n = 14; 10 with SSS), and Miniature Schnauzer (n = 13; all with SSS). Common presenting complaints were syncope (n = 66) and exercise intolerance or lethargy (n = 25). Half of the dogs (n = 52) had a history of acute onset of clinical signs (<2 weeks). Mean survival time for the 60 dogs who died during the study period was 2.2 years (range, 0.1-5.8 years). Major complications occurred in 13% of dogs and included lead displacement (n = 7), sensing problems that led to syncope (n = 3), infection at the pacemaker site (n = 1), bleeding (n = 1), and ventricular fibrillation during implantation (n = 1; successfully defibrillated). Minor complications occurred in 11 dogs (11%). The success rate of transvenous AP implantation was comparatively high (all dogs survived the first 48 hours), and the complication rate was comparatively low when compared with a previous multicenter study, most likely because of how commonly the procedure was performed and supervisory experience.

Gene Sequencing in Neonates and Infants with the Long QT Syndrome

The objective was to analyze the clinical and molecular findings in a cohort of neonates and infants with the autosomal dominant long QT syndrome (LQTS). Those affected face a high risk of ventricular arrhythmia resulting in syncope, seizure or sudden death. Blood samples submitted for molecular diagnostic studies on 7 infants were subject to DNA extraction and mutation analysis of 18 selected exons in 5 LQTS genes (KCNQ1, HERG, SCN5A, KCNE1, and KCNE2). We detected 11 mutations in these 7 patients. Four patients had 2 mutations in 1 gene (compound heterozygotes) or 2 different genes (digenic inheritance), while 3 patients had 1 mutation each. Except for 1 mutation in KCNE1, all other mutations were detected alone or in combination within HERG and the SCN5A genes. Four of the mutations we found are novel. The lethal nature of the LQTS demands careful attention to the family history and prompt and precise diagnosis and treatment with serious consideration of endocardial pacemaker implantation. While much larger studies are needed, our data suggest that compound heterozygotes or those with 2 mutations in different genes are likely to have a more severe LQTS including early manifestations in neonates and infants.

Left Ventricular Pacing Through the Anterior Interventricular Vein in a Patient With Mechanical Tricuspid, Aortic and Mitral Valves

Transvenous endocardial pacemaker implantation is contraindicated in patients after mechanical tricuspid valve replacement. A 76-year-old woman who suffered from bradyarrhythmia was implanted with a left ventricular pacing lead through a transvenous coronary vein after aortic, mitral, and tricuspid valve replacements. There were no complications and the stimulation thresholds were stable. The use of coronary vein leads provides a minimally invasive approach, safety, and effective stimulation for patients with a mechanical tricuspid valve.

Aspergillus pacemaker endocarditis presenting as pulmonary embolism

Pacemaker endocarditis (PME) is a rare but severe complication of endocardial pacemaker implantation. Fungal PME is extremely uncommon. The case of a 66-year-old female patient who was diagnosed as having a pulmonary embolus based upon the patient's clinical presentation and computed tomography angiography findings is presented. Transthoracic echocardiography demonstrated a huge vegetation attached to the pacemaker wire. The pacemaker system was removed surgically during cardiovascular bypass. The vegetation was cultured, the results of which were positive for Aspergillus spp. No risk factors for Aspergillus infection were found in the patient. She was treated with liposomal amphotericin B for 3 weeks, followed by itraconazole for 40 weeks. At 1 year later, the patient remains asymptomatic.

Septicémie récidivante après extraction incomplète de sondes de stimulateur cardiaque

Septicaemia on endocardial pacemaker leads is very rare but the presentation is insidious and the prognosis very bad if all the implanted materiel is not completely removed. A 55 year-old woman presented three episodes of Staphylococcus epidermidis septicaemia in three years, after incomplete removal of the pacing system. Permanent cure was finally obtained after complete removal of the pacemaker material. Emphasis must be placed on the difficulty in diagnosing and treating such affections, their severity and also the interest of a certain number of prophylactic measures.

Outcome of Right Ventricular Bifocal Pacing in Patients with Permanent Atrial Fibrillation and Severe Dilated Cardiomiopathy Due to Chagas Disease: Three Years of Follow-up

Several studies have shown that heart failure may benefit from cardiac resynchronization therapy (CRT). Studies have demonstrated a beneficial effect of right ventricular (RV) bifocal pacing, using two leads at different positions, in similar patient populations. The aim was to evaluate this approach in Chagas disease patients who developed both severe dilated cardiomiopathy and chronic atrial fibrillation. The study included 30 patients with a mean age of 52 +/- 6 years (16 male), who had atrioventricular block at functional class II or IV (NYHA). Patients underwent endocardial dual-chamber pacemaker implantation with two RV leads-one placed near the RV outflow tract and the other in the apex. Patients were examined by echocardiography, 24-hour Holter, and New York Heart Association (NYHA) class determination before and 3, 6, 12, 18, 24, and 36 months after CRT. Compared to the baseline, the left ventricular ejection fraction increased in the first month of CRT, the left ventricular end diastolic diameter decreased, all patients were downgraded to NYHA class I or II, and the incidence of ventricular arrhythmias decreased. However, these could not be maintained and worsened after 6 months CRT. There was a mortality rate of 43.3% during the first year, and only 23.3% of patients remained alive after 3 years. They underwent an electrophysiological study, which revealed complex arrhythmias justifying implantable cardioverter defibrillator (ICD) in six out of seven patients. The favorable effects of RV bifocal pacing could not be maintained beyond the first 6 months, likely due to the ventricular arrhythmias. Therefore, CRT combined with ICD from the outset may be recommended for this patient group.