Lead Placement (lead + placement)

Distribution by Scientific Domains

Kinds of Lead Placement

  • lv lead placement


  • Selected Abstracts


    Left Ventricular Endocardial Lead Placement Using a Modified Transseptal Approach

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 2 2004
    Ph.D., SEN JI M.D.
    Coronary sinus cannulation and placement of left ventricular (LV) leads can be difficult. Occasionally alternative approaches are required. We report the first case of a modified transseptal LV endocardial lead placement via the left axillary vein for cardiac resynchronization. (J Cardiovasc Electrophysiol, Vol. 15, pp. 234-236, February 2004) [source]


    Use of Radiofrequency Perforation for Lead Placement in Biventricular or Conventional Endocardial Pacing after Mustard or Senning Operations for D-Transposition of the Great Arteries

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2009
    SANTABHANU CHAKRABARTI M.D.
    Background: Endocardial pacemaker lead placement can be challenging after Mustard and Senning operations for transposition of the great arteries (D-TGA), if there is atresia of the systemic venous pathways and because the coronary sinus cannot be used for cardiac resynchronization therapy. Radiofrequency (RF)-assisted perforation techniques have been used in congenital heart disease but have not been reported for use in pacemaker implantation. Methods and Results: We describe RF perforation of an atretic superior systemic venous pathway and systemic venous baffles in three patients after Senning and Mustard operations to implant endocardial pacing systems to achieve conventional or biventricular pacing. Conclusions: RF-energy-assisted perforation is feasible and effective tool to facilitate endocardial lead placement during dual-chamber and biventricular pacemaker implantation in patients with Mustard or Senning operations for D-TGA. [source]


    Successful Balloon Dilatation of the Valve of Vieussens for Left Ventricular Lead Placement

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 6 2009
    CAN HASDEMIR M.D.
    Successful balloon dilatation of an obstructive valve of Vieussens for left ventricular lead placement is described in a case with severe left ventricular systolic dysfunction. [source]


    Upgrading Patients with Chronic Defibrillator Leads to a Biventricular System and Reducing Patient Risk: Contralateral LV Lead Placement

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2006
    DAVID J. FOX
    Increasing numbers of patients with indwelling single- or dual- chamber internal cardioverter defibrillators (ICDs) will require upgrading of an existing system to a biventricular ICD providing cardiac resynchronization with back-up defibrillation. Upgrading, usually by the addition of a new left ventricular (LV) lead, can be technically challenging with central venous occlusion or stenosis often being the main obstacle to a successful procedure. We report a new technique of implanting a LV lead from the contralateral side to the existing ICD system to minimize the peri- and postoperative risk to the patient. [source]


    Atrial Lead Placement During Atrial Fibrillation.

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 7 2000
    Is Restitution of Sinus Rhythm Required for Proper Lead Function?
    Unexpected atrial fibrillation (AF) during implantation of an atrial pacemaker lead is sometimes encountered. Infra-operative cardioversion may lengthen and complicate the implantation process. This study prospectively investigates the performance of atrial leads implanted during AF (group A) and compares atrial sensing and pacing properties to an age- and sex-matched control group in which sinus rhythm had been restored before atrial lead placement (group B). Patient groups consisted of 32 patients each. All patients received DDDE pacemakers and bipolar, steroid-elating, active fixation atrial leads. In patients with AF at the time of implantation (group A), a minimal intracardiac fibrillatory amplitude of at least 1.0 mV was required for acceptable atrial lead placement. In patients with restored sinus rhythm (group B). a voltage threshold < 1.5 V at 0.5 ms and a minimal atrial potential amplitude > 1.5 mV was required. Patients of group A in whom spontaneous conversion to sinus rhythm did not occur within 4 weeks after implantation underwent electrical cardioversion to sinus rhythm. Pacemaker interrogations were performed 3, 6, and 12 months after implantation. In group A, implantation time was significantly shorter as compared to group B (58.7 ± 8.6 minutes vs 73.0 ± 17.3 minutes, P < 0.001). Mean atrial potential amplitude during AF was correlated with the telemetered atrial potential during sinus rhythm (r = 0.49, P < 0.001), but not with the atrial stimulation threshold. Twelve months after implantation, sensing thresholds (1.74 ± 0.52 mV vs 1.78 ± 0.69 mV, P = 0.98) and stimulation thresholds (1.09 ± 0.42 V vs 1.01 ± 0.31 V.P = 0.66) did not differ between groups A and B. However, in three, patients of group A, chronic atrial sensing threshold was , 1 mV requiring atria) sensitivities of at least 0.35 mV to achieve reliable atrial sensing. Atrial lead placement during AF is feasible and reduces implantation time. However, bipolar atrial leads and the option to program high atrial sensitivities are required. [source]


    Resynchronization with Left Ventricle Lead Placement Through the Foramen Ovale

    CLINICAL CARDIOLOGY, Issue 6 2009
    Christophe D'Ivernois MD
    Left ventricle (LV) lead placement in a coronary sinus branch for cardiac resynchronization therapy may fail because of anatomical variants, phrenic nerve stimulation, and/or lead instability. We report a case of successful resynchronization from a lead inserted from the left subclavian vein and positioned through a patent foramen ovale (PFO). In conclusion, endocardial LV lead insertion through a PFO enables effective resynchronization delivery without the risks associated with a thoracotomy or atrial transseptal puncture. Copyright © 2009 Wiley Periodicals, Inc. [source]


    Temporary Epicardial Ventricular Stimulation in Patients with Atrial Fibrillation: Acute Effects of Ventricular Pacing Site on Bypass Graft Flows

    JOURNAL OF CARDIAC SURGERY, Issue 4 2009
    Navid Madershahian M.D.
    This study aimed to evaluate the optimal epicardial ventricular pacing site in patients with AF following coronary artery bypass surgery (CABG). Methods: In 23 consecutive patients (mean age = 69.2 ± 1.9 years, gender = 62% male, ejection fraction [EF]= 50.4 ± 2.1%) monoventricular stimulations (VVI) were tested with a constant pacing rate of 100 bpm. The impact of ventricular pacing on bypass graft flow (transit-time flow probe) and pulsatility index (PI) were measured after lead placement on the mid paraseptal region of the right (RVPS) and the left (LVPS) ventricle, on the right inferior wall (RVIW), and on the right ventricular outflow tract (RVOT). In addition, hemodynamic parameters were measured. Patients served as their own control. Results: Comparison of all tested pacing locations revealed that RVOT stimulation provided the highest bypass grafts flows (59.9 ± 6.1 mL/min) and PI (2.2 ± 0.1) when compared with RVPS (51.3 ± 4.7 mL/min, PI = 2.6 ± 0.2), RVIW (54.0 ± 5.1 mL/m; PI = 2.4 ± 0.2), and LVPS (53.1 ± 4.5 mL/min; PI = 2.3 ± 0.1), respectively (p < 0.05). When analyzing patients according to their preoperative LV function (group I = EF > 50%; group II = EF < 50%), higher bypass graft flows were observed with RVOT pacing in patients with lower EF (p = n.s.). Conclusions: Temporary RVOT pacing facilitates optimal bypass graft flows when compared with other ventricular pacing sites and should be the preferred method of temporary pacing in cardiac surgery patients with AF. Especially in patients with low EF following CABG, RVOT pacing may improve myocardial oxygen conditions for the ischemic myocardium and enhance graft patency in the early postoperative period. [source]


    Initial Clinical Experience with Cardiac Resynchronization Therapy Utilizing a Magnetic Navigation System

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 2 2007
    PETER GALLAGHER M.D.
    Introduction: The placement of left ventricular (LV) leads during cardiac resynchronization therapy (CRT) involves many technical difficulties. These difficulties increase procedural times and decrease procedural success rates. Methods and Results: A total of 50 patients with severe cardiomyopathy (mean LV ejection fraction was 21 ± 6%) and a wide QRS underwent CRT implantation. Magnetic navigation (Stereotaxis, Inc.) was used to position a magnet-tipped 0.014, guidewire (CronusÔ guidewire) within the coronary sinus (CS) vasculature. LV leads were placed in a lateral CS branch, either using a standard CS delivery sheath or using a "bare-wire" approach without a CS delivery sheath. The mean total procedure time was 98.1 ± 29.1 minutes with a mean fluoroscopy time of 22.7 ± 15.1 minutes. The mean LV lead positioning time was 10.4 ± 7.6 minutes. The use of a delivery sheath was associated with longer procedure times 98 ± 32 minutes vs 80 ± 18 minutes (P = 0.029), fluoroscopy times 23 ± 15 minutes vs 13 ± 4 minutes (P = 0.0007) and LV lead positioning times 10 ± 6 minutes vs 4 ± 2 minutes (P = 0.015) when compared to a "bare-wire" approach. When compared with 52 nonmagnetic-assisted control CRT cases, magnetic navigation reduced total LV lead positioning times (10.4 ± 7.6 minutes vs 18.6 ± 18.9 minutes; P = 0.005). If more than one CS branch vessel was tested, magnetic navigation was associated with significantly shorter times for LV lead placement (16.2 ± 7.7 minutes vs 36.4 ± 23.4 minutes; P = 0.004). Conclusions: Magnetic navigation is a safe, feasible, and efficient tool for lateral LV lead placement during CRT. Magnetic navigation during CRT allows for control of the tip direction of the CronusÔ 0.014, guidewire using either a standard CS delivery sheath or "bare-wire" approach. Although there are some important limitations to the 0.014, CronusÔ magnetic navigation can decrease LV lead placement times compared with nonmagnetic-assisted control CRT cases, particularly if multiple CS branches are to be tested. [source]


    Left Ventricular Endocardial Lead Placement Using a Modified Transseptal Approach

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 2 2004
    Ph.D., SEN JI M.D.
    Coronary sinus cannulation and placement of left ventricular (LV) leads can be difficult. Occasionally alternative approaches are required. We report the first case of a modified transseptal LV endocardial lead placement via the left axillary vein for cardiac resynchronization. (J Cardiovasc Electrophysiol, Vol. 15, pp. 234-236, February 2004) [source]


    Increase in Ventricular Tachycardia Frequency After Biventricular Implantable Cardioverter Defibrillator Upgrade

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 11 2003
    JOSE M. GUERRA M.D.
    We report the case of a patient in whom transvenous left ventricular pacing lead placement at the time of a biventricular upgrade led to an exacerbation of clinical monomorphic ventricular tachycardia (MVT). At implant, slow left ventricular pacing repeatedly induced sustained MVT. However, testing of the biventricular pacing showed no MVT inducibility, and the system was implanted. The patient was readmitted due to multiple episodes of the MVT observed at implant. The MVT was controlled with pharmacotherapy, allowing the patient to continue with biventricular pacing. (J Cardiovasc Electrophysiol, Vol. 14, pp. 1245-1247, November 2003) [source]


    Unilateral versus bilateral stage I neuromodulator lead placement for the treatment of refractory voiding dysfunction

    NEUROUROLOGY AND URODYNAMICS, Issue 8 2008
    Khanh Pham
    Abstract Aims To determine if bilateral S3 lead placement during the stage I trial period improves the "success" rate for advancing to stage II (permanent) sacral neuromodulator placement. Methods A retrospective chart review of 124 (20 male and 104 female) patients undergoing stage I sacral neuromodulation (InterStim®, Medtronic, Minneapolis, Minnesota) implantation for the treatment of refractory voiding dysfunction was performed. Patients were divided into two cohorts based on unilateral versus bilateral stage I lead placement in the S3 foramina. Both groups were then evaluated and compared with regards to overall "success", defined as progression from stage I to stage II placement. Results Fifty-five (44%) patients underwent unilateral stage I lead placement and 69 (56%) received bilateral S3 leads. Successful stage I trials were reported in 32/55 (58%) and 53/69 (76%) of unilateral and bilateral cohorts, respectively (P,=,0.03). Five wound infections were reported,2 (3.6%) following unilateral and 3 (4.3%) after bilateral stage I lead placement. No other complications were encountered. Conclusions Bilateral stage I neuromodulation trial provides a significantly higher rate of improvement in refractory voiding symptoms to allow for the progress to stage II implantation. Neurourol. Urodynam. 27:779,781, 2008, © 2008 Wiley-Liss, Inc. [source]


    Predicting implantation with a neuromodulator using two different test stimulation techniques: A prospective randomized study in urge incontinent women,

    NEUROUROLOGY AND URODYNAMICS, Issue 1 2007
    Kristy M. Borawski MD
    Abstract Aims The purpose of this study was to determine whether a percutaneous needle electrode (PNE) technique or a surgical first stage lead placement (FSLP) better predicted whether a patient would progress to implantation of a pulse generator (IPG) in older urge incontinent women. Methods Thirty subjects ,55 years with refractory urge incontinence who had been selected to undergo a test stimulation procedure were randomized to either PNE or FSLP. Thirteen underwent PNE placement and seventeen underwent FSLP placement. If during the test stimulation period subjects had greater than 50% improvement in their incontinence parameters they qualified for permanent lead and/or IPG implantation of the Interstim® device. Results Twenty-one subjects (70%) responded to the test stimulation and underwent implantation, 15/17 (88%) in the FSLP group and 6/13 (46%) in the PNE group. Subjects who were randomized to the FSLP group were significantly more likely to proceed to implantation of the IPG (P,=,0.02) than those in the PNE group. There was no significant difference in demographics, pre-test stimulation incontinence parameters or post-stimulation visual analog pain scores between the randomized groups or between test stimulation responders and non-responders. When comparing FSLP and PNE responders, there was no significant difference in the percent improvement in 24-hr pad weight, daily pad usage, or daily incontinence. Conclusion FSLP better predicted progression to implantation of the IPG than a test stimulation with a PNE in an older urge incontinent cohort. Neurourol. Urodynam. © 2006 Wiley-Liss, Inc. [source]


    Right Ventricular Septal Pacing: The Success of Stylet-Driven Active-Fixation Leads

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1 2010
    RAPHAEL ROSSO M.D.
    Background:The detrimental effects of right ventricular (RV) apical pacing on left ventricular function has driven interest in alternative pacing sites and in particular the mid RV septum and RV outflow tract (RVOT). RV septal lead positioning can be successfully achieved with a specifically shaped stylet and confirmed by the left anterior oblique (LAO) fluoroscopic projection. Such a projection is neither always used nor available during pacemaker implantation. The aim of this study was to evaluate how effective is the stylet-driven technique in septal lead placement guided only by posterior-anterior (PA) fluoroscopic view. Methods:One hundred consecutive patients with an indication for single- or dual-chamber pacing were enrolled. RV septal lead positioning was attempted in the PA projection only and confirmed by the LAO projection at the end of the procedure. Results:The RV lead position was septal in 90% of the patients. This included mid RV in 56 and RVOT in 34 patients. There were no significant differences in the mean stimulation threshold, R-wave sensing, and lead impedance between the two sites. In the RVOT, 97% (34/35) of leads were placed on the septum, whereas in the mid RV the value was 89% (56/63). Conclusions:The study confirms that conventional active-fixation pacing leads can be successfully and safely deployed onto the RV septum using a purposely-shaped stylet guided only by the PA fluoroscopic projection. (PACE 2010; 49,53) [source]


    Achieving Permanent Left Ventricular Pacing,Options and Choice

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 11 2009
    ERNEST W. LAU M.D.
    Cardiac resynchronization therapy (CRT) requires permanent left ventricular (LV) pacing. Coronary sinus (CS) lead placement is the first line clinical approach but can be difficult or impossible; may suffer from a high LV pacing threshold, phrenic nerve stimulation, and dislodgement; and produces epicardial LV pacing, which is less physiological and hemodynamically effective and potentially more proarrhythmic than endocardial LV pacing. CS leads can usually be extracted with direct traction but may require use of extraction sheaths. Half of CS side branches previously used for lead placement may be unusable for the same purpose after successful lead extraction, and 30% of CS lead reimplantation attempts may fail due to exhaustion of side branches. Surgical epicardial LV lead placement is the more invasive second line approach, produces epicardial LV pacing, and has a lead failure rate of ,15% in 5 years. Transseptal endocardial LV lead placement is the third line approach, can be difficult to achieve, but produces endocardial LV pacing. The major concern with transseptal endocardial LV leads is systemic thromboembolism, but the risk is unknown and oral anticoagulation is advised. Among the new CRT recipients in the United States and Western Europe between 2003 and 2007, 22,798 patients may require CS lead revisions, 9,119 patients may have no usable side branches for CS lead replacement, and 1,800 patients may require surgical epicardial LV lead revision in the next 5 years. The CRT community should actively explore and develop alternative approaches to LV pacing to meet this anticipated clinical demand. [source]


    Use of Radiofrequency Perforation for Lead Placement in Biventricular or Conventional Endocardial Pacing after Mustard or Senning Operations for D-Transposition of the Great Arteries

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2009
    SANTABHANU CHAKRABARTI M.D.
    Background: Endocardial pacemaker lead placement can be challenging after Mustard and Senning operations for transposition of the great arteries (D-TGA), if there is atresia of the systemic venous pathways and because the coronary sinus cannot be used for cardiac resynchronization therapy. Radiofrequency (RF)-assisted perforation techniques have been used in congenital heart disease but have not been reported for use in pacemaker implantation. Methods and Results: We describe RF perforation of an atretic superior systemic venous pathway and systemic venous baffles in three patients after Senning and Mustard operations to implant endocardial pacing systems to achieve conventional or biventricular pacing. Conclusions: RF-energy-assisted perforation is feasible and effective tool to facilitate endocardial lead placement during dual-chamber and biventricular pacemaker implantation in patients with Mustard or Senning operations for D-TGA. [source]


    Successful Balloon Dilatation of the Valve of Vieussens for Left Ventricular Lead Placement

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 6 2009
    CAN HASDEMIR M.D.
    Successful balloon dilatation of an obstructive valve of Vieussens for left ventricular lead placement is described in a case with severe left ventricular systolic dysfunction. [source]


    Electroanatomical Mapping in Partial Atrial Standstill for Visualization of Atrial Viability and a Suitable Pacing Site

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 4 2008
    TAKANORI ARIMOTO M.D.
    Partial atrial standstill is characterized by the failure of atrial activity either spontaneously or in response to electrical stimulation in restricted site of atria. In this case with bradycardia, atrial standstill was restricted to the lateral and posterior right atrium. The markedly prolonged intraatrial conduction delay was observed in the superior to septal region of the right atrium. The electroanatomical mapping was successfully utilized to estimate atrial activity and to find a suitable site for atrial lead placement. The electroanatomical mapping may become an innovated strategy to estimate atrial electrical status in partial atrial standstill. [source]


    Innovative Techniques for Placement of Implantable Cardioverter-Defibrillator Leads in Patients with Limited Venous Access to the Heart

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2 2006
    BRYAN C. CANNON
    Background: Because of venous occlusion, intracardiac shunting, previous surgery, or small size placement of implantable cardioverter-defibrillator (ICD) leads may not be possible using traditional methods. The purpose of this study was to evaluate and describe innovative methods of placing ICD leads. Methods: The records of all patients undergoing ICD implantation at our institution were reviewed to identify patients with nontraditional lead placement. Indications for ICD, method of lead and coil placement, defibrillation thresholds, complications, and follow-up results were reviewed retrospectively. Results: Eight patients (aged 11 months to 29 years) were identified. Six patients with limited venous access to the heart (four extracardiac Fontan, one bidirectional Glenn, one 8 kg 11-month-old) underwent surgical placement of an ICD coil directly into the pericardial sac. A second bipolar lead was placed on the ventricle for sensing and pacing. Two patients with difficult venous access had a standard transvenous ICD lead inserted directly into the right atrium (transatrial approach) and then positioned into the ventricle. All patients had a defibrillation threshold of <20 J, although one patient required placement of a second coil due to an elevated threshold. There have been no complications and two successful appropriate ICD discharges at follow-up (median 22 months, range 5,42 months). Conclusions: Many factors may prohibit transvenous ICD lead placement. Nontraditional surgical placement of subcutaneous ICD leads on the pericardium or the use of a transatrial approach can be effective techniques in these patients. These procedures can be performed at low risk to the patient with excellent defibrillation thresholds. [source]


    Balloon Occlusion Technique to Cannulate Angulated and Tortuous Coronary Sinus Branches in Cardiac Resynchronization Therapy

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 11 2005
    THOMAS H. MEADE
    We present two cases that demonstrate a new technique to cannulate angulated and tortuous coronary sinus branches during left ventricular lead placement for cardiac resynchronization therapy. The technique uses an occlusive pulmonary artery balloon just beyond the takeoff of the coronary sinus branch to assist in the cannulation of the branch. [source]


    Implant Experience with an Implantable Hemodynamic Monitor for the Management of Symptomatic Heart Failure

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 8 2005
    DAVID STEINHAUS
    Introduction: Management of congestive heart failure is a serious public health problem. The use of implantable hemodynamic monitors (IHMs) may assist in this management by providing continuous ambulatory filling pressure status for optimal volume management. Methods and Results: The Chronicle® system includes an implanted monitor, a pressure sensor lead with passive fixation, an external pressure reference (EPR), and data retrieval and viewing components. The tip of the lead is placed near the right ventricular outflow tract to minimize risk of sensor tissue encapsulation. Implant technique and lead placement is similar to that of a permanent pacemaker. After the system had been successfully implanted in 148 patients, the type and frequency of implant-related adverse events were similar to a single-chamber pacemaker implant. R-wave amplitude was 15.2 ± 6.7 mV and the pressure waveform signal was acceptable in all but two patients in whom presence of artifacts required lead repositioning. Implant procedure time was not influenced by experience, remaining constant throughout the study. Conclusion: Based on this evaluation, permanent placement of an IHM in symptomatic heart failure patients is technically feasible. Further investigation is warranted to evaluate the use of the continuous hemodynamic data in management of heart failure patients. [source]


    Colonic Perforation Following Intraoperative Temporary Pacemaker Implantation

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 4p1 2003
    PARIND M. OZA
    OZA, P.M., et al.: Colonic Perforation Following Intraoperative Temporary Pacemaker Implantation. This report describes the case of a 73-year-old man who was referred for consultation for increasing abdominal free air 1 week after he underwent surgery for aortic valve replacement and coronary artery bypass grafting with intraoperative pacemaker implantation. Laparoscopic exploration revealed that the pacemaker wires had passed through the left transverse colon. Although no previous reports of colonic perforation due to pacemaker lead placement was found, this experience suggests that physicians should suspect this complication in patients with increasing free intraabdominal air and peritoneal signs who have recently undergone placement of a temporary cardiac pacing system. (PACE 2003; 26[Pt. I]:918,919) [source]


    Biventricular Pacing Using Two Pacemakers and the Triggered VVT Mode

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 8 2001
    BRENDAN O'COCHLAIN
    O'COCHLAIN, B., et al.: Biventricular Pacing Using Two Pacemakers and the Triggered VVT Mode. Pacemaker dependent patients exhibit interventricular conduction delay due to right ventricular lead placement. The addition of a transvenous coronary sinus lead for biventricular pacing has been shown to be effective. Venous stenosis and thrombosis postpacemaker implantation can occur in up to 35% of patients. This report describes a patient with a preexisting left-sided dual chamber pacemaker and chronic left subclavian vein occlusion that was upgraded to a biventricular system by placing a coronary sinus lead and single chamber ventricular triggered pacemaker on the opposite side. [source]


    Atrial Lead Placement During Atrial Fibrillation.

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 7 2000
    Is Restitution of Sinus Rhythm Required for Proper Lead Function?
    Unexpected atrial fibrillation (AF) during implantation of an atrial pacemaker lead is sometimes encountered. Infra-operative cardioversion may lengthen and complicate the implantation process. This study prospectively investigates the performance of atrial leads implanted during AF (group A) and compares atrial sensing and pacing properties to an age- and sex-matched control group in which sinus rhythm had been restored before atrial lead placement (group B). Patient groups consisted of 32 patients each. All patients received DDDE pacemakers and bipolar, steroid-elating, active fixation atrial leads. In patients with AF at the time of implantation (group A), a minimal intracardiac fibrillatory amplitude of at least 1.0 mV was required for acceptable atrial lead placement. In patients with restored sinus rhythm (group B). a voltage threshold < 1.5 V at 0.5 ms and a minimal atrial potential amplitude > 1.5 mV was required. Patients of group A in whom spontaneous conversion to sinus rhythm did not occur within 4 weeks after implantation underwent electrical cardioversion to sinus rhythm. Pacemaker interrogations were performed 3, 6, and 12 months after implantation. In group A, implantation time was significantly shorter as compared to group B (58.7 ± 8.6 minutes vs 73.0 ± 17.3 minutes, P < 0.001). Mean atrial potential amplitude during AF was correlated with the telemetered atrial potential during sinus rhythm (r = 0.49, P < 0.001), but not with the atrial stimulation threshold. Twelve months after implantation, sensing thresholds (1.74 ± 0.52 mV vs 1.78 ± 0.69 mV, P = 0.98) and stimulation thresholds (1.09 ± 0.42 V vs 1.01 ± 0.31 V.P = 0.66) did not differ between groups A and B. However, in three, patients of group A, chronic atrial sensing threshold was , 1 mV requiring atria) sensitivities of at least 0.35 mV to achieve reliable atrial sensing. Atrial lead placement during AF is feasible and reduces implantation time. However, bipolar atrial leads and the option to program high atrial sensitivities are required. [source]


    Technical Mistakes during the Acquisition of the Electrocardiogram

    ANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 4 2009
    Javier García-Niebla R.N.
    In addition to knowledge of normal and pathological patterns, the correct interpretation of electrocardiographic (ECG) recordings requires the use of acquisition procedures according to approved standards. Most manuals on standard electrocardiography devote little attention to inadequate ECG recordings. In this article, we present the most frequent ECG patterns resulting from errors in limb and precordial lead placement, artifacts in 12-lead ECG as well as inadequate filter application; we also review alternative systems to the standard ECG, which may help minimize errors. [source]


    Predictive factors for successful sacral nerve stimulation in the treatment of faecal incontinence: a 10-year cohort analysis

    COLORECTAL DISEASE, Issue 3 2008
    T. C. Dudding
    Abstract Objective, Sacral nerve stimulation (SNS) is an established treatment for faecal incontinence. We aimed to identify specific factors that could predict the outcome of temporary and permanent stimulation. Method, A cohort analysis was performed to identify potential predictive factors in 81 patients who underwent temporary SNS at a single institution over a 10-year period (June 1996 to June 2006). Data were obtained from prospectively collected patient symptom diaries and quality of life questionnaires, operation reports, anorectal physiological studies, endoanal ultrasound images and radiology of lead placement. Results, Clinical outcome of temporary screening was not affected by patient gender, age, body mass index, severity or length of symptoms. The need for a repeated temporary procedure was associated with subsequent failure during screening (P = 0.008). A low threshold to obtain a motor response during temporary lead insertion was associated with improved outcome (P = 0.048). Evidence of anal sphincter trauma was associated with a greater risk of failure (P = 0.040). However, there was no difference in medium-term outcome between patients with external anal sphincter (EAS) defects and patients with intact anal sphincter muscles. Conclusion, Variables have been identified that help to predict the outcome of SNS. The presence of an EAS defect should not preclude treatment. [source]