Ventricular pacemaker upgrade: experience, complications and recommendations

Spontaneous Sinus Rhythm Restoration in Patients With Refractory, Permanent Atrial Fibrillation Who Underwent Conduction System Pacing and Atrioventricular Junction Ablation

Ablate and pace (A&P) with conduction system pacing (CSP) improves outcomes in patients with symptomatic permanent atrial fibrillation (AF). Data on spontaneous sinus rhythm restoration (SSRR) in this setting are lacking. This study aimed to assess the incidence and the predictors of SSRR in a population of patients with permanent AF who underwent A&P with CSP. Prospective, observational study, enrolling consecutive patients with symptomatic permanent AF (of documented duration >6 months) and uncontrolled, drug-refractory high ventricular rate, who underwent A&P with CSP. The incidence and predictors of SSRR were prospectively assessed. A total of 107 patients (79.0 ± 9.1 years, 33.6% male, 74.8% with New York Heart Association class ≥III, 56.1% with ejection fraction <40%) were enrolled: 40 received His' bundle pacing, 67 left bundle branch area pacing. During a median follow-up of 12 months SSRR was observed in 14 patients (13.1%), occurring a median of 3 months after A&P (interquartile range 1 to 6; range 0 to 17). Multivariable analysis identified a duration of permanent AF <12 months (hazard ratio 7.7, p = 0.040) and a left atrial volume index <49 ml/m2 (hazard ratio 14.8, p = 0.008) as independent predictors of SSRR. In patients with coexistence of both predictors the incidence of SSRR was of 41.4%. In a population of patients with symptomatic, permanent AF, treated with A&P with CSP, SSRR was observed in 13% of patients during follow-up. A duration of permanent AF <12 months and a left atrial volume index <49 ml/m2 were independent predictors of this phenomenon.

Consensus statement for implantation and follow-up of cardiac implantable electronic devices in India

Cardiac implantable electronic device (CIED) procedures are being done by many operators/centers and it is projected that this therapy will remarkably increase in India in the coming years. This document by IHRS, aims at guiding the Indian medical community in the appropriate use and method of implantation with emphasis on implanter training and center preparedness to deliver a safe and effective therapy to patients with cardiac rhythm disorders and heart failure.

Caudal fluoroscopy to guide venous access for pacemaker device implantation: should this now be standard practice?

We describe a technique that uses both posterior-anterior and caudal fluoroscopy to achieve venous access for pacemaker device implantation. A significant advantage of this technique is the ability to clearly demarcate both the anatomy of venous drainage and the lung border. We would encourage all centres to adopt this technique as a safe approach to venous access.

Detect Long-term Complications After ICD Replacement (DECODE): Rationale and Study Design of a Multicenter Italian Registry

The replacement of implantable cardioverter-defibrillators (ICDs) may give rise to considerable clinical consequences, the importance of which is underrated by the medical community. Replacement-related adverse events are difficult to identify and require monitoring of both short-term complications and long-term patient outcome. The aim of this study is to perform a structured evaluation of both short- and long-term adverse events and a cost analysis of consecutive ICD replacement procedures. Detect Long-term Complications After ICD Replacement (DECODE) is a prospective, single-arm, multicenter cohort study designed to estimate long-term complication rates (at 12 months and 5 years) in patients undergoing ICD generator replacement. The study will also evaluate predictors of complications, patient management before and during the replacement procedure in clinical practice, and the costs related to use of health care resources. About 800 consecutive patients with standard indications for ICD generator replacement will be enrolled in this study. The decision to undertake generator replacement/upgrade will be made according to the investigators' own judgment (which will be recorded). Patients will be followed for 60 months through periodic in-hospital examinations or remote monitoring. Detailed data on complications related to ICD replacement in current clinical practice are still lacking. The analysis of adverse events will reveal the value of new preventive strategies, thereby yielding both clinical and economic benefits. Moreover, assessment of complication rates after ICD replacement in a real-life setting will help estimate the actual long-term cost of ICD therapy and assess the real impact of increasing ICD longevity on cost-effectiveness.

Pacemaker insertion

A pacemaker (PM) (or artificial PM, so as not to be confused with the heart's natural PM) is a medical device that uses electrical impulses, delivered by electrodes contracting the heart muscles, to regulate the beating of the heart. The primary purpose of this device is to maintain an adequate heart rate, either because the heart's natural PM is not fast enough, or there is a block in the heart's electrical conduction system. Modern PMs are externally programmable and allow the cardiologist to select the optimum pacing modes for individual patients. Some combine a PM and defibrillator in a single implantable device. PMs can be temporary or permanent. Temporary PMs are used to treat short-term heart problems, such as a slow heartbeat that's caused by a heart attack, heart surgery, or an overdose of medicine. Permanent PMs are used to control long-term heart rhythm problems. A PM can relieve some arrhythmia symptoms, such as fatigue and fainting. A PM also can help a person who has abnormal HRs resume a more active lifestyle. In the current mini review we will focus on the insertion of a PM and the possible pneumothorax that can be caused.

Complication Rates Associated With Pacemaker or Implantable Cardioverter-Defibrillator Generator Replacements and Upgrade Procedures

Background—

Prospective studies defining the risk associated with pacemaker or implantable cardioverter-defibrillator replacement surgeries do not exist. These procedures are generally considered low risk despite results from recent retrospective series reporting higher rates.

Methods and Results—

We prospectively assessed predefined procedure-related complication rates associated with elective pacemaker or implantable cardioverter-defibrillator generator replacements over 6 months of follow-up. Two groups were studied: those without (cohort 1) and those with (cohort 2) a planned transvenous lead addition for replacement or upgrade to a device capable of additional therapies. Complications were adjudicated by an independent events committee. Seventy-two US academic and private practice centers participated. Major complications occurred in 4.0% (95% confidence interval, 2.9 to 5.4) of 1031 cohort 1 patients and 15.3% (95% confidence interval, 12.7 to 18.1) of 713 cohort 2 patients. In both cohorts, major complications were higher with implantable cardioverter-defibrillator compared with pacemaker generator replacements. Complications were highest in patients who had an upgrade to or a revised cardiac resynchronization therapy device (18.7%; 95% confidence interval, 15.1 to 22.6). No periprocedural deaths occurred in either cohort, although 8 later procedure-related deaths occurred in cohort 2. The 6-month infection rates were 1.4% (95% confidence interval, 0.7 to 2.3) and 1.1% (95% confidence interval, 0.5 to 2.2) for cohorts 1 and 2, respectively.

Conclusions—

Pacemaker and implantable cardioverter-defibrillator generator replacements are associated with a notable complication risk, particularly those with lead additions. These data support careful decision making before device replacement, when managing device advisories, and when considering upgrades to more complex systems.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00395447.

The Incidence of Reoperations in Pacemaker Recipients

OBJECTIVE

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.

METHODS

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.

RESULTS

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%).

CONCLUSION

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.

[Pacemaker longevity. Replacement of the device]

Life expectancy of patients implanted with cardiac pacemakers has largely increased, so that generator replacement is becoming an important part of the activity in most of the implanting centers. In more than 70% of the cases, the indication for pacemaker replacement is normal battery depletion. Since the new devices are more and more sophisticated and smaller, longevity optimization becomes a real challenge. The main determinant of pacemaker longevity is the output programmed for the pulse generator. It mainly depends on the output voltage and duration settings. The pacing impedance and the percentage of time with pacing are other major determinants of pacemaker longevity. Each manufacturer provides specific policy but the battery voltage and internal impedance are the more accurate and easy-to-obtain battery depletion parameters. The magnet rate is still frequently used but is less valuable since it can drop abruptly at the end of battery life. The complication rate of pacemaker replacement is three-fold higher than the one of first implant. Infections, skin erosions and lead related complications are not uncommon. The replacement should be systematically preceded by the checking of several points including the patient's pacemaker dependency, the necessity to replace or extract one or several leads, the venous system status, the compatibility between the new generator and the leads and the necessity to upgrade the pacing system or to change the pacemaker pocket.

Pocket Hematoma After Pacemaker or Implantable Cardioverter Defibrillator Surgery

STUDY OBJECTIVES

Pocket hematoma is a common complication after pacemaker or implantable cardioverter defibrillator (ICD) implantation. Thus, we investigated the influence of patient comorbidity, implantation strategy, operator experience, antiplatelet therapy, and anticoagulation therapy on hematoma rate.

DESIGN

Between 1990 and 2002, a total of 3,164 devices (pectoral pacemakers, 2,792; ICDs, 372) were implanted at our institution. Predictors of hematoma occurrence were determined prospectively and were analyzed by multivariate regression analysis. Operator experience was graded by individual implantation number, as follows: low, < 50; medium, 50 to 100; and high, > 100.

RESULTS

The incidence of pocket hematoma was 4.9%, leading to prolonged hospitalization in 2.0% of all patients. Reoperation for pocket hematoma was required in 1.0% of patients. High-dose heparinization (hazard ratio [HR], 4.2), combined acetylsalicylic acid (ASA)/thienopyridine treatment after coronary stenting (HR, 5.2), and low operator experience (HR, 1.6) were independently predictive of hematoma development. Therapy with ASA alone did not increase the hematoma rate compared to patients who did receive antiplatelet or anticoagulation therapy (3.1% vs 2.5%, respectively; difference not significant). In patients with nonvalvular atrial fibrillation, postoperative high-dose heparinization substantially increased the hematoma rate (10.7% vs 2.9%, respectively; p < 0.001) without reducing the rate of arterial embolism within the first month after implantation (0.18% vs 0.21%, respectively; difference not significant). The infection rate (0.28% within 3 months after implantation) was not influenced by the presence of the pocket hematoma.

CONCLUSIONS

The use of high-dose heparinization and combined ASA/thienopyridine treatment are highly predictive for the occurrence of intraoperative bleeding and pocket hematoma in patients who have undergone pacemaker and ICD surgery. We propose recommendations for the management of antiplatelet and anticoagulation therapy in patients undergoing these interventions.

Upgrade of Single Chamber Pacemakers with Transvenous Leads to Dual Chamber Pacemakers in Pediatric and Young Adult Patients

Children with single chamber pacemakers, in adolescence and young adulthood, may be upgraded to dual chamber systems, but there are no published data about indications, timing, and complications. Upgrading was attempted in 18 patients with transvenous pacing leads. A retrospective analysis of all collected data was performed. At initial pacemaker implantation (mean +/- SD, 9.3 +/- 4.1 years), the pacing mode was VVIR (n = 13 patients) and AAI/AAIR (n = 5 patients). After 72 +/- 41 months of follow-up, at the age of 15.5 +/- 5.2 years, upgrade was undertaken because of the patient's age at elective generator replacement (n = 3 patients), ventricular dysfunction (n = 7), syncope/presyncope (n = 3) in patients with VVIR pacing, atrioventricular block (n = 2), and/or drug refractory supraventricular tachyarrhythmias (n = 4) in patients with atrial pacing. In comparison with single chamber pacemaker implantations, the average procedural time and the average fluoroscopy time were not significantly longer. All suitable preexisting leads were incorporated in the new pacing system. Leads were inserted via the ipsilateral subclavian vein in 16 patients. Venous occlusion was found in two patients: in the first the procedure was not performed; in the second, the contralateral vein was used and the old lead was abandoned. There were no procedural complications. During a follow-up of 14 +/- 11 months, ventricular dysfunction worsened in five of seven patients; other patients benefitted symptomatically. In conclusion, pacemaker upgrade is technically challenging but feasible and safe and may be beneficial for some patients.

Pneumothorax resulting from subclavian puncture: a complication of permanent pacemaker lead implantation

Pneumothorax is a mild complication during pacemaker lead implantation using the subclavian puncture technique. We report on five-year experience in 433 pacemaker lead implantation procedures in 379 patients. The cephalic vein route was solely used in twelve patients. Three procedures were performed over time in four patients and one patient needed four repetitive punctures for pacemaker lead implantation and replacement. Thus 421 punctures were carried out in 367 patients. Eleven case of pneumothorax were observed: in eight patients (1.9%) a partial pneumothorax occurred and in three patients (0.7%) the pneumothorax was nearly complete. In the latter patients a chest tube was inserted and hospital admission was prolonged for 3, 6 and 6 days, respectively. Old age with a corresponding abnormality in the form of chest deformation were predominantly found in the patients with this type of complication.

Permanent Pacemakers:. Should Straightened Atrial Leads Be Repositioned?

The aim of this study was to assess if atrial leads whose "J" configuration has straightened significantly on the postprocedural chest X ray should be repositioned. Between January 1996 and December 1997, 445 patients underwent dual chamber pacemaker implantation at the Papworth Hospital. Postprocedural chest X rays were available in 410 of these. The degree of straightening of the tip of the atrial lead was assessed from the lateral chest X ray and was graded as mild (-10 to +10 degrees from the horizontal), moderate (+10 to +30 degrees), or severe (> or = +30 degrees). Patients were followed with regard to atrial sensing and pacing characteristics, lead displacements, and lead revisions. Fifty-two (12%) patients had some degree of straightening (graded mild, moderate, severe) of the atrial lead on the postprocedure chest X ray (passive fixation in 48, active 4). Of these, 12 patients underwent next day lead repositioning, 5 of whom had abnormalities of pacing and/or sensing parameters. Seven patients therefore underwent repositioning of the atrial lead despite normal pacing parameters in view of lead straightening alone. Of the 12 patients who underwent repositioning, 3 still had lead straightening after the second procedure. The cohort for follow-up consisted of 43 patients (24 [56%] men, age 69 +/- 11 years at the time of implant) who were left with significant atrial lead straightening but adequate atrial parameters. Straightening was mild in 26 patients, moderate in 10, and severe in 7 patients. At implant the P wave amplitude was 4.8 +/- 2.4 mV. Follow-up was for 4.8 +/- 2.1 years, a total of 178 patient years. At final follow-up, the P wave amplitude was 2.7 +/- 1.3 (P < 0.05 vs implant). Censoring events occurred in 16 cases, comprising 11 deaths (none suspected to be pacemaker or lead related), 3 cases of persistent atrial fibrillation, 1 system extraction for infection, and 1 lead extraction for erosion. There were no cases of inadequate atrial lead sensing or pacing in the remaining patients. Irrespective of the degree of lead straightening on the postoperative lateral chest X ray, atrial leads should not be repositioned unless there are abnormalities of pacing or sensing parameters.

Single versus dual chamber pacing in the young: noninvasive comparative evaluation of cardiac function

The advantages of atrial synchrony over asynchronous ventricular pacing remain unclear in the young, chronically right ventricular (RV) - paced patient. This is in contrast to the older patient with inherent diastolic dysfunction who has been shown to benefit from atrial synchrony with dual chamber (DDD,R/VDD), over single chamber rate response (VVI,R) ventricular pacing. The goal of this study was to noninvasively assess cardiac function in a group of young, RV-paced patients before and after establishment of atrial synchrony. Echocardiographic data were retrospectively analyzed from 10 patients with congenital or acquired complete AV block, who were VVI,R paced for 10.2 +/- 2 years (mean age at study 19.2 +/- 8.9 years), and were subsequently converted to DDD,R/VDD pacing (mean age at study 20.7 +/- 9.5 years). Paired t-test analysis of left ventricular (LV) systolic and diastolic function during VVI,R versus DDD,R/VDD pacing did not result in any short-term difference in LV short axis fractional area of change or FAC (53% +/- 7.5% vs 56.8% +/- 8.7%) or mitral maximal velocity (E) normalized to mitral flow velocity time integral (VTI) (5.2/s +/- 1.5 vs 4.4/s +/- 1.5). A decrease in mitral flow E/A ratio was observed after short-term DDD,R/VDD pacing (2.2 +/- 0.5 vs 1.9 +/- 0.3). Atrial synchronous dual chamber pacing in young patients with complete AV block does not lead to any appreciable early change in global LV function over single-site RV pacing. Therefore, early establishment of atrial synchrony in the young asymptomatic VVI,R-paced patient with normal intrinsic ventricular function may not be warranted.

Atrioventricular block and problems with atrioventricular conduction

This chapter has summarized briefly the current state of our knowledge on the incidence, etiology, presentation, investigation, and management of patients with AV block. The scope of the material covered has been widened intentionally to include a plethora of AV-conduction abnormalities because of the increases in the understanding of their clinical importance and contribution to left ventricular dysfunction. Under this heading, the critical importance of heart rate, maintenance of AV synchrony, and the sequence of ventricular activation and relaxation have been introduced and summarized briefly. The authors make a strong plea that, in the future, the reader consider AV-conduction abnormalities to be the parent topic, with the more-traditional, narrower subject of AV block forming a subunit thereof.