Choice Of Pacing Mode Research Articles

Operator and center characteristics, and choice of pacing mode

Operator and center characteristics, and choice of pacing mode

20 Appropriate Use of Single-Chamber Ventricular Pacing in a Large DGH – Are we Selecting the Right Patients?

Introduction In the UK, significant numbers of patients are treated with single-chamber ventricular pacing (VVI/R) for bradycardia indications, despite being in sinus rhythm. We evaluated the profile and outcomes of such patients at our institution. We demonstrate that when this mode of pacing is selectively chosen it is effective and well tolerated. Methods Electronic records at Ipswich Hospital NHS Trust from January 2010 to October 2013 were reviewed to identify the total number of new implants, and the underlying rhythm in those receiving VVI/Rs. Records of patients not in chronic atrial fibrillation (AF) were reviewed further to identify reasons for VVI/R implant, whether they developed AF, experienced symptoms of pacemaker syndrome or required an upgrade. Results Table 1 outlines the number and type of new pacemakers implanted, as well as the compliance with NICE guidelines. The three patients falling outside of NICE guidelines were intended to have DDD/R implants but operators were unable to position an atrial lead successfully. Of the remaining 38 patients in sinus rhythm, the choice of pacing mode was influenced by a combination of frailty, limited mobility, age and comorbidities (see Figure 1). The most common indication was atrioventricular block, the mean patient age was 91 (range 80 to 101), and the mean follow up period was 10 months (max. 43) with an expected drop out due to mortality. In those selected for VVI/R there were two new instances of paroxysmal AF and one patient experienced dizziness, which may have been attributable to her pacemaker (one possible mild pacemaker syndrome). In those with failed atrial lead placement, one patient with a prior history of paroxysmal AF developed persistent AF. No patients required a pacemaker upgrade (see Table 2). Conclusions In our institution, 14.6% of the patients treated with VVI/Rs were in sinus rhythm, which extrapolates to approximately 1,500 patients across England and Wales each year. 70% of the patients we selected for such a treatment strategy were over 90 years of age, and all had multiple additional influential factors. We demonstrate a low incidence of further symptoms, pacemaker syndrome and atrial fibrillation. In appropriately selected patients, simple VVI pacing is effective and well tolerated.

Spanish Pacemaker Registry. Ninth Official Report of the Spanish Society of Cardiology Working Group on Cardiac Pacing (2011)

Introduction and objectivesTo describe the results of the analysis of pacemaker implantations reported to the Spanish Pacemaker Registry in 2011, with particular reference to the population distribution and the selection of pacing modes. MethodsInformation provided by the European Pacemaker Patient Identification Card was processed using a purpose-built computer application. ResultsData from 115 hospitals were analyzed, totaling 13 373 cards, representing an estimated 38% of implantations. The number of pacemaker generators and resynchronization devices implanted was 738 and 56.2 units per million population, respectively. The mean age of the patients who received a device was 76.7 years. Overall, 57.2% of first implantations and 56.5% of replacements were performed in men. Most implantations (38.7%) and generator replacements (41.9%) were performed in patients aged between 80 and 89 years. Of the pacemaker leads used, 99.7% were bipolar and 63% used an active fixation system. Overall, 20% of the patients with atrioventricular block or sick sinus syndrome were paced in VVI/R mode despite being in sinus rhythm. ConclusionsWith respect to previous years, the use of conventional pacemakers remained stable and the implantation of resynchronization devices has increased. The number of implantation procedures continues to be higher in men and in younger patients. Age and the degree of blockage remain as factors influencing the appropriate choice of pacing mode.

Spanish Pacemaker Registry. 6 th Official Report of the Spanish Society of Cardiology Working Group on Cardiac Pacing (2008)

This article describes the findings of an analysis of data on pacemaker implantations and replacements reported to the Spanish Pacemaker Registry during 2008. The data came primarily from information recorded on European Pacemaker Patient Identification Cards. Data were received from 116 hospital units, which submitted a total of 11,855 identification cards representing 36.3% of all pacemakers implanted. There was a marked increase in the number of pacemaker units used, which rose to a rate of 708.3 per million inhabitants. The frequency of pacemaker implantation increased and the mean age of male patients decreased. The largest number of implantations were carried out in patients in their 70s, who comprised 39.1% of the total. The most frequent electrocardiographic indication was atrioventricular block. With regard to pacing leads, active fixation leads were used in the atrium in 59.3% of cases and in the ventricle in 37.9% of cases. There was an improvement in the choice of pacing mode, with age being a determining factor. For example, in sick sinus syndrome, the VVI/R mode was used in a 29% of patients aged over 80 years compared with 14% of those aged under 80 years. Age was found to be one factor influencing the selection of the most appropriate pacing mode. Active fixation leads were used more often, reaching 44.5% of leads implanted. Atrioventricular pacing was used in a greater percentage of cases than in any other time period covered by the pacemaker registry.

Choice of pacing mode in children: indications and results

The choice of the optimal mode for pacing in children depends on the age of the child and the indication. Ventricular demand pacing offers the advantage of simplicity and is ideal as a safety measure for children who have paroxysmal abnormalities. In the rate responsive ventricular pacing mode (VVIR) the pacing rate is adjusted automatically by an additional sensor that detects activity. Due to the potential risk of late venous thrombosis in young children, it is our policy to implant VVIR units in children less than 20kg who have atrioventricular (AV) block and normal heart structures, and to upgrade them to dual chamber units when the generator has to be replaced. The results of VVIR pacing are good and children have a normal level of exercise. The atrial demand mode (AAI) is indicated in children who present with symptoms related to sinus bradycardia, which is usually the consequence of atrial surgery. AAI pacing alone is selected when patients have satisfactory sinus acceleration and normal AV conduction at exercise; AAIR pacing is considered in those with permanent chronotropic incompetence. As the sinus node is the best sensor to increase the ventricular rate, atrial sensing ventricular pacemakers (DDD mode) are the best choice for children with congenital AV block. Infants are paced by the epicardial approach and the results have been very good in 34 patients who were operated in the last ten years. Transvenous endocardial DDD pacing is selected only in children older than 7 years (or 20–25kg) exept for those who have complex heart malformations and need AV synchrony. Pacemakers with mode switching algorithms should be selected in all patients who have AV block and paroxysmal atrial tachycardias. Finally, new indications have been developed in children with atrial tachycardia, in whom atrial antitachycardia pacemakers (AAIT) may terminate episodes of re-entry. Specific pacemaker options should be tailored to individual needs and close follow-up is necessary.

Survival of DDD pacing mode after atrioventricular junction ablation and pacing for refractory atrial fibrillation

Background Patients with recurrent forms of atrial fibrillation may receive dual-chamber pacemakers after atrioventricular junction ablation for refractory symptoms. These patients are at risk for chronic atrial fibrillation, which would negate the benefits of dual-chamber pacing. The purpose of this study was to examine the survival of dual-chamber pacing modes in patients undergoing ablate and pace therapy. Methods and Results One hundred fifty-six patients underwent ablate and pace therapy for medically refractory chronic (70 patients) or recurrent (86 patients) atrial fibrillation. Seventy-eight percent of patients had structural heart disease. The mean age was 66 ± 11 years, with an average ejection fraction of 48% ± 18%. The choice of pacing mode and programming were at the discretion of the investigators. At implantation, 91 patients (58%) were programmed to VVI mode, 47 (30%) were programmed to DDD mode, and 18 (12%) were programmed to DDI mode. After 1 year of follow-up, 10 DDD patients were reprogrammed to VVI mode (7 patients) or DDI mode (3 patients), most frequently for chronic atrial fibrillation (7 patients). Two patients with DDI mode were reprogrammed to VVI and DDD modes (1 patient each). Survival of the DDD mode was 76% at 1 year by Kaplan-Meier analysis. Reprogramming from DDD mode was not associated with patient age, left ventricular ejection fraction, discontinuation of antiarrhythmic drugs, or the duration of atrial fibrillation symptoms before ablation. Conclusions Seventy-six percent of patients with recurrent atrial fibrillation who are initially programmed to DDD mode remain in DDD mode 1 year after ablation and pacing therapy. The modest rate of progression to chronic atrial fibrillation supports the use of dual-chamber pacing in this setting. (Am Heart J 1999;137:682-5.)