Procedural Results of Patients Undergoing Transcatheter Aortic Valve Implantation With Aortic Annuli Diameter ≥26 mm: insights from the German Aortic Valve Registry

Patients presenting with severe aortic stenosis and large aortic annuli are challenging to treat because of the size limitations of available transcatheter heart valves. In this study, we aimed to determine clinical and hemodynamic outcomes in patients presenting with large aortic annuli who underwent transcatheter aortic valve implantation (TAVI). Patients from the German Aortic Valve Registry who underwent TAVI either with the Edwards Sapien (ES) or Medtronic CoreValve (MCV) systems from 2011 to 2017 were included. They were further stratified into a large (aortic annulus diameter 26 to 29 mm for ES; 26 to 30 mm for MCV) and extra-large (aortic annulus diameter >29 mm for ES; >30 mm for MCV) group and analyzed using propensity score adjustment. Extra-large was set beyond the sizing limitations according to the manufacturer's instructions for use. Patients in the large (n = 5,628) and extra-large (n = 509) groups were predominantly male (large: 92.6% vs extra-large: 91.9%). The 30-day mortality was comparable (large: 3.9% vs extra-large: 5.0%, p = 0.458). Procedure duration (large: 78.9 minutes ± 0.82 vs extra-large: 86.4 minutes ± 1.9, p <0.001) was longer in the extra-large group. Likewise, vascular complications (large: 6.2% vs extra-large: 12%, p = 0.002) and the need for a permanent pacemaker implantation (large: 18.8% vs extra-large: 26.0%, p = 0.027) were more often present in the extra-large group. Aortic regurgitation ≥II after valve implantation was numerically higher (large: 3.0% vs extra-large: 5.3%, p = 0.082) in patients with extra-large anatomy. In conclusion, patients with large and extra-large aortic annulus diameters who underwent TAVI have comparable 30-day mortality. Beyond the recommended annulus range, there is a higher risk for vascular complications and permanent pacemaker implantation.

Patient with sick sinus syndrome and implanted dual-chamber pacemaker with reduced P-wave duration following low interatrial septal pacing: Case report

INTRODUCTION

A dual-chamber pacemaker (DDD/R) for a sinus node disease is sometimes referred to as a physiological pacemaker as it maintains atrioventricular synchrony, however several clinical trials have proved its inferiority to a nonphysiological single-chamber ventricular back-up pacing.

PATIENT CONCERNS

A subject of the study is a 74-year-old woman with a sick sinus syndrome (SSS) and a previously implanted physiological DDD/R pacemaker. The SSS was diagnosed because of patient's very slow sinus rhythm of about 36 bpm, and due to several episodes of dizziness. After the DDD/R implantation the percentage of atrial pacing approached 100%, with almost none ventricular pacing.

DIAGNOSES

Sick sinus syndrome, complete Bachmann's bundle block, atrial fibrillation, atrial flutter.

INTERVENTIONS

The patient was previously implanted with a physiological DDD/R pacemaker. Several years after the implantation, the atrial fibrillation was diagnosed and the pulmonary vein isolation was then performed by cryoablation. During the follow-up after pulmonary vein isolation, the improvement of mitral filling parameters was assessed using echocardiography. Shortly thereafter the patient developed the persistent paroxysm of a typical atrial flutter which was successfully terminated using a radiofrequency ablation. No recurrence thereof has been observed ever since (24 months).

OUTCOMES

The atrial electrode of the pacing system was implanted within the low interatrial septal region that resulted in a reduced P-wave duration compared to native sinus rhythm P-waves. The said morphology was deformed because of the complete Bachmann bundle block. That approach, despite a nonphysiological direction of an atrial activation, yielded relatively short P-waves (paced P-wave: 179 ms vs intrinsic sinus P-wave: 237 ms). It also contributed to a significantly shorter PR interval (paced PR: 204 ms vs sinus rhythm PR: 254 ms).

CONCLUSIONS

The authors took into consideration different aspects of alternative right atrial pacing sites. This report has shown that in some patients with a sinus node disease, low interatrial septal pacing can reduce the P-wave duration but does not prevent from the development of atrial arrhythmias.

"Preventive" pacing in patients with tachy-brady syndrome (TBS): Confirming a common practice

AIMS

Many tachy-brady syndrome (TBS) patients, are implanted a permanent pacemaker (PPM) to allow continuation of anti-arrhythmic drug (AAD) therapy to maintain sinus rhythm. Many of these PPM's are implanted as a preventive measure, in absence of symptomatic bradycardia. Our primary aim was to evaluate pacing use among these patients and find predictors for PPM use. Our secondary aim was to appreciate the portion of these patients who progress to permanent atrial fibrillation (AF).

METHODS

Retrospective study of TBS patients implanted a PPM as preventive measure, dividing cases into defined categories regarding highest percent atrial and ventricular pacing documented in PPM clinic visits during 3 year follow-up (F/U) period. Patients' baseline characteristics and AAD therapy were compared between cases with a major (>90%) pacing use and cases with <90% pacing use to find predictors for pacing use. Multivariable logistic regression was applied to identify independent variables associated with major pacing use.

RESULTS

Our study included 119 TBS patients. Most (86.5%) TBS patients had a moderate (>50%) pacing use and 58% had a major pacing use. Significant association was found between pre-implant severe sinus bradycardia (<40 bpm), first degree atrioventricular block and amiodarone treatment to major pacing use on univariate analysis and severe sinus bradycardia was significantly associated with major pacing on multivariate analysis as well. Only minority (16.8%) of TBS patients progressed to permanent AF during the study F/U period.

CONCLUSION

Our study reveals most TBS patients succeed to maintain sinus rhythm using an AAD with a significant pacing use, suggesting preventive PPM implantation might be advantageous in these cases. Pre-implant severe sinus bradycardia (<40 bpm) is a possible predictor for major pacing use in this population.

Effect of Ventricular Pacing on Morbidity in Adults After Fontan Repair

Implantation of a permanent pacemaker is a negative prognostic marker in patients with Fontan palliation; however, data delineating outcomes in adult patients with pacemaker requirements are lacking. We hypothesize that high ventricular pacing burden is associated with adverse outcomes in adult Fontan patients. We performed a retrospective review comprising adult patients with history of Fontan repair. A high burden of ventricular pacing was defined as ≥40% pacing. Major adverse clinical events (MACE) were defined as all-cause mortality or need for advanced cardiac therapies (ventricular assist device or heart transplant). A total of 145 adult patients with Fontan were studied for a median of 3.1 years. Twenty (14%) patients had implanted pacemakers with ≥40% ventricular pacing. Twelve events occurred in those with ≥40% ventricular pacing (incidence 60.0%) versus 11 in those without (incidence 8.8%). In multivariable analysis, ≥40% ventricular-pacing (odds ratio 12.51, confidence interval [CI] 3.56 to 43.83, p <0.001) was associated with MACE independent of initial Fontan type, New York Heart Association functional class at baseline, or history of atrial tachyarrythmia. In survival analysis, patients with ≥40% ventricular pacing had nearly 8 times the risk of MACE compared with those with a lower ventricular pacing burden (hazard ratio 7.79, 95% CI 2.56 to 23.66, p <0.001), whereas patients with atrial-only or <40% ventricular pacing burden had a trend toward higher hazard of MACE compared with those without permanent pacemaker (hazard ratio 3.38, 95% CI 0.92 to 12.47, p = 0.07) that did not meet statistical significance. These findings suggest that high ventricular pacing burden contributes to poor outcomes in the adult Fontan patients and bear consideration when determining optimal treatment of tachyarrhythmias in this population.

The Utility of Prophylactic Pacemaker Implantation in Right Bundle Branch Block Patients Pre-Transcatheter Aortic Valve Implantation

BACKGROUND

Patients with right bundle branch block (RBBB) prior to transcatheter aortic valve implantation (TAVI) are at high risk for immediate post-procedural heart block and long-term mortality when discharged without a pacemaker.

OBJECTIVES

To test whether prophylactic permanent pacemaker implantation (PPI) is beneficial.

METHODS

Of 795 consecutive patients who underwent TAVI, 90 patients had baseline RBBB. We compared characteristics and outcomes of the prophylactic PPI with post-TAVI PPI. Need for pacing was defined as  greater than 1% ventricular pacing.

RESULTS

Forty patients with RBBB received a prophylactic PPI (group 1), and in 50 the decision was based on standard post-procedural indications (group 2). There were no significant differences in clinical baseline characteristics. One patient developed a tamponade after a PPI post-TAVI. A trend toward shorter hospitalization duration in group 1 patients was observed (P = 0.06). On long-term follow-up of 848 ± 56 days, no differences were found in overall survival (P = 0.77), the composite event-free survival of both mortality and hospitalizations (P = 0.66), or mortality and syncope (P = 0.65). On multivariate analysis, independent predictors of the need for pacing included baseline PR interval increase of 10ms (odds ratio [OR] 1.21 per 10 ms increment 95% confidence interval [95%CI] 1.02-1.44, P = 0.028), and the use of new generation valves (OR 3.92, 95%CI 1.23-12.46, P = 0.023).

CONCLUSIONS

In patients with baseline pre-TAVI RBBB, no outcome differences were found with prophylactic PPI. On multivariate analysis, predictors of the need for pacing included baseline long PR interval, and the use of newer generation valves.

Longitudinal Outcomes of Women Undergoing Transcatheter Aortic Valve Replacement

OBJECTIVE

Recent data have suggested that women have a survival benefit at 1-year follow-up. However, long-term gender-based TAVR outcomes are lacking.

METHODS

All patients undergoing isolated TAVR from 2011 to 2017 were included. Patients were stratified by gender. The primary outcomes of the study were 3-year mortality and 3-year hospital readmissions. Multivariable logistic regression analysis was used to evaluate the risk-adjusted impact of gender on TAVR outcomes.

RESULTS

A total of 1,036 patients were divided into male (n = 518) and female (n = 518) cohorts. Women had a borderline significantly increased STS PROM (8.3% ± 5 vs. 7.7% ± 4.4; P = 0.05). The majority of procedures were performed under conscious sedation (male: 89% vs. female: 88%; P = 0.62) and via transfemoral access (male: 81.8% vs. female: 81.4%; P = 0.46). There was no difference in operative (30-day) mortality (male: 15 [3.3%] vs. female: 17 [3.7%]; P = 0.77) or 30-day readmissions (male: 40 [10.8%] vs. female: 44 [12.2%]; P = 0.56). Perioperative blood product usage was higher for women (male: 8.1% vs. female: 14.1%; P = 0.002). There was no significant difference in major vascular complications (male: 0.4% vs. female: 1.0%; P = 0.26) or major bleeding (male: 0.2% vs. female: 0.4%; P = 0.56). Permanent pacemaker placement was higher for males (11.6% vs. 7.0%; P = 0.01). On risk-adjusted multivariable analysis, gender was not a factor associated with mortality (HR 0.99 [0.76 to 1.30]; P = 0.99) or readmission (HR 0.90 [0.72 to 1.14]; P = 0.42) at 5 years.

CONCLUSIONS

There was no difference in survival or readmissions on multivariable analysis for women undergoing TAVR at 3 years. Longitudinal multi-institutional data will be important to validate these findings.

Clinical Outcomes of Selective Versus Nonselective His Bundle Pacing

OBJECTIVES

The aim of the study was to evaluate the clinical outcomes of nonselective (NS) His bundle pacing (HBP) compared with selective (S) HBP.

BACKGROUND

HBP is the most physiologic form of ventricular pacing. NS-HBP results in right ventricular septal pre-excitation due to fusion with myocardial capture in addition to His bundle capture resulting in widened QRS duration compared with S-HBP wherein there is exclusive His bundle capture and conduction.

METHODS

The Geisinger and Rush University HBP registries comprise 640 patients who underwent successful HBP. Our study population included 350 consecutive patients treated with HBP for bradyarrhythmic indications who demonstrated ≥20% ventricular pacing burden 3 months post-implantation. Patients were categorized into S-HBP or NS-HBP based on QRS morphology (NS-HBP n = 232; S-HBP n = 118) at the programmed output at the 3-month follow-up. The primary analysis outcome was a combined endpoint of all-cause mortality or heart failure hospitalization.

RESULTS

The NS-HBP group had a higher number of men (64% vs. 50%; p = 0.01), higher incidence of infranodal atrioventricular block (40% vs. 9%; p < 0.01), ischemic cardiomyopathy (24% vs. 14%; p = 0.03), and permanent atrial fibrillation (18% vs. 8%; p = 0.01). The primary endpoint occurred in 81 of 232 patients (35%) in the NS-HBP group compared with 23 of 118 patients (19%) in the S-HBP group (hazard ratio: 1.38; 95% confidence interval: 0.87 to 2.20; p = 0.17). Subgroup analyses of patients at greatest risk (higher pacing burden or lower left ventricular ejection fraction) revealed no incremental risk with NS-HBP.

CONCLUSIONS

NS-HBP was associated with similar outcomes of death or heart failure hospitalization when compared with S-HBP. Multicenter risk-matched clinical studies are needed to confirm these findings.

Health care cost analysis of enhanced pacing modalities in bradycardia patients: Portuguese case study on the results of the MINERVA trial

INTRODUCTION

The MINERVA trial established that atrial preventive pacing and atrial antitachycardia pacing (DDDRP) in combination with managed ventricular pacing (MVP) reduces progression to permanent atrial fibrillation (AF) in patients with paroxysmal or persistent AF and bradycardia who need cardiac pacing, compared to standard dual-chamber pacing (DDDR). It was shown that AF-related health care utilization was significantly lower in the DDDRP + MVP group than in the control group. Cost analysis demonstrated significant savings related to this new algorithm, based on health care costs from the USA, Italy, Spain and the UK.

OBJECTIVE

To calculate the savings associated with reduced health care utilization due to enhanced pacing modalities in the Portuguese setting.

METHODS

The impact on costs was estimated based on tariffs for AF-related hospitalizations and costs for emergency department and outpatient visits in Portugal.

RESULTS

The MINERVA trial showed a 42% reduction in AF-related health care utilization thanks to the new algorithm. In Portugal, this represents a potential cost saving of 2323 euros per 100 patients in the first year and 17118 euros over a 10-year period. Considering the number of patients who could benefit from this new algorithm, Portugal could save a total of 75369 euros per year and 555410 euros over 10 years. Additional savings could accrue if heart failure and stroke hospitalizations were considered.

CONCLUSION

The combination of atrial preventive pacing, atrial antitachycardia pacing and an algorithm to minimize the detrimental effect of right ventricular pacing reduces recurrent and permanent AF. The new DDDRP + MVP pacing mode could contribute to significant costs savings in the Portuguese health care setting.

[Five years assessment of cardiac stimulation in two public hospitals in Burkina Faso: An experiment of collaboration with two hospitals in Auvergne]

OBJECTIVES

Cardiac stimulation becomes a reality in Burkina Faso. The aim of our study was to evaluate this activity over five years and to appreciate the impact of collaboration with French hospitals of Auvergne area in its development.

MATERIALS AND METHODS

Prospective study including consecutively patients who underwent pacemaker implantation since June 2011. Data collected included indications, time to care, type of stimulation, complications, cost of treatment, and education and quality of life of the patient.

RESULTS

Sixty-nine patients received definitive pacemaker from June 2011 to June 2016, of whom 45.5% were women. The mean age was 69 years (extremes 35 to 89s). Almost all patients (94%) were symptomatic (54% syncope and 30% dizziness and lipothymias). The main indication for definitive cardiac pacing was complete atrioventricular block of degenerative origin (83%). The mean time between indication and surgery was 8.2 days, and only 4% of patients received temporary stimulation. The lack of financial support was the main reason for the delay in taking charge. During the study period, the two health centers received support in the form of stimulation equipment, a technical platform, and regular training and practical training. This collaboration made it possible to overcome the lack of material, human and financial resources. We recorded as complications a case of case exteriorization, two cases of benign local hematoma and two cases of probe displacement. The quality of life of the patients improved markedly, none of patients undergoing surgery remained symptomatic.

CONCLUSION

The organization of cardiac stimulation in Burkina Faso is a reality. Efforts must be made to sustain the activity and strengthen collaboration with hospitals in the north.

Is mortality a useful parameter for public reporting in pacemaker implantation? Results of an obligatory external quality control programme

AIMS

To evaluate if public reporting of pacemaker implantation-associated mortality is meaningful in a large contemporary patient cohort.

METHODS AND RESULTS

The database of the obligatory external quality control programme in the Federal State of Hessen, Germany, of patients undergoing permanent pacemaker (PPM) implantation was evaluated retrospectively. We compared the baseline features of patients who died compared with those who did not during hospitalization after PPM. Of 5079 patients who underwent PPM implantation in 2009, 74 (1.5%) died during the hospital stay. Cause of death was available in 70/74 patients (94.6%) who died. Deceased patients were older (79.6 ± 8.7 vs. 76.3 ± 9.9 years, P = 0.006), had worse American Society of Anesthesiologists (ASA) physical status (P < 0.001), lower ejection fraction (P < 0.001), a greater prevalence of high-degree atrioventricular-block (44.3 vs. 35.0%, P = 0.001), and were more likely to receive single-chamber devices (41.4 vs. 25.0%, P < 0.002). Perioperative complications were similar in both cohorts. Death was not attributable directly to PPM procedure in any patients but was related to (i) non-device-related infections (28.6%), (ii) heart failure (25.7%), (iii) extracardiac diseases (21.4%), (iv) multiorgan failure (8.6%), (v) previous resuscitation with hypoxic brain damage (8.6%), and (vi) arrhythmogenic death (7.1%).

CONCLUSION

Mortality associated with PPM implantation in vast majority of cases was not related to the procedure, but to comorbidities and other existing diseases at the time of PPM implantation. Thus, PPM implantation in-hospital mortality should not be chosen for public reporting comparing hospital quality, even after adjusting for baseline risk.

[Predictors for need of antibradycardia and antitachycardia pacing after ICD implantation : Implications for the subcutaneous ICD]

BACKGROUND

Little is known about the incidence and risk factors for progression to pacemaker dependency or the need for cardiac resynchronization in typical patients with an implanted defibrillator with regard to an alternative implantation of a subcutaneous ICD (S-ICD).

STUDY DESIGN AND METHODS

After retrospective analysis of 291 patients with first implantation of a transvenous single chamber ICD (VVI-ICD) from 2010-2016 and excluding those with an indication for pacemaker or lack of follow-up data, 121 patients were included and investigated with regard to the following endpoints: need for pacemaker stimulation, upgrade for cardiac resynchronization (CRT), and secondary occurrence and effectiveness of antitachycardia pacing (ATP). We compared the results with those of fundamental S‑ICD studies and tried to determine risk factors on the basis of medical history and pre-implant data.

RESULTS

The study population and the rate of endpoints were significantly different to those of fundamental S‑ICD studies. Within a 2.2-year follow-up, 14.9 % of the patients developed a need for pacemaker stimulation and 0.8 % the need for cardiac resynchronization. Excluding patients who at implantation were already at high risk for pacemaker dependency, 7.4 % remained with a reached endpoint. We identified atrial fibrillation and bundle-branch-block as risk factors. All episodes of ventricular tachycardia (VT) could be terminated by ATP in 9.9 % of the patients. They more often had ischemic heart disease and a secondary prophylactic indication for an ICD.

CONCLUSION

The low rate of conversions from S‑ICD to a transvenous ICD in case of pacemaker-dependency as stated in fundamental S‑ICD studies should not be transferred to other typical collectives of ICD recipients. The latter group is at significantly higher risk for developing pacemaker-dependency.

Minimizing right ventricular pacing in pacemaker patients with intact and compromised atrioventricular conduction : Results from the EVITA Trial

INTRODUCTION

Unnecessary ventricular pacing is associated with increased morbidity and mortality. Over the years different algorithms have been developed to reduce right ventricular pacing.

OBJECTIVES

Goal of the present study was to test the efficacy of the ventricular intrinsic preference (VIP) algorithm in patients with atrioventricular intact (AVi) and atrioventricular compromised (AVc) AV-conduction.

METHODS

Evaluation of VIP feature in pacemaker patients (EVITA) was a multicenter, prospective, randomized trial (Trials.gov Identifier: NCT00366158). In total, 389 patients were randomized to AVc group: n = 140/132 VIP OFF/VIP On, AVi group: n = 54/63 VIP OFF/VIP ON). One-month post-implantation AV conduction testing (AVc: PR/AR interval > 210 ms) was performed. Follow-up visits occurred 6 and 12 months after DDD-pacemaker implantation.

RESULTS

In AVi and AVc-patients initiation of the VIP feature significantly reduced incidence of ventricular pacing (AVi: 53 ± 38 vs. 9 ± 21%, p = 0.0001; AVc: 79 ± 31 vs. 28 ± 35%, p = 0.0001). DDD-pacemaker implantation per se significantly reduced incidence of AF in VIP ON (AVi 27 vs. 0%, p < 0.0001; AVc 29 vs. 3%, p < 0.0001) and VIP OFF patients (AVi 43 vs. 4%, p < 0.0001; AVc 33 vs. 3, p < 0.0001), without significant differences between VIP ON and OFF groups (p > 0.05). In the AVc group activation of VIP significantly reduced incidence of adverse events (AE). All-cause mortality was not significantly different in VIP ON (n = 5) and VIP OFF (n = 4, p > 0.05) patients.

CONCLUSION

AV search hysteresis (VIP) markedly reduces ventricular pacing both in patients with normal AV conduction and in patients with prolonged PR interval or intermittent AV block.

Spanish Pacemaker Registry. Twelfth Official Report of the Spanish Society of Cardiology Working Group on Cardiac Pacing (2014)

INTRODUCTION AND OBJECTIVES

This report describes the results of the analysis of pacemaker implant and replacement data submitted to the Spanish Pacemaker Registry in 2014, with special reference to pacing mode selection.

METHODS

The report is based on the processing of information provided by the European Pacemaker Patient Identification Card.

RESULTS

Information was received from 117 hospitals, with a total of 12 358 cards, representing 34% of estimated activity. Use of conventional generators and resynchronization devices was 784 and 64.4 units per million population, respectively. The mean age of patients receiving an implant was 77.3 years. Men received 59% of implants and 56.4% of replacements. Most patients receiving generator implants and replacements were in the age range 80 to 89 years. Most endocardial leads used were bipolar, and 84.2% had an active fixation system. Pacing was in VVI/R mode despite being in sinus rhythm in 24.7% of patients with sick sinus syndrome and 24% of those with atrioventricular block.

CONCLUSIONS

The use of pacemaker generators and resynchronization devices per million population continued to increase. Most implanted leads had active fixation and approximately 20% had magnetic resonance imaging protection. Age and sex directly influenced pacing mode selection, which could have been improved in more than 20% of cases.

[TRENDS OF PERMANENT PACEMAKER IMPLANTATION IN A SINGLE CENTER OVER A 20-YEAR PERIOD]

AIMS

To review the changes in permanent pacemaker implantation indications, pacing modes and patients' demographics over a 20-year period.

METHODS AND RESULTS

We retrospectively retrieved data on patients who underwent first implantation of the pacemaker between 1-1-1991 and 31-12-2010. One thousand and nine (1,009) patients underwent a first pacemaker implantation during that period; 535 were men (53%), their mean age was 74.6±19.5 years; the highest rate of implanted pacemaker was in patients ranging in age from 70-79 years, however there was an increasing number of patients aged over 80 years. The median survival time after initial pacemaker implantation was 8 years. Syncope was the most common symptom (62.5%) and atrioventricular block was the most common electrocardiographic indication (56.4%) leading to pacemaker implantation. There was increased utilization of dual chamber and rate responsive pacemakers over the years. There was no difference regarding mode selection between genders.

CONCLUSIONS

Pacemaker implantation rates have increased over a 20-year period. Dual chamber replaced most of the single ventricular chamber pacemaker and rate responsive pacemakers became the norm. The data of a small volume center are similar to those reported in pacemaker surveys of high volume pacemaker implantation centers. They confirm adherence to the published guidelines for pacing.

Spanish Pacemaker Registry. Eleventh official report of the Spanish Society of Cardiology Working Group on Cardiac Pacing (2013)

INTRODUCTION AND OBJECTIVES

The present report summarizes the analysis of pacemaker implantation and replacement data sent to the Spanish Pacemaker Registry in 2013, with specific discussion of pacing mode selection.

METHODS

This study was based on information obtained from the European Pacemaker Patient Identification Card.

RESULTS

Information was received on 118 hospital centers, with a total of 12 831 cards, or 35% of the estimated activity. There were 755 and 58.1 conventional and resynchronization devices per million population, respectively. The mean age of patients receiving an implant was 77.4 years. Men received 59.5% of first implantations and 56.6% of replacements. Most implantations and generator replacements were performed in patients older than 80 years. Almost all endocardial leads used were bipolar, and 78.7% of leads had an active fixation mechanism. Despite being in sinus rhythm, 24% of patients with sick sinus syndrome and 25% of those with atrioventricular block were paced in VVIR mode.

CONCLUSIONS

The use of pacemaker generators and resynchronization devices per million population continues to increase in Spain. Active fixation mechanisms predominate for leads but just 20% of leads are compatible with magnetic resonance imaging. The factors influencing the correct selection of pacing mode were age and, to a lesser extent, the type of atrioventricular block, and sex. Implementation of home monitoring of pacemakers remains low.

Relationship between seasonal weather changes, risk of dehydration, and incidence of severe bradyarrhythmias requiring urgent temporary transvenous cardiac pacing in an elderly population

There is little information on any seasonal variations or meteorological factors associated with symptomatic bradyarrhythmias requiring cardiac pacing. The aim of this single-center study was to investigate the seasonal distribution of the incidence of severe, life-threatening bradyarrhythmias requiring urgent temporary transvenous cardiac pacing in an elderly population. Consecutive patients who underwent urgent temporary transvenous cardiac pacing between 2007 and 2012 were enrolled. The baseline characteristics of the patients and some meteorological parameters, including the calculation the daily heat index (HI), were recorded. During the study period, 79 consecutive patients (mean age 82 ± 8 years, 41% male) underwent urgent temporary transvenous cardiac pacing, mainly for third-degree atrioventricular block (79%). The incidence of bradyarrhythmias was significantly higher in summer than in the other seasons (P < 0.001). Moreover, the highest incidence was observed in months with HI > 90 °F for >3 h per day for at least 10 days (P < 0.001). A direct correlation was found between the average monthly temperature and the monthly number of patients undergoing temporary cardiac pacing (r = 0.54, P < 0.001). Compared with other patients, those observed during the hottest months were significantly older and more frequently affected by chronic disabling neurological diseases (all P < 0.05). In addition, they more frequently showed biochemical indices of dehydration, renal function impairment and hyperkalemia (all P < 0.05). This study showed an increased incidence of severe bradyarrhythmias in an elderly population during the hottest months of the year. In these months, in subjects characterized by increased susceptibility to dehydration, the risk of developing bradyarrhythmias was increased significantly.

[Pacing in vasovagal syncope]

This article presents a critical review of the literature about the potential benefit of cardiac pacing in patients suffering from vasovagal or neurocardiogenic syncope. The manifestation of vasovagal syncope comprises some reflex bradycardia and vasoplegia resulting in cerebral hypoperfusion that ultimately leads to a loss of consciousness. The literature reports conflicting results of the potential benefit of cardiac pacing on the prevention of recurrence of vasovagal events. A detailed analysis of the inclusion criteria of these studies permits to clarify the discrepancy. Only patients older than 50 years with prolonged sinus pause at time of syncope benefit of the implantation of a cardiac pacemaker.

Gender differences in patients with atrial fibrillation

AIMS

We aimed to compare gender differences with respect to presentation of consecutive ambulatory patients with atrial fibrillation (AF), management of their disease, and outcomes.

METHODS

Post-hoc analysis of an observational (non-interventional) study performed by 616 office- and hospital-based cardiologists in Germany. Consecutive (mainly ambulatory) patients with Electrocardiography (ECG) -confirmed AF and available data from baseline (BL) and two follow-up visits at 6 and 12 months were assessed.

RESULTS

A total of 2,742 patients (62.8% males, mean age 67.5 years; 37.2% women, mean age 71.2 years) were analysed. Women had more frequently paroxysmal and less frequently permanent AF. Quality of life scores were slightly worse in women compared to men, for all types of AF. For class III anti-arrhythmic drugs at baseline (more frequent in men), and for digitalis (less frequent in men at BL and 1 year) statistically significant differences were noted. Oral anti-coagulation (OAC) without anti-platelet drugs was given in 67.9% at BL and in 62.7% at 1 year (no differences between genders). During follow-up, drug conversions in men/women were reported in 12.3%/14.9% (p=0.054), and electrical conversions in 14.6%/11.7% (p=0.03). Hospitalisations occurred in 25.9% and strokes in 3.5%. Patients with higher CHA2DS2-VASc scores had increased stroke rates (0, 1 and ≥2 points: 0.0, 1.5 and 3.9%, respectively; with no significant gender differences).

CONCLUSION

In everyday management of patients with AF, there were no differences in treatment and major outcomes, in particular stroke, between women and men. This finding is opposed to earlier studies reporting OAC undertreatment of women and higher stroke rates.

Incidence and prognostic significance of spontaneous and inducible antidromic tachycardia

AIMS

Orthodromic atrioventricular reentrant tachycardia (ORT) is the most common arrhythmia at electrophysiological study (EPS) in patients with pre-excitation. The purpose of the study was to determine the clinical significance and the electrophysiological characteristics of patients with inducible antidromic tachycardia (ADT).

METHODS AND RESULTS

Electrophysiological study was performed in 807 patients with a pre-excitation syndrome in control state and after isoproterenol. Antidromic tachycardia was induced in 63 patients (8%). Clinical and electrophysiological data were compared with those of 744 patients without ADT. Patients with and without ADT were similar in term of age (33 ± 18 vs. 34 ± 17), male gender (68 vs. 61%), clinical presentation with spontaneous atrioventricular reentrant tachycardia (AVRT) (35 vs. 42%), atrial fibrillation (AF) (3 vs. 3%), syncope (16 vs. 12%). In patients with induced ADT, asymptomatic patients were less frequent (24 vs. 37%; <0.04), spontaneous ADT and spontaneous malignant form more frequent (8 vs. 0.5%; <0.001) (16 vs. 6%; <0.002). Left lateral accessory pathway (AP) location was more frequent (51 vs. 36%; P < 0.022), septal location less frequent (40 vs. 56%; P < 0.01). And 1/1 conduction through AP was more rapid. Orthodromic AVRT induction was as frequent (55.5 vs. 55%), but AF induction (41 vs. 24%; P < 0.002) and electrophysiological malignant form were more frequent (22 vs. 12%; P < 0.02). The follow-up was similar; four deaths and three spontaneous malignant forms occurred in patients without ADT. When population was divided based on age (<20/≥20 years), the older group was less likely to have criteria for malignant form.

CONCLUSION

Antidromic tachycardia induction is rare in pre-excitation syndrome and generally is associated with spontaneous or electrophysiological malignant form, but clinical outcome does not differ.

Impact of right ventricular pacing on right ventricular function

BACKGROUND

The benefits of right ventricular pacing in patients with symptomatic bradycardia are well recognized. Currently, left ventricular (LV) function after cardiac pacing has already been extensively investigated. However existing data on right ventricular (RV) function in these patients is extremely limited.

MATERIAL AND METHOD

To test this, records of RV and tricuspid valve function of patients with a pacemaker measured at least a year after implantation were reviewed for a prevalence of RV dysfunction. The patients were also divided into those with and without RV dysfunction. Factors affecting the two groups were evaluated.

RESULTS

RV dysfunction and moderate to severe tricuspid valve regurgitation were found in approximately 4% and 21% respectively in cardiac pacing patients with mean implantation duration of 6.4 years. Compared to normal RV function, factors presumed to affect on RV dysfunction including site of pacing, pacing mode and percentage of ventricular pacing were not significantly different (p = 0.54, 0.37 and 0.12 respectively).

CONCLUSION

Based on these data, the prevalence of right ventricular dysfunction appears to be infrequent and factors that were assumed as contributors to LV dysfunction failed to show significant contributions to RV dysfunction.

Left ventricular function after permanent pacemaker in pacemaker clinic follow-up

BACKGROUND

Chronic right ventricular pacing has deleterious effects to left ventricular function which may be asymptomatic. Prevalence of LV dysfunction (LVEF < 50%) in RV pacing in Thai patients is not known.

MATERIAL AND METHOD

Patients in the Central Chest Institute of Thailand (CCIT) pacemaker clinic were retrospectively reviewed for their demographic and pacemaker data together with echocardiographic data for LV function. Analysis was done for those who were implanted for more than one year period.

RESULTS

Among the studied 118patients, male = 51 and female = 67, mean follow-up time 6.43 +/- 5.66 years, LV systolic dysfunction was identified in 21 (17.80%). Compared to those with no LV dysfunction, echocardiographic parameters showed larger LVsize (EDD 49.86 +/- 8.95 vs. 43.81 +/- 5.56 mm) and less thickness of the LV wall (11.05 +/- 1.60 vs. 12.49 +/- 2.79 mm). Studied clinical and pace parameters for correlation were hypertension (p = 0.048), coronary artery disease (p = 0.008), percent of ventricular pacing (p = 0.06), duration after implantation (p = 0.23), mode of pacing (p = 0.275), indication of implantation (p = 0.32, site of pacing lead (p = 0.279), moderate to severe MR (p = 0.003) and moderate to severe TR (p = 0.04).

CONCLUSION

LV dysfunction after pacemaker implantation was not infrequent. Parameters correlated to it were previous LV dysfunction, hypertension, coronary artery disease and increased amount of ventricular pacing. Mode of pacing and site of pacing lead were not correlated.

Severity of cardiovascular disease patients transported by air ambulance

INTRODUCTION

Although helicopters have been used in an air ambulance system for the past decade in Japan, the appropriate selection of patients for this transport mode has not been investigated. The present study investigates which patients could potentially benefit the most from helicopter emergency medical service (HEMS).

METHODS

We investigated the extent of circulatory and respiratory support required in the intensive care unit (ICU) and ultimate outcomes of 2340 patients with cardiovascular disease admitted to 1 institution between October 2001 and December 2009. Two hundred and seventy were transported by HEMS (HEMS group), and 2070 were transported by other means (non-HEMS group).

RESULTS

Temporary cardiac pacing, ventilator management, intra-aortic balloon pumping, percutaneous cardiopulmonary support, electrical defibrillation, and therapeutic hypothermia were more frequently required by patients in the HEMS group vs. the non-HEMS group (10.4%, 28.1%, 17.0%, 5.2%, 10.0% and 3.4% vs. 8%, 17.9%, 10.9%, 2.3%, 4.5% and 0.4%, respectively). The mortality rate was higher in the HEMS group than in the non-HEMS group in the ICU (9.6% vs. 5.3%).

CONCLUSION

Disease was more clinically severe and the outcome was poorer among patients with cardiovascular diseases transported by HEMS than by other means.

Improved access to temporary pacing in Denmark

INTRODUCTION

The aim was to illustrate current use of temporary pacing (TP) in Denmark by replicating a questionnaire study from 1986 and to compare the results of the two studies.

MATERIAL AND METHODS

The questionnaire was sent to Danish hospitals treating patients with acute myocardial infarction (AMI). To illustrate potential changes in the indications for TP, the questionnaire included two case reports also used in 1986.

RESULTS

Thirty-three of 39 hospitals returned the questionnaire. Thirty-one (94%) were able to perform transcutaneous TP, and 20 (61%) had access to transvenous TP. Transcutaneous TP was preferred in five hospitals, and transvenous TP was the procedure of choice in 15. In 1986, 13 of 74 (18%) hospitals were able to perform transcutaneous TP, and 33 of 74 (45%) had access to transvenous TP. Over the two decades, the proportion of patients with AMI undergoing TP decreased from 3.7% to 0.7% (p < 0.00001). No significant difference was found with regard to the indications for TP except for patients with posterior AMI complicated with a third degree atrioventricular block in whom a higher rate of TP was found (85%) compared with the 1986 results (56%) (p < 0.05).

CONCLUSION

The proportion of hospitals with TP facilities has nearly doubled since 1986. Over the same time period, the number of Danes undergoing TP in association with AMI was reduced. At present, TP is being performed in less than 1% of AMI patients.

FUNDING

Not relevant.

TRIAL REGISTRATION

Not relevant.

Prevalence and predictors of off-label use of cardiac resynchronization therapy in patients enrolled in the National Cardiovascular Data Registry Implantable Cardiac-Defibrillator Registry

OBJECTIVES

The purpose of the study was to define the extent and nature of cardiac resynchronization therapy (CRT) device usage outside consensus guidelines using national data.

BACKGROUND

Recent literature has shown that the application of CRT in clinical practice frequently does not adhere to evidence-based consensus guidelines. Factors underlying these practices have not been fully explored.

METHODS

From the National Cardiovascular Data Registry's Implantable Cardiac-Defibrillator Registry, we defined a cohort of 45,392 cardiac resynchronization therapy-defibrillator (CRT-D) implants between January 2006 and June 2008 with a primary prevention indication. We defined "off-label" implants as those in which the ejection fraction was >35%, the New York Heart Association functional class was below III, or the QRS interval duration was <120 ms in the absence of a documented need for ventricular pacing. The relationships between patient, implanting physician, and hospital characteristics with off-label use were explored with multivariable hierarchical logistic regression models.

RESULTS

Overall, 23.7% of devices were placed without meeting all 3 implant criteria, most often due to New York Heart Association functional class below III (13.1% of implants) or QRS interval duration <120 ms (12.0%). Atrial fibrillation/flutter, previous percutaneous coronary intervention, and the performance of an electrophysiology study before implant were independently associated with increased odds of off-label use, whereas diabetes mellitus, increasing age, and female sex were associated with decreased odds. Physician training and insurance payer were weakly associated with the likelihood of off-label use.

CONCLUSIONS

Nearly 1 in 4 patients receiving CRT devices in the study time frame did not meet guideline-based indications. Given the evolving evidence base supporting the use of CRT, these practices require careful scrutiny.

Predictors of successful defibrillation threshold test during CRT-D implantation

BACKGROUND

The assessment of defibrillation energy requirement (DER) is a standard practice during cardioverter-defibrillator (ICD) implantation. It is recommended to assure that the energy at least 10 J below the maximal energy deliverable by the implanted device successfully converts the induced ventricular fibrillation (VF). The cardiac resynchronisation therapy with defibrillator (CRT-D) recipients are at increased risk of developing serious complications due to repeated VF induction.

AIM

To define the prevalence of high DER among CRT-D recipients and to determine the factors which allow to obtain defibrillation safety margin.

METHODS

We examined all patients who underwent CRT-D implantation between June 2006 and June 2009 in our institution. The verification of the DER required at least one termination of the induced VF with the energy at least 10 J below the maximal energy deliverable by the implanted device.

RESULTS

The CRT-D was implanted in 65 patients. The first defibrillation test was successful in 57 (88%) patients. In the remaining 8 patients (12%), the defibrillation test was unsuccessful. These patients required system revision: reprogramming shocking polarity (2), reversing polarity and adjusting waveform (3), lead repositioning (1) and adding a subcutaneous lead (2). The use of high output devices (maximal energy > 30 J) and dual-coil leads was associated with a significantly (p < 0.05) lower rate of high DER, although high DER occurred in one patient implanted with the high output device. There was a correlation between the probability of successful defibrillation and renal function. It was less likely to obtain successful defibrillation safety margin in patients with creatinine > 175 micromol/L. During the follow up, ventricular tachyarrhythmia detected in the VF detection zone occurred in 13 (20%) patients, including two patients, who required system modification during implantation. In both cases, VF was terminated by the first defibrillation with the maximal energy of the implanted devices.

CONCLUSIONS

High DER occurred in a significant number of CRT-D recipients. There is a correlation between high DER and impaired renal function. The use of high output devices significantly decreases the number of patients who required system modification in order to obtain an adequate defibrillation safety margin.

[Atrial fibrillation before and after pacemaker implantation (WI and DDD) in patients with complete atrioventricular block]

Atrial fibrillation (AF) is a frequent problem of patients with pacemakers, and depends not only on disease but also on stimulation method. The aim of the study was to estimate the prevalence of AF before and after pacemaker implantation as well as to assess the influence of VVI and DDD cardiac pacing on onset of AF in patients with complete atrioventricularblock (AVB).

MATERIAL AND METHODS

We included 155 patients controlled between 2000 and 2008 in Pacemaker Clinic because of AVB III degree, treated with VVI or DDD pacemaker implantation. Information about the health status of the patients was gathered from medical documentation and analysis of clinical ambulatory electrocardiograms.

RESULTS

The study group comprised of 68 women and 87 men, mean age 68.7 +/- 13.9 years during implantation. 69% of patients had VVI pacemaker. There were 72.3% of patients with sinus rhythm before pacemaker implantation. During follow-up 4 +/- 2.8 years in 19.6% cases onset of atrial fibrillation de novo was diagnosed (in 31.3% in VVI mode vs. 2.2% in DDD mode; p = 0.00014). Mean time to AF since implantation was approximately 2.5 years. In VVI group (21 persons) amounted 32.1 months, while in 1 patient with DDD pacemaker 18 months. Between group with AF after implantation and with sinus rhythm preserved there was no statistically significant difference in age or gender (p = 0.89512 and p = 0.1253, respectively). Prevalence of atrial fibrillation after pacemaker implantation increased to 40%.

CONCLUSIONS

Atrial fibrillation is frequent in patients before and after pacemaker implantation, especially in patients stimulated in VVI mode. Major possibility of atrial fibrillation onset after pacemaker implantation should result in more attention during routine ECG examination.

RIVER: Portuguese registry to monitor unnecessary right ventricular pacing

The aim of this prospective registry is to evaluate a new algorithm designed to reduce the percentage of unnecessary ventricular pacing (%VP) in patients implanted with a dual-chamber pacemaker, through a dedicated pacing mode (called AAISafeR2) operating in AAI mode with back-up ventricular pacing in DDD mode, and to describe the incidence and distribution of atrioventricular (AV) block in this population. Investigators were free to assign patients to AAISafeR2 mode or to standard DDD (if AAISafeR was contraindicated, mainly due to permanent high-degree AV block). Patients underwent routine follow-up visits at 3, 6, 12, 18 and 24 months after implantation. At each follow-up visit, data were retrieved from pacemaker memories and analyzed to extract %VP and incidence of AV block. Up to December 2006, 158 patients (94 men, mean age 69 +/- 14 years) from nine Portuguese centers had been consecutively included. We also determined the distribution of AV block (according to the criteria used by the pacemaker to classify AV block and switch to DDD mode). AAISafeR was shown to be effective in reducing unnecessary VP in our patient population. The analysis also reveals a high incidence of paroxysmal AV block, often unknown at the time of implantation. There were no complications associated with AAISafeR programming.

[Gender bias in women with myocardial infarction: ten years after]

OBJECTIVE

Previous studies show that the women with acute myocardial infarction (AMI) receive less fibrinolitic treatment than the men. The objective of this study is to analyze if it exists any difference in fibrinolysis related to gender and to compare the results with those obtained 10 years ago.

DESIGN

Retrospective descriptive study that compare patients with AMI of less than 24 hours of evolution of studies Analysis of Delay in Acute Infarct of Myocardium (ARIAM) in 2003-2004 and Project of Analysis Epidemiologist of Critical Patient (PAEEC) of 1992-1993.

SETTING

ICUs from 86 hospitals in Spain that participated in the PAEEC study and 120 ICUs in the ARIAM.

PATIENTS

We compared data of 9,981 patients including in study ARIAM in 2003-2004 with 1,668 of the PAEEC of 1992-1993.

RESULTS

Women were less likely to receive thrombolytic therapy than men (odds ratio= 0.82, p < 0.01), after adjusting for age, origin, size of the hospital and antecedents. The probability of fibrynolisis is lower in elderly, patients referred from the general ward, in hospitals of more than 1,000 beds and patients with arterial hypertension, stroke, diabetes or peripheral vascular disease. The probability of fibrinólisis is higher when patient is transferred from another hospital (followed by those of Emergencies Room), in the hospitals by less than 300 beds (followed by those of 300-1,000) and when history of prior ischemic heart disease exists. Comparing the two periods, has increased the frequency of fibrynolisis in both genders, although the increment has been greater in the women.

CONCLUSIONS

The women with AMI continue receiving less fibrynolisis, although exists an increase in the number of treatments superior to register in the men.

[Cardiac pacing activities in Lithuania in the background of other European countries]

Survey of pacemaking activities of the three Lithuanian centers (located in Kaunas, Vilnius and Klaipeda) is presented. Results of the last eight years are analyzed and compared with the activities of the rest European countries. According to the index of number of primary implantations per 1 million of population/per year Lithuania has ranked in 19th position. Annual number of implantations of cardioverter-defibrillators is approximately 5-10. These results demonstrate that Lithuania lags behind the majority of European countries. There is a need to increase the activities both in implantation of pacemakers and cardioverter-defibrillators as well.

Determinants of pacemaker dependency after coronary and/or mitral or aortic valve surgery with long-term follow-up

The aim of the present study was to investigate potential preoperative, operative, and postoperative predictors of pacemaker (PM) dependency after coronary, mitral valve, and aortic valve surgery. One hundred two patients (mean age 68 +/- 11 years; 62% men) who had received a permanent PM after cardiac surgery were included. The presence of any pacing activity in VVI mode with a lower rate of 30 beats/min was defined as PM dependency. Median time to PM implantation was 10 days after the index surgery. Pacemaker indications were atrioventricular block (AVB), sinus node dysfunction, and slow atrial fibrillation in 70%, 20%, and 11% of patients, respectively. At baseline, PM dependency rates were 0%, 9%, and 15% for patients with sinus node dysfunction, slow atrial fibrillation, and AVB, respectively (p = 0.158). Corresponding values at last follow-up were 15%, 9%, and 41% (p = 0.02). During long-term follow-up, new PM dependency developed in 21 patients (23%). Most patients had AVB as the PM indication (18 of 21 patients; 86%). Cumulative probabilities of freedom from PM dependency in patients with AVB were 63% and 30% at 5 and 10 years, respectively. Of several demographic, preoperative clinical, electrocardiographic, operative, and postoperative characteristics of patients, preoperative history of syncope (odds ratio [OR] 6.58, 95% confidence interval [CI] 1.11 to 38.87), body mass index >or=28.5 kg/m2 (OR 2.88, 95% CI 1.08 to 7.67), bypass time >or=105 minutes (OR 4.81, 95% CI 1.54 to 15.02), and AVB as PM indication (OR 5.14, 95% CI 1.51 to 17.44) were independent predictors of long-term PM dependency in multivariate logistic regression analysis. In conclusion, the long-term PM dependency rate was relatively high in patients with postoperative AVB requiring permanent PM implantation. A preoperative history of syncope, body mass index >or=28.5 kg/m2, bypass time of 105 minutes, and AVB as PM indication were independent predictors of long-term PM dependency after cardiac surgery.

A simulation framework for dual chamber heart rhythm and cardiac pacing

A previously developed open source computer model allows realistic simulation of ventricular intervals in atrial fibrillation, while taking into account of ventricular pacing. In this paper, we further improve this model and present a new simulation framework based on an integrated dual-chamber heart and pacer (IDHP) model. The IDHP model incorporates more realistic atrial and ventricular rhythm generators and an industry-standard dual-chamber pacemaker timing control logic. Moreover, it simulates various interactions between intrinsic heart activity and extrinsic cardiac pacing. The IDHP model provides a new simulation platform where it is possible to bench test advanced pacemaker algorithms in the presence of different types of cardiac rhythms.

Sex differences in the relationship between amiodarone use and the need for permanent pacing in patients with atrial fibrillation

BACKGROUND

Amiodarone use was associated with an increased need for pacemaker insertion in a retrospective study of patients with atrial fibrillation (AF) and prior myocardial infarction. The aims of this study were to determine prospectively whether amiodarone increases the need for pacemakers in a general population of patients with AF and whether this effect is modified by sex.

METHODS

The study included 1005 patients with new-onset AF who were enrolled in the Fibrillation Registry Assessing Costs, Therapies, Adverse events, and Lifestyle (FRACTAL). Multivariable Cox regression models, including time-dependent covariates accounting for medication exposure, were used to evaluate the risk of pacemaker insertion associated with amiodarone use.

RESULTS

Amiodarone use was associated with an increased risk of pacemaker insertion (hazard ratio [HR], 2.01; 95% confidence interval [CI], 1.08-3.76) after adjustment for age, sex, atrial flutter, coronary artery disease, heart failure, and hypertension. The effect of amiodarone use was modified by sex, with a significant risk in women but not in men (HR, 4.69; 95% CI, 1.99-11.05 vs HR, 1.05; 95% CI, 0.42-2.58 [P = .02]). This interaction remained significant after adjustment for weight, body mass index, weight-adjusted amiodarone dose, and use of other antiarrhythmic or rate control drugs.

CONCLUSION

The risk of bradyarrhythmia requiring pacemaker insertion associated with amiodarone use for AF is significantly greater in women than in men, independent of weight or body mass index.

Transvenous cardiac pacing in children: problems and complications during follow-up

OBJECTIVE

Transvenous permanent cardiac pacing (TPCP) has become a frequently used therapeutic modality in children. The purpose of this study was to evaluate the outcome of pediatric TPCP regarding problems and complications.

METHODS

Records of 155 patients (mean age 9.2+/-4.7 years) who underwent implantation of TPCP between 1993 and 2003 were reviewed retrospectively. Indications for pacing included atrioventricular block in 76% and sinus node dysfunction in 22% patients. In 92 patients, bradyarrhythmia was secondary to cardiac surgery. Percutaneous subclavian puncture was used for lead implantation in 96% of patients. Pacemakers were placed to the right side of the chest in 84% and in the subpectoral area in 68%. Pacing modes were VVIR in 72%, VDD in 13%, AAIR in 8%, and DDD in 7% of patients at the initial implantation time. Of all electrodes, 95% had steroid elution and 53% had an active fixation mechanism. Mean follow-up period was 37+/-28 (1-120) months.

RESULTS

Forty-five (29%) patients had 21 minor and 45 major complications. Forty-four of 76 revisions were due to lead problems and battery extraction. Most of the lead problems were dislodgment and stretching (n=14). Kaplan Meier analysis of lead survival did not show any difference between lead types. During the follow-up, there were three sudden unexpected deaths.

CONCLUSIONS

In children, TPCP can be used safely and effectively. Although, complications are possible and sometimes lead or generator revision may be necessary, long-term outcome is favorable.

Utility of T-wave alternans in congestive heart failure

The use of implantable cardioverter defibrillator (ICD) in heart failure patients decreases the arrhythmic mortality with the cost of increasing the number of patients to be treated, and microvolt T-wave alternans (MTWA) testing can be used as a good criteria to better select the candidate for such a therapy. This article examines generalities about the mechanism of alternans, definitions of positive, negative, and indeterminate MTWA tests, and factors that can modify these results. We review clinical studies that have found MTWA as a marker of ventricular arrhythmias in patients with heart failure, independent of etiology, ischemic or idiopathic. Microvolt T-wave alternans permits the selection of low risk patients who may not benefit of ICD implantation by standard criteria, due to high negative predictive values in most studies.

Alternans amplification following a two-stimulus protocol in a one-dimensional cardiac ionic model of reentry: from annihilation to double-wave quasiperiodic reentry

Electrical pacing is a common procedure in both experimental and clinical settings to study and/or annihilate anatomical reentry. A previous study [Comtois and Vinet, Chaos 12, 903 (2002)] has described new ways to terminate reentry in a one-dimensional loop model by a protocol consisting of only two stimulations. Annihilation of the reentrant activity was much more likely with these new scenarios than through a unidirectional block. This paper investigates the sensitivity of these scenarios of annihilation to the length of the pathway. It shows that double-pulse stimulation can stop the reentry if the circuit is shorter than a limiting length. Beyond this upper limit, stimulation rather yields sustained double-wave reentry. The same dynamical mechanism, labeled alternans amplification, is found to be responsible for these two types of post-stimulus dynamics.

Ventricular Function and Long-Term Pacing in Children with Congenital Complete Atrioventricular Block

OBJECTIVE

To determine the sequela of right ventricular pacing in children with congenital complete atrioventricular block.

BACKGROUND

Pacing is a well-accepted therapy for patients with congenital complete atrioventricular block. The long-term sequela of right ventricular pacing in this population has not been well described.

METHODS

We performed a cohort study on all patients with congenital complete atrioventricular block who underwent pacemaker implantation at our institution from 1972 to 2004. Patients with associated congenital heart disease or ventricular dysfunction prior to pacemaker implantation were excluded.

RESULTS

A total of 63 patients were included in the study. The median age at pacemaker implantation was 6.5 years, with an average follow-up of 9.9 years. The cumulative dysfunction free survival at 20 years was 92%. In total, four patients (6%) were noted to develop LV dysfunction an average of 15.1 years after pacemaker implantation. Of 30 patients who were paced for >10 years, only three (10%) developed echocardiographic evidence of LV dysfunction. Right ventricular apex pacing and prolonged QRS duration were found to be predictive of decreased long-term LV systolic function (P < 0.05).

CONCLUSIONS

Left ventricular dysfunction in patients with congenital complete atrioventricular block is a rare finding, even in those who have been paced for more than 10 years. Right ventricular apex pacing and prolonged QRS duration may be associated with decreased ventricular function over time. At this time, with such a low incidence of cardiac dysfunction, right ventricular pacing should be considered an acceptable first-line therapy in this population.

The impact of reimbursement on the usage of pacemakers, implantable cardioverter defibrillators and radiofrequency ablation

An international questionnaire survey was carried out in Asia Pacific, Europe, Latin America and North America to assess the impact of reimbursement on the indications, types of device prescription and waiting time for pacemakers, implantable cardioverter defibrillators (ICD) and radiofrequency ablation therapy for cardiac arrhythmias. The indications for cardiac pacing can be restricted to more symptomatic patients when funding is limited, and new therapy such as cardiac resynchronization therapy (CRT) is restricted in many regions. ICD usage may be limited to secondary prevention candidates because of reimbursement, but referral doctor's ambivalence and knowledge are also important issues independent of the types of health care system. Radiofrequency ablation is generally well accepted, but reimbursement is heterogeneous, with non-fluoroscopic mapping being reimbursed only in a limited way worldwide. Thus with the exception of a well-developed health care system, reimbursement has a major impact on the delivery of arrhythmia management devices and procedures worldwide.

The contribution of rate adaptive pacing with single or dual sensors to health-related quality of life

AIMS

The characteristics of sensors to perform rate adaptive pacing are well established but whether their contribution improves health-related quality of life (QoL) remains disputable. To compare the effects on QoL with an integrated dual sensor [minute ventilation (MV) and acceleration, TT sensor] with a single MV sensor, and with no rate adaptive pacing.

METHODS AND RESULTS

This Dutch multi centre, prospective, single- (patient) blind study was performed in patients after first pacemaker (PM) implant for sick sinus syndrome or AV block. After a 3-month 'sensor off'-period following DDD PM implantation, where the latter 2 months permitted the MV sensor to learn the intrinsic rhythm, a 2-month period of DDDR with TT sensor or 2 months of DDDR with MV sensor, subsequently the two modes were crossed over. Quality of life was determined with Aquarel, the disease-specific instrument for PM patients. Heart rate, percentages of sensor driven and intrinsic rhythm were retrieved from PM memories. Sixty-four patients completed the 7-month study. In sick sinus patients, percentages of sensor-driven pacing occurred significantly more frequently than in AV block patients After implant QoL improved significantly: before 71.3 and after 83.5% (P < 0.001) measured with Aquarel and in 3 of 9 SF-36 scales, but no significant additive QoL benefit with dual or MV sensor pacing was observed. Pacing diagnosis, percentages of rate adaptive pacing, and heart rate influencing medication did not influence this result.

CONCLUSION

Pacemaker implantation strongly improves QoL, but neither single- nor dual- sensor-driven pacing offered additional improvement in QoL during the initial 8 months after the first PM implant.