DDDR Pacing Research Articles

Closed loop stimulation reduces the incidence of atrial high-rate episodes compared with conventional rate-adaptive pacing in patients with sinus node dysfunctions.

Subclinical atrial fibrillation (AF) is associated with increased risk of progression to clinical AF, stroke, and cardiovascular death. We hypothesized that in pacemaker patients requiring dual-chamber rate-adaptive (DDDR) pacing, closed loop stimulation (CLS) integrated into the circulatory control system through intra-cardiac impedance monitoring would reduce the occurrence of atrial high-rate episodes (AHREs) compared with conventional DDDR pacing. Patients with sinus node dysfunctions (SNDs) and an implanted pacemaker or defibrillator were randomly allocated to dual-chamber CLS (n = 612) or accelerometer-based DDDR pacing (n = 598) and followed for 3 years. The primary endpoint was time to the composite endpoint of the first AHRE lasting ≥6 min, stroke, or transient ischaemic attack (TIA). All AHREs were independently adjudicated using intra-cardiac electrograms. The incidence of the primary endpoint was lower in the CLS arm (50.6%) than in the DDDR arm (55.7%), primarily due to the reduction in AHREs lasting between 6 h and 7 days. Unadjusted site-stratified hazard ratio (HR) for CLS vs. DDDR was 0.84 [95% confidence interval (CI), 0.72-0.99; P = 0.035]. After adjusting for CHA2DS2-VASc score, the HR remained 0.84 (95% CI, 0.71-0.99; P = 0.033). In subgroup analyses of AHRE incidence, the incremental benefit of CLS was greatest in patients without atrioventricular block (HR, 0.77; P = 0.008) and in patients without AF history (HR, 0.73; P = 0.009). The contribution of stroke/TIA to the primary endpoint (1.3%) was low and not statistically different between study arms. Dual-chamber CLS in patients with SND is associated with a significantly lower AHRE incidence than conventional DDDR pacing.

STRANGE DUAL CHAMBER STIMULATION

Implantable cardiac devices (pacemaker, ICD, resynchronisation) are increasingly indicated in recent years. Complications secondary to these implants are encountered more frequently.We report the case of a 60 year old patient with a double chamber pacing device, implanted 6 months before her consultation date for a complete AVB.She was referred by her attending physician for exertional dyspnea and lipothymic discomfort following the implantation of the device.Clinical examination revealed no abnormalities. The ECG showed a spontaneous sinus rhythm at 60cpm.The interrogation of the device showed a DDDR pacing mode with the most frequent pacing mode in ASVS found at 80%.The EGMs listed were not consistent with the programmed dual chamber mode. The atrial endocavitary signals are labelled VS and the ventricular ones AP. The change of mode to VVI which should generate a ventricular drive showed us a spontaneous atrial signal coded VS. The AAI mode produces ventricular pacing with AP coded ventriculograms.A reversal of the lead connection at the box level was evoked.The patient has undergone a correct reconnection of the leads to the box with a rhythm at the end of the procedure in DDD.Follow-up telemetry 1 month after reconnection showed atrial and ventricular EGM signals appropriate to the paced and detected chamber.

A Case Report on Permanent Dual Chamber Pacemaker

Background: The dual-chamber, rate-modulated mode (referred to as DDDR) is the most recent cardiac pacing mode to become available. It restores both rate responsiveness and atrioventricular synchronization in patients with sinus node dysfunction and atrioventricular block. This pacing method combines rate-modulated dual-chamber and single-chamber technology. As a result, it is required to program both a maximum and a minimum. tracking rate and a maximum sensor rate, as in dual-chamber and single-chamber rate-modulated devices, respectively.
 Case Presentation: A 55-year-old female was admitted to A.V. B.R. Hospital with a complaint of breathlessness on exertion chest pain last 10 days. The patient has had hypothyroidism seen 2 years. No history of Hypertension and Diabetes Mellitus, Patient was conscious and oriented, All the investigation was done. FORTIFY SSURA VVED DDDR pacing (MRI compatible) was connected to lead, P-wave 3:2- 4.0, R- wave 9.2- 11.5mV. Device positioned in right infra-clavicular pocket.
 Conclusions: A 55-year-old female patient was admitted to the hospital with the chief complaint of breathlessness on exertion chest pin last 10 days. After all investigation patient was diagnosed with a case of permanent DDDR pacemaker. Now she is going to under a pacemaker procedure and treatment. Now patient prognosis is better than the previous and I advise the patient for the regular 15 days follow-up.

Prevention of long-lasting atrial fibrillation through antitachycardia pacing in DDDR pacemakers.

The MINERVA trial showed that in pacemaker patients with atrial fibrillation (AF) history, DDDRP pacing combining three algorithms - (a) atrial antitachycardia pacing with Reactive ATP enabled, (b) atrial preventive pacing and (c) managed ventricular pacing (MVP)-may effectively delay progression to persistent/permanent AF compared with standard DDDR pacing. We performed a comparative non-randomised evaluation to evaluate if Reactive ATP can be the main driver of persistent/permanent AF reduction independently on preventive pacing. Thirty-one centres included consecutive dual-chamber pacemaker patients with AF history. Reactive ATP was programmed in all patients while preventive atrial pacing was not enabled. These patients were compared with the three groups of MINERVA randomised trial (Control DDDR, MVP, and DDDRP). The main endpoint was the incidence of AF longer than 7 consecutive days. A total of 146 patients (73years old, 54% male) were included and followed for a median observation period of 31months. The 2-year incidence of AF>7days was 12% in the Reactive ATP group, very similar to that found in the DDDRP arm of the MINERVA trial (13.8%, P=.732) and significantly lower than AF incidence found in the MINERVA Control DDDR arm (25.8%, P=.012) and in the MINERVA MVP arm (25.9%, P=.025). In a real-world population of dual-chamber pacemaker patients with AF history, the use of Reactive ATP is associated with a low incidence of persistent AF, highlighting that the positive results of the MINERVA trial were related to the effectiveness of Reactive ATP rather than to preventive pacing.

VVI pacing with normal QRS duration and ventricular function: MOST trial findings relevant to leadless pacemakers.

Leadless pacemakers (LPs) provide ventricular pacing without the risks associated with transvenous leads and device pockets. LPs are appealing for patients who need pacing, but do not need defibrillator or cardiac resynchronization therapy. Most implanted LPs provide right ventricular pacing without atrioventricular synchrony (VVIR mode). The Mode Selection Trial in Sinus Node Dysfunction (MOST) showed similar outcomes in patients randomized to dual-chamber (DDDR) versus ventricular pacing (VVIR). We compared outcomes by pacing mode in LP-eligible patients from MOST. Patients enrolled in the MOST study with an left ventricular ejection fraction (LVEF)>35%, QRS duration (QRSd) <120ms and no history of ventricular arrhythmias or prior implantable cardioverter defibrillators were included (LP-eligible population). Cox proportional hazards models were used to test the association between pacing mode and death, stroke or heart failure (HF) hospitalization and atrial fibrillation (AF). Of the 2010 patients enrolled in MOST, 1284 patients (64%) met inclusion criteria. Baseline characteristics were well balanced across included patients randomized to DDDR (N=630) and VVIR (N=654). Over 4 years of follow-up, there was no association between pacing mode and death, stroke or HF hospitalization (VVIR HR 1.28 [0.92-1.75]). VVIR pacing was associated with higher risk of AF (HR 1.32 [1.08-1.61], P=.007), particularly in patients with no history of AF (HR 2.38 [1.52-3.85], P<.001). In patients without reduced LVEF or prolonged QRSd who would be eligible for LP, DDDR, and VVIR pacing demonstrated similar rates of death, stroke or HF hospitalization; however, VVIR pacing significantly increased the risk of AF development.

Prevention of long-lasting atrial fibrillation through antitachycardia pacing in 584 dual-chamber pacemaker patients

Abstract Background Atrial fibrillation (AF) is a frequent arrhythmia in pacemaker patients and is associated with poor quality of life and increased risks of heart failure, dementia, stroke, and death. The MINERVA trial has shown that the combination of 3 pacing algorithms – 1) atrial antitachycardia pacing (aATP), 2) atrial preventive pacing and 3) managed ventricular pacing (MVP) - delays progression to persistent and permanent AF, compared with standard DDDR pacing mode and with MVP mode, in pacemaker patients with AF history. Purpose We performed a comparative non randomized evaluation to confirm the hypothesis that aATP is the main driver of persistent/permanent AF reduction independently on the effect of preventive atrial pacing. Methods Thirty-one Italian and Japanese Cardiology centers included consecutive dual-chamber pacemaker patients with AF history. aATP was programmed in all patients while preventive atrial pacing was not enabled. Comparison was made with all the 3 groups in MINERVA randomized trial. The main endpoint was incidence of AF longer than 7 consecutive days, as detected by device diagnostics. Results A total of 146 patients (73 years old, 54% male) were included and followed for a median observation period of 31 months. The 2-year incidence of AF&amp;gt;7 days was 12% in the aATP group, very similar to that found in the arm of the MINERVA trial with aATP enabled (13.8%, p=0.732) and significantly lower than AF incidence found in the MINERVA Control DDDR arm (25.8%, p=0.012) and in the MINERVA MVP arm (25.9%, p=0.025). Conclusions In a real-world population of dual-chamber pacemaker patients with AF history, use of aATP was associated with low incidence of persistent AF during follow up, highlighting that the positive results of the MINERVA trial are related to the effectiveness of aATP rather than to the effects of preventive atrial pacing. Funding Acknowledgement Type of funding source: None

Effect of PR interval and pacing mode on persistent atrial fibrillation incidence in dual chamber pacemaker patients: a sub-study of the international randomized MINERVA trial.

Per standard of care, dual-chamber pacemakers are programmed in DDDR mode with fixed atrioventricular (AV) delay or with long AV delay to minimize ventricular pacing. We aimed to evaluate whether the PR interval may be a specific criterion of choice between standard DDDR, to preserve AV synchrony in long PR patients, and managed ventricular pacing (MVP), to avoid ventricular desynchronization imposed by right ventricle apical pacing, in short PR patients. In the MINERVA trial, 1166 patients were randomized to Control DDDR, MVP, or atrial anti-tachycardia pacing plus MVP (DDDRP + MVP). We evaluated the interaction of PR interval with pacing mode by comparing the risk of atrial fibrillation (AF) longer than 7 consecutive days as a function of PR interval. Out of 906 patients with available data, the median PR interval was 180 ms. The PR interval was found to significantly (P = 0.012) interact with pacing mode for AF incidence: the risk of AF > 7 days was lower [hazard ratio (HR) 0.58, 95% confidence interval (95% CI) 0.34-0.99; P = 0.047] in patients with short PR (shorter than median PR) if programmed in MVP mode compared with DDDR mode and it was lower (HR 0.65, 95% CI 0.43-0.99; P = 0.049) in patients with long PR (equal to or longer than median PR) if programmed in DDDR mode compared with MVP. Our data show that PR interval may be used as a selection criterion to identify the optimal physiological pacing mode. Persistent AF incidence was lower in short PR patients treated by right ventricular pacing minimization and in long PR patients treated by standard dual-chamber pacing.

Addition of minute ventilation to rate-response pacing improves heart rate score more than accelerometer alone

Heart rate score (HRSc) ≥70%, a novel parameter, predicts risk of mortality in patients with implantable cardioverter-defibrillators and identifies patients who have survival benefit with DDDR vs DDD pacing. The purpose of this study was to determine if DDDR pacing lowers HRSc, and a blended sensor with minute ventilation (MV) and accelerometer (XL) improves HRSc more than accelerometer (XL) alone in patients requiring pacemakers (PMs). HRSc, the percentage of all beats in the tallest 10-beat/min device histogram bin, was calculated. Data from the Limiting Chronotropic Incompetence for Pacemaker Recipients Study, a prospective randomized trial of PM patients, comparing XL to blended-sensor (XL + MV) rate-responsive pacing, were analyzed retrospectively for HRSc changes from baseline. The relationship of patient activity (sensor-detected from device memory) to HRSc was examined. Of the 501 randomized patients, 215 (43%) patients had HRSc ≥70% during DDD pacing at baseline. In these patients, HRSc decreased after DDDR programming by 14.2%, while it increased by 0.4% in those with baseline HRSc <70% (n = 286) (HRSc ≥70% vs HRSc <70%; P < .01). No differences were detected between the 2 randomized sensor-based groups at baseline. Blended-sensor (MV + XL) programming reduced HRSc more than the XL sensor alone (MV + XL: 18% vs XL: 10%; P < .001). No correlation was observed between patient activity and HRSc (correlation = -0.14; P = .07). HRSc improved (reduced) with rate-response (DDDR) programming in PM patients with high HRSc during DDD pacing. Blended sensors (MV + XL) improved HRSc more than XL alone. HRSc does not correlate with patient activity levels, suggesting that other patient factors determine this parameter. This programming approach needs to be investigated prospectively in a PM outcomes trial.

Клиническая значимость алгоритмов минимизации правожелудочковой электростимуляции у пациентов с синдромом слабости синусного узла и анамнезом фибрилляции предсердий

to assess effectiveness of algorithms of minimization of right ventricular pacing (MRVP) for prevention of progression of atrial fibrillation (AF), lowering of frequency of hospitalizations due to cardiovascular causes, and mortality in patients with sick sinus syndrome (SSS) and history of paroxysmal AF compared with standard compared with dual-chamber pacing (DDDR). We included in this single-center prospective study 74 consecutive patients with indications to permanent DDDR pacing because of SSS combined with documented history of paroxysmal AF. Patients were randomized in the groups of DDDR pacing (n=36) and with activated algorithms of MRVP (n=38). Pacemaker check up was made after 6 months during 1 year after device implantation. Primary composite endpoint included development of persistent AF, hospitalization due to cardiovascular causes, and all cause death. During follow-up there was no statistically significant difference in achievement of the primary endpoint (27.8 and 18.4% in groups of DDDR pacing and activated algorithms of MRVP respectively (relative risk 1.29% confidence interval 0.43 to 3.86; p=0.25). Rate of development of persistent AF in both groups was comparable (8.6 and 5.3% in DDDR and MRVP groups, respectively; p=0.47). Median AF burden was 6.0 (0;42) and 6.0 (0;42) min/day in DDDR and MRVP groups, respectively (p=0.67). Our study failed to demonstrate advantages of the use of algorithms of decreasing "unmotivated" right ventricular pacing over standard regimen of standard DDDR pacing in patients with SSS and history of paroxysmal AF.

Leadless pacemaker implantation in young adults with vasovagal syncope and major cardioinhibitory component: About 2 cases

Vasovagal syncope is generally benign but may associated to pacing indication. We report two cases of vasovagal requiring pacemaker implantation. A leadless pacemaker was preferred to conventional pacing. Clinical cases: two women aged 24 and 16, were showing repetitive faintness. They presented prodromal symptoms, without triggering factor, that lead to collapse accompanied by convulsions or serious traumas. After a full neurological check-up and elimination of underlying cardiopathy, the diagnosis of vagal syncope with major cardioinhibitory component was made: for one through an implantable loop recorder with sinusal pauses of more than one minute, for the other with a positive tilt test and demonstration of a 18 seconds sinusal pause on a 72 h Holter ECG. The postural and the beta-blocker treatment being inefficient, pacing was decided. A Medtronic MICRA was implanted, via the right femoral vein, on the interventricular septum. Mean procedure time was 50 minutes. Micra was positioned at the first attempt in both patients with thresholds < 0.5 V. No complications were observed and both patients were treated in our outpatient clinic. No syncope occurred since then in both patients over a follow-up of 2 and 12 months without significant change in electrical parameters. Even if the DDDR pacing is to be favoured as first intention in this indication, the new leadless pacemakers show many advantages: no surgical approach, infections and haemorrhages decrease, displacement risk decrease, aesthetic keeping up with a same longevity to current simple room pacemakers. Thus, leadless pacemaker can be discussed for young patients with indication for pacing associated to vagal syncope. However, data is lacking in these patients, particularly concerning long-term follow-up.

Single lead atrial vs. dual chamber pacing in sick sinus syndrome: extended register-based follow-up in the DANPACE trial.

The DANPACE trial randomized patients with sick sinus syndrome (SSS) to single lead atrial (AAIR) or dual chamber (DDDR) pacemaker (PM). After 5 years follow-up, no difference in overall survival, stroke or heart failure (HF) was observed, whereas risk of atrial fibrillation (AF) and PM reoperation were increased in the AAIR group. The present study aimed to investigate very long term risk of death, AF hospitalization, stroke, HF and rate of change in pacing mode using national register-based data. The study population consisted of all 1384 patients included at Danish PM centres in the DANPACE trial randomized to AAIR (n = 696) or DDDR (n = 688). Long-term follow-up data was obtained from Danish national registers. Analysis was intention-to-treat. results: During mean follow-up of 8.9 years, 413 patients (59.3%) died in the AAIR-group compared to 367 (53.3%) in the DDDR-group (adjusted hazard ratio 1.03; 95% confidence interval 0.90-1.19; P = 0.65). We observed no difference in risk of AF hospitalization, stroke or HF. During extended follow-up, annual rate of pacing mode change to DDDR in the AAIR group was 4.5%, and higher than the 2.3% observed during trial conduct. This register-based long-term follow-up study indicates that there is no difference in mortality among patients with SSS randomized to AAIR or DDDR pacing, even with very long follow-up. Nor is there any difference in risk of AF hospitalization, stroke or HF. The higher rate of pacing mode-change to DDDR in the AAIR group suggests a different management of patients with an AAIR PM after the DANPACE trial.

Health economic evaluation of single-lead atrial pacing vs. dual-chamber pacing in sick sinus syndrome

The recent Danish Multicentre Randomized Trial on Single-Lead Atrial (AAIR) Pacing versus Dual-Chamber (DDDR) Pacing in Sick Sinus Syndrome (DANPACE) suggested DDDR pacing as standard care. However, previous findings supported the routine use of AAIR pacing. This study investigated the cost-effectiveness of DDDR pacing compared with AAIR pacing for sick sinus syndrome. A decision-analytical model based on patient-level data from three randomized trials was designed from the Danish healthcare system's perspective. The main outcomes were lifetime costs, quality-adjusted lifeyears (QALYs), and net monetary benefit. Quality-adjusted lifeyears were calculated by utilizing community-based preferences. Costs were calculated by utilizing the extensive data on resource consumption, from the DANPACE trial. Data were pooled and adjusted for baseline differences. Dual-chamber pacing was shown to be cost-effective in all the analyses using a willingness-to-pay (WTP) threshold of £20,000/QALY, and most analyses using a WTP of £30,000/QALY. When pooling the data and adjusting for baseline differences, Monte Carlo simulations revealed a 51-71% probability of DDDR pacing being cost-effective at a WTP of £20,000/QALY, and a 42-58% probability at a WTP of £30,000/QALY. Dual-chamber pacing was most likely to be cost-effective among elderly patients with comorbidity. The expected value of perfect information was low and initiation of additional publicly funded Danish trials was discouraged. Dual-chamber pacing is likely to be a cost-effective treatment for sick sinus syndrome patients.

CHADS2 and CHA2DS2-VASc score to assess risk of stroke and death in patients paced for sick sinus syndrome

ObjectiveThe risk of stroke in patients with atrial fibrillation (AF) can be assessed by use of the CHADS2 and the CHA2DS2-VASc score system. We hypothesised that these risk scores and...

System upgrade and its complications in patients with a single lead atrial pacemaker: data from the DANPACE trial

To investigate the indications for system upgrade with single lead atrial pacing (AAIR), complications associated with these re-interventions, and possible predictors for system upgrade among patients included in the Danish Multicenter Randomized Trial on AAIR vs. dual-chamber pacing (DDDR) in sick sinus syndrome (DANPACE). A total of 707 of 1415 patients were randomized to AAIR pacing. Mean follow-up was 5.5 ± 2.6 years. Information on indications for system upgrade and complications were collected by reviewing patient charts. Multiple logistic regression was used to estimate adjusted odds ratios (aOR) with 95% confidence intervals (CI) for the association between predictors and system upgrade. Sixty-six patients (9.3%) in the AAIR group underwent system upgrade. Fifty-nine of these patients (89.3%) had a documented class I indication for system upgrade. Age (aOR 0.98 for each 1-year increase in age; 95% CI 0.6-1.0), and left atrial enlargement (aOR 1.9; 95% CI 1.0-3.8) were predictors for system upgrade. No single clinically applicable predictor for upgrade was identified. A total of 11 patients (16.7%) experienced at least one major complication after system upgrade. The majority of patients with AAIR pacing who underwent system upgrade had a class I indication. The incidence of major complications after system upgrade was high. The present data support the use of DDDR pacing rather than AAIR pacing in sick sinus syndrome.

Systolic Pulmonary and Hepatic Vein Flow Reversal Due to Pacemaker‐Induced Retrograde Ventriculoatrial Conduction

Systolic pulmonary and hepatic vein flow reversals can typically be seen with severe atrioventricular (AV) valve regurgitation and during atrial fibrillation (AF). We report the case of a 67-year-old woman who presented with recent-onset exertional dyspnea. Her pacemaker was near end-of-life and reverted to a VVI mode from the preset DDDR mode. Electrocardiography demonstrated retrograde 1:1 ventriculoatrial (VA) conduction and spectral Doppler analysis revealed prominent systolic pulmonary and hepatic vein flow reversals. Symptoms, electrocardiogram (ECG) findings, and the spectral Doppler abnormalities resolved completely following a generator replacement and resumption of DDDR pacing.

Performance of atrial tachyarrhythmia-sensing algorithms in dual-chamber pacing using a fixed long AV delay in patients with sinus node dysfunction

The aim of the study was to evaluate the performance of pacemakers (PM) atrial tachyarrhythmia (AT)-sensing algorithms in sinus node dysfunction (SND) patients with DDDR pacing programmed with a fixed long atrioventricular (AV) delay. In a prospective study, a total of 60 patients with SND were implanted with a dual-chamber PM with two different algorithms for detection of ATs. The study was done with a 3 month data collection period retrieved from the memory of PM and with a 7 day external Holter recording period. In 13 of 16 (81 %) patients whose Holter recording revealed the presence of ATs, episodes of AT sensing were retrieved from the PM memory with electrograms verifications, confirming that the devices had detected the ATs. Very short ATs seen in Holter recordings were missed by the PM with three patients. However, with all these patients after 3 months of follow up period, there were recognized periods of ATs by the PM. With ten (17 %) patients, there were intermittent periods of undersensing by the PM although continuous atrial fibrillation (AF) was seen in the Holter recording. Retrograde conduction caused false AT detection due to repetitive non-reentrant ventriculoatrial synchronous rhythm (RNRVAS) in six (25 %) of the 24 patients with retrograde conduction. Even with long AV delay, ATs can be accurately identified. However, transient undersensing of continuous AF and non-detection of very short AT episodes can still occur. Programming a long AV delay predisposes to RNRVAS which can cause false AT detection and symptoms in SND patients who have retrograde conduction.

Method of Pacing Does Not Affect the Recurrence of Syncope in Carotid Sinus Syndrome

Pacemaker therapy is effective in reducing recurrent syncope in patients with symptomatic carotid sinus hypersensitivity (CSH), yet the optimal pacing modality for this syndrome is not known. The objective of this study is to prospectively investigate the impact of three pacing methods (DDDR vs DDDR with sudden bradycardia response [SBR] vs VVI) on recurrent syncope and quality of life. Twenty-one patients with symptomatic CSH (syncope or near syncope) were randomized to VVI, DDDR, or DDDR with SBR on a double-blinded basis in a sequential crossover fashion with 6 months in each mode. The primary endpoints were recurrent events and quality of life (assessed by SF-36). The mean number of events and SF-36 scores were compared. At baseline, over the preceding 6 months, there were a total of 29 syncopal events and 258 presyncopal events among 21 patients. Following pacing in any mode, the total number of these syncopal events reduced to two in two patients (P < 0.001) and 17 presyncopal events (P < 0.001) in 12 patients. The mean number of events was not significantly different between the three pacing methods. SF-36 scores revealed some minor benefits of DDDR pacing versus baseline in the categories, but no pacing method was found to be superior. The study was unable to confirm the initial study hypothesis of a superiority of one pacing modality over another. Quality of life measures allude to potential benefit from DDDR pacing alone.

Heart failure in patients with sick sinus syndrome treated with single lead atrial or dual-chamber pacing: no association with pacing mode or right ventricular pacing site

Previous studies indicate that ventricular pacing may precipitate heart failure (HF). We investigated occurrence of HF during long-term follow-up among patients with sick sinus syndrome (SSS) randomized to AAIR or DDDR pacing. Furthermore, we investigated effects of percentage of ventricular pacing (%VP) and pacing site in the ventricle. We analysed data from 1415 patients randomized to AAIR (n = 707) or DDDR pacing (n = 708). Ventricular pacing leads were recorded as located in either an apical or a non-apical position. The %VP and HF hospitalizations were recorded during follow-up. Patients were classified with new HF, if in New York Heart Association (NYHA) functional class IV or if presence of ≥2 of: oedema; dyspnoea; NYHA functional class III. Mean follow-up was 5.4 ± 2.4 years. Heart failure hospitalizations did not differ between groups. In the AAIR group, 170 of the 707 (26%) patients developed HF vs. 169 of the 708 (26%) patients in the DDDR group, hazard rate ratio (HR) 1.00, 95% confidence interval (CI) 0.79-1.22, P = 0.87. In DDDR patients, 146 of the 512 patients (29%) with ventricular leads in an apical position developed HF vs. 28 of the 161 patients (17%) with the leads in a non-apical position, HR 0.67, CI 0.45-1.00, P = 0.05. After adjustments this difference was non-significant. The incidence of HF was not associated with %VP (P = 0.57). In patients with SSS, HF was not associated with pacing mode, %VP, or ventricular lead localization. This suggests that DDDR pacing is safe in patients with SSS without precipitating HF.

AAIR or DDDR pacing for sick sinus syndrome: the physiologic conundrum

The results of the DANPACE multicentre trial were recently published.1 There were 1415 patients with symptomatic sick sinus syndrome (SSS) and normal QRS width, randomly assigned to single-chamber AAIR pacing (707 patients) or dual-chamber DDDR pacing with a tailored atrio-ventricular (AV) delay, designed to prevent ventricular pacing (708 patients). During a mean follow-up period of 5.4 ± 2.6 years, paroxysmal atrial fibrillation (AF) was observed in 28.4% in the AAIR group vs. 23% in the DDDR group ( P < 0.024). There were significantly more deaths ( P = 0.024) and pacemaker reoperations ( P < 0.001) in the single-chamber group, whereas there was no difference with chronic AF, stroke, and hospitalization for heart failure. Despite AV-delay tailoring, ventricular pacing in the DDDR group was 65% with a mean AV delay of 225 ± 39 ms. These data are in contrast to the original Danish trial published in 2003 with the lead author being involved with both trials.2 This smaller study of 177 patients had three groups randomized to AAIR, DDDR with short AV delay (DDDR-s), and DDDR with fixed long AV delay (DDDR-l). During a mean follow-up period of 2.9 ± 1.1 years, AF, both paroxysmal and chronic, was significantly less common in the AAIR group. Long-term DDDR pacing also induced left atrial dilatation, and in the DDDR-s group (90% ventricular pacing) there was also reduced left ventricular function. Seeing the results are so different how does this compare with other studies? In 2003, Sweeney et al .3 reported a …

Brain natriuretic peptide: a marker of cardiac dysfunction with ventricular or dual-chamber pacing

Background/Objectives The inability of trials to exhibit the superiority in survival of atrioventricular compared to ventricular pacing can be partially explained by the apical stimulation of the right ventricle, which adversely aff ects both short- and long-term ventricular performance. We evaluated the impact of pacing mode (DDDR vs VVIR) on the brain natriuretic peptide (BNP) level in patients with sick-sinus syndrome (SSS).Methods Sixty-seven patients were treated with DDDR pacemaker implantation due to SSS. They were randomized during the fi rst post-implant day either to DDDR or VVIR pacing mode and were reevaluated after 30 days. Group A comprised 35 patients on DDDR pacing mode and group B 32 patients on VVIR pacing mode. Peripheral blood samples were drawn for BNP measurement at the time of randomization and one month later.Results BNP levels increased signifi cantly in both groups at 30 days (group A: 85.6 ± 29.5 pg/ml to 107.2 ± 34.6 pg/ml, group B: 82.7 ± 27.6 pg/ml to 253.1 ± 60.2 pg/ml). On day 30, BNP levels in group B were signifi cantly higher than in group A (P < 0.0001).Conclusions Pacing from the apex of the right ventricle provokes an increase in the BNP levels regardless of the pacing mode. BNP is probably a very early marker predicting the structural and/or functional heart changes after long-term pacing from the apex of the right ventricle.