Dual-chamber Pacemaker Patients Research Articles

Optimal Pacing Mode in Dual Chamber Pacing with Long AV-Intervals:A Pressure Volume Loop Study

Objectives: This study aimed to assess if dual chamber pacemaker patients with prolonged atrioventricular (AV-) intervals at rest and maintained LV function will benefit from spontaneous AV-conduction compared to AV synchronous pacing at optimized AV-intervals (DDD-OPT). Background: AV-hysteresis and mode change algorithms allow very long AV-intervals to avoid right ventricular pacing, however, the optimal long AV interval remains undefined. Methods: LV pressure volume loops were obtained via a conductance catheter in 19 dual chamber pacemakers patients with resting AV-intervals >250 ms. Hemodynamic data were recorded during atrial pacing at 70/min (AAI) and DDD-OPT. The optimal AV-interval was defined by the largest consequent stroke work. Results: Mean AV-interval during atrial pacing was 302{±}32 ms. Systolic parameters were not different between pacing modes with the exception of +dp/dt max (AAI: 1398{±}393 mmHg/s; DDD-OPT 1319{±}377 mmHg/s; p=0.006). Stroke work was higher in 9/19 patients with AAI and in 10/19 with DDD-OPT. The diastolic parameters tau (DDD-OPT: 38{±}8 ms; AAI: 35{±}8 ms; p=0.002) and peak filling rate (DDD-OPT: 832{±}450 ml/s; AAI: 627{±}231 ml/s; p=0.001) showed superior results for DDD-OPT. Differential values between the two modes for stroke work and +dp/dtmax correlated significantly with the resting AV-interval ( 320 ms favored DDD-OPT whereas AV-intervals <280ms favored AAI. Conclusion: In dual chamber pacemaker patients with long resting AV-intervals there is a trade-off between pacing-induced LV systolic dysfunction and impaired diastolic filling. Maintaining spontaneous AV-conduction at all cost might not be the preferred option in this patient group.

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.

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

P6556Prevention of long-lasting atrial fibrillation through device therapy in dual-chamber pacemakers: analysis on 1384 patients of the role of Reactive ATP and atrial preventive pacing

Abstract Background Atrial fibrillation (AF) is the most prevalent heart rhythm disorder in clinical practice and it is associated with poor quality of life and increased risks of heart failure, dementia, stroke, and death. Moreover AF management is a huge cost for healthcare systems. AF is irregular, typically originates from the pulmonary veins, and as such, requires cardioversion to terminate persistent episodes. AF is not susceptible to pace-termination, however, the MINERVA trial has shown that AF may transform in slower organized rhythms such as atrial flutter or atrial tachycardia, which can often be terminated by atrial anticahycardia pacing (ATP); in particular by Reactive ATP, a specific ATP feature which can be re-armed when atrial arrhythmias get slower or more regular. The MINERVA trial showed that the combination of ATP, preventive atrial pacing algorithms and minimal ventricular pacing (MVP) was associated with lower progression to persistent and permanent AF, compared with standard DDD pacing mode and to MVP mode, in pacemaker patients with clinical history of AF. Purpose We aimed to confirm MINERVA trial results in real-world clinical practice and to evaluate whether AF prevention was associated with preventive atrial pacing or solely with ATP. Indeed in our project atrial preventive pacing algorithms were not enabled and the pacing mode (DDD or MVP) was chosen according to patients' AV conduction characteristics. Methods Consecutive dual-chamber pacemaker patients with sinus node disease and device detected AT/AF were prospectively followed by 30 Italian cardiologic centers in an observational research. Clinical and device data were collected and reviewed by expert cardiologists to assess AT/AF occurrence through in clinic visit and/or remote transmissions of device data. Results A total of 239 patients (73 years old, 56% male) wearing a dual-chamber pacemaker with Reactive ATP were included in the project, followed for a median observation period of 13 months and compared with 1145 patients included in the MINERVA trial followed for a median observation period of 34 months and programmed with DDD pacing mode (383 patients), MVP (389 patients) and MVP+Reactive ATP+preventive algorithms (373 patients). As shown in the following figure incidence of 7 consecutive days of AF in the patients treated by DDD/MVP+Reactive ATP in real-world clinical practice was very similar to that found in the MINERVA trial arm programmed with MVP+Reactive ATP+preventive algorithms. Incidence of AF longer than 7 days Conclusions Our analysis performed in a population of sinus node disease patients with dual-chamber pacemakers confirmed MINERVA trial results in terms of prevention of long-lasting AF episodes. In particular these results confirm the benefit associated with the use of Reactive ATP, rather than preventive atrial pacing algorithms.

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.

Increased healthcare utilization associated with complete atrioventricular block in pacemaker patients

PurposeThe purpose of the current study is to characterize and quantify the impact of complete atrioventricular block (cAVB) on heart failure hospitalization (HFH) and healthcare utilization in pacemaker (PM) patients.MethodsPatients ≥ 18 years implanted with a dual-chamber PM from April 2008 to March 2014 were selected from the MarketScan® Commercial and Medicare Supplemental claims databases. Patients with ≤ 1-year continuous MarketScan enrollment prior to and post-implant, and those with prior HF diagnosis were excluded. Patients were dichotomized into those with cAVB, defined as a 3rd degree AVB diagnosis or AV node ablation in the year prior to PM implant, versus those without any AVB (noAVB). Post-implant HFH and associated costs were compared based on inpatient claims.ResultsThe study cohort included 21,202 patients, of which 14,208 had no AVB and 6994 had cAVB, followed for 2.39 and 2.27 years, respectively. Patients with cAVB were associated with a significantly increased risk of cumulative HFH (HR 1.59 [95% CI 1.35–1.86] p < 0.001) and significantly higher costs ($636 [609–697] vs $369 [353–405] per pt-year, p < 0.001) compared to those with no AVB.ConclusionsAmong dual-chamber PM patients without prior HF, cAVB is associated with a significantly increased risk of HFH and greater HF-related healthcare utilization. Identifying patients at high risk for HF in the setting of RV pacing, and potentially earlier use of biventricular or selective conduction system pacing, may reduce HF-related healthcare utilization.

16-56: Sleep Apnea Syndrome in a Multicentric Study on Patients with Device Remote Monitoring System

Background: Sleep apnea syndrome (SAS) has up to 60% prevalence in the Pacemaker population, with 80% remaining undiagnosed. The ApneaScan TM is an implanted impedance-based respiratory sensor system embedded with Boston Scientific defibrillator devices: apneic events are expressed with the Apnea Hypopnea Index (AHI) (i.e the average number of events per hour of sleep). The aim of the study was to describe the prevalence of SAS in a french population of patients implanted as well as with a pace-maker or an implanted cardioverter defibrillator using the ApneaScan. Methods: In this 4-centers study, we retrospectively included 118 patients who had a Boston Scientific device with remote monitoring follow-up. The AHI was used to classify the severity of the sleep apnea, mild :5-14 events per hour of sleep, moderate : between 15-29, severe : more than 30. Results: Among the 118 patients (mean age, 68 ±14 years), 55% had a severe sleep apnea (average of AHI 44.9 ± 12.9/h) and 31% a moderate sleep apnea (AHI 22.9 ± 4.3/h); 46 patients were implanted with a dual chamber pace maker, 72 patients with an implantable cardioverter defibrillator (ICD): 41 dual chamber ICD and 31 CRT-D. The AHI was comparable in the CRT-D patients (AHI 29.2 ± 14.7/h), dual chamber ICD patients (32.5 ±17.2/h) or dual chamber pace-maker patients (36.1 ± 18.1/h) (ANOVA p = 0.222). An inverse correlation between the percentage of atrial pacing and the AHI (r = -0.25 p = 0.002) was found. The percentage of patient activity level (% per day) was inversely correlated with the AHI (r = -0.269 p = 0.005). The AHI was correlated with the age of patients (r = 0.2990, p = 0.0010). The percentage of ventricular pacing had no influence on AHI (p = 0.120). Conclusion: High prevalence of sleep apnea syndrome was found in patients implanted with device as well pacemaker or defibrillator. There were no differences of prevalence between patients implanted with pace-maker, ICD or CRT-D. Preliminary results identified a profile of patients at risk.

Effects of enhanced pacing modalities on health care resource utilization and costs in bradycardia patients: An analysis of the randomized MINERVA trial.

Many patients who suffer from bradycardia and need cardiac pacing also have atrial fibrillation (AF). New pacemaker algorithms, such as atrial preventive pacing and atrial antitachycardia pacing (DDDRP) and managed ventricular pacing (MVP), have been specifically designed to reduce AF occurrence and duration and to minimize the detrimental effects of right ventricular pacing. The randomized MINimizE Right Ventricular pacing to prevent Atrial fibrillation and heart failure trial established that DDDRP + MVP pacing modality reduced permanent AF in bradycardia patients as compared with standard dual-chamber pacing (DDDR). The aim of this study was to estimate the cost savings due to lower AF-related health care utilization events based on health care costs from the United States and the European Union. Dual-chamber pacemaker patients with a history of paroxysmal or persistent AF were randomly assigned to receive DDDR (n = 385) or the advanced features (DDDRP + MVP; n = 383). We used published health care costs from the United States and the European Union (Italy, Spain, and the United Kingdom) to estimate the costs associated with AF-related hospitalizations and emergency visits. The rate of AF-related hospitalizations was significantly lower in the DDDRP + MVP group than in the conventional pacemaker group (DDDR group; 42% reduction; incidence rate ratio 0.58). Similarly, a significant reduction of 68% was observed for AF-related emergency department visits (incidence rate ratio 0.32; P < .001). As a consequence, DDDRP + MVP could potentially reduce health care costs by 40%-44%. Over a ten-year period, the cost savings per 100 patients ranged from $35,702 in the United Kingdom to $121,831 in the United States. New pacing algorithms such as DDDRP + MVP used in the MINimizE Right Ventricular pacing to prevent Atrial fibrillation and heart failure trial successfully reduced AF-related health care utilization, resulting in significant cost savings to payers.

Predictive value of atrial high‐rate episodes for arterial stiffness and endothelial dysfunction in dual‐chamber pacemaker patients

Various pacing studies have demonstrated an association between right ventricular pacing (RVp) and atrial fibrillation (AF), even after preserving atrioventricular (AV) synchrony. We aimed to assess the interaction between arterial stiffness, endothelial function and atrial high-rate episodes (AHRE) in patients with dual-chamber pacemakers. We studied 101 patients with dual-chamber pacemakers incorporated with sophisticated AF detection and therapy algorithms. Macrovascular endothelial dysfunction (ED) was measured by the relative change in aortic augmentation index (AIx), using carotid artery applanation tonometry in response to inhaled salbutamol and sublingual glyceryl trinitrate. Microvascular ED was measured by cutaneous laser Doppler flowmetry (LDF) in response to acetylcholine (Ach, endothelium dependent) and sodium nitroprusside (SNP, endothelium independent). Arterial stiffness was measured using carotid-femoral pulse wave velocity (PWVcf). 'Reservoir pressure' (Pr, MATLAB) describes the aortic 'cushioning' properties. Mean age of the cohort was 72.1 ± 10.8 years; men (n = 69) 68.3%. Of 101 dual-chamber pacemaker patients, 23.8% (n = 24) had AHRE detected on the baseline pacemaker interrogation. PP, PWVcf and Pr were significantly higher in patients with AHRE compared with those without AHRE. The change in AIx with salbutamol (∆% AIx Sal) and acetylcholine-induced changes in LDF (Δ%LDF Ach) were lower in patients with AHRE compared with those without AHRE. In patients with AHRE, significant correlations were observed between%Vp and Δ%LDF Ach (P = 0.03) as well as between PP and Δ%LDF Ach (P = 0.05). On multivariate analysis, PP, Pr, PWVcf and ∆% AIx Sal remained as independent predictors of AHRE. In patients with dual-chamber pacemakers, both higher arterial stiffness and greater endothelial dysfunction independently predicted AHRE, irrespective of the degree (or mode) of pacing. Arterial stiffness and endothelial dysfunction may potentially contribute to the perpetuation of atrial arrhythmias beyond the adverse effects of ventricular pacing alone.

AV interval optimization using pressure volume loops in dual chamber pacemaker patients with maintained systolic left ventricular function

Atrioventricular (AV) interval optimization is often deemed too time-consuming in dual-chamber pacemaker patients with maintained LV function. Thus the majority of patients are left at their default AV interval. To quantify the magnitude of hemodynamic improvement following AV interval optimization in chronically paced dual chamber pacemaker patients. A pressure volume catheter was placed in the left ventricle of 19 patients with chronic dual chamber pacing and an ejection fraction >45 % undergoing elective coronary angiography. AV interval was varied in 10 ms steps from 80 to 300 ms, and pressure volume loops were recorded during breath hold. The average optimal AV interval was 152 ± 39 ms compared to 155 ± 8 ms for the average default AV interval (range 100-240 ms). The average improvement in stroke work following AV interval optimization was 935 ± 760 mmHg/ml (range 0-2,908; p < 0.001), which translates into an average improvement of 14 ± 9 % (range 0-28). A 10 ms variation of the AV interval changes the average stroke work by 207 ± 162 mmHg/ml. AV interval optimization also leads to improved systolic dyssynchrony indices (17.7 ± 7.0 vs. 19.4 ± 7.1 %; p = 0.01). The overall hemodynamic effect of AV interval optimization in patients with maintained LV function is in the same range as for patients undergoing cardiac resynchronization therapy for several parameters. The positive effect of AV interval optimization also applies to patients who have been chronically paced for years.

Where to pace and where not to pace?

Where to pace and where not to pace?

676 Right ventricular pacing does not affect the occurrence of atrial tachyarrhythmias in dual chamber pacemaker patients

676 Right ventricular pacing does not affect the occurrence of atrial tachyarrhythmias in dual chamber pacemaker patients

676 Right ventricular pacing does not affect the occurrence of atrial tachyarrhythmias in dual chamber pacemaker patients

676 Right ventricular pacing does not affect the occurrence of atrial tachyarrhythmias in dual chamber pacemaker patients

Permanent ventricular and dual chamber cardiac stimulation: role of pacing mode in relation to chronic atrial fibrillation risk and stroke development

Ventricular single chamber permanent cardiac pacing undoubtedly eliminates symptoms related to extremely low cardiac rate, but also contributes to increased morbidity due to onset of permanent atrial fibrillation (PAF). Many studies have shown the superiority of atrial and dual chamber cardiac pacing in reducing atrial fibrillation risk and in preventing correlated embolic complications. It is not known, however, if this advantage is maintained in the elderly and in particular in the oldest old people. From 1986 onwards, we analyzed 690 chronically paced patients, 472 received a single chamber ventricular pacemaker (VP), while 218 received a dual chamber pacemaker (DP). All patients underwent regular controls every 6 months. End points of the study were the onset of atrial fibrillation, embolic events and death. Life table analysis of the incidence of all the events during a follow-up of 120 months was carried out, distinguishing two groups (VP and DP) homogeneous in mean age and type of cardiopathy. The total incidence of PAF was 51.4% in the VP and 11.4% in the DP group ( P<0.05). After 7 years from implant, PAF was present in 90% of VP and 20% of DP patients ( P<0.001). We found a significantly higher occurrence of cerebral ischemic events (stroke or transient ischemic attacks) in the VP group ( P<0.05). Even if no great difference in mortality was found between the two groups, a significant reduction of cardiovascular mortality associated with DP has been observed in the subgroup of patients with sick sinus syndrome.

Comparison of Low Rate Dual Chamber Pacing to Activity Responsive Rate Variable Ventricular Pacing

A study was undertaken to evaluate exercise performance in 18 dual chamber pacemaker patients believed to be chronotropically incompetent. All patients were paced in a DDD AV synchronous mode at 80 beats per minute (beats/min) as well as an externally triggered, activity responsive VVIR mode. Patients underwent two single blind, randomized symptom-limited treadmill tests (Sheffield protocol). Four of the 18 patients achieved intrinsic rates greater than 100 beats/min and were deleted from the primary study. It was noted that all four of these patients performed best with intrinsic rate response and AV synchrony. Thirteen of the remaining 14 patients demonstrated improved exercise tolerance in the VVIR mode. Average exercise time in the VVIR mode (7:25 +/- 3:12 min) was significantly greater (P less than 0.05) than the DDD mode (6:01 +/- 2:27 min). Work performed was significantly greater (P less than 0.05) in the VVIR mode (4.77 +/- 1.97 METS) than in the DDD mode (3.78 +/- 0.77 METS). Maximum heart rates were 83.86 +/- 5.11 beats/min in DDD mode versus 116.00 +/- 10.56 beats/min in VVIR mode. The results demonstrated that improved exercise tolerance can be achieved with single chamber rate variable pacing compared to DDD pacing in patients with chronotropic incompetence. However, potential symptoms associated with loss of AV synchrony should be ruled out.