Incidence of new onset atrial fibrillation in patients with permanent pacemakers and the relation to the pacing mode

The incidence of atrial fibrillation detected by implantable loop recorders: a comparison between patients with and without embolic stroke of undetermined source

Aims

Stroke is the most debilitating outcome of atrial fibrillation (AF). The use of implantable loop recorders increases the detection of AF episodes among patients with embolic stroke of undetermined source. The significance of device-detected AF, or subclinical AF, is unknown. This study aimed to compare the incidence of AF detected by implantable loop recorder in patients with and without embolic stroke of undetermined source.

Methods and results

We retrospectively studied all patients without known AF who were referred to our institution for implantable loop recorder implantation following embolic stroke of undetermined source, syncope, or palpitations from March 2009 to November 2019. The primary endpoint was any detection of AF or atrial flutter by implantable loop recorder. Seven hundred and fifty patients were included and followed up for a mean duration of 731 days (SD 443). An implantable loop recorder was implanted following embolic stroke of undetermined source in 323 and for assessment of syncope, palpitations, or another reason in 427 patients. The incidence of AF was significantly (P < 0.001) higher among patients with embolic stroke of undetermined source compared with the non-embolic stroke of undetermined source group; 48.6% vs. 13.8% (for any duration of AF) and 32.2% vs. 12.4% (for AF lasting ≥30 s) both P < 0.001. Kaplan-Meier analysis showed significantly higher incidence of AF for incremental durations of AF up to >5.5 h, but not >24 h. This was driven by longest AF durations of <6 min and between 5.5 h and 24 h, suggesting a bimodal distribution. In a multivariable Cox regression analysis, embolic stroke of undetermined source independently conferred an almost 5-fold increase in the hazard for any duration of AF.

Conclusion

The incidence of AF is significantly higher amongst embolic stroke of undetermined source vs. non-embolic stroke of undetermined source patients monitored constantly by an implantable loop recorder. A high number of embolic stroke of undetermined source survivors have short-duration AF episodes. Further work is needed to determine the optimal treatment strategy of these AF episodes in embolic stroke of undetermined source.

Diagnosis and Treatment of New-Onset Perioperative Atrial Fibrillation

This article reviews medical and surgical risk factors for developing atrial fibrillation (AF), the most common sustained dysrhythmia in the United States. Evidence for assessment and management of patients with AF, including AF newly identified in the preoperative clinic, immediately preoperatively, intraoperatively, and unstable AF, is presented. A stepwise approach to guide anesthetic decision-making in the assessment of newly identified preoperative AF is proposed. Anesthetic considerations, including the potential impacts of anesthetic and vasopressor selection, and current evidence related to rate control and rhythm control via pharmacologic or electrical cardioversion as well as anticoagulation strategies are discussed.

Two-year Outcomes of Ventricular-demand Leadless Pacemaker Therapy for Heart Block After Transcatheter Aortic Valve Replacement

Ventricular-demand leadless pacemakers (VVI-LPMs) have often been used as an alternative to atrioventricular (AV) synchronous transvenous pacemakers (DDD-TPMs) in patients with high-grade AV block following transcatheter aortic valve replacement (TAVR). However, the clinical outcomes of this unusual usage are not elucidated. Patients who received permanent pacemakers (PPMs) owing to new-onset high-grade AV block after TAVR from September 2017 to August 2020 at a high-volume center in Japan were included in the analysis, and the clinical courses of VVI-LPM and DDD-TPM implants through 2 years of follow-up were compared retrospectively. Out of 413 consecutive patients who underwent TAVR, 51 (12%) patients received a PPM. After excluding 8 patients with chronic atrial fibrillation (AF), 3 with sick sinus syndrome, and 1 with incomplete data, 17 VVI-LPMs and 22 DDD-TPMs were included in our final cohort. The VVI-LPM group had lower serum albumin levels (3.2 ± 0.5 vs. 3.9 ± 0.4 g/dL, P < .01) than the DDD-TPM group. Follow-up revealed no significant differences between the 2 groups in terms of the incidence of late device-related adverse events (0% vs. 5%, log-rank P = .38) and new-onset AF (6% vs. 9%, log-rank P = .75); however, there were increases in the rates of all-cause death (41% vs. 5%, log-rank P < .01) and heart failure rehospitalization (24% vs. 0%, log-rank P = .01) in the VVI-LPM group. This small retrospective study reveals favorable post-procedural complication rates but higher all-cause mortality with VVI-LPM compared to DDD-TPM therapy for high-grade AV block after TAVR at 2 years of follow-up.

Clinical Outcomes of Non-Atrial Fibrillation Bradyarrhythmias Treated With a Ventricular Demand Leadless Pacemaker Compared With an Atrioventricular Synchronous Transvenous Pacemaker - A Propensity Score-Matched Analysis

BACKGROUND

Implanting a ventricular demand leadless pacemaker (VVI-LPM) for patients with non-atrial fibrillation (AF) bradyarrhythmias such as sick sinus syndrome (SSS) or high-grade (i.e., second- or third-degree) atrioventricular (AV) block is not recommended unless they have limited vascular access or a high infection risk; nevertheless, an unexpectedly high number of VVI-LPM implantations have been performed. This study investigated the clinical outcomes of these unusual uses.

METHODS AND RESULTS

This study retrospectively analyzed 193 patients who were newly implanted with a VVI-LPM or an atrioventricular synchronous transvenous pacemaker (DDD-TPM) for non-AF bradyarrhythmias at a high-volume center in Japan from September 2017 to September 2020. Propensity score-matching produced 2 comparable cohorts treated with a VVI-LPM or DDD-TPM (n=58 each). Each group had 20 (34%) patients with SSS and 38 (66%) patients with high-grade AV block. During a median follow up of 733 (interquartile range 395-997) days, there were no significant differences between the VVI-LPM and DDD-TPM groups regarding late device-related adverse events (0% vs. 4%, log-rank P=0.155), but the VVI-LPM group had a significantly increased readmission rate for heart failure (HF) (29% vs. 2%, log-rank P=0.001) and a tendency to have higher all-cause mortality (28% vs. 4%, log-rank P=0.059).

CONCLUSIONS

The implantation of a VVI-LPM for non-AF bradyarrhythmias increased the incidence of HF-related rehospitalization at the mid-term follow up compared to the use of a DDD-TPM.

Trends, Associations, and Impact of Atrial Fibrillation in Patients With Light-chain Cardiac Amyloidosis

BACKGROUND

In this study, we investigated the temporal trends in the prevalence and prognostic implication of atrial fibrillation (AF) in patient with light-chain cardiac amyloidosis (AL-CA).

METHODS

We identified 3030 patients with AL-CA from the 2015 to 2017 National Inpatient Sample, of which 1577 (52%) had AF. We used trend analysis to assess the temporal trends in the prevalence of AF by subtype from 2015 to 2017. We compared inhospital mortality, acute on chronic heart failure, stroke, length of stay (LOS), and total cost in patients with to those without AF, stratified by subtype of AF.

RESULTS

The prevalence of AF among patients with AL-CA was unchanged from 2015 to 2017 (50%-53%; adjusted odds ratio, 1.1 [0.9-1.5]; P = 0.3). The trend was unchanged in the stratified analysis by subtype of AF. Patients with AF were older and had more comorbidities. After propensity matching, acute on chronic heart failure was significantly higher in patients with AL-CA and AF, compared with those with AL-CA alone (55.6% vs. 48.3%; P < 0.0001). There was no difference in inhospital mortality (7.5% vs. 7.5%; P = 0.9), stroke (2.0% vs. 2.5%; P = 0.5), median LOS (5 [3-9] vs. 5 [3-8]; P = 0.3), and median total hospital cost $42,469 ([$21,309-$92,855] vs. $44,008 [$22,889-$94,200]; P = 0.6). In the stratified analysis, acute on chronic heart failure remained significant higher in patients with paroxysmal and nonparoxysmal AF, while LOS became significantly longer in patients with paroxysmal AF.

CONCLUSIONS

Among patients with AL-CA, AF is associated with a higher risk of acute on chronic heart failure.

Effects of atrial electromechanical delay and ventriculoatrial conduction over the atrial functions in patients with frequent extrasystole and preserved ejection fraction

BACKGROUND

The deterioration of left atrial and ventricular functions was demonstrated in patients with frequent ventricular extrasystole (fVES). The exact pathophysiology of left atrial dysfunction in patients with fVES is unclear. Retrograde ventriculoatrial conduction (VAC) often accompanies fVES, which may contribute to atrial dysfunction. We investigated whether atrial electromechanical delay and VAC are related to these atrial functions in patients with frequent right ventricular outflow tract (RVOT) VES and preserved ejection fraction (pEF).

METHODS

This study included 21 patients with pEF (eight males, 48 ± 11 years), who had experienced more than 10 000 RVOT-VES during 24-h Holter monitoring and had undergone electrophysiological study/ablation. The study also included 20 healthy age- and sex-matched control subjects. Transthoracic echocardiography was performed on all of the subjects. Atrial conduction time was obtained by using tissue Doppler imaging. Strain analysis was performed with two-dimensional speckle tracking echocardiography.

RESULTS

The peak atrial longitudinal strain was significantly impaired in patients with fVES (P = 0.01). In addition, although the interatrial and left atrial conduction delay times were significantly different between each group (P < 0.001, P < 0.001), the right atrial conduction delay times were similar. When patients with fVES were divided into groups depending on the existence of retrograde VAC, atrial deformation parameters and conduction delay time did not significantly differ between either group.

CONCLUSION

Frequent RVOT-VES causes left atrial dysfunction. This information is obtained through strain analyses and recordings of left atrial conduction times in patients with pEF. Regardless, retrograde VAC is not related to atrial dysfunction.

A novel wavelet-based filtering strategy to remove powerline interference from electrocardiograms with atrial fibrillation

OBJECTIVE

The electrocardiogram (ECG) is currently the most widely used recording to diagnose cardiac disorders, including the most common supraventricular arrhythmia, such as atrial fibrillation (AF). However, different types of electrical disturbances, in which power-line interference (PLI) is a major problem, can mask and distort the original ECG morphology. This is a significant issue in the context of AF, because accurate characterization of fibrillatory waves (f-waves) is unavoidably required to improve current knowledge about its mechanisms. This work introduces a new algorithm able to reduce high levels of PLI and preserve, simultaneously, the original ECG morphology.

APPROACH

The method is based on stationary wavelet transform shrinking and makes use of a new thresholding function designed to work successfully in a wide variety of scenarios. In fact, it has been validated in a general context with 48 ECG recordings obtained from pathological and non-pathological conditions, as well as in the particular context of AF, where 380 synthesized and 20 long-term real ECG recordings were analyzed.

MAIN RESULTS

In both situations, the algorithm has reported a notably better performance than common methods designed for the same purpose. Moreover, its effectiveness has proven to be optimal for dealing with ECG recordings affected by AF, since f-waves remained almost intact after removing very high levels of noise.

SIGNIFICANCE

The proposed algorithm may facilitate a reliable characterization of the f-waves, preventing them from not being masked by the PLI nor distorted by an unsuitable filtering applied to ECG recordings with AF.

Prevalence and predictors of atrial arrhythmias in patients with sinus node dysfunction and atrial pacing

PURPOSE

This study aimed to determine the incidence, prevalence, and predictors of atrial arrhythmias (AAs) in patients with symptomatic sinus node dysfunction (SND) who required permanent pacemaker implantation. Also, we evaluated the impact of atrial pacing (AP) on AAs.

METHODS

All consecutive patients who underwent pacemaker implantation from 2005 to 2011 were included. Atrial fibrillation (AF), atrial flutter (AFL), atrial tachycardia (AT), and AV nodal reentrant tachycardia (AVNRT) were detected via pacemaker interrogation and clinical documentation.

RESULTS

The study group included 322 patients (44% male) with mean age 68.8 ± 15 years and followed for an average of 5.6 ± 2.2 years (median 5.7 years). Overall, 61.8% were found to have any AA at follow-up. Individual prevalence of AAs was high as follows: AF 43.5%, AFL 6.5%, AT 25%, and AVNRT 6.8%. AF was documented in 23% of patients (n = 74) prior to pacemaker; among those, 15% (n = 11) had no recurrence of AF with average AP of 74%. The incidence of new-onset AF after pacemaker was 15.8%. In subgroup analysis, prevalence of AF was increased by 16% with high rate of AP (81-100%) and 17% with lower rate of AP (0-20%). Incidence of new-onset AF was not affected by AP. Diabetes, hypertension, and left atrial enlargement were predictors of AAs. White men and women had higher prevalence of AF.

CONCLUSIONS

AAs are highly prevalent in SND, particularly in white patients. Paroxysmal AF is suppressed with AP in minority, but there is no impact of AP on new-onset AF. Patients with diabetes, hypertension, and dilated atria must be monitored closely for early detection of AAs.

Olmesartan Reduces New-onset Atrial Fibrillation and Atrial Fibrillation Burden after Dual-chamber Pacemaker Implantation in Atrioventricular Block Patients

Background:

Atrial fibrillation (AF) is the most frequent tachyarrhythmia in patients with a permanent pacemaker. Angiotensin II receptor antagonists have a protective effect against the occurrence of AF in patients with heart diseases. This study aimed to assess the effectiveness of olmesartan in the prevention of new-onset AF and AF burden in atrioventricular block (AVB) patients with dual-chamber (DDD) pacemaker implantation.

Methods:

This was a single-center, prospective, randomized, single-blind, controlled clinical study. A total of 116 AVB patients, who received DDD pacemakers implantation with the percentage of ventricular pacing (VP%) ≥40% from April 22, 2011 to December 24, 2012, were prospectively randomized to olmesartan group (20 mg per day; n = 57) or control group (n = 59). Patients were followed up using pacemaker programming, 12-lead electrocardiography in the intrinsic sinus rhythm, laboratory examinations, and transthoracic echocardiography at 24 months. Atrial high rate events (AHREs) were defined as 180 beats/min over a minimum of 5 min. AF burden was calculated by the number of hours with AHREs divided by the number of measurement hours.

Results:

Ten (17.5%) patients in the olmesartan group and 24 patients (40.7%) in the control group occurred new-onset AF, and the difference between two groups was statistically significant (P = 0.04). AF burden was lower in olmesartan group than that in control group (8.02 ± 3.10% vs. 13.66 ± 6.14%, P = 0.04). There were no significant differences in mean days to the first occurrence of AHREs and mean cumulative numbers of AHREs between two groups (P = 0.89 and P = 0.42, respectively). Moreover, olmesartan group had smaller values of maximal P-wave durations and P-wave dispersion (PD) after 24 months follow-up compared with the control group (109.5 ± 7.4 ms vs. 113.4 ± 7.1 ms, P = 0.00; and 40.6 ± 4.5 ms vs. 43.3 ± 4.4 ms, P = 0.02, respectively). Left ventricular end-diastolic diameter and left ventricular ejection fraction were not significantly different between two groups (both P > 0.05).

Conclusion:

This study suggested that 24-month of olmesartan therapy could reduce new-onset AF and AF burden in patients with DDD pacemakers.

Clinical Trial Registration:

ChiCTR-TRC-12004443; http://www.chictrdb.org.

Device-identified atrial fibrillation at pacing clinics. Should it guide anticoagulation?

In recent years, there has been a significant increase in the number of devices implanted following improvement in their safety profile, extension of indications and reduction in cost. Although the reason remains largely the beneficial effect on heart rhythm stabilisation, implanted devices might also have additional advantages, notably identification of silent arrhythmia. Should clinicians therefore act on device-identified atrial fibrillation (AF) and should such identification be used to guide anticoagulation management? This review evaluates the current evidence on the management of device-identified asymptomatic AF.

Use of Implantable Cardioverter Defibrillators in Heart Failure Patients and Risk of Mortality: A Meta-Analysis

BACKGROUND

The purpose of this study was to evaluate the effect of implantable cardioverter defibrillators (ICD) in heart failure (HF) patients compared to pharmacologic/conventional management.

MATERIAL AND METHODS

We searched PubMed, Embase, and Springer Link Library databases up to February 10th, 2014. Pooled risk ratio (RR) and 95% confidence interval (CI) for the mortality of the patients with HF were collected and calculated in a fixed-effects model or a random-effects model, as appropriate. Summary effect estimates were also stratified by sex and follow-up time. Egger's regression asymmetry tests were utilized for publication bias detection.

RESULTS

A total of 7 separate studies including 15 520 patients (10 801 ICD cases and 4719 controls) with HF were considered in the meta-analysis. The overall estimates showed that ICD could statistically significantly reduce the mortality of male (RR=0.73, 95% CI: 0.66-0.80) and female (RR=0.75, 95% CI: 0.63-0.90) patients. In addition, the further stratification subgroup analysis indicated that ICD presented a significant reduction (male: RR=0.72, 95% CI: 0.64-0.81; female: RR=0.69, 95% CI: 0.56-0.85) of mortality after 2-3 years of ICD therapy. The RR (95% CI) effects of mortality after 4-5 years of ICD therapy for males and females were 0.76 (0.51-1.14) and 0.96 (0.68-1.37), respectively.

CONCLUSIONS

This meta-analysis suggests that ICD could reduce HF patient mortality despite the sex difference.