The latest medical research on Clinical Cardiac Electrophysiology

The research magnet gathers the latest research from around the web, based on your specialty area. Below you will find a sample of some of the most recent articles from reputable medical journals about clinical cardiac electrophysiology gathered by our medical AI research bot.

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P-wave alternans rebound following pulmonary vein isolation predicts atrial arrhythmia recurrence.

Journal of Cardiovascular Magnetic Resonance

Numerous P-wave indices have been explored as biomarkers to assess atrial fibrillation (AF) risk and the impact of therapy with variable success.

We investigated the utility of P-wave alternans (PWA) to track the effects of pulmonary vein isolation (PVI) and to predict atrial arrhythmia recurrence.

This medical records study included patients who underwent PVI for AF ablation at our institution, along with 20 control subjects without AF or overt cardiovascular disease. PWA was assessed using novel artificial intelligence-enabled modified moving average (AI-MMA) algorithms. PWA was monitored from the 12-lead ECG at ~1 h before and ~16 h after PVI (n = 45) and at the 4- to 17-week clinically indicated follow-up visit (n = 30). The arrhythmia follow-up period was 955 ± 112 days.

PVI acutely reduced PWA by 48%-63% (p < .05) to control ranges in leads II, III, aVF, the leads with the greatest sensitivity in monitoring PWA. Pre-ablation PWA was ~6 µV and decreased to ~3 µV following ablation. Patients who exhibited a rebound in PWA to pre-ablation levels at 4- to 17-week follow-up (p < .01) experienced recurrent atrial arrhythmias, whereas patients whose PWA remained reduced (p = .85) did not, resulting in a significant difference (p < .001) at follow-up. The AUC for PWA's prediction of first recurrence of atrial arrhythmia was 0.81 (p < .01) with 88% sensitivity and 82% specificity. Kaplan-Meier analysis estimated atrial arrhythmia-free survival (p < .01) with an adjusted hazard ratio of 3.4 (95% CI: 1.47-5.24, p < .02).

A rebound in PWA to pre-ablation levels detected by AI-MMA in the 12-lead ECG at standard clinical follow-up predicts atrial arrhythmia recurrence.

Application of artificial intelligence in the diagnosis and treatment of cardiac arrhythmia.

Pacing Clin Electrophysiol

The rapid growth in computational power, sensor technology, and wearable devices has provided a solid foundation for all aspects of cardiac arrhyth...

Gradual development of left bundle branch current of injury during left bundle branch pacing lead implantation.

Pacing Clin Electrophysiol

A larger left bundle branch (LBB) potential or LBB current of injury (COI) indicates a low LBB capture threshold in LBB pacing. During LBB pacing i...

The Role of Soluble Urokinase Plasminogen Activator Receptor (suPAR) as an Early Indicator of Mortality in Pediatric Septic Shock.

Clinical Laboratory

Despite advancements in antibiotic therapy and resuscitation protocols, sepsis and septic shock remain major contributors to morbidity and mortality in children. We aimed to investigate the utility of soluble urokinase plasminogen activator receptor (suPAR) for the early detection of septic shock and to evaluate its accuracy in predicting mortality.

A prospective study was conducted in a tertiary pediatric emergency department (ED), enrolling patients diagnosed with the sepsis, severe sepsis, or septic shock. In addition to assessing infection biomarkers such as C-reactive protein and procalcitonin, suPAR levels were quantified upon admission using enzyme-linked immunosorbent assay. The primary outcome measure was 30-day mortality.

Overall 72 patients and 80 healthy children included. Plasma suPAR levels demonstrated a statistically significant elevation in the sepsis, severe sepsis, and septic shock groups compared with the control group (p < 0.001 for all). The septic shock group exhibited the highest suPAR levels upon admission, surpassing both the sepsis and severe sepsis groups (p = 0.009 and 0.042). ROC analysis underscored the promising potential of suPAR with an AUC of 0.832 for septic shock. Analysis of mortality prediction revealed significantly higher suPAR levels in nonsurvivors than survivors (9.7 ng/mL vs. 4.2 ng/mL; p < 0.001). Employing plasma suPAR levels to discriminate between mortality and survival, a threshold of ≥7.0 ng/mL demonstrated a sensitivity of 90.9% and specificity of 71.0%.

Plasma suPAR levels have the potential as a biomarker for predicting mortality in children with septic shock. In pediatric septic shock, the presence of plasma suPAR ≥7 ng/mL along with an underlying disease significantly increases the risk of mortality.

Contemporary trends of leadless pacemaker implantation in the United States.

Journal of Cardiovascular Magnetic Resonance

Leadless pacemakers (LPM) have established themselves as the important therapeutic modality in management of selected patients with symptomatic bradycardia. To determine real-world utilization and in-hospital outcomes of LPM implantation since its approval by the Food and Drug Administration in 2016.

For this retrospective cohort study, data were extracted from the National Inpatient Sample database from the years 2016-2020. The outcomes analyzed in our study included implantation trends of LPM over study years, mortality, major complications (defined as pericardial effusion requiring intervention, any vascular complication, or acute kidney injury), length of stay, and cost of hospitalization. Implantation trends of LPM were assessed using linear regression. Using years 2016-2017 as a reference, adjusted outcomes of mortality, major complications, prolonged length of stay (defined as >6 days), and increased hospitalization cost (defined as median cost >34 098$) were analyzed for subsequent years using a multivariable logistic regression model.

There was a gradual increased trend of LPM implantation over our study years (3230 devices in years 2016-2017 to 11 815 devices in year 2020, p for trend <.01). The adjusted mortality improved significantly after LPM implantation in subsequent years compared to the reference years 2016-2017 (aOR for the year 2018: 0.61, 95% CI: 0.51-0.73; aOR for the year 2019: 0.49, 95% CI: 0.41-0.59; and aOR for the year 2020: 0.52, 95% CI: 0.44-0.62). No differences in adjusted rates of major complications were demonstrated over the subsequent years. The adjusted cost of hospitalization was higher for the years 2019 (aOR: 1.33, 95% CI: 1.22-1.46) and 2020 (aOR: 1.69, 95% CI: 1.55-1.84).

The contemporary US practice has shown significantly increased implantation rates of LPM since its approval with reduced rates of inpatient mortality.

AV-optimized conduction system pacing for treatment of AV dromotropathy: A randomized, cross-over study.

Journal of Cardiovascular Magnetic Resonance

Severe first-degree atrioventricular (AV) block may produce symptoms similar to heart failure due to AV dyssynchrony, a syndrome termed AV dromotropathy. According to guidelines, it should be considered for permanent pacemaker implantation, yet evidence supporting this treatment is scarce.

This study aimed to determine the impact of AV-optimized conduction system pacing (CSP) in patients with symptomatic severe first-degree AV block and echocardiographic signs of AV dyssynchrony.

Patients with symptomatic first-degree AV block (PR > 250 ms), preserved left ventricular ejection fraction, narrow QRS, and AV dyssynchrony were included in the study. In a single-blind cross-over design, patients were randomized to AV sequential CSP or backup VVI pacing with a base rate of 40 bpm. We compared exercise capacity, echocardiographic parameters, and symptom occurrence at the end of 3 months of each period.

Fourteen patients completed the study. During the AV-optimized CSP compared to the backup pacing period, patients achieved a higher workload on exercise test (147.2 ± 50.9 vs. 140.7 ± 55.8 W; p = .032), with a trend towards higher peak VO2 (23.3 ± 7.1 vs. 22.8 ± 7.1 mL/min/kg; p = .224), and higher left ventricular stroke volume (LVSV 74.5 ± 13.8 vs. 66.4 ± 12.5 mL; p < .001). Symptomatic improvement was recorded, with fewer patients reporting general tiredness and 71% of patients preferring the AV-optimized CSP (p = .008).

AV-optimized CSP could improve symptoms, exercise capacity and LVSV in patients with severe first-degree AV block.

Beware of atrial pacing-induced ventricular depolarization: A case of lead malfunction.

Pacing Clin Electrophysiol

Although ventricular capture during the atrial threshold test is possible, there are rare reports on the insulation defect and inactive leads there...

Adjunctive low-voltage area ablation for patients with atrial fibrillation: An updated meta-analysis of randomized controlled trials.

Journal of Cardiovascular Magnetic Resonance

The efficacy and safety of adjunctive low-voltage area (LVA) ablation on outcomes of catheter ablation (CA) for atrial fibrillation (AF) remains uncertain.

PubMed, Embase, Cochrane Library, and ClinicalTrials.gov were searched for randomized controlled trials (RCTs) comparing CA with versus without LVA ablation for patients with AF. Risk ratios (RR) with 95% confidence intervals (CI) were pooled with a random-effects model. Our primary endpoint was recurrence of atrial tachyarrhythmia (ATA), including AF, atrial flutter, or atrial tachycardia. We used R version 4.3.1 for all statistical analyses.

Our meta-analysis included 10 RCTs encompassing 1780 patients, of whom 890 (50%) were randomized to LVA ablation. Adjunctive LVA ablation significantly reduced recurrence of ATA (RR 0.76; 95% CI 0.67-0.88; p < .01) and reduced the number of redo ablation procedures (RR 0.54; 95% CI 0.35-0.85; p < .01), as compared with conventional ablation. Among 691 (43%) patients with documented LVAs on baseline substrate mapping, adjunctive LVA ablation substantially reduced ATA recurrences (RR 0.57; 95% CI 0.38-0.86; p < .01). There was no significant difference between groups in terms of periprocedural adverse events (RR 0.78; 95% CI 0.39-1.56; p = .49).

Adjunctive LVA ablation is an effective and safe strategy for reducing recurrences of ATA among patients who undergo CA for AF.

Left bundle branch area pacing using a lumenless lead: A systematic literature review and meta-analysis.

Journal of Cardiovascular Magnetic Resonance

Although left bundle branch area pacing (LBBAP) has been shown to be a feasible option for delivering physiological pacing, data are largely limited to single-center reports. The aim of this analysis was to systematically assess the safety and efficacy of LBBAP with the Model 3830 lead among primarily bradycardia patients.

PubMed, Embase, Cochrane Library, and Google Scholar were searched for full-text articles on LBBAP using the SelectSecure Model 3830 lumenless lead. Rates and means were estimated using random- and mixed-effects models. Of 3395 articles, 53 met inclusion criteria, representing 6061 patients undergoing an implant attempt. Average patient age was 68.1 years (95% CI: 66.6, 69.6) and 53.1% were male (95% CI: 50.5%, 55.7%). The average implant success rate among bradycardia-indicated patients was 92.7% (95% CI: 89.5%, 94.9%). The overall estimated procedural adverse event rate was 2.5% (95% CI: 1.1%, 5.4%). The estimated septal perforation rate at implant was 1.6% (95% CI: 1.0%, 2.6%) with no adverse clinical sequelae reported. Pacing thresholds were low at implant (0.67 V [95% CI: 0.64, 0.70]) and remained stable through 12 months (0.76 V [95% CI: 0.72, 0.80]). Among bradycardia-indicated patients, LVEF remained stable from baseline to post-implant (59.5% [95% CI: 57.9%, 61.1%] vs. 60.1% [95% CI: 58.5%, 61.7%]).

This meta-analysis including 6061 patients implanted with a Model 3830 lead for LBBAP found an average implant success rate of 92.7% and a procedural adverse event rate of 2.5% with stable electrical parameters and LVEF post-implant.

Safety of catheter ablation in patients with recently implanted cardiac implantable electronic device: A 5-year experience.

Pacing Clin Electrophysiol

Catheter ablation (CA) can interfere with cardiac implantable electronic device (CIED) function. The safety of CA in the 1st year after CIED implantation/lead revision is uncertain.

This single center, retrospective cohort included patients who underwent CA between 2012 and 2017 and had a CIED implant/lead revision within the preceding year. We assessed the frequency of device/lead malfunctions in this population.

We identified 1810 CAs in patients between 2012 and 2017, with 170 CAs in 163 patients within a year of a CIED implant/lead revision. Mean age 68 ± 12 years (68% men). Time between the CIED procedure and CA was 158 ± 99 days. The CA procedures included AF ablation (n = 57, 34%), AV node ablation (n = 40, 24%), SVT ablation (n = 37, 22%), and PVC/VT ablations (n = 36, 21%). The cumulative frequency of lead dislodgement, significant CIED dysfunction, and/or CIED-related infection following CA was (n = 1/170, 0.6%). There was a single atrial lead dislodgement (0.6%). There were no instances of power-on-reset or CIED-related infection. Following CA, there was no significant difference in RA or RV lead sensing (p = 0.52 and 0.84 respectively) or thresholds (p = 0.94 and 0.17 respectively). The RA impedance slightly decreased post-CA from 474 ± 80 Ohms to 460 ± 73 Ohms (p = 0.002), as did the RV impedance (from 515 ± 111 Ohms to 497 ± 98 Ohms, p < 0.0001).

CA can be performed within 1 year following CIED implantation/lead revision with a low risk of CIED/lead malfunction or lead dislodgement. The ideal time to perform CA after a CIED remains uncertain.

Patient characteristics, predictors and outcome of pacemaker patients upgraded to an implantable cardioverter defibrillator.

Pacing Clin Electrophysiol

Pacemaker (PM) patients may require a subsequent upgrade to an implantable cardioverter defibrillator (ICD). Limited data exists on this patient population. We sought to characterize this population, to assess predictors for ICD upgrade, and to report the outcome.

From our prospective PM and ICD implantation registry, all patients who underwent PM and/or ICD implantations at our center were analyzed. Patient characteristics and outcomes of PM patients with subsequent ICD upgrade were compared to age- and sex-matched patients with de novo ICD implantation, and to PM patients without subsequent upgrade.

Of 1'301 ICD implantations, 60 (5%) were upgraded from PMs. Median time from PM implantation to ICD upgrade was 2.6 years (IQR 1.3-5.4). Of 2'195 PM patients, 28 patients underwent subsequent ICD upgrades, corresponding to an estimated annual incidence of an ICD upgrade of at least 0.33%. Lower LVEF (p = .05) and male sex (p = .038) were independent predictors for ICD upgrade. Survival without death, transplant and LVAD implantation were worse both for upgraded ICD patients compared to matched patients with de novo ICD implantation (p = .05), as well as for PM patients with subsequent upgrade compared to matched PM patients not requiring an upgrade (p = .036).

One of 20 ICD implantations are upgrade of patients with a PM. At least one of 30 PM patients will require an ICD upgrade in the following 10 years. Predictors for ICD upgrade are male sex and lower LVEF at PM implantation. Upgraded patients have worse outcomes.

A real-time signal processing software package for the electrophysiology laboratory.

Journal of Cardiovascular Magnetic Resonance

Real-time signal processing has to date been difficult to implement in the clinical electrophysiology laboratory. To date, no open access software solutions are available in electrophysiology (EP) laboratories to facilitate real-time intraprocedural signal analysis. We aimed to develop an open access, scalable Python plug-in to allow real-time signal processing during human EP procedures.

A Python-based plug in for the widely available EnsiteX mapping system was developed. This plug-in utilized the LiveSync feature of the system to allow real-time signal analysis. An open access library was developed to allow end-users to implement real-time signal analysis using this platform, implemented in the Python programming language https://github.com/anand9176/WaveWatch5000Public.

We have developed and demonstrated the feasibility of a readily scalable and open-access Python-based plug in to an electroanatomic mapping system (EnSiteX) to allow real-time processing and display of electrogram (EGM) based information for the procedural electrophysiologist to view intraprocedurally in the electrophysiology laboratory. The availability, to the clinician, of traditional and novel EGM-based metrics at the time of intervention, such as atrial fibrillation ablation, allows for key mechanistic insights into critical unresolved questions regarding arrhythmia mechanism.