Pace-Pacing and Clinical Electrophysiology最新文献

Background: Intracardiac echocardiography (ICE) has been widely used in the catheter ablation of atrial fibrillation (AF). However, the value of ICE in the training of transseptal puncture (TSP) is unclear.

Methods: ICE-Training Study was a single-center, parallel-group, unmasked, randomized controlled trial registered in ChineseClinicalTrials.gov. Participants were randomly assigned (1:1) to different groups (1) the ICE simulator training group (ICE-ST), in which TSP was trained and performed under the guidance of both ICE and x-ray; and (2) the conventional simulator training group (Con-ST), in which TSP was trained and performed only under the guidance of x-ray. The trainees need to undergo the training stage and the evaluation stage.

Results: From October 2022 to December 2022, 18 consecutive fellows (age 32.4 ± 4.4 years, 12 males) without experience of TSP were included. The training period (16.9 ± 6.6 vs. 29.6 ± 8.7 times, p = 0.003) and the fluoroscopy time (120.3 ± 25.3 vs. 189.3 ± 40.2 s, p < 0.001) of the ICE-ST group was significantly shorter than that of the Con-ST group. No significant difference was found in the comprehensive performance of TSP in the ICE-ST group (composite score 96.7 ± 5.7) and the Con-ST group (composite score 95.9 ± 6.3, p = 0.62), but the selection of TSP sites in the ICE-ST group was commonly better than that in the Con-ST group.

Conclusions: ICE could improve the efficiency of TSP training and optimize the site of TSP to facilitate catheter manipulation in the ablation.

Trial registration: ChineseClinicalTrials.gov identifier: ChiCTR2200058377.

Background: Atrial fibrillation (AF) inducibility with burst pacing (BP) after radiofrequency ablation (RFA) has been reported to be associated with AF recurrence. In contrast, the relevance of inducibility and recurrence after cryoablation (CRA) is unclear.

Methods: We investigated 367 patients undergoing initial ablation for paroxysmal AF (RFA: 174, CRA: 193). Propensity score matching was conducted, retaining 134 patients in each group. Following pulmonary vein isolation (PVI), the inducibility by BP was tested. Inductions at 250 ppm were defined as low-frequency burst pacing (LFBP) positive, and those at 300 ppm were classified as medium-frequency burst pacing (MFBP) positive. They were followed for 600 days.

Results: Forty-eight patients (18%) had AF recurrence. There was no significant difference in the recurrence rate between RFA and CRA (17% vs. 19%, Log-rank p = 0.79). In RFA, significant differences were observed for both LFBP (Log-rank p < 0.001) and MFBP (Log-rank p < 0.001). In contrast, in CRA, there were no significant differences for either LFBP (Log-rank p = 0.39) or MFBP (Log-rank p = 0.19). Multivariable analysis revealed that LFBP-positive (hazards ratio [HR] = 5.75, 95% confidence interval [CI] 2.41-13.7, p < 0.001) was an independent predictor for recurrence with RFA. Acute reconnection (HR = 2.73, 95% CI 1.13-6.56, p = 0.025) was an independent predictor for recurrence with CRA.

Conclusion: The inducibility by BP after RFA predicted recurrence at both low and medium frequencies. LFBP-positive was an independent predictor of recurrence in multivariable analysis. In contrast, the inducibility by BP after CRA was not a predictor of recurrence.

Trail registration: This study did not require clinical trial registration.

In a 55-year-old man with nonischemic cardiomyopathy, a unique tachycardia was recorded on a dual-chamber implantable cardioverter defibrillator (St. Jude Medical [Abbott]) as an automatic mode switch episode. This case report discusses the mechanism of tachycardia, how it can be differentiated from similar rhythms, and its clinical implications. The report explores device limitations in managing such tachycardias and presents reprograming strategies to prevent recurrence. This case emphasizes the importance of careful analysis of device-mediated arrhythmias and appropriate programming.

Background: Event monitors are being increasingly used in pediatric and adult congenital heart disease (ACHD) patients for arrhythmia evaluation. Data on their diagnostic yield are limited.

Objectives: To evaluate the diagnostic yield of event monitors, patient characteristics associated with critical events, and clinical response to events.

Methods: We retrospectively assessed event monitors prescribed to patients at our institution's Heart Center from 2017 to 2020. Thirty-day event monitor tracings were reviewed by an electrophysiologist (EP) to identify critical events defined as supraventricular tachycardia (SVT, re-entrant, atrial tachycardia, atrial flutter, and atrial fibrillation), ventricular tachycardia (VT), atrioventricular block, and pauses greater than 3 s. Patient characteristics and treatment data were collected. Characteristics associated with events were assessed using multivariable logistic regression. Trends in monitor prescription over time, diagnostic yield, and clinical response to events were analyzed.

Results: 204/2330 (8.8%) event monitors had EP-confirmed critical events. Critical events included SVT (51.5%), VT (38.5%), atrioventricular block (4%), and pauses (6%). 129/198 (65%) patients with critical events underwent treatment. Event monitoring usage increased by 52% between 2017 and 2020 (p < 0.0001). Complex CHD (OR 2.1, 95% CI 1.3-3.4, p = 0.004), cardiomyopathy (OR 2.9, 95% CI 1.5-4.8, p < 0.001), and EP-ordered monitors (OR 1.6, 95% CI 1.2-2.1, p = 0.001) were more highly associated with critical events.

Conclusion: Event monitor use is common, and critical events were captured in 8.8% of patients. The majority of patients with critical events underwent treatment. Factors associated with critical events include EPs as ordering providers, complex CHD, and cardiomyopathy.

Background: Atrial fibrillation (AF) is usually triggered by frequent atrial premature complexes (APC) and atrial tachycardias originated in the pulmonary veins. The aim of the current study is to clarify the relationship between AF and APCs observed during treadmill exercise testing through long-term patient follow-up.

Material and methods: Our study only examined the data of patients who did not have any obstructive coronary artery disease and had an exercise test. In total, 1559 patients were included in this research. The study data were divided into two groups according to the development of AF during follow-up. The patients who developed any type of AF during the follow-up period were classified as AF (+). Mean follow-up time for AF (+) and (-) groups were 48 and 47 months, respectively.

Results: In the univariable analysis, age, LAAP, and the presence of APCs (HR: 3.906, 95% CI: 2.848-5.365, p < 0.001) during the treadmill exercise test were significantly associated with the development of AF. In the multivariable analysis, age (adjusted HR: 1.063, 95% CI: 1.043-1.083, p < 0.001) and the presence of APCs during the treadmill exercise test (adjusted HR: 2.504, 95% CI: 1.759-3.565, p < 0.001) emerged as independent risk factors for the development of AF. The AF-free survival was significantly lower in the APCs (+) patients compared with the APCs (-) patients (log rank p < 0.001).

Conclusion: Our study revealed that individuals without obstructive CAD who exhibited frequent APCs during treadmill exercise tests were more likely to develop AF.

Background and objective: Treating recurrent atrial arrhythmias after persistent atrial fibrillation (PeAF) ablation is often challenging. This single-center, prospective study aimed to observe the effectiveness of different combinations of oral antiarrhythmic drugs (AADs) in reverting to sinus rhythm (SR) in patients with recurrent atrial arrhythmias after PeAF ablation.

Methods: Forty-five patients who experienced recurrent atrial arrhythmias after PeAF ablation were included. Based on their medication regimens, patients were divided into two groups, with the study group being a triple-drug group (digoxin combined with amiodarone/ propafenone and β-blocker), and the control group being a non-triple-drug group.

Results: The rate of reversion to SR was significantly higher in the study group (n = 29) than in the control group (n = 16) at 3 weeks (34.48% vs. 0%, p < 0.01) and 1 month (44.84% vs. 6.25%, p = 0.02) after initiating AADs. No patients with asymptomatic bradycardia were observed in either group.

Conclusions: For patients with recurrent atrial arrhythmias after PeAF ablation, a regimen of low-dose digoxin combined with amiodarone/propafenone and β-blocker may effectively improve short-term reversion rates.

Background: Patients with subcutaneous implantable cardioverter-defibrillators (S-ICDs) experience an oversensing episode (OS) more frequently than those with transvenous ICDs. However, no established electrocardiography (ECG) parameters can accurately detect an OS. This study aimed to evaluate the incidence of an OS in real-world clinical practice and the association of synthesized 18-lead ECG (syn18-ECG) parameters with an OS.

Methods: We retrospectively included 21 consecutive patients who underwent S-ICD implantation and collected syn18-ECG parameters. We placed the generator in a deep posterior position and defined an OS as an inappropriate charging episode caused by cardiac or noncardiac signals. A SMART pass filter and two tachyarrhythmia zones were programed.

Results: The most frequent underlying heart disease was Brugada/J wave syndrome (n = 7). During a median follow-up period of 1188 days, an OS was observed in six patients (28.6%). The QRS amplitude in synthesized V7 lead (synV7) was significantly lower in the OS group than in the non-OS group (0.59 ± 0.17 vs. 0.91 ± 0.35 mV, p = 0.019). The optimal cutoff value of synV7 QRS amplitude was 0.61 mV, with a sensitivity of 80.0% and a specificity of 83.7% for predicting an OS. Univariate logistic analysis showed that a synV7 QRS amplitude of <0.61 mV was only associated with an OS (odd ratio, 20.0; 95% confidence interval, 1.66-241.72; p = 0.018).

Conclusions: In patients with S-ICDs, an OS was not a rare complication during long-term follow-up. A low synV7 QRS amplitude was associated with a high OS incidence.

Ventricular diverticula are saccule-like structures formed by the protrusion of the ventricular myocardium from the endocardial surface towards the free wall. Most diverticula are muscular structures, and patients usually have no obvious clinical symptoms. However, diverticula may contribute to arrhythmogenesis due to localized myocardial structural disturbances. Right ventricular apical diverticulum (RVAD) is very rare, and we report a case of highly symptomatic accelerated idioventricular rhythm (AIVR) originating from the RVAD that underwent intracardiac echocardiography (ICE)-guided catheter ablation with no recurrence during follow-up.

Background: When using lesion size index (LSI) to guide catheter ablation, it is unclear what combination of power, contact force and time would be preferable to use and what LSI target value to aim for. This study aimed at identifying desirable ablation settings and LSI targets by using tissue impedance drop as indicator of lesion formation.

Methods: Consecutive patients, undergoing their first left atrial (LA) catheter ablation for atrial fibrillation, with radiofrequency energy (RF) powers of 20, 30 and 40 W were enrolled. Tissue impedance, contact force (CF), Force Time Integral (FTI) and LSI values were continuously recorded during ablation and sampled at 100 Hz. Mean CF and Contact Force Variability (CFV) were calculated for every lesion. The effect of RF power, ablation time, CF and CFV on impedance drop and LSI were assessed.

Results: A total of 3258 lesions were included in the analysis. For any target LSI value, use of higher RF powers translated into progressively higher impedance drops. The impact of lower CF and higher CFV on impedance drop was more relevant when using lower powers. Target LSI values corresponding to maximum impedance drop were identified depending on RF power, mean CF and CFV used.

Conclusions: Even in the context of an LSI-guided ablation strategy, use of lower or higher powers might lead to different lesion sizes. Different LSI targets might be needed depending on the combination of RF power, CF and CFV used for ablation. Incorporating indicators of catheter stability, like CFV, in the LSI formula could improve the predictive value of LSI for lesion size. Studies with clinical outcomes are required to confirm the clinical relevance of these findings.

The pacing threshold is important for leadless pacemakers, as the pacing output has a significant impact on battery longevity. Acute pacing rate-dependent threshold increases have also been reported with leadless pacemakers. In the present case, we experienced a case in which the threshold, which had been raised in the acute phase, once showed a tendency to improve, but then worsened again. And, as in previous reports, thresholds improved completely in the chronic phase. Repeated retrieval and reimplantation of leadless pacemakers increases the likelihood of fatal complications, so being aware of such phenomenon may prevent unnecessary procedure and complications.