Pace-Pacing and Clinical Electrophysiology最新文献

We present the case of a 64-year-old man who, during the implantation of an active-fixation leadless pacemaker (LP, Aveir VR, Abbott, USA), underwent several external defibrillation shocks up to 240 Joules, due to symptomatic sustained supraventricular tachycardia at 160 bpm. The shocks, delivered both before and after the screwing of the device in the low interventricular septum, did not cause any technical damage to the device, and no complications were observed. The device was then deployed successfully. To our knowledge, this is the first documented case of external cardioversion (ECV) in a patient with an active-fixation LP. The results suggest that ECV in these patients appears to be safe and feasible.

Background: Painful left bundle branch block (PLBBB) syndrome remains a poorly understood cardiac anomaly. This systematic review consolidates case report evidence to elucidate effective management strategies and patient outcomes.

Methods: Databases including PubMed, Scopus, Web of Science, and Scielo were searched without restrictions on language or publication date. Following PRISMA guidelines, 128 articles were identified, with 31 meeting inclusion criteria. Data were extracted on patient demographics, clinical presentation, treatment regimens, and outcomes using Microsoft Excel and assessed for bias with the Joanna Briggs Institute's tool.

Results: The analysis included 45 patients with a mean age of 55.46 ± 12.23. Predominantly, LBBB episodes occurred during exercise (73.3%). Initial treatments comprised beta-blockers/calcium channel blockers (55.56%), pacemaker implantation (13.3%), antianginal medications (13.3%), and other modalities (17.7%). Refractoriness to initial treatment was observed in 66.7% of patients, with subsequent pacemaker implantation resolving symptoms in most cases. An overall satisfactory response was seen in 73.3% of patients post-treatment adjustments.

Conclusions: The diverse approaches in treatment highlight the necessity for tailored therapeutic strategies. While pacemakers have demonstrated efficacy in controlling symptoms in several reported cases, it is essential to recognize the complex nature of this intervention. Pacemaker implantation, being a surgical procedure, carries long-lasting implications for patients. Hence, the continuation of pharmacological treatments might still be preferable until more definitive research is available. This review emphasizes the urgent need for further research to establish evidence-based guidelines, particularly concerning the selection of first line of treatment, to optimize outcomes for PLBBB syndrome.

Aims: The aim of this study was to investigate the topological distribution of single nucleotide variants (SNVs) in the KCNH2 gene from patients with type 2 long QT syndrome (LQT2) and to explore the genotype-phenotype relationships.

Methods: Information on KCNH2 variants in LQT2 patients was retrospectively obtained from the HGMD, ClinVar, and PubMed databases through October 2022. Pathogenicity of SNV was classified according to the American College of Medical Genetics and Genomics (ACMG) guidelines. Unpaired t-tests and Fisher's exacts were used to analyze the SNV distributions across structural and functional domains, and their correlation with clinical phenotypes.

Results: A total of 2826 variants were obtained; 2152 were SNVs, 1328 of which were nonsynonymous SNVs (nsSNVs) associated with LQT2. Enrichment analysis revealed that 602 pathogenic (P) and likely pathogenic (LP) nsSNVs were significantly enriched at S5, H5, S6, Extra3, and Extra4. In addition, 759 nsSNVs and 289 P/LP nsSNVs within function domain were enriched at the per-arnt-sim (PAS) and selectivity filter (SF) functional domain. Clinical data revealed that patients with nsSNVs enriched at the N-terminal, S5-H5-S6 region and PAS domain were associated with an increased risk of syncope. Moreover, nsSNVs located at the N-terminal, S5-H5-S6 region, and PAS, SF domains were associated with an increased risk of life-threatening cardiac events, including Torsade de Pointes (TdP) and sudden cardiac death (SCD), and were predominantly female.

Conclusion: KCNH2 nsSNVs located at the N-terminal, S5-H5-S6 region, and the PAS and SF functional domains are associated with an increased risk of life-threatening cardiac events in LQT2 patients.

Background: The degree and time course of improvement in left ventricular (LV) function with treatment in patients with tachycardiomyopathy (TCMP) is highly variable. This study aims to clinically characterize the recovery of TCMP based on the extent and course of improvement in LV function and identify predictors of complete myocardial recovery.

Methods: In this prospective, single-center, observational study, patients with suspected TCMP who underwent successful tachyarrhythmia termination/control were included. Clinical and echocardiographic assessment of LV function was done at baseline, within 1 h after tachyarrhythmia termination, 24 h later, and at 12 weeks follow-up.

Results: Ninety-nine patients were enrolled in the study. Six patients had immediate normalization of LV ejection fraction (LVEF) with reversion to sinus rhythm and were labeled as "pseudo-TCMP"; the remaining 93 patients were included in the analysis. Based on complete versus partial normalization of LVEF at 12-week follow-up, 50 patients (53.8%) were labeled as completely recovered TCMP and 43 (46.2%) as partially recovered TCMP respectively. Causative arrhythmias included atrial fibrillation (38%), focal atrial tachycardia (28%), atrial flutter (22%), ventricular arrhythmias (11%), and orthodromic re-entrant tachycardia (2%). The LVEF at presentation was 0.25 ± 0.05 which improved to 0.36 ± 0.11 within 1 h after tachycardia termination (p < 0.0001), 0.41 ± 0.14 24 h later (p = 0.009) and to 0.52 ± 0.12 at 12 weeks follow-up (p < 0.0001). Male gender was the only differentiating statistically significant variable between completely recovered and partially recovered TCMP, 24 (48%) versus 30 (69.7%) respectively (p = 0.0339).

Conclusion: Nearly half of the TCMP patients have complete recovery of LV function at 12 weeks follow-up, while the other half have a partial recovery only. There was no robust predictor of complete myocardial recovery.

Background: Concurrent Micra leadless pacemaker (Medtronic, Minneapolis, Minnesota) implantation and atrioventricular node (AVN) ablation has been shown to be feasible and safe in patients with symptomatic, drug-refractory atrial fibrillation (AF). However, major complications within the 30 days after concurrent Micra implantation and AVN ablation have been reported. We evaluated the efficacy and safety of the concurrent procedure at our institution.

Methods: We conducted a single-center, retrospective case series of patients who underwent concurrent Micra implantation and radiofrequency (RF) AVN ablation from January 2019 to May 2023. A simulated computer model was created to characterize the interaction between the dissipated power at the Micra cathodal electrode as a function of the distance between the RF ablation catheter and the location of the return electrode.

Results: Fifteen patients were included. Most were elderly, White, female, and had persistent AF. One had transient, acute loss of ventricular capture that resulted in asystole and required emergent pacing from the ablation catheter. A proposed strategy of moving the RF return electrode to a cranial position from a caudal position was shown by computer modeling to direct more RF current away from the Micra and lower the dissipated power at the Micra cathodal electrode.

Conclusion: Concurrent Micra implantation and AVN ablation is feasible and safe and has high procedural success. An acute rise in pacing threshold can occur from RF energy, resulting in asystole. Computer modeling showed that placing the RF return electrode in the cranial position resulted in lower dissipated power at the Micra cathodal electrode.

Background: Temporary transvenous pacing (TTP) is a common procedure, predominantly performed in the catheterization laboratory (cath lab) because of presumed lower complication rate. This study aims to evaluate the efficacy and safety of TTP placement in the ICU compared to TTP placement in the cath lab.

Methods: This retrospective, real-life study included all patients requiring TTP in a tertiary care ICU between 2019 and 2022. Patients' characteristics, TTP-related data, outcomes, and complications were compared between groups (ICU vs. cath lab).

Results: Data from 193 patients receiving TTP were analyzed; 68.4% received TTP in the ICU and 31.6% in the cath lab. The main indication was atrioventricular block in 154 patients (79.8%). The operator was less frequently an interventional cardiologist in the ICU (12.1%) compared to the cath lab (100%, p < 0.001). TTP in the ICU was more frequently performed using a jugular access (72.0% vs. 1.6%), a right-sided laterality (88.7% vs. 43.6%), and a balloon-tipped catheter (100% vs. 0%, p < 0.001 for all comparisons). Success was 100% in both groups. The overall complication rate was 16.6%, with no significant difference between both groups (14.4% ICU vs. 21.3% cath lab, p = 0.13), but a tendency toward higher complications in the cath lab group (especially tamponade, lead displacement, and CIED infection).

Conclusion: In a daily clinical scenario, TTP placement appears as safe in the ICU than in the cath lab, regardless of the operator's level of expertise when performed in accordance with best practices. Nevertheless, TTP complications remain high, and alternatives should be used whenever possible.

Background: An indicator of successful cryoballoon (CB)-assisted pulmonary vein (PV) isolation is complete PV occlusion. However, CBs may exhibit a weaker freezing effect on the equatorial plane. This study investigates the predictors of failed left superior PV (LSPV) isolation despite complete occlusion with novel CBs.

Methods: This retrospective analysis enrolled 300 consecutive patients who underwent first-time ablation with POLARx or POLARxFIT between November 2021 and October 2023. Of the total, complete occlusion of the LSPV was achieved in 200 patients. Patients in whom LSPV isolation was achieved with additional nonocclusive freezing of the LSPV roof due to nonisolation of LSPV despite complete occlusion (Group A) were compared with those in whom isolation was achieved with complete PV occlusion alone (Group B).

Results: Group A had a larger LSPV diameter (21.5 ± 4.6 mm vs. 18.8 ± 3.3 mm, p = 0.052), larger left atrial volume on CT (142.3 ± 47.8 cc vs. 117.8 ± 39.0 cc, p = 0.028), higher nadir temperature (-54.1 ± 5.1°C vs. -60.2 ± 4.4°C, p < 0.001), and smaller northern latitude of the balloon contact site on the LSPV roof side (20.9° ± 3.8° vs. 38.9° ± 6.7°, p < 0.001) compared with Group B. A 27.5° north latitude was observed in most of Group A (sensitivity, 100%; specificity, 96%).

Conclusions: Adequate contact positioning of the northern hemisphere to the LSPV is critical for effective isolation, particularly when isolation is challenging despite complete occlusion. In such cases, nonocclusive cryoablation against the LSPV roof might be effective.

The use of conduction system pacing (CSP) in adults with congenital heart disease (CHD) is growing, however data remain limited. In patients with congenitally corrected transposition of the great arteries following the double switch operation, existing CSP tools and techniques require modification to allow for the anterior displacement of the atrioventricular node and proximal conduction system in addition to navigating the tortuous route of the atrial redirection. We report the successful use of CSP focusing on the technique of delivery tool modification to allow stability on the basal septum for deployment to the area of the distal His bundle and proximal left bundle branch.

This case report presents the management of tachycardiomyopathy (TCM) in a patient with Friedreich ataxia, a hereditary disorder characterized by progressive neurodegeneration and associated cardiac complications. The patient exhibited severe tachycardia-induced cardiac dysfunction, complicating the clinical picture due to the overlapping neurological symptoms of Friedreich ataxia. Utilizing a 3D mapping system, catheter ablation was performed to accurately identify and target the arrhythmogenic foci contributing to the patient's TCM. The procedure resulted in significant symptom relief and improvement in cardiac function, underscoring the potential benefits of advanced electrophysiological techniques in managing complex cases. This report highlights the importance of a multidisciplinary approach in diagnosing and treating cardiac manifestations in patients with Friedreich ataxia, as well as the efficacy of 3D mapping technology in guiding successful ablation therapies.