Journal of Interventional Cardiac Electrophysiology最新文献

Background: Orthotopic heart transplant (OHT) is among the final armamentariums for end-stage heart disease. Many patients who have had OHT require a post-transplant permanent pacemaker (PPM) implantation due to an abnormal conduction system. We aimed to evaluate the risk of mortality and acute rejection in patients with OHT who had received PPM compared to patients without PPM and to determine predictors for PPM placement in this population.

Methods: We comprehensively searched for studies from MEDLINE, EMBASE, and Cochrane databases from inception to September 2023. Inclusion criteria focused on patients who had undergone OHT and PPM implantation post-transplant. Data from each study were combined using a random-effects model. Results were expressed as relative risk (RR) or odd ratios (OR) with a 95% confidence interval (CI).

Results: A total of 9 studies were included in this meta-analysis incorporating a total of 54,848 patients (3.3% had PPM). The pooled all-cause mortality rate among patients with PPM post-OHT was 26% (95% CI: 19-33%, I² = 1%). There were no differences between post-heart transplant patients with PPM and those without PPM in risk of all-cause mortality (RR 0.76, 95% CI: 0.43-1.34; I² = 45%) and acute rejection (RR 1.22, 95% CI: 0.74-2.00, I² = 59%). Bi-atrial anastomosis was associated with an increased risk of PPM implantation post-OHT (OR 7.74, 95% CI: 3.55-16.91, I² = 0%), while pre-OHT mechanical circulatory support (MCS) was associated with a decreased risk of PPM implantation post-OHT (OR 0.45, 95% CI 0.27-0.76, I² = 0%).

Conclusion: There were no significant differences in all-cause mortality or acute rejection between post-OHT recipients who required PPM compared to those who did not receive PPM. Further, bi-atrial anastomosis portended the need for PPM implantation, while MCS was associated with a decreased occurrence of PPM.

Background: Pulsed field ablation (PFA) is an emerging non-thermal ablation method. The primary challenge is the control of multiple parameters in PFA, as the interplay of these parameters remains unclear in terms of ensuring effective and safe tissue ablation.

Purpose: This study employs the response surface method (RSM) to explore the interactions between various PFA parameters and ablation outcomes, and seeks to enhance the efficacy and safety of PFA.

Methods: In vivo experiments were conducted using rabbit liver for varying PFA parameters: pulse amplitude (PA), pulse interval (PI), number of pulse trains (NT), and number of pulses in a pulse train (NP). Ablation outcomes assessed included three ablation sizes, surface temperature, and muscle contraction strength. Additionally, histological analysis was performed on the ablated tissue. We analyzed the relationship between PFA parameters and ablation outcomes, and results were then compared with those from a simulation using an electric-thermal coupling PFA finite element model.

Results: A linear relationship between ablation outcomes and PFA parameters was established. PA and NT exhibited extremely significant (P < 0.0001) and significant effects (P < 0.05) on all ablation outcomes, respectively. NP showed an extremely significant impact (P < 0.0001) on surface temperature and muscle contraction strength, while PI significantly influenced (P < 0.05) muscle contraction strength alone. Histological analysis revealed that PFA produces controlled, well-defined areas of liver tissue necrosis. Surface temperature results from simulations and experiments were highly consistent (R² > 0.97).

Conclusions: This study clarifies the relationship between various PFA parameters and ablation outcomes, and aims to improve the efficacy and safety of PFA.

Introduction: Pulsed-field ablation (PFA) and fluoroless ablation (FA) are emerging techniques in contemporary in electrophysiology. With widespread use of 3D electroanatomic mapping systems and advanced intracardiac echo (ICE) imaging, fluoroless ablation has become more widely adopted. However, with the importance of tissue contact for lesion durability, initial PFA has been used with fluoroscopic guidance, but both ICE and electroanatomic mapping make fluoroless PFA feasible. The objective of this study is to demonstrate that PFA can be done safely and effectively without fluoroscopy.

Methods: At a single center, consecutive patients undergoing ablation with a pentaspline PFA catheter using a fluoroless approach are described. The standard 3D anatomic map settings were adjusted with changes in interior and exterior projection, respiratory compensation, and interpolation. In addition, projection map lesions were used to confirm adequate circumferential ablation lesions. ICE was used extensively for wire guidance and evaluation of contact with tissue.

Results: Beginning on March 15, 2024, 50 consecutive subjects (19 female/31 male) aged 68.0 (± 13.7) underwent PFA ablation. The average CHA₂DS₂-VA₂Sc score was 3.0 (± 1.9). The average LVEF was 57.3% (± 10.0) and the average LA size was 3.9 cm (± 1.2). Projection lesions were placed with every application of PFA. An average of 41.7 (± 8.5) PFA applications were placed. In 100% (50/50) of subjects, acute isolation of the pulmonary veins was achieved. Eighteen subjects also underwent concomitant posterior wall isolation and in 100% of these subjects, posterior isolation was achieved. There were zero complications in this cohort. In 50/50 subjects (100%), fluoroscopy was not used. In comparison to the control cohort, the LA dwell time of the ablation catheter was similar (p = 0.34).

Conclusion: In comparison to the traditional PFA with fluoroscopy, this proof-of-concept study shows fluoroless PFA ablation can be performed safely and with similar acute success rates as with use of fluoroscopy.

Background: Advances in medical treatment and outcomes in implantable cardioverter-defibrillator (ICD) recipients incentivize a need for improved candidate selection and identification of risk factors for ICD therapy. We examined contemporary rates of and risk factors for ICD therapy.

Methods: Patients with ICD for primary (PP) or secondary prevention (SP), implanted between January 2010 and December 2020, were followed for appropriate and inappropriate incident and recurrent shock.

Results: Overall, 2998 patients (mean age 61.8 ± 12.7 years, 20% female, 73% ICD carriers, and 47.1% SP) were analyzed with a median follow-up of 4.3 (interquartile range (IQR) 2.1-7.4) years. A total of 426/2998 (14.2%) patients had shock; 364/2998 (12.1%) had appropriate and 82/2998 (2.7%) inappropriate shock, with annualized event rates of 2.34 (2.11-2.59) and 0.49 (0.39-0.61) per 100 person-years, respectively. Of those with shock, 133/364 (36.5%) experienced recurrent appropriate shock and 8/364 (2.2%) received recurrent inappropriate shock, with event rates of 10.57 (8.85-12.53) and 0.46 (0.20-0.92), respectively. In multivariable analyses, female sex was associated with a reduced risk of incident appropriate shock (hazard ratio 0.69 [95% confidence interval 0.52; 0.91]). Of other variables, only revascularization status was associated with recurrent appropriate shock in PP, and CRT-D with recurrent appropriate shock in the overall cohort.

Conclusion: One in eight ICD recipients received appropriate shock 2-7 years after guideline-directed implantation. More than one-third of patients with a first shock experienced recurrent shock. Few clinical variables showed potential in predicting shocks, illustrating a need for more advanced tools to select candidates for implantation.

Background: TactiFlex is a next-generation catheter that is being used increasingly in ablation-treatment strategies. The purpose of this study was to investigate the differences in ablation lesions when the ablation power, time, and perfusion flow are varied with TactiFlex and TactiCath catheters.

Methods: The TactiFlex and TactiCath catheters were contacted perpendicularly/obliquely/parallel to the swine myocardium at varying powers (30, 40, and 50 W), time points (10, 15, 20, 25, 30, and 40 s), and forces (5, 10, 15, 20, and 30 g); the depth, width, and area of each lesion were measured, and the number of steam pops that occurred was counted.

Results: A total of 672 (336 lesions for each catheter) radiofrequency (RF) energy applications were delivered and 648 lesions were analyzed, excluding steam pops. The surface area and volume increased significantly with an increasing contact force for the TactiCath. The TactiCath lesions were significantly deeper than those for TactiFlex in most groups with the same power and seconds. The surface area was significantly larger when the catheters were contacted obliquely/parallel to the myocardium than perpendicularly using TactiCath, whereas the difference was less significant in the case of TactiFlex. In a 10-g contact force ablation experiment, TactiFlex did not cause pops, but TactiCath caused pops in 9.8% of cases.

Conclusion: The TactiFlex lesions were shallower than those of TactiCath. However, TactiFlex catheters reduced the steam pops during RF applications. Those data should help clinicians understand the characteristics of the catheters and develop adequate strategies.

Background: Subtypes of atrial fibrillation (AF) can differ, and exact mechanisms in which patients benefit from the pulmonary vein isolation (PVI) remain not fully understood. During PVI, vagal innervation of the heart may also be affected. Thus, non-invasive methods of intraprocedural assessment of such PVI impact are sought.

Methods: From 1-minute ECG recordings performed before and after PVI, we investigated short-term deceleration capacity (ST-DC) and short-term heart rate variability (ST-HRV) to determine their potential as indicators of parasympathetic activity before and after ablation.

Results: In 24 consecutive patients with paroxysmal AF included in the study, there were a significant differences in ST-DC and ST-HRV parameters measured before and after PVI. After 3 months, patients with baseline ST-DC ≥ 7.5 ms were less likely to experience AF recurrence when compared to patients with baseline ST-DC < 7.5 ms (0% vs 31%, p = 0.0496). There were no differences in AF recurrence after 12 months of follow-up (36% vs 38%, p = 0.52).

Conclusion: PVI leads to significant changes in ST-DC and ST-HRV, and these parameters can serve as indicators of vagal denervation after AF ablation. Patients with more prominent baseline ST-DC are less likely to experience AF recurrence during the post-PVI 3-month blanking period.

Background: MICRA implantation is not commonly done as a day-case procedure. Elective leadless pacemakers are implanted routinely in our centre.

Objective: To assess whether the day-case MICRA procedure is safe.

Methods: We retrospectively collected data from all patients undergoing elective MICRA implantation at our centre between May 2014 and Nov 2022 (n = 81). Two patient groups were stratified: those planned to be discharged on the same day (SD, n = 52) and those planned to be observed overnight after the procedure (ON, n = 29). Patient demographics, size of the sheath used, type of MICRA device, and rate of complications were recorded. In patients with successful implants (n = 80), device function at discharge and first routine follow-up were evaluated.

Results: There were 58% males in the SD group and 45% in the ON group. Median age was 49 years in the SD and 67 years in the ON. Among patients who were planned as a day case, 8 patients had to stay in the hospital but for < 48 h: 2 due to minor groin bleeding, 1 due to patient's request despite fit to discharge, 4 due to the procedure carried out later in the day, and 1 for observation due to procedural complexity. MICRA implantation was successful in 80 patients. The rate of the major complications was 2% in the SD group and 7% in the ON group (p = 0.223), and none of the co-morbidities assessed showed an association with any complications. Device parameters at the follow-up were available in 76 patients. The rate of patients with low and stable PCT at follow-up was also 98% in the SD group and 96% in the ON group.

Conclusions: Day case MICRA procedure can be performed safely in an appropriately selected patient population.

Background: In vitro models to evaluate cardiac pulsed field ablation (PFA) have not been well established. We sought to create a standardized vegetable model and staining protocol for assessing unipolar PFA using a surface electrode.

Methods: We exposed potato slabs to unipolar PFA in a saline bath using a 3.5 mm electrode catheter and grounding pad connected to a custom-built high-voltage generator. Lesions were clearly visualized after staining with 2,3,5-triphenyltetrazolium chloride (TTC) using a timed protocol to reveal a necrotic center and a periphery of electroporated cells with intact mitochondria.

Results: Lesion volume increased linearly with increasing voltage and logarithmically with repetitive PFA applications.

Conclusion: The findings observed in this vegetable model using a TTC staining protocol are consistent with findings observed with cardiomyocytes.