Pace-Pacing and Clinical Electrophysiology最新文献

The goal of a cardiac pulsed field ablation (PFA) system is to provide safe, effective, and usable therapy for the treatment of cardiac arrhythmias. Achieving this goal is a complex exercise in system design, requiring optimization of catheter, waveform, and dosing. This optimization is often iterative, as myriad design factors are balanced to achieve the goal while making use of computational modeling, bench testing, preclinical animal studies, and human clinical studies to evaluate system performance. It is important for both engineers and clinicians to understand the fundamentals of cardiac PFA system design in order to partner to continuously improve performance of this expanding ablation modality.

As pulsed-field ablation (PFA) emerges as a promising therapy for atrial arrhythmias, an understanding of the cellular injury to cardiac tissue is critical to evaluating and interpreting results for each PFA system. This review aims to detail the mechanism of cell death for PFA, compare the cell death mechanism to thermal ablation modalities, clarify common histology markers, detail the progression of PFA lesions from the acute, to subacute, to chronic maturation states, and discuss clinical indicators of PFA lesions.

With the ever-growing population of patients undergoing cardiac ablation with pulsed electric fields, there is a need to understand secondary effects from the therapy. Coronary artery spasm is one such effect that has recently emerged as the subject of further investigation in electrophysiology literature. This review aims to elucidate the basic anatomy underlying vascular spasm due to pulsed electric fields and the effects of irreversible electroporation on coronary arteries. This review also aims to gather the current preclinical and clinical data regarding the physiology and function of coronary arteries following electroporation.

Background: Age has been found as an important factor affecting the low voltage area (LVA) in patients with atrial fibrillation (AF). This study aims to investigate the potential benefit of LVA modification in older AF patients.

Methods: This study constitutes a sub-analysis of the STABLE-SR-II and STABLE-SR-III trials, wherein patients with persistent AF (PeAF) or paroxysmal AF (PAF) were randomized to undergo either circumferential pulmonary vein isolation (CPVI) alone or additional LVA modification. Patients aged ≥65 years were analyzed. The primary outcome was freedom from atrial tachyarrhythmias (ATAs).

Results: A total of 510 patients (mean age 70.2 ± 3.8 years, 264 male) were analyzed, comprising 96 PeAF and 414 PAF patients. Among patients without LVA, the risk of ATAs recurrence was similar between PeAF and PAF patients in the propensity score-matched model (adjusted HR, 1.49 [0.54-4.33]; p = 0.431). Both PeAF (adjusted HR, 0.35 [95% CI, 0.12-0.98]; p = 0.048) and PAF patients (adjusted HR, 0.41 [0.19-0.81]; p = 0.013) could benefit from additional LVA modification in the Cox proportional hazards model.

Conclusions: In older patients with AF, the recurrence rate following CPVI alone is comparable between those with PAF and PeAF in the absence of LVA. However, the presence of LVA is associated with higher recurrence rates in both PAF and PeAF patients, while additional LVA modification effectively reduces recurrence irrespective of AF type.

Recent reports highlighted the role of functional substrate mapping during sinus rhythm to predict the critical isthmus of left atrial tachycardias (AT). In this article, we reported a case of a 63-year-old female patient who was admitted with recurrent AT after pulmonary vein isolation. Although sinus rhythm revealed normal left atrium voltages, programmed stimulation with extrastimulus revealed decrement evoked potentials with prolongation in local electrograms on the anterior wall. Critical isthmus of AT was colocalized with deceleration zones during functional substrate mapping. Radiofrequency ablation successfully terminated AT.

Background: The novel POLARx cryoballoon ablation (CBA) system offers enhanced cooling properties for the treatment of atrial fibrillation (AF); however, these capabilities may damage adjacent tissues. This study aimed to assess the prevalence and predictors of gastric hypomotility (GH) in patients undergoing pulmonary vein isolation (PVI) and left atrial (LA) roofline ablation using the POLARx.

Methods: Patients who underwent CBA for PVI using the POLARx system were included in this study. Additional LA roofline ablation was performed in patients with non-paroxysmal AF and paroxysmal AF with LA enlargement. GH occurrence was assessed postoperatively by esophagogastroscopy, and the distance between the esophagus and surrounding tissues were measured.

Results: Among the 61 patients who underwent PVI, 22 underwent additional LA roofline ablation. GH was confirmed in 12 patients (30.8%) who underwent PVI only and 12 patients (54.5%) who underwent additional LA roofline ablation. Symptomatic GH with acute gastric dilation occurred in three patients, all of whom had undergone roofline ablation. Multivariate analysis, a shorter distance between the esophagus and the midpoint of the vertebral body (odds ratio, 0.74; 95% confidence interval, 0.55-0.98; p = 0.04) was identified as the sole predictor of GH, with a cutoff of 20.0 mm (sensitivity, 80.0%; specificity, 81.8%).

Conclusion: Adding LA roofline ablation to PVI using the POLARx may increase the risk of GH, particularly when the esophagus is in close proximity to the midpoint of the vertebral body.

Micra AV leadless pacemakers aim to maintain atrioventricular (AV) synchrony across various body positions. This report describes a case of position-dependent AV dyssynchrony in an 81-year-old man with nocturnal palpitations despite having normal routine evaluations. Rate histogram analysis revealed an unusual distribution pattern, and manual atrial mechanical (MAM) testing demonstrated an increased A3 signal amplitude in the left lateral position, which resulted in oversensing. Adjusting the A3 threshold and window end settings resolved the symptoms and normalized the rate histogram. This case highlights the importance of position-dependent signal variations and rate histogram analyses in patients with a Micra AV.

Background: Left bundle branch area pacing (LBBAP) offers cardiac synchrony benefits over conventional ventricular pacing. Although many studies on LBBAP have used lumenless pacing leads (LLLs), stylet-driven pacing leads (SDLs) can also be used. In this study, we compared LLLs and SDLs for LBBAP through a systematic review and meta-analysis of the literature.

Methods: The PubMed, Embase, and Cochrane Library databases were searched for full-text articles on LBBAP from their respective inception dates to April 9, 2024. The studies comparing LLLs and SDLs were extracted, and electrophysiological characteristics and procedural outcomes were analyzed. Of 2201 articles on LBBAP, 7 met the inclusion criteria of comparing LLLs and SDLs as implanted pacing leads.

Results: The overall pooled analysis showed noninferiority in implant success rates for SDLs compared with LLLs for LBBAP (89% vs. 94%, odds ratio: 0.80, 95% confidence interval [CI]: 0.37-1.72, p = 0.566). The paced QRS duration of LBBAP using SDLs was not significantly different from that using LLLs (standardized mean difference: -0.19 ms, 95% CI: -0.50 to 0.12, p = 0.239). There were no differences in the stimulus to the left ventricular activation time and paced QRS duration between the two groups. Follow-up pacing parameters were stable in both groups.

Conclusion: LBBAP using SDLs is noninferior to that using LLLs in terms of implantation success. There were no differences in procedural and electrophysiological characteristics between the two groups.

Background: Pacemaker pocket pseudoaneurysm is a rare complications after pacemaker implantation and often do not respond to conservative treatments.

Case presentation: We present a case of a 93-year-old man who developed pocket swelling and a significant hemoglobin decrease one week after pacemaker implantation. Conservative management, including compression and blood transfusion, proved ineffective. Angiography identified bleeding from the thoracoacromial artery, which was successfully addressed with coil embolization. The patient exhibited a favorable recovery during follow-up.

Conclusion: Arterial injury should be considered in cases of persistent hematoma after pacemaker implantation. Early imaging and embolization are crucial for effective management.

Introduction: Right ventricular apex (RVA) pacing has been reported to induce pacing-induced cardiomyopathy (PICM), with biventricular pacing being the standard cardiac resynchronization therapy (CRT) for RVA-PICM. However, recent studies suggest that left bundle branch area pacing (LBBAP) may provide even better outcomes as a CRT. In this case, we observed a dynamic alteration in the left ventricular (LV) activation pattern when transitioning from RVA-PICM to LBBAP, including changes in the functional block line.

Case: A female patient with dilated-phase hypertrophic cardiomyopathy (d-HCM), septal, and apical myocardial damage caused by cardiomyopathy, and prior ventricular tachycardia ablations experienced worsening heart failure due to dyssynchronous LV activation from RVA pacing (paced QRS duration of 250 ms). She underwent an upgrade to LBBAP (paced QRS duration of 160 ms) as CRT. Six months later, three-dimensional LV activation mapping was performed during both RVA pacing and LBBAP. During RVA pacing, a functional conduction block was observed in the anterior wall, resulting in unidirectional excitation propagation in a counterclockwise direction from the septum and a significant delay in the basal-mid anterior wall. In contrast, with LBBAP, the functional conduction block shifted to the septal-apical region, enabling bidirectional excitation propagation to the basal-mid lateral wall and facilitating synchronized excitation in vertically opposing LV segments.

Conclusion: The change in LV activation is specific to this d-HCM case with damaged septum and apex; however, it provides one of the insights into the mechanisms by which LBBAP exerts its beneficial effects when upgrading from RVA-PICM.