Journal of Interventional Cardiac Electrophysiology最新文献

Background: Catheter ablation of accessory pathway is the treatment of choice for patients with symptomatic Wolff-Parkinson-White (WPW) syndrome. Accessory pathway (AP) identification relies on point-by-point mapping, raising the need for more precise and efficient methods. High-density open window mapping (OWM) combined with the extended early meets late (EEML) algorithm, utilizing 3D electroanatomic mapping systems, is a promising alternative. However, its role in clinical practice lacks comprehensive investigation, necessitating a comparison with conventional mapping.

Methods: A prospective cohort study of patients referred for AP ablation evaluated the OWM strategy, comparing it with a retrospective cohort using conventional mapping. Procedure variables, including radiofrequency (RF), fluoroscopy, mapping and procedure times along with total mapping points were compared. Long-term recurrence rates were assessed.

Results: 42 patients in the OWM group and 34 in the conventional group were included. The OWM strategy exhibited a significantly lower total mapping time (p = 0.030) despite acquiring more points (p < 0.001) than the conventional group. OWM was associated with reduced fluoroscopy time (12.0 (9.0-16) vs. 19 (11-30) minutes, p = 0.009) and RF time (p = 0.021). Long-term recurrence rates were comparable between groups (7.1% OWM vs. 17.7% conventional mapping, p = 0.284). At a median follow-up of 16.2 (4.6-39.4) months there were not significant differences in recurrence-free survival (p = 0.509).

Conclusion: OWM with the EEML algorithm is a feasible tool for precise AP location and ablation, associated with less fluoroscopy time, RF time, and total mapping time. Long-term recurrence rates were similar to conventional mapping. Prospective studies are warranted for further validation.

Background: Pulsed field ablation (PFA) is a new modality for pulmonary vein isolation (PVI) for atrial fibrillation (AF). PFA is performed under general anaesthetic (GA) or deep sedation with propofol, but this requires anaesthetic support in many countries, restricting use. No study has tested the feasibility of PFA under mild conscious sedation (MCS).

Methods: We prospectively recruited patients undergoing PFA PVI, offered the option of MCS delivered by electrophysiologists, and compared these with patients who opted for GA. MCS comprised intravenous midazolam and fentanyl. All procedures were performed under anaesthetic supervision in case of requirement to convert to GA, which formed the primary outcome.

Results: Twenty-three patients were recruited (8 MCS, 15 GA). One patient (1/8 [12.5%]) required conversion from MCS to GA. Total procedural times were similar between groups (MCS 92 ± 12.4 min vs. GA 101 ± 17.3 min; p = 0.199). High mean sedative doses were required in the MCS group (5.12 ± 0.83 mg midazolam and 209 ± 40 mcg fentanyl). Median intraprocedural pain perception by the patient, rated from 0 to 100 was 45 (IQR 22.5-72.5) in the MCS group. Post-procedural groin pain (0 [0-0] vs. 5 [0-35]; p = 0.027) and throat pain (0 [0-0] vs. 10 [5-40]; p = 0.001) were lower in the MCS group.

Conclusion: PFA under MCS is feasible in selected patients but pain and tolerance may be suboptimal, and high sedative doses are required.

Background: Clinical experience during trans-patch ventricular ablations shows difficult lesion formation when using standard RF ablation technology. The aim of this exploratory study is to test if ultralow temperature cryoblation (ULTC) technology could be suitable for trans-patch ventricular ablations.

Materials and methods: Ex vivo ablations were performed on 16 porcine tenderloin specimens of 5 × 7 × 3 cm, eight with and eight without pericardial patch (Supple Peri-Guard Repair Patch, Baxter, USA). RF energy was applied for 1 min, with a power of 40W. ULTC was applied as a 2 × 2 min freeze. Temperature was measured using an array of thermocouples ranging between 0.5 and 13.1 mm below the tissue surface.

Results: For RF, the maximum temperatures without and with patch respectively reached 58.9 °C and 48.5 °C. The thermocouple closest to the tissue surface displayed a 41% temperature range drop when RF energy was applied trans-patch, whereas the same thermocouple showed a 16% and 13% drop for the first and second ULTC freeze cycle when ULTC was applied trans-patch. The 45 °C isotherm depth was reduced by 55% for RF ablations, whereas the - 25 °C isotherm depth was reduced by 23% and 19% for the first and second freeze cycles, respectively.

Conclusion: Both energy modalities show reduced efficacy for trans-patch ablations when considering absolute temperature differences and estimated lesion depths. However, when considering relative differences, ULTC is more effective than RF for trans-patch lesions. Additionally, ULTC did not show visible damage to either the patch or the ex vivo specimen, while RF resulted in visible damage to both the tissue and patch.

Background: The atrial electroanatomic substrate is an essential component in the pathogenesis of atrial fibrillation (AF). However, the electrophysiological markers of susceptible atria for AF are not well-characterized. This study aimed to assess atrial conduction indices on surface electrocardiogram (ECG) and intracardiac electrogram (EGM) as predictors of initiation and recurrence of AF after successful ablation.

Methods: We studied all consecutive patients who underwent electrophysiological study and catheter ablation for AF (study group) or atrioventricular nodal reentrant tachycardia (AVNRT) (control group) from 2013 to 2018. Atrial conduction indices were measured on ECG and EGM during the electrophysiology study. Clinical data was obtained from the medical record.

Results: A total of 387 patients with AF (mean age 63 years, 31% female) were studied and compared to 94 patents in control group. The initiation of AF was associated with significant prolongation of atrial conduction indices on ECG and EGM (p < 0.05). During a mean follow up of 5 ± 2 years, recurrence of AF (48%) after successful ablation occurred in patients with prolonged P wave duration, left atrial (LA) conduction interval, proximal to distal coronary sinus (pCS-dCS) interval, and P wave to dCS interval (p < 0.05). Machine learning modeling determined that pCS-dCS interval, QRS duration, and LA duration in leads V1 and II are most impactful conduction indices in association with AF recurrence.

Conclusion: Prolonged atrial conduction intervals, particularly LA (pCS-dCS), indicate susceptible substrate for the onset and the recurrence of AF after ablation. LA conduction indices can facilitate early detection and management of AF.

Background: Radiofrequency balloon (RFB) ablation (HELIOSTAR™, Biosense Webster) has been developed to improve pulmonary vein ablation efficiency over traditional point-by-point RF ablation approaches. We aimed to find effective parameters for RFB ablation that result in chronic scar verified by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR).

Methods: A chronic canine model (n = 8) was used to ablate in the superior vena cava (SVC), the right superior and the left inferior pulmonary vein (RSPV and LIPV), and the left atrial appendage (LAA) with a circumferential ablation approach (RF energy was delivered to all electrodes simultaneously) for 20 s or 60 s. The electroanatomical map with the ablation tags was projected onto the 3-month post-ablation LGE-CMR. Tags were divided into two groups depending on whether they correlated with CMR-based scar (ScarTags) or non-scar tissue (Non-ScarTags). The effective parameters for scar formation were estimated by multivariate logistic regression.

Results: This study assessed 80 lesions in the SVC, 80 lesions in the RSPV, 20 lesions in the LIPV, and 30 lesions in the LAA (168 ScarTags and 42 Non-ScarTags). In the multivariate analysis, two variables were associated with chronic scar formation: temperature of electrode before energy application (odds ratio (OR) 0.805, p = 0.0075) and long RF duration (OR 2.360, p = 0.0218), whereas impedance drop was not associated (OR 0.986, p = 0.373).

Conclusion: Lower temperature of the electrode before ablation and long ablation duration are critical parameters for durable atrial scar formation with RFB ablation.

Background: Electrographic flow (EGF) mapping reconstructs atrial electrical wavefront propagation, potentially revealing sources of atrial fibrillation (AF). Electrographic flow consistency (EGFC) measures the concurrence of wavefront patterns and may provide insights into atrial substrate health. This study aimed to compare EGF patterns during atrial fibrillation (AF) with sinus rhythm (SR) and explore the correlation between EGFC and regional bipolar voltage.

Methods: In this single-center, prospective study, AF patients underwent mapping of the atria using bipolar voltage and EGF mapping. Mapping was performed during both AF and SR using a 16-electrode grid catheter (bipolar mapping) and a 64-pole basket catheter (EGF mapping). EGFC was computed as the average modulus of individual EGF vectors, reflecting flow pattern consistency.

Results: Ten patients were enrolled. EGF identified 11 sources with a mean source activity of 32 ± 9% during AF. Eight out of eleven sources in AF converted to passive "sinks" when mapped in SR. EGFC was significantly lower during AF compared to SR (0.74 ± 0.14 vs 1.0 ± 0.11 AUs, P < 0.01), consistent with EGFC quantifying the more chaotic wavefront propagation during arrhythmia. No spatial correlation between areas of high EGFC during AF and SR was observed. EGFC correlated with bipolar voltage across rhythms and atria (r = 0.647, P < 0.0001).

Conclusion: EGF patterns varied by rhythm with AF showing lower EGFC values. EGFC correlated with bipolar voltage across rhythms and atria, suggesting its potential as an atrial myopathy marker akin to high-density voltage mapping and offering insights into atrial substrate health. Trial registration ClinicalTrials.gov Identifier: NCT06260670.