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1.
Europace ; 26(5)2024 May 02.
Article in English | MEDLINE | ID: mdl-38696675

ABSTRACT

AIMS: Contact force (CF)-sensing radiofrequency (RF) catheters with an ablation index have shown reproducible outcomes for the treatment of atrial fibrillation (AF) in large multicentre studies. A dual-energy (DE) focal CF catheter to deliver RF and unipolar/biphasic pulsed field ablation (PFA), integrated with a three-dimensional (3D) mapping system, can provide operators with additional flexibility. The SmartfIRE study assessed the safety and efficacy of this novel technology for the treatment of drug-refractory, symptomatic paroxysmal AF. Results at 3 months post-ablation are presented here. METHODS AND RESULTS: Pulmonary vein isolation (PVI) was performed using a DE focal, irrigated CF-sensing catheter with the recommendation of PFA at posterior/inferior and RF ablation at the anterior/ridge/carina segments. Irrespective of energy, a tag size of 3 mm; an inter-tag distance ≤6 mm; a target index of 550 for anterior, roof, ridge, and carina; and a target index of 400 for posterior and inferior were recommended. Cavotricuspid isthmus ablation was permitted in patients with documented typical atrial flutter. The primary effectiveness endpoint was acute procedural success. The primary safety endpoint was the rate of primary adverse events (PAEs) within 7 days of the procedure. A prespecified patient subset underwent oesophageal endoscopy (EE; 72 h post-procedure), neurological assessment (NA; pre-procedure and discharge), and cardiac computed tomography (CT)/magnetic resonance angiogram (MRA) imaging (pre-procedure and 3 months post-procedure) for additional safety evaluation, and a mandatory remapping procedure (Day 75 ± 15) for PVI durability assessment. Of 149 patients enrolled between February and June 2023, 140 had the study catheter inserted (safety analysis set) and 137 had ablation energy delivered (per-protocol analysis set). The median (Q1/Q3) total procedure and fluoroscopy times were 108.0 (91.0/126.0) and 4.2 (2.3/7.7) min (n = 137). The acute procedural success rate was 100%. First-pass isolation was achieved in 89.1% of patients and 96.8% of veins. Cavotricuspid isthmus ablations were successfully performed in 12 patients [pulsed field (PF) only: 6, RF only: 5, and RF/PF: 1]. The PAE rate was 4.4% [6/137 patients; 2 pulmonary vein (PV) stenoses, 2 cardiac tamponades/perforations, 1 stroke, and 1 pericarditis]. No coronary artery spasm was reported. No oesophageal lesion was seen in the EE subset (0/31, 0%). In the NA subset (n = 30), microemboli lesions were identified in 2 patients (2/30, 6.7%), both of which were resolved at follow-up; only 1 was symptomatic (silent cerebral lesion, 3.3%). In the CT/MRA subset (n = 30), severe PV narrowing (of >70%) was detected in 2 patients (2/30, 6.7%; vein level 2/128, 1.6%), of whom 1 underwent dilatation and stenting and 1 was asymptomatic; both were associated with high index values and a small inter-tag distance. In the PV durability subset (n = 30), 100/115 treated PVs (87%) were durably isolated and 18/30 patients (60.0%) had all PVs durably isolated. CONCLUSION: A DE focal CF catheter with 3D mapping integration showed a 100% acute success rate with an acceptable safety profile in the treatment of paroxysmal AF. Prespecified 3-month remapping showed notable PVI durability. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05752487.


Subject(s)
Atrial Fibrillation , Catheter Ablation , Pulmonary Veins , Humans , Pulmonary Veins/surgery , Atrial Fibrillation/surgery , Atrial Fibrillation/physiopathology , Male , Female , Catheter Ablation/methods , Catheter Ablation/instrumentation , Middle Aged , Treatment Outcome , Aged , Imaging, Three-Dimensional , Cardiac Catheters , Time Factors , Equipment Design , Prospective Studies , Recurrence
2.
Europace ; 26(5)2024 May 02.
Article in English | MEDLINE | ID: mdl-38701222

ABSTRACT

AIMS: Pulsed field ablation (PFA) for the treatment of atrial fibrillation (AF) potentially offers improved safety and procedural efficiencies compared with thermal ablation. Opportunities remain to improve effective circumferential lesion delivery, safety, and workflow of first-generation PFA systems. In this study, we aim to evaluate the initial clinical experience with a balloon-in-basket, 3D integrated PFA system with a purpose-built form factor for pulmonary vein (PV) isolation. METHODS AND RESULTS: The VOLT CE Mark Study is a pre-market, prospective, multi-centre, single-arm study to evaluate the safety and effectiveness of the Volt™ PFA system for the treatment of paroxysmal (PAF) or persistent AF (PersAF). Feasibility sub-study subjects underwent phrenic nerve evaluation, endoscopy, chest computed tomography, and cerebral magnetic resonance imaging. Study endpoints were the rate of primary serious adverse event within 7 days and acute procedural effectiveness. A total of 32 subjects (age 61.6 ± 9.6 years, 65.6% male, 84.4% PAF) were enrolled and treated in the feasibility sub-study and completed a 30-day follow-up. Acute effectiveness was achieved in 99.2% (127/128) of treated PVs (96.9% of subjects, 31/32) with 23.8 ± 4.2 PFA applications/subject. Procedure, fluoroscopy, LA dwell, and transpired ablation times were 124.6 ± 28.1, 19.8 ± 8.9, 53.0 ± 21.0, and 48.0 ± 19.9 min, respectively. Systematic assessments of initial safety revealed no phrenic nerve injury, pulmonary vein stenosis, or oesophageal lesions causally related to the PFA system and three subjects with silent cerebral lesions (9.4%). There were no primary serious adverse events. CONCLUSION: The initial clinical use of the Volt PFA System demonstrates acute safety and effectiveness in the treatment of symptomatic, drug refractory AF.


Subject(s)
Atrial Fibrillation , Catheter Ablation , Feasibility Studies , Pulmonary Veins , Humans , Male , Female , Atrial Fibrillation/surgery , Atrial Fibrillation/therapy , Atrial Fibrillation/physiopathology , Middle Aged , Pulmonary Veins/surgery , Treatment Outcome , Prospective Studies , Catheter Ablation/methods , Catheter Ablation/instrumentation , Aged , Equipment Design , Phrenic Nerve/injuries , Time Factors
3.
J Vis Exp ; (206)2024 Apr 19.
Article in English | MEDLINE | ID: mdl-38709062

ABSTRACT

Radiofrequency (RF) ablation to perform pulmonary vein isolation (PVI) for the treatment of atrial fibrillation involves some risk to collateral structures, including the esophagus. Proactive esophageal cooling using a dedicated device has been granted marketing authorization by the Food and Drug Administration (FDA) to reduce the risk of ablation-related esophageal injury due to RF cardiac ablation procedures, and more recent data also suggest that esophageal cooling may contribute to improved long-term efficacy of treatment. A mechanistic underpinning explaining these findings exists through the quantification of lesion placement contiguity defined as the Continuity Index (CI). Kautzner et al. quantified the CI by the order of lesion placement, such that whenever a lesion is placed non-adjacent to the prior lesion, the CI is incremented by the number of segments the catheter tip has moved over. To facilitate real-time calculation of the CI and encourage further adoption of this instrument, we propose a modification in which the placement of non-adjacent lesions increments the CI by only one unit, avoiding the need to count potentially nebulous markers of atrial segmentation. The objective of this protocol is to describe the methods of calculating the CI both prospectively during real-time PVI cases and retrospectively using recorded case data. A comparison of the results obtained between cases that utilized proactive esophageal cooling and cases that used luminal esophageal temperature (LET) monitoring is then provided.


Subject(s)
Atrial Fibrillation , Catheter Ablation , Esophagus , Atrial Fibrillation/surgery , Esophagus/surgery , Humans , Catheter Ablation/methods , Catheter Ablation/instrumentation , Pulmonary Veins/surgery
4.
Circ Arrhythm Electrophysiol ; 17(5): e012667, 2024 May.
Article in English | MEDLINE | ID: mdl-38655693

ABSTRACT

BACKGROUND: We previously presented the safety and early efficacy of the inspIRE study (Study for Treatment of Paroxysmal Atrial Fibrillation [PAF] by Pulsed-field Ablation [PFA] System With Irreversible Electroporation [IRE]). With the study's conclusion, we report the outcomes of the full pivotal study cohort, with an additional analysis of predictors of success. METHODS: InspIRE was a prospective, multicenter, single-arm clinical trial of drug-refractory paroxysmal atrial fibrillation. Pulmonary vein isolation was performed with a variable-loop circular catheter integrated with a 3-dimensional mapping system. Follow-up with 24-hour Holter was at 3, 6, and 12 months, as well as remote rhythm monitoring: weekly from 3 to 5 months, monthly from 6 to 12 months, and for symptoms. The primary effectiveness end point (PEE) was acute pulmonary vein isolation plus freedom from any atrial arrhythmia at 12 months. Additional subanalyses report predictors of PEE success. RESULTS: The patient cohort included 186 patients: aged 59±10 years, female 30%, and CHA2DS2-VASc 1.3±1.2. The previously reported primary adverse event rate was 0%. One serious procedure-related adverse event, urinary retention, was reported. The PEE was achieved in 75.6% (95% CI, 69.5%-81.8%). The clinical success of freedom from symptomatic recurrence was 81.7% (95% CI, 76.1%-87.2%). Simulating a monitoring method used in standard real-world practice (without protocol-driven remote rhythm monitoring), this translates to a freedom from all and symptomatic recurrence of 85.8% (95% CI, 80.8%-90.9%) or 94.0% (95% CI, 90.6%-97.5%), respectively. Multivariate analyses revealed that left ventricular ejection fraction ≥60% (adjusted odds ratio, 0.30) and patients receiving ≥48 PFA applications (adjusted odds ratio, 0.28) were independent predictors of PEE success. Moreover, PEE success was 79.2% in patients who received ≥12 PFA applications per vein compared with 57.1% in patients receiving fewer PFA applications. CONCLUSIONS: The inspIRE study confirms the safety and effectiveness of pulmonary vein isolation using the novel 3-dimensional mapping integrated circular loop catheter. An optimal number of PFA applications (≥48 total or ≥12 per vein) resulted in an improved 1-year success rate of ≈80%. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04524364.


Subject(s)
Atrial Fibrillation , Catheter Ablation , Pulmonary Veins , Humans , Pulmonary Veins/surgery , Pulmonary Veins/physiopathology , Female , Atrial Fibrillation/surgery , Atrial Fibrillation/physiopathology , Atrial Fibrillation/diagnosis , Male , Middle Aged , Catheter Ablation/instrumentation , Catheter Ablation/methods , Catheter Ablation/adverse effects , Prospective Studies , Aged , Time Factors , Heart Rate , Action Potentials , Electrocardiography, Ambulatory/instrumentation , Recurrence , Cardiac Catheters , Predictive Value of Tests , Treatment Outcome , Imaging, Three-Dimensional , Risk Factors , Equipment Design , Electrophysiologic Techniques, Cardiac
5.
Europace ; 26(4)2024 Mar 30.
Article in English | MEDLINE | ID: mdl-38619048

ABSTRACT

AIMS: A three-dimensional electroanatomic mapping system-guided transseptal puncture (3D-TSP), without fluoroscopy or echocardiography, has been only minimally reported. Indications for 3D-TSP remain unclear. Against this background, this study aims to establish a precise technique and create a workflow for validating and selecting eligible patients for fluoroless 3D-TSP. METHODS AND RESULTS: We developed a new methodology for 3D-TSP based on a unipolar electrogram derived from a transseptal needle tip (UEGM tip) in 102 patients (the derivation cohort) with intracardiac echocardiography (ICE) from March 2018 to February 2019. The apparent current of injury (COI) was recorded at the muscular limbus of the foramen ovalis (FO) on the UEGM tip (sinus rhythm: 2.57 ± 0.95 mV, atrial fibrillation: 1.92 ± 0.77 mV), which then disappeared or significantly reduced at the central FO. Changes in the COI, serving as a major criterion to establish a 3D-TSP workflow, proved to be the most valuable indicator for identifying the FO in 99% (101/102) of patients compared with three previous techniques (three minor criteria) of reduction in atrial unipolar or bipolar potential and FO protrusion. A total of 99.9% (1042/1043) patients in the validation cohort underwent successful 3D-TSP through the workflow from March 2019 to July 2023. Intracardiac echocardiography guidance was required for 6.6% (69/1042) of patients. All four criteria were met in 740 patients, resulting in a 100% pure fluoroless 3D-TSP success rate. CONCLUSION: In most patients, fluoroless 3D-TSP was successfully achieved using changes in the COI on the UEGM tip. Patients who met all four criteria were considered suitable for 3D-TSP, while those who met none required ICE guidance.


Subject(s)
Atrial Fibrillation , Electrophysiologic Techniques, Cardiac , Imaging, Three-Dimensional , Punctures , Humans , Male , Female , Atrial Fibrillation/surgery , Atrial Fibrillation/physiopathology , Atrial Fibrillation/diagnosis , Electrophysiologic Techniques, Cardiac/methods , Aged , Middle Aged , Catheter Ablation/methods , Catheter Ablation/instrumentation , Needles , Heart Septum/surgery , Heart Septum/diagnostic imaging , Workflow , Echocardiography
6.
Europace ; 26(4)2024 Mar 30.
Article in English | MEDLINE | ID: mdl-38584468

ABSTRACT

AIMS: Pulsed field ablation (PFA) has significant advantages over conventional thermal ablation of atrial fibrillation (AF). This first-in-human, single-arm trial to treat paroxysmal AF (PAF) assessed the efficiency, safety, pulmonary vein isolation (PVI) durability and one-year clinical effectiveness of an 8 Fr, large-lattice, conformable single-shot PFA catheter together with a dedicated electroanatomical mapping system. METHODS AND RESULTS: After rendering the PV anatomy, the PFA catheter delivered monopolar, biphasic pulse trains (5-6 s per application; ∼4 applications per PV). Three waveforms were tested: PULSE1, PULSE2, and PULSE3. Follow-up included ECGs, Holters at 6 and 12 months, and symptomatic and scheduled transtelephonic monitoring. The primary and secondary efficacy endpoints were acute PVI and post-blanking atrial arrhythmia recurrence, respectively. Invasive remapping was conducted ∼75 days post-ablation. At three centres, PVI was performed by five operators in 85 patients using PULSE1 (n = 30), PULSE2 (n = 20), and PULSE3 (n = 35). Acute PVI was achieved in 100% of PVs using 3.9 ± 1.4 PFA applications per PV. Overall procedure, transpired ablation, PFA catheter dwell and fluoroscopy times were 56.5 ± 21.6, 10.0 ± 6.0, 19.1 ± 9.3, and 5.7 ± 3.9 min, respectively. No pre-defined primary safety events occurred. Upon remapping, PVI durability was 90% and 99% on a per-vein basis for the total and PULSE3 cohort, respectively. The Kaplan-Meier estimate of one-year freedom from atrial arrhythmias was 81.8% (95% CI 70.2-89.2%) for the total, and 100% (95% CI 80.6-100%) for the PULSE3 cohort. CONCLUSION: Pulmonary vein isolation (PVI) utilizing a conformable single-shot PFA catheter to treat PAF was efficient, safe, and effective, with durable lesions demonstrated upon remapping.


Subject(s)
Atrial Fibrillation , Cardiac Catheters , Catheter Ablation , Pulmonary Veins , Recurrence , Humans , Pulmonary Veins/surgery , Atrial Fibrillation/surgery , Atrial Fibrillation/physiopathology , Atrial Fibrillation/diagnosis , Catheter Ablation/methods , Catheter Ablation/instrumentation , Male , Female , Middle Aged , Aged , Treatment Outcome , Equipment Design , Electrophysiologic Techniques, Cardiac , Time Factors , Heart Rate , Action Potentials
7.
Int J Cardiol ; 406: 132025, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38583595

ABSTRACT

INTRODUCTION: In patients with paroxysmal atrial fibrillation, pulsed-field ablation has been developed as an alternative to thermal ablation. Three devices are currently available: Farawave by Boston, PulseSelect by Medtronic, and Varipulse by Johnson. In the present report, we studied the outcomes at 12 months of these three devices using indirect comparisons. METHODS: A standard PubMed search was conducted that identified all studies evaluating these devices in patients with paroxysmal atrial fibrillation. The endpoint was freedom from arrhythmia recurrence. Kaplan-Meier curves were subjected to the IPDfromKM method that generated reconstructed patients. Standard time-to-event statistical testss (including heterogeneity assessment) were performed. RESULTS: Our analysis included 9 studies (8 single-arm and 1 randomized trial based on Farawave for a total of 1916 patients). A significant heterogeneity was found across the trials using Farawave because the outcomes found in the single-arm trials were better than those found in the randomized trial. Farawave (according exclusively to the results of the randomized trial), PulseSelect, and Varipulse showed a similar time-course of their respective outcomes with no significant difference. The single-arm trials using Farawave showed better outcomes than the randomized trial using Farawave and the pivotal trials using PulseSelect and Varipulse. DISCUSSION: Our study provided an updated overview of all the studies that have so far used pulsed-fileld ablation in patients with paroxysmal atrial fibrillation.


Subject(s)
Atrial Fibrillation , Catheter Ablation , Randomized Controlled Trials as Topic , Atrial Fibrillation/surgery , Atrial Fibrillation/physiopathology , Humans , Catheter Ablation/methods , Catheter Ablation/instrumentation , Randomized Controlled Trials as Topic/methods , Treatment Outcome
9.
J Cardiovasc Electrophysiol ; 35(5): 886-894, 2024 May.
Article in English | MEDLINE | ID: mdl-38433316

ABSTRACT

INTRODUCTION: Through systematic scientific rigor, the CLOSE guided workflow was developed and has been shown to improve pulmonary vein isolation durability. However, this technique was developed at a time when using power-controlled ablation catheters with conventional power ranges was the norm. There has been increased adoption of a high-power and very high-power short-duration ablation practice propelled by the availability of the temperature-controlled radiofrequency QDOT MICRO catheter. METHODS: There are fundamental differences in biophysics between very high-powered temperature guided ablation and conventional ablation strategy that may impact patient outcomes. The catheter's design and ablation modes offer flexibility in technique while accommodating the individual operator's clinical discretion and preference to deliver a durable, transmural, and contiguous lesion set. RESULTS: Here, we provide recommendations for 3 different workflows using the QDOT MICRO catheter in a step-by-step manner for pulmonary vein isolation based on our cumulative experience as early adopters of the technology and the data available in the scientific literature. CONCLUSIONS: With standardization, temperature-controlled ablation with the QDOT MICRO catheter provides operators the flexibility of implementing different ablation strategies to ensure durable contiguous pulmonary vein isolation depending on patient characteristics.


Subject(s)
Atrial Fibrillation , Cardiac Catheters , Catheter Ablation , Equipment Design , Pulmonary Veins , Humans , Action Potentials , Atrial Fibrillation/surgery , Atrial Fibrillation/physiopathology , Atrial Fibrillation/diagnosis , Catheter Ablation/instrumentation , Heart Rate , Pulmonary Veins/surgery , Pulmonary Veins/physiopathology , Temperature , Time Factors , Treatment Outcome , Workflow
10.
JACC Clin Electrophysiol ; 10(4): 762-767, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38456859

ABSTRACT

Current catheter designs used for radiofrequency (RF) in cardiac tissue achieve limited ablation depth as lesion size is driven heavily by resistive heating at the tissue surface. A catheter with a truncated, dome-shaped tip with a toroidal surface designed for focal RF ablation was recently described. This in vivo study compares lesion characteristics between a second-generation focused electric field (FEF) catheter vs a standard irrigated catheter using RF energy in a beating heart model. We performed in vivo ablations using RF energy with the FEF ablation catheter tip (Focused Therapeutics) and an irrigated Blazer catheter (Boston Scientific) under identical power, duration, and irrigation rates. In addition, RF dosing at high power and duration was examined using the FEF catheter. Intracardiac echocardiography was used to evaluate steam pops and catheter tip angle relative to the tissue surface. Studies were terminal and lesion size was measured following 2,3,5-triphenyltetrazolium chloride staining. Ablations were performed in 6 swine (FEF, n = 31; control, n = 8). FEF ablation lesions (n = 7) were deeper (15.6 ± 2.6 mm vs 7.5 ± 1.9 mm; P < 0.001) and wider (18.4 ± 2.9 mm vs 12.6 ± 2.4 mm; P < 0.001) than lesions delivered with the control irrigated catheter (n = 8) under the same parameters. Thirty-two percent (n = 10 of 31) of lesions delivered from the left ventricle endocardial surface using the FEF catheter were transmural. No steam pops were observed with delivery of FEF lesions (n = 31). The angle of incidence did not significantly affect FEF lesion size. In this in vivo preclinical study, the FEF catheter, which provides focused energy delivery, resulted in significantly larger lesions than the irrigated control catheter without steam pops. Approximately one-third of ablations with the FEF catheter delivered from the endocardial left ventricular surface resulted in transmural lesions.


Subject(s)
Cardiac Surgical Procedures , Catheter Ablation , Animals , Cardiac Catheters , Catheter Ablation/instrumentation , Catheter Ablation/methods , Echocardiography , Equipment Design , Swine , Cardiac Surgical Procedures/instrumentation , Cardiac Surgical Procedures/methods
12.
BMC Cardiovasc Disord ; 21(1): 500, 2021 10 16.
Article in English | MEDLINE | ID: mdl-34656104

ABSTRACT

BACKGROUND: Renal denervation with radiofrequency ablation has become an accepted treatment for drug-resistant hypertension. However, there is a continuing need to develop new catheters for high-accuracy, targeted ablation. We therefore developed a radiofrequency bipolar electrode for controlled, targeted ablation through Joule heating induction between 60 and 100 °C. The bipolar design can easily be assembled into a basket catheter for deployment inside the renal artery. METHODS: Finite element modeling was used to determine the optimum catheter design to deliver a minimum ablation zone of 4 mm (W) × 10 mm (L) × 4 mm (H) within 60 s with a 500 kHz, 60 Vp-p signal, and 3 W maximum. The in silico model was validated with in vitro experiments using a thermochromic phantom tissue prepared with polyacrylamide gel and a thermochromic ink additive that permanently changes from pink to magenta when heated over 60 °C. RESULTS: The in vitro ablation zone closely matched the size and shape of the simulated area. The new electrode design directs the current density towards the artery walls and tissue, reducing unwanted blood temperature increases by focusing energy on the ablation zone. In contrast, the basket catheter design does not block renal flow during renal denervation. CONCLUSIONS: This computational model of radiofrequency ablation can be used to estimate renal artery ablation zones for highly targeted renal denervation in patients with resistant hypertension. Furthermore, this innovative catheter has short ablation times and is one of the lowest power requirements of existing designs to perform the ablation.


Subject(s)
Catheter Ablation/instrumentation , Catheters , Computer Simulation , Electrodes , Hypertension/surgery , Kidney/blood supply , Renal Artery/innervation , Sympathectomy/instrumentation , Blood Pressure , Electric Conductivity , Equipment Design , Finite Element Analysis , Humans , Hypertension/physiopathology , Temperature
14.
BMC Cardiovasc Disord ; 21(1): 387, 2021 08 09.
Article in English | MEDLINE | ID: mdl-34372779

ABSTRACT

BACKGROUND: Transmural lesion creation is essential for effective atrial fibrillation (AF) ablation. Lesion characteristics between conventional energy and high-power short-duration (HPSD) setting in contact force-guided (CF) ablation for AF remained unclear. METHODS: Eighty consecutive AF patients who received CF with conventional energy setting (power control: 25-30 W, force-time integral = 400 g s, n = 40) or with HPSD (power control: 40-50 W, 10 s, n = 40) ablation were analyzed. Of them, 15 patients in each conventional and HPSD group were matched by age and gender respectively for ablation lesions analysis. Type A and B lesions were defined as a lesion with and without significant voltage reduction after ablation, respectively. The anatomical distribution of these lesions and ablation outcomes among the 2 groups were analyzed. RESULTS: 1615 and 1724 ablation lesions were analyzed in the conventional and HPSD groups, respectively. HPSD group had a higher proportion of type A lesion compared to conventional group (P < 0.01). In the conventional group, most type A lesions were at the right pulmonary vein (RPV) posterior wall (50.2%) whereas in the HPSD group, most type A lesions were at the RPV anterior wall (44.0%) (P = 0.04). The procedure time and ablation time were significantly shorter in the HPSD group than that in the conventional group (91.0 ± 12.1 vs. 124 ± 14.2 min, P = 0.03; 30.7 ± 19.2 vs. 57.8 ± 21 min, P = 0.02, respectively). At a mean follow-up period of 11 ± 1.4 months, there were 13 and 7 patients with recurrence in conventional and HPSD group respectively (P = 0.03). CONCLUSION: Optimal ablation lesion characteristics and distribution after conventional and HPSD ablation differed significantly. HPSD ablation had shorter ablation time and lower recurrence rate than did conventional ablation.


Subject(s)
Atrial Fibrillation/surgery , Catheter Ablation/methods , Pulmonary Veins/injuries , Age Factors , Anti-Arrhythmia Agents/therapeutic use , Atrial Fibrillation/drug therapy , Case-Control Studies , Catheter Ablation/instrumentation , Catheter Ablation/statistics & numerical data , Electrophysiologic Techniques, Cardiac , Female , Humans , Male , Middle Aged , Operative Time , Pulmonary Veins/physiopathology , Recurrence , Sex Factors , Smart Materials , Time Factors , Treatment Outcome
15.
BMC Cardiovasc Disord ; 21(1): 388, 2021 08 10.
Article in English | MEDLINE | ID: mdl-34376149

ABSTRACT

BACKGROUND: Catheter-based renal denervation (RDN) has been introduced to treat resistant hypertension. Although the technology of RDN has been largely improved, denervation of tortuous renal arteries remains challenging. CASE PRESENTATION: This is a case report of a 49-year-old man with drug resistant hypertension. The patient was selected for RDN after ruling out possible causes of secondary hypertension. Computed tomography angiography showed a highly tortuous left renal artery. An Iberis multielectrode ablation catheter failed to reach the target vessel with a regular guiding catheter. A 5-French extension catheter was introduced into the proximal segment of the main left renal artery to provide extra support force, which enabled successful ablation of the highly tortuous left renal artery. His ambulatory blood pressure was significantly decreased at 1 month follow-up. CONCLUSIONS: It is feasible and effective to use a guide extension catheter for denervation of highly tortuous renal arteries. The present study provides a useful method to ablate tortuous and angled renal arteries and branches.


Subject(s)
Catheter Ablation/instrumentation , Essential Hypertension/surgery , Renal Artery/abnormalities , Renal Artery/innervation , Sympathectomy/instrumentation , Catheterization, Peripheral/instrumentation , Computed Tomography Angiography , Drug Resistance , Essential Hypertension/drug therapy , Humans , Male , Middle Aged , Renal Artery/diagnostic imaging , Sympathectomy/methods
16.
Pacing Clin Electrophysiol ; 44(9): 1585-1592, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34287967

ABSTRACT

BACKGROUND: To test in vivo a new design prototype for radio frequency (RF) ablation. METHODS: A prototype based on a concept of endo-epicardial biparietal bipolar RF ablation with the atrial tissue interposed and consisting of two specular endocardial-epicardial catheters was tested in four pigs (80±5 kg). The endocardial catheter was introduced into the left atrium through the left atrial appendage on the beating heart. The epicardial counterpart was placed manually on the atrial epicardial surface. The coupling of the two catheters was achieved using a neodymium magnet around the gold plate electrode, and RF was applied to the interposed tissue. The hearts were excised, and the lesions were examined using morphometric evaluation. RESULTS: The RF application resulted in transmural lesions in all of the four animals tested. In these animals the maximum endocardial width (Wendo ) was 6.34 ± 0.25, 6.54 ± 0.33, 6.36 ± 0.57, and 6.49 ± 0.96 mm. The pericardial width (Wepi ) was similar: 6.37 ± 0.47, 6.58 ± 0.32, 6.35 ± 0.56 and 6.53 ± 0.94 mm. The lesion area was 924.78, 949.25, 944.25, and 926.05 mm2 , and the lesion volume was 92.47, 94.92, 94.42, and 92.60 mm3 , respectively. CONCLUSIONS: The idea of an endocardial-epicardial bidirectional biparietal bipolar radiofrequency tool such that the atrial tissue is fully interposed between the two RF poles might be promising for future clinical applications. Further research is warranted.


Subject(s)
Catheter Ablation/instrumentation , Heart Atria/surgery , Magnets , Animals , Equipment Design , Neodymium , Swine
17.
Sci Rep ; 11(1): 15353, 2021 07 28.
Article in English | MEDLINE | ID: mdl-34321494

ABSTRACT

Irreversible electroporation (IRE) is a local non-thermal ablative technique currently used to treat solid tumors. Here, we investigated the clinical potency and safety of IRE with an endoscope in the upper gastrointestinal tract. Pigs were electroporated with recently designed endoscopic IRE catheters in the esophagus, stomach, and duodenum. Two successive strategies were introduced to optimize the electrical energy for the digestive tract. First, each organ was electroporated and the energy upscaled to confirm the upper limit energy inducing improper tissue results, including bleeding and perforation. Excluding the unacceptable energy from the first step, consecutive electroporations were performed with stepwise reductions in energy to identify the energy that damaged each layer. Inceptive research into inappropriate electrical intensity contributed to extensive hemorrhage and bowel perforation for each tissue above a certain energy threshold. However, experiments performed below the precluded energy accompanying hematoxylin and eosin staining and terminal deoxynucleotidyl transferase dUTP nick-end labeling assays showed that damaged mucosal area and depth significantly decreased with decreased energy. Relevant histopathology showed infiltration of inflammatory cells with pyknotic nuclei at the electroporated lesion. This investigation demonstrated the possibility of endoscopic IRE in mucosal dysplasia or early malignant tumors of the hollow viscus.


Subject(s)
Catheter Ablation/methods , Duodenum/surgery , Electroporation/methods , Endoscopy/methods , Esophagus/surgery , Stomach/surgery , Animals , Catheter Ablation/instrumentation , Duodenum/diagnostic imaging , Electroporation/instrumentation , Endoscopy/instrumentation , Eosine Yellowish-(YS) , Esophagus/diagnostic imaging , Female , Hematoxylin , Hemorrhage/prevention & control , Histocytochemistry , In Situ Nick-End Labeling , Stomach/diagnostic imaging , Swine
20.
Expert Rev Med Devices ; 18(4): 343-350, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33724120

ABSTRACT

Introduction: Despite advances in imaging technology to guide ablative therapies, catheter ablation of more complex arrhythmias continues to be a challenge in part due to suboptimal mechanistic understanding of these arrhythmias by conventional mapping systems. A novel noncontact charge density mapping system has been designed to overcome some of these limitations.Areas covered: Hereby, we present an overview of this novel, charge density-based global chamber mapping approach. We initially highlight the concept of charge density, describe further the device technology and finally summarize the clinical application of this system.Expert opinion: Noncontact charge density mapping provides a more localized, high-resolution global panoramic assessment of cardiac activation. This might contribute to uncover the mechanisms of more complex arrhythmias such as persistent atrial fibrillation or unstable atrial tachycardias with the ultimate goal to guide the ablation therapy.


Subject(s)
Atrial Fibrillation/surgery , Catheter Ablation/instrumentation , Catheter Ablation/methods , Clinical Trials as Topic , Electricity , Humans , Ultrasonics
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