INTRODUCTION: Despite technical progress, ventricular tachycardia (VT) recurrence after unipolar ablation remains relatively high (12%-47%). Bipolar ablation has been proposed as an appealing solution that may overcome limitations associated with unipolar ablation settings. We designed an animal study to compare bipolar (BPA) vs sequential unipolar ablation (UPA) using contact force-sensing technology on both ablation catheters. METHODS: Twenty large white female pigs (6-months-old, 50-60 kg) underwent multiple RF ablations (30 W, 60 seconds, 30 mL/min irrigation) on the ventricular myocardium from the epicardial and endocardial sides. The hearts were fixed and scanned with high-resolution cardiac magnetic resonance imaging. Thermal lesions were located and characterized in volume, depth, width, and transmurality. RESULTS: Lesion volume was calculated as the sum of epicardial or endocardial conjoined/isolated lesions at one location. Linear dimensions (width and depth) were measured twice for each location, on the endocardial and epicardial side. We evaluated 35 lesions across the intraventricular septum (UPA, N = 17 vs BPA, N = 18). No difference in volume, linear dimensions or impedance drop was observed in this area between UPA and BPA. However, BPA required half RF time and showed an increased transmurality trend. We then analyzed 73 lesions from the endocardial side (UPA, N = 35 vs BPA, N = 38) and 50 from the epicardial side (UPA, N = 11 vs BPA N = 39) of the ventricular free walls. Lesion transmurality was markedly improved by BPA (P = .030, odds ratio, 23.73 [4.71,31.96]). Ventricular BPA lesions were significantly deeper on the epicardial side (P < .0001) and endocardial side (P = .015). CONCLUSION: Bipolar ablation is more likely to create transmural and epicardial lesions in the ventricle wall. Half the time is needed for the creation of comparably deep and large lesions.

• MeSH
• design vybavení MeSH
• katetrizační ablace škodlivé účinky   přístrojové vybavení   MeSH
• magnetická rezonanční tomografie MeSH
• měniče tlakové * MeSH
• myokard patologie   MeSH
• srdeční katétry * MeSH
• srdeční komory diagnostické zobrazování   patologie   chirurgie   MeSH
• Sus scrofa MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

BACKGROUND: Choosing the appropriate animal model for development of novel technologies requires an understanding of anatomy and physiology of these different models. There are little data about the characteristics of different animal models for the study of technologies used for epicardial ablation. We aimed to compare the incidence of ventricular arrhythmias during epicardial radiofrequency ablation between swine and canine models using novel epicardial ablation catheters. METHODS: We conducted a retrospective study using data obtained from epicardial ablation experiments performed on swine (Sus Scrofa) and canine (Canis familiaris) models. We compared the incidence of ventricular arrhythmias during ablation between swine and canine using multivariate regression analysis. Six swine and six canine animals underwent successful epicardial radiofrequency ablation. A total of 103 ablation applications were recorded. RESULTS: Ventricular arrhythmias requiring cardioversion occurred in 13.11% of radiofrequency ablation applications in swine and 9.75% in canine (relative risk: 117.6%, 95% confidence interval [CI]: 83.97-164.69, animal-based odds ratio [OR]: .55, 95% CI: .23-61.33; P = .184). When adjusting for application position, duration of ablation and power, the odds of developing potentially lethal ventricular arrhythmia in swine increased significantly compared to canine (OR: 3.60, 95% CI: 1.35-9.55; P = .010). CONCLUSIONS: The swine myocardium is more susceptible to developing ventricular arrhythmias compared to canine model during epicardial ablation. This issue should be carefully considered in future studies.

• MeSH
• incidence MeSH
• katetrizační ablace metody   MeSH
• komorová tachykardie etiologie   MeSH
• modely nemocí na zvířatech * MeSH
• perikard chirurgie   MeSH
• prasata MeSH
• psi MeSH
• retrospektivní studie MeSH
• zvířata MeSH
• Check Tag
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH

• MeSH
• elektroporace MeSH
• fibrilace síní * MeSH
• lidé MeSH
• nízká teplota MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• dopisy MeSH
• komentáře MeSH

Atrial fibrillation (AF) is one of the most important problems in modern cardiology. Thermal ablation therapies, especially radiofrequency ablation (RF), are currently "gold standard" to treat symptomatic AF by localized tissue necrosis. Despite the improvements in reestablishing sinus rhythm using available methods, both success rate and safety are limited by the thermal nature of procedures. Thus, while keeping the technique in clinical practice, safer and more versatile methods of removing abnormal tissue are being investigated. This review focuses on irreversible electroporation (IRE), a nonthermal ablation method, which is based on the unrecoverable permeabilization of cell membranes caused by short pulses of high voltage/current. While still in its preclinical steps for what concerns interventional cardiac electrophysiology, multiple studies have shown the efficacy of this method on animal models. The observed remodeling process shows this technique as tissue specific, triggering apoptosis rather than necrosis, and safer for the structures adjacent the myocardium. So far, proposed IRE methodologies are heterogeneous. The number of devices (both generators and applicators), techniques, and therapeutic goals impair the comparability of performed studies. More questions regarding systemic safety and optimal processes for AF treatment remain to be answered. This work provides an overview of the electroporation process, and presents different results obtained by cardiology-oriented research groups that employ IRE ablation, with focus of AF-related targets. This contribution on the topic aspires to be a practical guide to approach IRE ablation for cardiac arrhythmias, and to highlight controversial features and existing knowledge, to provide background for future improved experimentation with IRE in arrhythmology.

• MeSH
• ablace * škodlivé účinky   MeSH
• akční potenciály MeSH
• apoptóza MeSH
• elektroporace * MeSH
• fibrilace síní diagnóza   patofyziologie   terapie   MeSH
• lidé MeSH
• remodelace síní * MeSH
• srdeční frekvence MeSH
• srdeční síně patologie   patofyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Hybridní ablace (hybrid ablation, HABL) fibrilace síní jako kombinace endoskopické, minimálně invazivní, epikardiální ablace při zavřeném hrudníku spolu s přesností endokardiální metody vedené systémem CARTO byla zavedena ve snaze překonat limitace současných možností léčby pacientů s perzistující fibrilací síní (persistent atrial firbrillation, PSAF) a dlouhodobě perzistující fibrilací síní (long-standing persistent atrial fibrillation, LSPAF). Smyslem toho monocentrického, prospektivního klinického registru bylo zhodnotit bezpečnost a proveditelnost i účinnost HABL u pacientů s PSAF a LSPAF jeden rok po výkonu. V období od července 2009 do prosince 2014 byla HABL provedena celkem u devadesáti (n = 90) pacientů (PSAF, n = 39 a LSPAF, n = 51). Průměrná délka incidence fibrilace síní byla 4,5 ± 3,7 roku. Šest měsíců po ablaci bylo 78 % pacientů v sinusovém rytmu. Dvanáct měsíců po výkonu bylo v sinusovém rytmu 86 % pacientů a 62,3 % v sinusovém rytmu bez podávání antiarytmik skupin I/III. Na základě těchto výsledků lze usuzovat, že u pacientů s perzistující a dlouhodobě perzistující fibrilací síní je třeba uvažovat o kombinaci epikardiální a endokardiální radiofrekvenční ablace, protože se jedná a bezpečnou a účinnou metodu obnovy sinusového rytmu.

The hybrid ablation (HABL) of atrial fibrillation which combines endoscopic, minimally invasive, closed chest epicardial ablation with endocardial CARTO-guided accuracy was introduced to overcome limitations of current therapeutic options for patients with persistent (PSAF) and long-standing persistent atrial fibrillation (LSPAF). The purpose of this single-centre, prospective clinical registry was to evaluate procedural safety and feasibility as well as effectiveness of the HABL in patients with PSAF and LSPAF 1-year post-procedure. From July 2009 to December 2014, ninety (n = 90) patients with PSAF (n = 39) and LSPAF (n = 51) underwent HABL. Mean AF duration was 4.5 ± 3.7 years. At 6 months post-procedure 78% patients were in SR. At 12 months post-procedure 86% patients were in SR and 62.3% in SR and of class I/III AADs. These results suggest that combination of epicardial and endocardial RF ablation should be considered as a treatment option for patients with persistent and long-standing persistent atrial fibrillation as it is safe and effective in restoring sinus rhythm.

• MeSH
• ablace metody   MeSH
• fibrilace síní * chirurgie   MeSH
• kardiovaskulární chirurgické výkony metody   MeSH
• katetrizační ablace metody   přístrojové vybavení   MeSH
• kombinovaná terapie metody   MeSH
• lidé MeSH
• miniinvazivní chirurgické výkony metody   MeSH
• prospektivní studie MeSH
• stupeň závažnosti nemoci MeSH
• venae pulmonales chirurgie   MeSH
• výsledek terapie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH