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BACKGROUND: The circuit boundaries for reentrant ventricular tachycardia (VT) have been historically conceptualized within a 2-dimensional (2D) construct, with their fixed or functional nature unresolved. This study aimed to examine the correlation between localized lines of conduction block (LOB) evident during baseline rhythm with lateral isthmus boundaries that 3-dimensionally constrain the VT isthmus as a hyperboloid structure. METHODS: A total of 175 VT activation maps were correlated with isochronal late activation maps during baseline rhythm in 106 patients who underwent catheter ablation for scar-related VT from 3 centers (42% nonischemic cardiomyopathy). An overt LOB was defined by a deceleration zone with split potentials (≥20 ms isoelectric segment) during baseline rhythm. A novel application of pacing within deceleration zone (≥600 ms) was implemented to unmask a concealed LOB not evident during baseline rhythm. LOB identified during baseline rhythm or pacing were correlated with isthmus boundaries during VT. RESULTS: Among 202 deceleration zones analyzed during baseline rhythm, an overt LOB was evident in 47%. When differential pacing was performed in 38 deceleration zones without overt LOB, an underlying concealed LOB was exposed in 84%. In 152 VT activation maps (2D=53, 3-dimensional [3D]=99), 69% of lateral boundaries colocalized with an LOB in 2D activation patterns, and the depth boundary during 3D VT colocalized with an LOB in 79%. In VT circuits with isthmus regions that colocalized with a U-shaped LOB (n=28), the boundary invariably served as both lateral boundaries in 2D and 3D. Overall, 74% of isthmus boundaries were identifiable as fixed LOB during baseline rhythm or differential pacing. CONCLUSIONS: The majority of VT circuit boundaries can be identified as fixed LOB from intrinsic or paced activation during sinus rhythm. Analysis of activation while pacing within the scar substrate is a novel technique that may unmask concealed LOB, previously interpreted to be functional in nature. An LOB from the perspective of a myocardial surface is frequently associated with intramural conduction, supporting the existence of a 3D hyperboloid VT circuit structure. Catheter ablation may be simplified to targeting both sides around an identified LOB during sinus rhythm.
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Ablación por Catéter , Taquicardia Ventricular , Humanos , Cicatriz , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/cirugía , Arritmias Cardíacas , Frecuencia Cardíaca/fisiología , Bloqueo CardíacoRESUMEN
INTRODUCTION: The novel cryoballoon with 28 mm or 31 mm adjustable diameters, aims to achieve a wide antral pulmonary vein isolation (PVI). However, the distribution of antral lesions and their variations based on left atrial (LA) remodeling require further clarification. METHODS: We evaluated 22 patients (67 [59.5-74.8] years, 19 males) who underwent PVI of atrial fibrillation (AF) (13 paroxysmal AF [PAF] and 9 non-PAF) using size-adjustable cryoballoons. LA electro-anatomical mapping was performed post-PVI with three-dimensional mapping systems. We assessed the shapes of the LA and pulmonary veins (PVs) and the distribution of isolated areas (IAs), comparing the results between PAF and non-PAF patients. RESULTS: In the left PVs (LPVs), the distance between the PV orifice and IA edge (PVos-IA) was larger on the roof and posterior segments (~15 mm) but relatively smaller on the anterior segment near the PV ridge (<10 mm). For the right PVs (RPVs), it was more extensive in the posterior segment (10-15 mm). Comparing PAF and non-PAF, there were no significant differences in the PVos-IA except for the right posterior-carina segment, antrum IA (LPVs: 5.9 ± 1.6 vs. 5.8 ± 0.8 cm², p = .81; RPVs: 4.8 ± 2.3 vs. 4.8 ± 1.2 cm², p = .81), distances between the right and left IAs on the LA posterior wall (LAPW), and un-isolated LAPW area (9.0 ± 4.9 vs. 9.9 ± 2.5 cm², p = .62). No individual PVIs were observed in either group. Two patients exhibited overlapping IAs on the roof, and one patient who underwent 31 mm balloon applications for all PVs exhibited an LAPW isolation. CONCLUSION: The size-adjustable cryoballoon achieved a wide antral PVI even in non-PAF patients.
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BACKGROUND: Safety data of the latest radiofrequency (RF) technologies during atrial fibrillation (AF) ablation in real-world clinical practice are limited. OBJECTIVES: We sought to evaluate the acute procedural safety of the four latest ablation catheters commonly used for AF ablation. METHODS: A total of 3957 AF ablation procedures performed between January 2022 and December 2023 at 20 centers with either the THERMOCOOL SMARTTOUCH SF (STSF), TactiCath (TC), QDOT Micro (QDM), or TactiFlex (TF) were retrospectively analyzed. RESULTS: In total, QDM, STSF, TF, and TC were used in 343 (8.7%), 1793 (45.3%), 1121 (28.4%), and 700(17.7%) procedures. Among 2406 index procedures, electrical pulmonary vein isolations were successfully achieved in 99.5%. Despite similar total procedure times in the four groups, the total fluoroscopic time was significantly shorter for QDM/STSF with CARTO than TF/TC with EnSite (18.7 ± 14 vs. 27.6 ± 20.6 min, p < .001) and longest in the TF group. The incidence of cardiac tamponade was 0.7% (0.5% and 0.9% during index and redo procedures, 0.8% and 0.3% for paroxysmal and non-paroxysmal AF) and was significantly lower for QDM/STSF than TF/TC (0.2% vs. 1.1%, p = .008) and highest in the TF group. The incidence of cardiac tamponade was higher for TF than TC and STSF than QDM. In the multivariate analysis, TF/TC with EnSite was a significant independent predictor of cardiac tamponade during both the index (odds ratio [OR] = 4.8, 95% confidence interval [CI] = 1.3-17.5, p = .02) and all procedures (OR = 3.0, 95% CI = 1.3-7.2, p = .01). CONCLUSIONS: The incidence of cardiac tamponade and the fluoroscopic time during AF ablation significantly differed among the latest RF catheters and mapping systems in real-world clinical practice.
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AIMS: Phrenic nerve injury (PNI) is the most common complication during cryoballoon ablation. Currently, two cryoballoon systems are available, yet the difference is unclear. We sought to compare the acute procedural efficacy and safety of the two cryoballoons. METHODS: This prospective observational study consisted of 2,555 consecutive atrial fibrillation (AF) patients undergoing pulmonary vein isolation (PVI) using either conventional (Arctic Front Advance) (AFA-CB) or novel cryoballoons (POLARx) (POLARx-CB) at 19 centers between January 2022 and October 2023. RESULTS: Among 2,555 patients (68.8 ± 10.9 years, 1,740 men, paroxysmal AF[PAF] 1,670 patients), PVIs were performed by the AFA-CB and POLARx-CB in 1,358 and 1,197 patients, respectively. Touch-up ablation was required in 299(11.7%) patients. The touch-up rate was significantly lower for POLARx-CB than AFA-CB (9.5% vs. 13.6%, p = 0.002), especially for right inferior PVs (RIPVs). The touch-up rate was significantly lower for PAF than non-PAF (8.8% vs. 17.2%, P < 0.001) and was similar between the two cryoballoons in non-PAF patients. Right PNI occurred in 64(2.5%) patients and 22(0.9%) were symptomatic. It occurred during the right superior PV (RSPV) ablation in 39(1.5%) patients. The incidence was significantly higher for POLARx-CB than AFA-CB (3.8% vs. 1.3%, P < 0.001) as was the incidence of symptomatic PNI (1.7% vs. 0.1%, P < 0.001). The difference was significant during RSPV (2.5% vs. 0.7%, P < 0.001) but not RIPV ablation. The PNI recovered more quickly for the AFA-CB than POLARx-CB. CONCLUSIONS: Our study demonstrated a significantly higher incidence of right PNI and lower touch-up rate for the POLARx-CB than AFA-CB in the real-world clinical practice.
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Fibrilación Atrial , Criocirugía , Traumatismos de los Nervios Periféricos , Nervio Frénico , Venas Pulmonares , Sistema de Registros , Humanos , Nervio Frénico/lesiones , Masculino , Femenino , Fibrilación Atrial/cirugía , Fibrilación Atrial/epidemiología , Venas Pulmonares/cirugía , Anciano , Criocirugía/efectos adversos , Criocirugía/métodos , Estudios Prospectivos , Incidencia , Traumatismos de los Nervios Periféricos/etiología , Traumatismos de los Nervios Periféricos/epidemiología , Traumatismos de los Nervios Periféricos/prevención & control , Persona de Mediana Edad , Resultado del Tratamiento , Ablación por Catéter/efectos adversosRESUMEN
Recently, a novel size-adjustable cryoballoon has been introduced in clinical practice, which can be inflated to two different diameters (28 and 31 mm). The 31 mm cryoballoon is specifically designed to achieve better contact with remodeled pulmonary veins (PVs) that have wider ostia while avoiding deep cannulation, thereby potentially reducing the risk of phrenic nerve injury (PNI) associated with deep balloon cannulation. However, we encountered two cases of PNI during cryoballoon ablation using the novel system among our initial 25 consecutive case series. Herein, we present two cases that exhibited PNI during freezing of the right superior PV with a size-adjustable balloon. While larger balloons are expected to create a larger area of isolation, the safety of this novel balloon system needs to be evaluated in a large-scale clinical study.
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Fibrilación Atrial , Ablación por Catéter , Criocirugía , Traumatismos de los Nervios Periféricos , Venas Pulmonares , Humanos , Fibrilación Atrial/cirugía , Nervio Frénico/lesiones , Traumatismos de los Nervios Periféricos/etiología , Traumatismos de los Nervios Periféricos/prevención & control , Traumatismos de los Nervios Periféricos/cirugía , Venas Pulmonares/cirugía , Resultado del TratamientoRESUMEN
BACKGROUND/OBJECTIVES: The QDOT-MICRO™ catheter allows very high-power and short-duration (vHPSD) ablation. This study aimed to investigate lesion characteristics using different ablation settings. METHODS: Radiofrequency applications (90 W/4 s, temperature-control mode with 55°C or 60°C target) were performed in excised porcine myocardium using three different approaches: single (SA), double nonrepetitive (DNRA), and double repetitive applications (DRA). Applications were performed with an interval of 1 min for DNRA, and without interval for DRA. RESULTS: A total of 480 lesions were analyzed. Lesion depth and volume were largest for DRA followed by DNRA and SA regardless of catheter direction (depth: 3.8 vs. 3.3 vs. 2.6 mm, p < .001 for all comparisons; volume: 176.6 vs. 145.1 vs. 97.0 mm3 , p < .001 for all comparisons). Surface area was significantly larger for DRA than for SA (45.1 vs. 38.3 mm2 , p < .001) and larger for DNRA than for SA (44.5 vs. 38.3 mm2 , p < .001), but was similar between DRA and DNRA (45.1 vs. 44.5 mm2 , p = .54). Steam-pops more frequently occurred for DRA than for SA (15.6% vs. 4.4%, p = .004) and DNRA (15.6% vs. 6.9%, p = .061), but the incidence was similar between SA and DNRA (4.4% vs. 6.9%, p = 1). Although surface area and lesion volume were larger in lesions with steam-pops than without steam-pops (46.5 vs. 38.1 mm2 , p = .018 and 128.3 vs. 96.8 mm3 , p = .068, respectively), lesions were not deeper (pop(+): 2.5 mm vs. pop(-): 2.6 mm, p = .75). CONCLUSIONS: DNRA produces larger lesions than SA without increasing the risk of steam-pops. DRA produces the largest lesions among the three groups, but with an increased risk of steam-pops. Even with steam-pops, lesions do not become deeper in vHPSD ablation.
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Ablación por Catéter , Vapor , Porcinos , Animales , Ablación por Catéter/efectos adversos , Irrigación Terapéutica/efectos adversos , Diseño de Equipo , CatéteresRESUMEN
INTRODUCTION: The QDOT-MicroTM catheter is a novel irrigated contact force (CF) sensing catheter which benefits from thermocouples for temperature monitoring, allowing temperature-flow-controlled (TFC) ablation. We compared lesion metrics at fixed ablation index (AI) value during TFC-ablation and conventional power-controlled (PC)-ablation. METHODS: A total of 480 RF-applications were performed on ex-vivo swine myocardium with predefined AI targets (400/550) or until steam-pop occurred, using the QDOT-MicroTM (TFC-ablation) and Thermocool SmartTouch SFTM (PC-ablation). RESULTS: Both TFC-ablation and PC-ablation produced similar lesions in volume (218 ± 116 vs. 212 ± 107 mm3 , p = .65); however, lesions using TFC-ablation were larger in surface area (41.3 ± 8.8 vs. 34.8 ± 8.0 mm2 , p < .001) and shallower in depth (4.0 ± 1.0 vs. 4.2 ± 1.1 mm, p = .044). Average power tended to be lower in TFC-alation (34.2 ± 8.6 vs. 36.9 ± 9.2, p = .005) compared to PC-ablation due to automatic regulation of temperature and irrigation-flow. Although steam-pops were less frequent in TFC-ablation (24% vs. 15%, p = .021), they were particularly observed in low-CF (10 g) and high-power ablation (50 W) in both PC-ablation (n = 24/240, 10.0%) and TFC-ablation (n = 23/240, 9.6%). Multivariate analysis revealed that high-power, low-CF, long application time, perpendicular catheter orientation, and PC-ablation were risk factors for steam-pops. Furthermore, activation of automatic regulation of temperature and irrigation-flow was independently associated with high-CF and long application time while ablation power had no significant relationship. CONCLUSIONS: With a fixed target AI, TFC-ablation reduced the risk of steam-pops, producing similar lesions in volume, but with different metrics in this ex-vivo study. However, lower CF and higher power in fixed-AI ablation may increase the risk of steam-pops.
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Ablación por Catéter , Vapor , Porcinos , Animales , Temperatura , Ablación por Catéter/efectos adversos , Irrigación Terapéutica/efectos adversos , Diseño de EquipoRESUMEN
BACKGROUND: The impact of filtering on bipolar electrograms (EGMs) has not been systematically examined. We tried to clarify the optimal filter configuration for ventricular tachycardia (VT) ablation. METHODS: Fifteen patients with VT were included. Eight different filter configurations were prospectively created for the distal bipoles of the ablation catheter: 1.0-250, 10-250, 100-250, 30-50, 30-100, 30-250, 30-500, and 30-1000 Hz. Pre-ablation stable EGMs with good contact (contact force > 10 g) were analyzed. Baseline fluctuation, baseline noise, bipolar peak-to-peak voltage, and presence of local abnormal ventricular activity (LAVA) were compared between different filter configurations. RESULTS: In total, 2276 EGMs with multiple bipolar configurations in 246 sites in scar and border areas were analyzed. Baseline fluctuation was only observed in the high-pass filter of (HPF) ≤ 10 Hz (p < .001). Noise level was lowest at 30-50 Hz (0.018 [0.012-0.029] mV), increased as the low-pass filter (LPF) extended, and was highest at 30-1000 Hz (0.047 [0.041-0.061] mV) (p < .001). Conversely, the HPF did not affect the noise level at ≤30 Hz. As the HPF extended to 100 Hz, bipolar voltages significantly decreased (p < .001), but were not affected when the LPF was extended to ≥100 Hz. LAVAs were most frequently detected at 30-250 Hz (207/246; 84.2%) and 30-500 Hz (208/246; 84.6%), followed by 30-1000 Hz (205/246; 83.3%), but frequently missed at LPF ≤ 100 Hz or HPF ≤ 10 Hz (p < .001). A 50-Hz notch-filter reduced the bipolar voltage by 43.9% and LAVA-detection by 34.5% (p < .0001). CONCLUSION: Bipolar EGMs are strongly affected by filter settings in scar/border areas. In all, 30-250 or 30-500 Hz may be the best configuration, minimizing the baseline fluctuation, baseline noise, and detecting LAVAs. Not applying the 50-Hz notch filter may be beneficial to avoid missing VT substrate.
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Ablación por Catéter , Taquicardia Ventricular , Humanos , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/cirugía , Cicatriz , Ablación por Catéter/efectos adversosRESUMEN
INTRODUCTION: Little is known about the impact of blood-pool local impedance (LI) on lesion characteristics and the incidence of steam pops. METHODS: Radiofrequency applications at a range of powers (30, 40, and 50 W), contact forces (CF) (5, 15, and 25 g), and durations (15, 30, 45, and 120 s) using perpendicular/parallel catheter orientation were performed in 40 excised porcine preparations, using a catheter capable of monitoring LI (StablePoint©, Boston Scientific). To simulate the variability in blood-pool impedance, the saline-pool LI was modulated by calibrating saline concentrations. Lesion characteristics were compared under three values of saline-pool LI: 120, 160, and 200 Ω. RESULTS: Of 648 lesions created, steam pops occurred in 175 (27.0%). When power, CF, time, and catheter orientation were adjusted, ablation at a saline-pool impedance of 160 or 200 Ω more than doubled the risk of steam pops compared with a saline-pool impedance of 120 Ω (Odds ratio = 2.31; p = .0002). Lesions in a saline-pool impedance of 120 Ω were significantly larger in surface area (50 [38-62], 45 [34-56], and 41 [34-60] mm2 for 120, 160, and 200 Ω, p < .05), but shallower in depth (4.0 [3-5], 4.4 [3.2-5.3], and 4.5 [3.8-5.5] mmfor 120, 160, and 200 Ω, respectively, p < .05) compared with the other two settings. The correlation between the absolute LI-drop and lesion size weakened as the saline-pool LI became higher (e.g., 120 Ω group (r2 = .30, r2 = .18, and r2 = .16, respectively for 120, 160, and 200 Ω), but the usage of %LI-drop (= absolute LI-drop/initial LI) instead of absolute LI-drop may minimize this effect. CONCLUSIONS: In an experimental model, baseline saline-pool impedance significantly affects the lesion metrics and the risk of steam pops.
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Ablación por Catéter , Vapor , Porcinos , Animales , Impedancia Eléctrica , Benchmarking , Ablación por Catéter/efectos adversos , Solución SalinaRESUMEN
AIMS: The usefulness of coronary venous system mapping has been reported for assessing intramural and epicardial substrates in patients with scar-related ventricular tachycardia (VT). However, there has been little data on mapping from coronary arteries. We investigated the safety and utility of mapping from coronary arteries with a novel over-the-wire multielectrode catheter in scar-related VT patients. METHODS AND RESULTS: Ten consecutive scar-related VT patients with non-ischaemic cardiomyopathy who underwent mapping from a coronary artery were analysed. Six patients underwent simultaneous coronary venous mapping. High-density maps were created by combining the left ventricular endocardium and coronary vessels. Substrate maps were created during the baseline rhythm with 2438 points (IQR 2136-3490 points), including 329 (IQR 59-508 points) in coronary arteries. Abnormal bipolar electrograms were successfully recorded within coronary arteries close to the endocardial substrate in seven patients. During VT, isthmus components were recorded within the coronary vessels in three patients with no discernible isthmus components on endocardial mapping. The ablation terminated the VT from an endocardial site opposite the earliest site in the coronary arteries in five patients. CONCLUSION: The transcoronary mapping with an over-the-wire multielectrode catheter can safely record abnormal bipolar electrograms within coronary arteries. Additional mapping data from the coronary vessels have the potential to assess three-dimensional ventricular substrates and circuit structures in scar-related VT patients.
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Ablación por Catéter , Taquicardia Ventricular , Humanos , Cicatriz/complicaciones , Cicatriz/diagnóstico por imagen , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/etiología , Taquicardia Ventricular/cirugía , Arritmias Cardíacas , Ventrículos Cardíacos , Endocardio , Ablación por Catéter/efectos adversos , Ablación por Catéter/métodosRESUMEN
AIMS: Although the mechanism of an atrial tachycardia (AT) can usually be elucidated using modern high-resolution mapping systems, it would be helpful if the AT mechanism and circuit could be predicted before initiating mapping. OBJECTIVE: We examined if the information gathered from the cycle length (CL) of the tachycardia can help predict the AT-mechanism and its localization. METHODS: One hundred and thirty-eight activation maps of ATs including eight focal-ATs, 94 macroreentrant-ATs, and 36 localized-ATs in 95 patients were retrospectively reviewed. Maximal CL (MCL) and minimal CL (mCL) over a minute period were measured via a decapolar catheter in the coronary sinus. CL-variation and beat-by-beat CL-alternation were examined. Additionally, the CL-respiration correlation was analysed by the RhythmiaTM system. : Both MCL and mCL were significantly shorter in macroreentrant-ATs [MCL = 288 (253-348) ms, P = 0.0001; mCL = 283 (243-341) ms, P = 0.0012], and also shorter in localized-ATs [MCL = 314 (261-349) ms, P = 0.0016; mCL = 295 (248-340) ms, P = 0.0047] compared to focal-ATs [MCL = 506 (421-555) ms, mCL = 427 (347-508) ms]. An absolute CL-variation (MCL-mCL) < 24â ms significantly differentiated re-entrant ATs from focal-ATs with a sensitivity = 96.9%, specificity = 100%, positive predictive value (PPV) = 100%, and negative predictive value (NPV) = 66.7%. The beat-by-beat CL-alternation was observed in 10/138 (7.2%), all of which showed the re-entrant mechanism, meaning that beat-by-beat CL-alternation was the strong sign of re-entrant mechanism (PPV = 100%). Although the CL-respiration correlation was observed in 28/138 (20.3%) of ATs, this was predominantly in right-atrium (RA)-ATs (24/41, 85.7%), rather than left atrium (LA)-ATs (4/97, 4.1%). A positive CL-respiration correlation highly predicted RA-ATs (PPV = 85.7%), and negative CL-respiration correlation probably suggested LA-ATs (NPV = 84.5%). CONCLUSION: Detailed analysis of the tachycardia CL helps predict the AT-mechanism and the active AT chamber before an initial mapping.
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Ablación por Catéter , Taquicardia Supraventricular , Humanos , Estudios Retrospectivos , Técnicas Electrofisiológicas Cardíacas , Taquicardia , Atrios Cardíacos , Resultado del TratamientoRESUMEN
BACKGROUND: For lesion size prediction, each input parameter, including ablation energy (AE), and output parameter, such as impedance, is individually used. We hypothesize that using both parameters simultaneously may be more optimal.MethodsâandâResults: Radiofrequency applications at a range of power (30-50 W), contact force (10 g and 20 g), duration (10-60 s), and catheter orientation with normal saline (NS)- or half-normal saline (HNS)-irrigation were performed in excised porcine hearts. The correlations, with lesion size of AE, absolute impedance drop (∆Imp-drop), relative impedance drop (%Imp-drop), and AE*%Imp-drop were examined. Lesion size was analyzed in 283 of 288 lesions (NS-irrigation, n=142; HNS-irrigation, n=141) without steam pops. AE*%Imp-drop consistently showed the strongest correlations with lesion maximum depth (NS-irrigation, ρ=0.91; HNS-irrigation, ρ=0.94), surface area (NS-irrigation, ρ=0.87; HNS-irrigation, ρ=0.86), and volume (NS-irrigation, ρ=0.94; HNS-irrigation, ρ=0.94) compared with the other parameters. Moreover, compared with AE alone, AE*%Imp-drop significantly improved the strength of correlation with lesion maximum depth (AE vs. AE*%Imp-drop, ρ=0.83 vs. 0.91, P<0.01), surface area (ρ=0.73 vs. 0.87, P<0.01), and volume (ρ=0.84 vs. 0.94, P<0.01) with NS-irrigation. This tendency was also observed with HNS-irrigation. Parallel catheter orientation showed a better correlation with lesion depth and volume using ∆Imp-drop, %Imp-drop, and AE*%Imp-drop than perpendicular orientation. CONCLUSIONS: The combination of input and output parameters is more optimal than each single parameter for lesion prediction.
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Ablación por Catéter , Solución Salina , Animales , Porcinos , Ventrículos Cardíacos/patología , Corazón , Catéteres , Ablación por Catéter/métodos , Diseño de Equipo , Impedancia EléctricaRESUMEN
The 12-lead electrocardiogram (ECG) is a fundamental modality to help determine the mechanism and the localization of atrial tachycardias (ATs). Although macroreentrant ATs and focal ATs typically show F-waves and discrete P-waves respectively on the 12-lead ECG, this is not universally the case in scar-related ATs.1, We present three cases clearly showing the discrepancy between the AT morphology on the 12-lead ECG and the AT-mechanism.
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Ablación por Catéter , Taquicardia Atrial Ectópica , Taquicardia Supraventricular , Humanos , Cicatriz , ElectrocardiografíaRESUMEN
BACKGROUND AND AIMS: The safety evaluation of TactiFlex, a novel contact-force sensing catheter with a flexible 4-mm tip irrigated through laser-cut kerfs, has been ongoing. This study aimed to verify the safety of this type of catheter. METHODS: Study 1: Radiofrequency (RF) applications at a range of powers (30-50 W), contact forces (10-20 g), and durations (10-60 s) using perpendicular/parallel catheter orientation with half-normal (HNS) or normal saline irrigation were compared between TactiFlex (4-mm tip) and TactiCath (3.5-mm tip) with temperature-controlled mode in excised porcine hearts. Study 2: The relation between RF applications using TactiFlex and the incidence of steam-pops in the real clinical cases were examined. RESULTS: Study-1: 576 RF lesions were examined. TactiFlex demonstrated a significantly lower risk of steam-pops (5[1.7%] vs. 59[20.5%], p < .0001). Compared to 3.5-mm-tip catheter (TactiCath), 4-mm-tip catheter (TactiFlex) produced smaller lesion volume at perpendicular (193[98-554]mm3 vs. 263[139-436]mm3 , p < .0001), but relatively similar lesion volume at parallel contact (243[105-443]mm3 vs. 278[180-440]mm3 , p = .06). HNS-irrigation tended to increase the lesion volume in both catheters and to increase the incidence of steam-pops with TactiCath, but not with TactiFlex. The cut-off value of %impedance-drop ( = absolute impedance-drop/initial impedance) of 20% predicted steam-pops with a sensitivity = 100% and specificity = 89.6% in TactiFlex. Study-2: 5496 RF applications in 84 patients (51AFs/8ATs/3AVNRTs/4AVRTs/17PVCs/4VTs) using TactiFlex were analyzed. Four steam-pops (0.07%) in three patients with pericardial effusion were observed (%impedance-drop = 24%/26%/29%/35%, respectively). The cut-off value of %impedance-drop = 20%, derived from ex-vivo study, showed sensitivity = 100% and specificity = 90.1% in detecting steam-pops. CONCLUSION: TactiFlex reduced the risk of steam-pops than TactiCath. %impedance-drop ≤ 20% may be reasonable for safely use with a sufficient safety margin. For 4-mm-tip catheter, parallel-contact may be recommended for larger lesion creation.
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Ablación por Catéter , Vapor , Humanos , Animales , Porcinos , Irrigación Terapéutica , Diseño de Equipo , CatéteresRESUMEN
BACKGROUND: Fast ventricular tachycardias (VTs) have historically been attributed to shorter path lengths with smaller reentrant circuit dimensions in animal models. The relationship between the dimensions of the reentrant VT circuit and tachycardia cycle length (TCL) has not been examined in humans. This study aimed to analyze the determinants of the rate of human VT with comparison of circuit dimensions and conduction velocity (CV) across a wide range of both stable and unstable VTs delineated by high-resolution mapping. METHODS: Fifty-four VTs with complete circuit delineation (>90% TCL) by high-resolution multielectrode mapping were analyzed in 49 patients (men, 88%; age, 65 years [58-71 years]; nonischemic, 47%). Fast VT was defined as TCL <333 milliseconds (rate >180 bpm). Unstable VT was defined by hemodynamic deterioration with an intrinsic mean arterial pressure <60 mm Hg during a sustained episode. RESULTS: The median TCL of VT was 365 milliseconds (306-443 milliseconds), and 24 fast VTs were characterized. A wide range of CVs was observed within the entrance (0.03-0.55 m/s), common pathway (0.03-0.77 m/s), exit (0.03-0.53 m/s), and outer loop (0.17-1.13 m/s). There were no significant differences in the median dimensions of the isthmus and path length between fast and slow VTs and between unstable and stable VTs. The outer loop CV was the only circuit component that correlated with TCL in both ischemic cardiomyopathy (r=-0.5, P=0.006) and nonischemic cardiomyopathy (r=-0.45, P=0.028). The duration of the longest diastolic electrogram was inversely correlated with the dimensions of common pathway (length: r=-0.46, P=0.001, width: r=-0.3, P=0.047) and predictive of rapid VT termination by a single radiofrequency application (r=-0.41, P=0.023). CONCLUSIONS: Because of a wide spectrum of CV observed within the reentrant path during human VT, the dimensions of the circuit were not predictive of VT cycle length. For the first time, we demonstrate that the CV of the outer loop, rather than isthmus, is the principal determinant of the rate of VT. The size of the circuit was similar between fast and slow VTs and between unstable and stable VTs. Long, continuous electrograms were indicative of spatially confined isthmus dimensions, confirmed by rapid termination of VT during radiofrequency delivery.
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Mapeo del Potencial de Superficie Corporal/métodos , Sistema de Conducción Cardíaco/fisiopatología , Frecuencia Cardíaca/fisiología , Taquicardia Ventricular/diagnóstico por imagen , Taquicardia Ventricular/fisiopatología , Anciano , Ablación por Catéter/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Taquicardia Ventricular/cirugíaRESUMEN
BACKGROUND: This study was aimed to investigate the efficacy of the over-the-wire (OTW) microelectrodes catheter in coronary venous system (CVS) mapping and treatment of outflow tract ventricular arrhythmia (OTVA) arising from the vicinity of the left ventricular summit (LVS). METHODS: Consecutive 62 patients with idiopathic OTVA in whom the OTW microelectrodes catheter was routinely used for CVS mapping were analyzed. CVS mapping was performed for both main trunk (from great cardiac vein to anterior interventricular vein) and branches including the annular branch or septal branch. RESULTS: The earliest activation site (EAS) was within the CVS in 21 patients. Among them, the EAS was within the main trunk of the CVS in seven (33%) and within the branch of the CVS in 14 (67%) patients. Radiofrequency catheter ablation was started at an anatomically adjacent site to the EAS, which eliminated OTVA in 16 (76%) patientsã(the endocardial LVOT in 10 and the aortic sinus of Valsalva in six patients). For the remaining five patients with unsuccessful catheter ablation at an anatomically adjacent site, targeted OTVA was eliminated by catheter ablation at the EAS within the CVS in two patients and by chemical ablation with ethanol injection in one patient, resulting in the overall success rate of 90% (19/21). CONCLUSION: The OTW microelectrodes-guided ablation of OTVA from the vicinity of the LVS was effective. In maximizing the efficacy of ablation, CVS branch mapping is important since the earliest activation was commonly recorded not in the main trunk but within the branch of the CVS.
Asunto(s)
Ablación por Catéter , Taquicardia Ventricular , Arritmias Cardíacas/cirugía , Ablación por Catéter/métodos , Catéteres , Electrocardiografía , Etanol , Ventrículos Cardíacos , Humanos , Microelectrodos , Resultado del TratamientoRESUMEN
BACKGROUND: Accurate and expedited identification of scar regions most prone to reentry is needed to guide ventricular tachycardia (VT) ablation. We aimed to prospectively assess outcomes of VT ablation guided primarily by the targeting of deceleration zones (DZ) identified by propagational analysis of ventricular activation during sinus rhythm. METHODS: Patients with scar-related VT were prospectively enrolled in the University of Chicago VT Ablation Registry between 2016 and 2018. Isochronal late activation maps annotated to the latest local electrogram deflection were created with high-density multielectrode mapping catheters. Targeted ablation of DZ (>3 isochrones within 1cm radius) was performed, prioritizing later activated regions with maximal isochronal crowding. When possible, activation mapping of VT was performed, and successful ablation sites were compared with DZ locations for mechanistic correlation. Patients were prospectively followed for VT recurrence and mortality. RESULTS: One hundred twenty patients (median age 65 years [59-71], 15% female, 50% nonischemic, median ejection fraction 31%) underwent 144 ablation procedures for scar-related VT. 57% of patients had previous ablation and epicardial access was employed in 59% of cases. High-density mapping during baseline rhythm was performed (2518 points [1615-3752] endocardial, 5049±2580 points epicardial) and identified an average of 2±1 DZ, which colocalized to successful termination sites in 95% of cases. The median total radiofrequency application duration was 29 min (21-38 min) to target DZ, representing ablation of 18% of the low-voltage area. At 12±10 months, 70% freedom from VT recurrence (80% in ischemic cardiomyopathy and 63% in nonischemic cardiomyopathy) was achieved. The overall survival rate was 87%. CONCLUSIONS: A novel voltage-independent high-density mapping display can identify the functional substrate for VT during sinus rhythm and guide targeted ablation, obviating the need for extensive radiofrequency delivery. Regions with isochronal crowding during the baseline rhythm were predictive of VT termination sites, providing mechanistic evidence that deceleration zones are highly arrhythmogenic, functioning as niduses for reentry.
Asunto(s)
Arritmias Cardíacas/fisiopatología , Mapeo del Potencial de Superficie Corporal , Cardiomiopatías/fisiopatología , Taquicardia Ventricular/fisiopatología , Anciano , Arritmias Cardíacas/terapia , Mapeo del Potencial de Superficie Corporal/métodos , Cardiomiopatías/terapia , Ablación por Catéter/métodos , Electrocardiografía/métodos , Técnicas Electrofisiológicas Cardíacas/métodos , Femenino , Frecuencia Cardíaca/fisiología , Ventrículos Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/fisiopatología , Isquemia Miocárdica/terapia , Taquicardia Ventricular/terapiaRESUMEN
We present a rare case of reentrant ventricular tachycardia proven by entrainment maneuvers that was successfully ablated from the noncoronary cusp. The case highlights regional anatomy, pacing maneuvers with multi-modality images from fluoroscopy, intracardiac echo, and electroanatomical mapping.
Asunto(s)
Bloqueo de Rama/cirugía , Ablación por Catéter , Taquicardia Ventricular/cirugía , Potenciales de Acción , Bloqueo de Rama/diagnóstico , Bloqueo de Rama/fisiopatología , Electrocardiografía , Técnicas Electrofisiológicas Cardíacas , Frecuencia Cardíaca , Humanos , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/fisiopatología , Factores de Tiempo , Resultado del Tratamiento , Adulto JovenRESUMEN
INTRODUCTION: Pulmonary vein isolation (PVI) and linear ablation with a roof line and bottom line on the left atrial (LA) posterior wall (LAPW) can be achieved with a cryoballoon (CB). This study sought to investigate the long-term durability of these linear lesions. METHODS AND RESULTS: Among 290 persistent patients with atrial fibrillation (AF) who had undergone linear ablation with a CB on the roof and bottom line of the LAPW in addition to the PVI, we analyzed those patients who underwent a re-do AF ablation. Arrhythmia recurrence was confirmed in 70 (24%) out of 290 patients, and 47 (16%) patients underwent re-do sessions. At the beginning of the re-do ablation, we examined the reconnection sites of the linear lesions on the LAPW and PVI. Maintenance of the conduction block on the LAPW roof and bottom lines was observed in 35 out of 47 patients (74.5%), and 16 out of 35 patients (45.7%), respectively. The length of the roof line was significantly shorter in patients with preservation of the conduction block on the LAPW roof than in those without (36.2 ± 6.5 mm vs 41.6 ± 4.7 mm, P = .02). CONCLUSION: Durable lesions could be obtained after linear ablation with the CB for the LAPW roof line, especially in those with a relatively short LAPW roof line. However, patients requiring touch-up ablation with radiofrequency were included, and that was associated with a potential financial implication.
Asunto(s)
Fibrilación Atrial/cirugía , Criocirugía , Venas Pulmonares/cirugía , Potenciales de Acción , Anciano , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/fisiopatología , Ablación por Catéter , Criocirugía/efectos adversos , Femenino , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Venas Pulmonares/fisiopatología , Recurrencia , Reoperación , Estudios Retrospectivos , Factores de Riesgo , Factores de Tiempo , Resultado del TratamientoRESUMEN
PURPOSE: The aim of this study was to test regional pharmacological effects of an antiarrhythmic agents to predict ablative effects. BACKGROUND: The vein of Marshall (VOM) providing vascular access to myocardial tissue has been used for ablative purposes using ethanol. METHODS: A total of 35 patients (male 21, 63.2 ± 7.8 years old) were included. A balloon-tipped infusion catheter was inserted into the VOM. Endocardial ultrahigh-resolution mapping was performed along the VOM region to record the change in atrial electrograms (AEs) after VOM injection of cibenzoline of 3.5 mg during sustained atrial fibrillation (AF). Subsequently, ethanol was infused into the VOM and ablative region was mapped. RESULTS: In 17 patients (49 %), cibenzoline reduced AEs amplitude by >50%, all of which had also complete elimination of AEs following ethanol (Group A). In 18 patients (Group B), cibenzoline failed to eliminate AEs; yet, in 13 of 18 AEs were eliminated by ethanol. In the remaining five patients, ethanol did not eliminate AE. CONCLUSIONS: Cibenzoline into the VOM could reliably predicts the results of subsequent ethanol infusion into the VOM using ultrahigh-resolution mapping system, which leads to avoid unnecessary permanent lesion creation by ethanol infusion.