Durable pulmonary vein isolation with optimized high-power and very high-power short-duration temperature-controlled ablation: A step-by-step guide.

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.

Fibrilación auricular recurrente posterior a ablación de venas pulmonares: serie de casos / Recurrent atrial fibrillation after ablation of pulmonary veins: case series / Fibrilação atrial recorrentes pós ablação das veias pulmonares: série de casos

La ablación de las venas pulmonares se ha convertido en un tratamiento clave para fibrilación auricular (FA). Sin embargo, pueden ocurrir recurrencias. La estrategia disponible para la ablación después de una recurrencia de FA es controvertida, compleja y desafiante, y la información es limitada. Mediante la presentación de una serie de casos se resumen y discuten elementos clave en la comprensión y tratamiento del paciente con FA recurrente sintomática después de un procedimiento inicial de ablación de venas pulmonares que requiere un nuevo procedimiento de ablación. En las últimas décadas se ha obtenido una mejor comprensión de los mecanismos fisiopatológicos implicados en la FA recurrente posterior a ablación de venas pulmonares, lo que permite identificar factores asociados, crear scores predictores e implementar técnicas de optimización o estrategias adicionales para mejorar la durabilidad y la eficacia del aislamiento de venas pulmonares. Debido a que la reconexión de venas pulmonares es un hallazgo típico durante los procedimientos repetidos, ésta debe ser considerada el objetivo principal de una nueva ablación. Las estrategias de ablación adicional (desencadenantes extrapulmonares o sustratos arritmogénicos) son controvertidas y requieren investigaciones futuras.

Pulmonary vein ablation has become a key treatment for atrial fibrillation (AF). However, recurrences can occur. The ideal strategy for ablation after AF recurrence is controversial, complex, and challenging, with limited data available. By presenting a series of cases, we summarize and discuss key elements in the understanding and treatment of patients with symptomatic recurrent AF after an initial pulmonary vein ablation procedure who are subjected to a new ablation procedure. In recent decades, there has been a better understanding of the pathophysiological mechanisms involved in recurrent AF after pulmonary vein ablation, making it possible to identify associated factors, create predictive scores and implement optimization techniques or additional strategies to improve the durability and efficacy of pulmonary veins isolation. Because pulmonary vein reconnection is a typical finding during repeat procedures, it should be considered the primary goal for a repeat ablation procedure. Additional ablation strategies (extrapulmonary triggers or arrhythmogenic substrates) are controversial and require further investigation.

A ablação das veias pulmonares tornou-se um tratamento chave para fibrilação atrial (FA). No entanto, podem ocorrer recorrências. A estratégia ideal para a ablação após uma recorrência da FA é controversa, complexa e desafiadora e existem dados limitados. Através da apresentação de uma série de casos resumimos e discutimos elementos chave no entendimento e tratamento do paciente com FA recorrente sintomática após um procedimento inicial de ablação de veias pulmonares, que são submetidos a um novo procedimento de ablação. Nas últimas décadas obteve-se uma melhor compressão dos mecanismos fisiopatológicos envolvidos na FA recorrente pós-ablação de veias pulmonares, isso permite identificar fatores associados, criar scores preditores, implementar técnicas de otimização ou estratégias adicionais para melhorar a durabilidade e eficácia do isolamento de veias pulmonares. Dado que a reconexão de veias pulmonares é um achado típico durante os procedimentos repetidos deve ser considerado o objetivo principal para uma nova ablação. As estratégias de ablação adicional (desencadeadores extrapulmonares ou substratos arritmogénicos) são controversas e requerem investigação futura.

Severe coronary artery spasm during left atrial appendage closure plus catheter ablation for atrial fibrillation: case presentation.

BACKGROUND: Left atrial appendage closure (LAAC) combined with radiofrequency catheter ablation (RFCA) as a hybrid procedure is commonly performed to treat atrial fibrillation (AF). Although this treatment carries a low risk of coronary artery spasm (CAS), and has never been observed in LAAC procedure, caution still needed to be taken. We presented a case of CAS that occurred in an AF patient during the hybrid procedure. CASE PRESENTATION: The patient was a 65-year-old man with paroxysmal AF who developed CAS during RFCA and LAAC. In this case, LAAC was performed ahead of RFCA. After atrial septal puncture, the occluder was advanced into left atrium through delivery sheath, and successfully deployed in the LAA. After verifying the assessment of "PASS" criteria, we decided to release the device. However, before releasing the occluder in LAAC, the patient's blood pressure (BP) fell to 70/45 mmHg with heart rate (HR) drop and ST-segment elevation in II, III, and aVF and reciprocal ST-segment depression in I and aVL. Isotonic sodium chloride load was administered. After 3 min, the BP and HR raised, and ST-segment returned to normal. The occluder was successfully released after the stable condition of the patient. Then, RFCA was sequentially performed. When isolating the right pulmonary veins, the patient's BP and HR fell again with ST-segment elevation in inferior leads. Spontaneous ventricular tachycardia and fibrillation developed rapidly and defibrillation was performed immediately with success. Coronary angiography revealed the obstruction of the right coronary artery which disappeared completely after intracoronary nitroglycerin injection (1 mg). Under systemic diltiazem infusion, the RFCA procedure was accomplished. After the procedure, the patient recovered without any neurologic deficit, and CAS has never recurred with isosorbide mononitrate treatment during follow-up. CONCLUSIONS: CAS is a rare complication associated with AF hybrid procedure. Attention should be paid to this rare but potentially life-threatening complication.

Quantitative assessment the longitudinal changes of pulmonary vascular counts in chronic obstructive pulmonary disease.

BACKGROUND: Chest computed tomography (CT) is a widely used method to assess morphological and dynamic abnormalities in chronic obstructive pulmonary disease (COPD). The small pulmonary vascular cross-section (CSA), quantitatively extracted from volumetric CT, is a reliable indicator for predicting pulmonary vascular changes. CSA is associated with the severity of symptoms, pulmonary function tests (PFT) and emphysema and in COPD patients the severity increases over time. We analyzed the correlation longitudinal changes in pulmonary vascular parameters with clinical parameters in COPD patients. MATERIALS AND METHODS: A total of 288 subjects with COPD were investigated during follow up period up to 6 years. CT images were classified into five subtypes from normal to severe emphysema according to percentage of low-attenuation areas less than -950 and -856 Hounsfield units (HU) on inspiratory and expiratory CT (LAA-950, LAA-856exp). Total number of vessels (Ntotal) and total number of vessels with area less than 5 mm2 (N<5 mm) per 1 cm2 of lung surface area (LSA) were measured at 6 mm from the pleural surface. RESULTS: Ntotal/LSA and N<5 mm/LSA changed from 1.16 ± 0.27 to 0.87 ± 0.2 and from 1.02 ± 0.22 to 0.78 ± 0.22, respectively, during Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage progression. Both parameters changed from normal to severe emphysema according to CT subtype from 1.39 ± 0.21 to 0.74 ± 0.17 and from 1.18 ± 0.19 to 0.67 ± 0.15, respectively. LAA-950 and LAA-856exp were negatively correlated with Ntotal/LSA (r = - 0.738, - 0.529) and N<5 mm /LSA (r = - 0.729, -- .497). On the other hand, pulmonary function test (PFT) results showed a weak correlation with Ntotal/LSA and N<5 mm/LSA (r = 0.205, 0.210). The depth in CT subtypes for longitudinal change both Ntotal/LSA and N<5 mm/LSA was (- 0.032, - 0.023) and (- 0.027) in normal and SAD, respectively. CONCLUSIONS: Quantitative computed tomography features faithfully reflected pulmonary vessel alterations, showing in particular that pulmonary vascular alteration started.

First-in-Human Experience and Acute Procedural Outcomes Using a Novel Pulsed Field Ablation System: The PULSED AF Pilot Trial.

BACKGROUND: Pulsed field ablation (PFA) is a novel form of ablation using electrical fields to ablate cardiac tissue. There are only limited data assessing the feasibility and safety of this type of ablation in humans. METHODS: PULSED AF (Pulsed Field Ablation to Irreversibly Electroporate Tissue and Treat AF; https://www.clinicaltrials.gov; unique identifier: NCT04198701) is a nonrandomized, prospective, multicenter, global, premarket clinical study. The first-in-human pilot phase evaluated the feasibility and efficacy of pulmonary vein isolation using a novel PFA system delivering bipolar, biphasic electrical fields through a circular multielectrode array catheter (PulseSelect; Medtronic, Inc). Thirty-eight patients with paroxysmal or persistent atrial fibrillation were treated in 6 centers in Australia, Canada, the United States, and the Netherlands. The primary outcomes were ability to achieve acute pulmonary vein isolation intraprocedurally and safety at 30 days. RESULTS: Acute electrical isolation was achieved in 100% of pulmonary veins (n=152) in the 38 patients. Skin-to-skin procedure time was 160±91 minutes, left atrial dwell time was 82±35 minutes, and fluoroscopy time was 28±9 minutes. No serious adverse events related to the PFA system occurred in the 30-day follow-up including phrenic nerve injury, esophageal injury, stroke, or death. CONCLUSIONS: In this first-in-human clinical study, 100% pulmonary vein isolation was achieved using only PFA with no PFA system-related serious adverse events. Graphic Abstract: A graphic abstract is available for this article.

Total anomalous pulmonary venous connection: Influence of heterotaxy and venous obstruction on outcomes.

BACKGROUND: Previous studies have demonstrated increased early mortality and pulmonary vein reintervention for patients with total anomalous pulmonary venous connection (TAPVC) and heterotaxy syndrome (HTX+) compared with patients with TAPVC without heterotaxy syndrome (HTX-). We aimed to evaluate the longitudinal risk of pulmonary vein reintervention and mortality in HTX + patients. METHODS: A retrospective review was performed to identify longitudinal interventions in patients with TAPVC seen at a single center from 1995 to 2019. The mean cumulative interventions were described for all patients using the Nelson-Aalen estimator. Survival with TAPVC was described using Kaplan-Meier estimates. RESULTS: A total of 336 patients were identified with TAPVC, of whom 118 (35%) had heterotaxy syndrome. Functional single ventricles were identified in 106 of these 118 HTX + patients (90%) and in 14 of 218 HTX- patients (6%) (P < .001). Obstructed TAPVC (OBS+) was present in 49 of 118 HTX + patients (42%) and in 87 of 218 HTX- patients (40%) (P = .89). The median duration of follow-up was 6.5 years. Five-year survival was 69% for HTX+/OBS + patients, 72% for HTX+/OBS- patients, 86% for HTX-/OBS + patients, and 95% for HTX-/OBS- patients (P < .0001, log-rank test). The mean number of pulmonary vein interventions at the median follow-up time was greater in the HTX+/OBS + patients compared with HTX+/OBS- patients (mean, 2.0 vs 1.1; P = .030), HTX-/OBS + patients (mean, 1.3; P = .033), and HTX-/OBS- patients (mean, 1.3; P = .029). CONCLUSIONS: Among the 4 cohorts, HTX+ was associated with a higher rate of mortality, and HTX+/OBS+ was associated with a greater number of pulmonary vein interventions. This may be due in part to the high prevalence of single ventricle physiology in the HTX + cohort.

The predictive role of early recurrences of atrial arrhythmias after pulmonary vein cryoballoon ablation. Is blanking period an outdated concept? Insights from 12-month continuous cardiac monitoring.

BACKGROUND: Early recurrences of atrial arrhythmias (ERAA) after atrial fibrillation (AF) catheter ablation do not predict procedural failure. A well-demarcated homogeneous lesion delivered by cryoballoon is less arrhythmogenic, and the recommended three-months blanking period may not refer to cryoballoon ablation (CBA). OBJECTIVE: We aimed to evaluate the predictive role of ERAA after second-generation CBA using an implantable loop recorder. METHODS: This prospective observational study enrolled 100 patients (58 males, median age 58) with paroxysmal/persistent AF undergoing pulmonary vein (PV) CBA using second-generation cryoballoon with simultaneous ECG loop recorder implantation. The duration of follow-up was 12 months, with scheduled visits at 3, 6 and 12 months. RESULTS: 99 patients from 100 completed the 12-month follow-up period. ERAA occurred in 31.3 % of patients. 83.9 % of patients with ERAA also developed late recurrences. The 12-month freedom from AF in patients with ERAA was significantly lower than in those without ERAA (p < 0.0001). Non-paroxysmal AF and longer arrhythmia history were associated with increased risk of both early (HR 3.27; 95 % CI 1.32-8.08; p = 0.010 and HR 1.0147; 95 % CI 1.008-1.086; p = 0.015, respectively) and late recurrences (HR 3.89; 95 % CI 1.67-9.04; p = 0.002 and HR 1.0142; 95 % CI 1.007-1.078; p = 0.019, respectively) of AF. ERAA were another predictor for procedural failure (HR 15.2; 95 % CI (6.42-35.99; p = 0.019). CONCLUSIONS: ERAA occurred in the third of the patients after PV second-generation CBA and are strongly associated with procedural failure. Longer duration of AF history and persistent AF are independent predictors of AF's early and late recurrence.

High-power, short-duration ablation for atrial fibrillation: Pros and cons.

This article reviews and compares the rationale and evidence supporting high-power, short-duration radiofrequency (RF) ablation with those of conventional-power, conventional-duration RF ablation for atrial fibrillation (AF). The pros and cons of each approach, biophysics of ablation, pre-clinical studies informing clinical utilization, and the accumulated clinical evidence are presented. Both conventional-power, conventional-duration RF ablation and high-power, short-duration ablation are similarly safe, and effective approaches for AF ablation. Theoretical advantages of high-power, short-duration ablation, including greater procedure efficiency and limited conductive heating of collateral structures, must be weighed against the narrower safety margin related to rapid energy delivery during high power ablation.

Comparison of lesion characteristics between conventional and high-power short-duration ablation using contact force-sensing catheter in patients with paroxysmal atrial fibrillation.

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.

Implementation of a zero fluoroscopic workflow using a simplified intracardiac echocardiography guided method for catheter ablation of atrial fibrillation, including repeat procedures.

OBJECTIVE: Pulmonary vein isolation (PVI) is the cornerstone of the interventional treatment of atrial fibrillation (AF). Traditionally, during these procedures the catheters are guided by fluoroscopy, which poses a risk to the patient and staff by ionizing radiation. Our aim was to describe our experience in the implementation of an intracardiac echocardiography (ICE) guided zero fluoroscopic (ZF) ablation approach to our routine clinical practice. METHODS: We developed a simplified ICE guided technique to perform ablation procedures for AF, with the aid of a 3D electroanatomical mapping system. The workflow was implemented in two phases: (1) the Introductory phase, where the first 16 ZF PVIs were compared with 16 cases performed with fluoroscopy and (2) the Extension phase, where 71 consecutive patients (including repeat procedures) with ZF approach were included. Standard PVI (and redoPVI) procedures were performed, data on feasibility of the ZF approach, complications, acute and 1-year success rates were collected. RESULTS: In the Introductory phase, 94% of the procedures could be performed with complete ZF with a median procedure time of 77.5 (73.5-83) minutes. In one case fluoroscopy was used to guide the ICE catheter to the atrium. There was no difference in the complication, acute and 1-year success rates, compared with fluoroscopy guided procedures. In the Extension phase, 97% of the procedures could be completed with complete ZF. In one case fluoroscopy was used to guide the transseptal puncture and in another to position the ICE catheter. Acute success of PVI was achieved in all cases, 64.4% patients were arrhythmia free at 1-year. Acute major complications were observed in 4 cases, all of these occurred in the redo PVI group and consisted of 2 tamponades, 1 transient ischemic attack and 1 pseudoaneurysm at the puncture site. The procedures were carried out by all members of the electrophysiology unit in the Extension phase, including less experienced operators and electrophysiology fellows (3 physicians) under the supervision of the senior electrophysiologist. Consequently, procedure times became longer [90 (75-105) vs 77.5 (73.5-85) min, p = 0.014]. CONCLUSIONS: According to our results, a ZF workflow of AF ablations can be successfully implemented into the routine practice of an electrophysiology laboratory, without compromising safety and effectivity.

High density mapping guided partial antral ablation for a pulmonary vein isolation.

The muscular discontinuities at the pulmonary vein (PV)-left atrial (LA) junction are known. The high-density mapping may help to find the muscular discontinuity. This study evaluated the efficacy of a partial antral ablation for a pulmonary vein (PV) isolation using high density (HD) mapping. A total of 60 drug-refractory atrial fibrillation (AF) patients undergoing catheter ablation were enrolled. The detailed activation mapping of each PV and LA junction was performed using an HD mapping system, and each PV segment's activation pattern was classified into a "directly-activated from the LA" or "passively-activated from an adjacent PV segment" pattern. The antral ablations were performed at the directly-activated PV segments only when the PV had "passively-activated segments". If the PV did not contain passively-activated segments, a circumferential antral ablation was performed on those PVs. A "successful partial antral ablation" was designated if the electrical isolation of targeted PV was achieved by ablation at the directly-activated segments only. If the isolation was not achieved even though all directly-activated segments were ablated, a "failed partial antral ablation" was designated, and then a circumferential ablation was performed. Among 240 PVs, passively-activated segments were observed in 140 (58.3%) PVs. Both inferior PVs had more passively-activated segments than superior PVs, and the posteroinferior segments had the highest proportion of passive activation. The overall rate of successful partial antral ablation was 85%. The atrial tachyarrhythmia recurrence was observed in 10 patients (16.7%) at 1-year. HD mapping allowed the evaluation of the detailed activation patterns of the PVs, and passively-activated segments may represent muscular discontinuity. Partial antral ablation of directly-activated antral segments only was feasible and effective for a PVI.

Clinical Significance of Partial Anomalous Pulmonary Venous Connections (Isolated and Atrial Septal Defect Associated) Determined by Cardiovascular Magnetic Resonance.

BACKGROUND: Partial anomalous venous connections (PAPVC) are associated with left to right shunting and right heart dilatation. Identification of PAPVC has increased with widespread use of cross-sectional imaging modalities. However, management strategies are mostly based on expert opinion given the scarcity of data from large series. We aimed to define types and significance of isolated and atrial septal defect (ASD) associated PAPVC detected by cardiovascular magnetic resonance. METHODS: We retrospectively reviewed our cardiovascular magnetic resonance database from 2002 to 2018 to identify isolated or ASD-associated PAPVC cases. RESULTS: A total of 215 patients (median age 46 years; range, 6-83) with isolated or ASD-associated PAPVC were identified among 102 135 clinical cardiovascular magnetic resonance studies. Of these, 104 were isolated and 111 were associated with an ASD. Anomalous connection of right upper pulmonary vein was the most common single venous anomaly (99/215), but in the isolated PAPVC group there were more anomalous left than right upper pulmonary veins (39 versus 34). The Qp/Qs was significantly higher for isolated anomalous single right upper pulmonary vein than left upper pulmonary vein (1.6 versus 1.4 respectively; P=0.01) as were right ventricular end-diastolic volumes (113.7±30.9 versus 90 [57-157] mL/m2, P=0.004). In the PAPVC with an ASD group, sinus venosus ASDs (82%) were associated with right-sided PAPVCs while both right and left-sided venous anomalies were seen in secundum ASDs (18%). In a substantial number of patients (30 out of 91) with sinus venosus ASDs, PAPVCs were more complex and involved more than a single anomalous right upper pulmonary vein; and in 5 patients with ASD, PAPVC was identified only after the ASD closure. CONCLUSIONS: This large series provides descriptive and hemodynamic features for isolated and ASD-associated PAPVCs. Anomalous isolated right upper pulmonary vein may cause a significant shunt (Qp/Qs >1.5). PAPVC associated with sinus venosus and secundum ASDs might be more complex than a single anomalous pulmonary vein and missed before ASD correction.