A case of successful radiofrequency catheter ablation for atrial tachycardia originating from the inferior vena cava using high-resolution mapping

A 60-year-old man presented with sustained supraventricular tachycardia. Atrial tachycardia (AT), with the earliest atrial activation (EAA) occurring at the ostium of the coronary sinus, was reproducibly induced.Three-dimensional electroanatomical mapping (3DEAM) using a 3.5-mm distal electrode tip linear catheter (Thermocool) and radiofrequency energy (RF) was performed at the fractionated atrial electrogram site. It preceded at 30 ms to the EAA but did not terminate AT. Further 3DEAM using a multielectrode mapping catheter (Pentaray) demonstrated a centrifugal propagation pattern at the boundary zone between the right atrium and inferior vena cava. RF application here terminated AT, which then became non-inducible.     

Initial experience with AcQMap catheter for treatment of persistent atrial fibrillation and atypical atrial flutter

IntroductionThe AcQMap High Resolution Imaging and Mapping System was recently introduced. This system provides 3D maps of electrical activation across an ultrasound-acquired atrial surface.MethodsWe evaluated the feasibility and the acute and short-term efficacy and safety of this novel system for ablation of persistent atrial fibrillation (AF) and atypical atrial flutter.ResultsA total of 21 consecutive patients (age (mean ± standard deviation) 62 ± 8 years, 23% female) underwent catheter ablation with the use of the AcQMap System. Fourteen patients (67%) were treated for persistent AF and 7 patients (33%) for atypical atrial flutter. Eighteen patients (86%) had undergone at least one prior ablation procedure. Acute success, defined as sinus rhythm without the ability to provoke the clinical arrhythmia, was achieved in 17 patients (81%). At 12 months, 4 patients treated for persistent AF (29%) and 4 patients treated for atypical flutter (57%) remained in sinus rhythm. Complications included hemiparesis, for which intra-arterial thrombolysis was given with subsequent good clinical outcome (n = 1), and complete atrioventricular block, for which a permanent pacemaker was implanted (n = 2). No major complications attributable to the mapping system occurred.ConclusionThe AcQMap System is able to provide fast, high-resolution activation maps of persistent AF and atypical atrial flutter. Despite a high acute success rate, the recurrence rate of persistent AF was relatively high. This may be due to the selection of the patients with therapy-resistant arrhythmias and limited experience in the optimal use of this mapping system that is still under development.Supplementary InformationThe online version of this article (10.1007/s12471-021-01636-w) contains supplementary material, which is available to authorized users.     

Right atrial appendage tachycardia: A rare cause of tachycardia induced cardiomyopathy in a 4-year-old child

We present a rare case of tachycardiomyopathy in a 4-year-old girl. The child had incessant atrial tachycardia (AT) and refractory heart failure. Right atrial appendage (RAA) was localised as the source of the ectopic tachycardia. The child underwent successful radiofrequency ablation (RFA) using 3-D electroanatomical mapping. Fluoroscopy was used sparingly only to rule out underlying anomalies. The left ventricular functions returned to normal by one month after the procedure. RAA AT is rare in very young children and usually necessitates surgical appendectomies. RFA is a challenge in such age groups and there are very few published literature on RAA AT in very young children.     

Intra-septal radiofrequency ablation within the transseptal puncture hole targeting an interatrial connection during a bi-atrial tachycardia

A 74-year-old man after multiple mitral valve surgeries underwent catheter ablation of a bi-atrial tachycardia (BiAT). Ultra-high resolution activation mapping exhibited a reentrant circuit propagating around the inferior to anterior mitral annulus and right atrial (RA) septum with two interatrial connections. At the transeptal puncture site, continuous fractionated electrograms were recorded during the BiAT, and entrainment pacing revealed a post-pacing interval similar to the tachycardia cycle length, which suggested that the interatrial conduction from the RA to the left atrium (LA) was located just at the transseptal puncture site. A radiofrequency application inside the transseptal puncture hole could successfully eliminate the BiAT. The ablation target for BiATs propagating around the mitral annulus and RA septum is generally the anatomical mitral isthmus (MI). Since the present case had multiple incisions on both the RA and LA septum due to mitral valve surgeries, there was the possibility of the occurrence of a BiAT including the RA and LA septum after performing an MI linear ablation. Therefore, the preferable ablation target for the BiAT in the present case appeared to be the interatrial connection. Ultra-high resolution detailed mapping not only on the atrial endocardium but also in the transseptal puncture hole may be useful for identifying a critical interatrial connection of BiAT circuits.     

Management of paroxysmal ectopic atrial tachycardia with long sinus pauses in a teenager

Sinus pauses in the setting of supraventricular tachycardia is rare in children. We describe an asymptomatic teen with irregular heart rate detected during an incidental exam who was found to have short runs of a slow ectopic atrial tachycardia on electrocardiogram and prolonged sinus pauses on routine ambulatory ECG. Successful catheter ablation of the ectopic atrial tachycardia led to resolution of the sinus pauses.     

High-density activation map of atrial tachycardia within left atrial appendage

Identification of the critical isthmus of the reentrant tachycardia is essential to maximize the effect of catheter ablation (CA) and to minimize the myocardial injury of CA. An 81-year-old woman presented recurrent palpitations after CA of atrial fibrillation (AF) and atrial tachycardia (AT). She had moderate aortic valve stenosis and coronary artery disease. She had received a pulmonary vein isolation, left atrial (LA) posterior wall isolation, and LA anterior linear ablation for atrial fibrillation 1 year prior. At the start of the procedure, she was in sinus rhythm. Atrial burst pacing induced an AT (230msec). High-density mapping revealed a figure-of-eight activation pattern within the LA appendage (LAA), accounting for 99% of the tachycardia cycle length. The critical isthmus was identified at the mid LAA and the local electrogram of the critical isthmus was not fractionated. A single radiofrequency application at the critical isthmus of the AT, terminated the AT. She was free from any ATs for 28 months.Radiofrequency ablation of the localized reentrant AT was usually performed targeting long fractionated electrograms. In our case, the local electrogram at the critical isthmus was not fragmented compared with the LAA distal part. Long fractionated electrograms were recorded at a more distal part of the LAA than the common isthmus and we could avoid the potential risk of a perforation. A recent developed 3-dimensional electro-anatomical mapping system can identify the critical isthmus and allow us to select a new therapeutic strategy for a critical isthmus ablation of an AT within the LAA.     

Cryoballoon ablation of focal atrial tachycardia originating from right atrial appendage: Case report and review of the literature

The right atrial appendage (RAA) is a rare site of focal atrial tachycardia (AT). Sometimes, catheter ablation cannot successfully be accomplished at this location due to the difficulty in reaching the exact ablation site as well as the associated possible life-threatening complications like pericardial tamponade or perforation. Although radiofrequency (RF) ablation is preferred for the treatment of RAA tachycardias, alternative tools may be required in rare instances. This report presents a case of RAA tachycardia that was not terminated by RF ablation, instead, has been successfully ablated using cryoballoon. In addition, an overview of the literature and therapeutic options for the AT originating from RAA have also been included.     

An unusual mechanism of sustained right atrial tachycardia

Lower loop re-entry (LLR) flutter is a rare type of atypical right atrial flutter. Most of the reported cases occurred in association with typical flutter patterns as a transient arrhythmia. Our case is unique in the fact the LLR was sustained and persisted independently.     

Clinical outcome of ablation for long-standing persistent atrial fibrillation with or without defragmentation

Objective

To assess the outcome and associated risks of atrial defragmentation for the treatment of long-standing persistent atrial fibrillation (LSP-AF).

Methods

Thirty-seven consecutive patients (60.4 ± 7.3 years; 28 male) suffering from LSP-AF who underwent pulmonary vein isolation (PVI) and linear ablation were compared. All patients were treated with the Stereotaxis magnetic navigation system (MNS). Two groups were distinguished: patients with (n = 20) and without (n = 17) defragmentation. The primary endpoint of the study was freedom of AF after 12 months. Secondary endpoints were AF termination, procedure time, fluoroscopy time and procedural complications. Complications were divided into two groups: major (infarction, stroke, major bleeding and tamponade) and minor (fever, pericarditis and inguinal haematoma).

Results

No difference was seen in freedom of AF between the defragmentation and the non-defragmentation group (56.2 % vs. 40.0 %, P = 0.344). Procedure times in the defragmentation group were longer; no differences in fluoroscopy times were observed. No major complications occurred. A higher number of minor complications occurred in the defragmentation group (45.0 % vs. 5.9 %, P = 0.009). Mean hospital stay was comparable (4.7 ± 2.2 vs. 3.4 ± 0.8 days, P = 0.06).

Conclusion

Our study suggests that complete defragmentation using MNS is associated with a higher number of minor complications and longer procedure times and thus compromises efficiency without improving efficacy.     

Correlation between the sudden jump-like increases of the atrio-Hisian interval induced during burst atrial pacing and during programmed atrial stimulation in patients with atrioventricular nodal reentrant tachycardia

Purpose

To study the correlation between the sudden prolongations of the atrio-Hisian (AH) interval with ≥50 ms during burst and programmed atrial stimulation, and to define whether the AH jump during burst atrial pacing is a reliable diagnostic criterion for dual AV nodal physiology.

Atrial flutter catheter ablation in adult congenital heart diseases

The important increase in life expectancy of adult patients with congenital heart disease (ACHD) has generated new challenges, including arrhythmias that represent one of the main late complications. Reentrant atrial arrhythmias are by far the main mechanism encountered, and catheter ablation has been now presented as a first-line therapy in this patient population. The number of procedures is expected to continuously increase year after year. The heterogeneity and complexity of phenotypes encountered require these cases to be performed by highly experienced operators, in specialized centers with multidisciplinary competencies. A thorough knowledge and understanding of anatomic specificities, vascular access issues, and main circuits encountered according to underlying phenotype is essential. Acute success rates have significantly improved and are now excellent, but recurrences remain a common issue, with different mechanisms or circuits frequently encountered. Observational data have suggested the interest of systematically targeting all inducible atrial arrhythmias, whether previously documented or not, and a lot of hope and research is based on the prediction of arrhythmia substrate before arrhythmia development by imaging or electroanatomic mapping to deliver a prophylactic patient tailored ablation approach. In this review, we summarize those different points in the most common or distinctive defects to offer a didactic overview of atrial flutter catheter ablation in ACHD patients.     

Comparison between cryoballoon double stop and single stop in patients with paroxysmal atrial fibrillation

BackgroundCurrently, cryoballoon (CB) thawing after single stop is generally performed. Previous research had reported that long thawing time using a single stop affects pulmonary veins tissue injury. However, it is uncertain whether CB thawing after single stop affects clinical outcomes.ObjectiveThis study aimed to clarify clinical significance of CB thawing in patients with paroxysmal atrial fibrillation.MethodsTwo hundred ten patients with paroxysmal atrial fibrillation who underwent CB from January 2018 to October 2019 were analyzed. We compared the clinical outcomes of patients whose CB applications were completely stopped with only the double stop technique (DS group, n = 99) and patients with single stop (SS group, n = 111). In DS group, we performed double stop technique for all CB application regardless of phrenic nerve injury or the temperature of esophagus.ResultsThe atrial arrhythmia free-survival rate at 2 years after CB was significantly lower for the DS group than the SS group (76.8% vs 87.4%; p = 0.045). Complications occurred in 2 patients from the DS group and no complications were observed in patients from the SS group (p = 0.13). Mean procedural time was shorter in the DS group than in the SS group (53.1 vs 58.1 min; p = 0.046)ConclusionDS group had higher recurrence rate than SS group. There was no significant difference regarding safety between both the groups. We found that the thawing process after single stop is very important for CB application.     

The symbiosis of contact force catheter use for hybrid ablation for atrial fibrillation

Objective

Reconduction across an ablation line is a common reason for arrhythmia recurrence over time. The hybrid procedure combines epicardial ablation of the pulmonary vein (PV) and creation of a box lesion with endocardial touch-ups for any electrical gaps. A high contact force (CF) between the ablation tip and cardiac tissue may increase the risk of thrombus formation, catheter tip charring, steam pop formation, and even cardiac perforation. CF monitoring is a significant new parameter for titration of the CF for creating an adequate lesion.

Methods

Thirty-eight consecutive patients underwent epicardial ablation using bipolar radiofrequency devices. After checking electrical bidirectional block of the ablation lines, an endocardial CF catheter was used for further ablation (if needed) to complete the isolation of PVs, box lesion, cavotricuspid isthmus (CTI), and complex fractionated atrial electrograms (CFAE).

Results

Endocardial touch-up was needed for 2 PVs (1.3 %) and 10 (26.3 %) box lesions. It was also used for the CTI line in 7 (18.4 %) patients, atrial tachycardia in 3 (7.9 %) patients, and additional CFAE ablation in 17 (44.7 %) patients. All 5 patients with arrhythmia recurrence had a mean CF < 10 g (p = 0.03). Procedure duration was significantly shorter in the CF group (223 ± 57 vs. 256 ± 60 min, p = 0.03) compared with control group.

Conclusion

Use of CF catheters is safe, feasible, and complementary to a hybrid procedure setup for atrial fibrillation ablation. Its real-time monitoring may predict future arrhythmia recurrence, and decrease procedure time.     

Ventricular tachycardia based on cardiac sarcoidosis with a narrow QRS complex,ablated on the left ventricle free-wall

A septuagenarian female with cardiac sarcoidosis suffered from drug refractory ventricular tachycardia (VT) requiring multiple implantable cardioverter-defibrillator shocks. The QRS complex during the VT was very similar to that during sinus rhythm although the QRS width during the VT (142 ms) was relatively wider than that during sinus rhythm (107 ms). The VT exit was located on the ventricular septum close to the His-bundle recording region. However, the critical pathway of this VT was detected on the anterior free wall of the left ventricle (LV), and a radiofrequency application at that site could terminate the VT. No Purkinje potentials were recorded there during the VT or sinus rhythm. According to the electrophysiological study, 3-D mapping, and the response to the ablation, the critical circuit of the VT was surrounded by a protected area of scar associated with cardiac sarcoidosis. As a result, the VT circuit was connected to the basal septal area close to the His-Purkinje system as an outer loop of the VT circuit. This unique trajectory of the VT might have caused a similar QRS morphology to that of sinus rhythm, and the relatively narrow QRS complex despite the critical isthmus was located on the anterior free wall of the LV.     

Successful ablation of frequent atrial premature beats from non-coronary aortic cusp with remote magnetic navigation

A 59-year-old female with structurally normal heart was admitted to our hospital for treatment of highly symptomatic, drug refractory atrial premature beats (APB). ECG revealed atrial parasystolic trigeminy. The arrhythmogenic focus was mapped and ablated using magnetic remote navigation and 3D electroanatomical mapping system. To our knowledge, this is the first report on successful ablation of frequent APBs in the non-coronary aortic cusp.     

Successful Ablation of Cavotricuspid Isthmus-dependent Atrial Flutter Guided by Contact Force Vector in a Patient After a Tricuspid Valve Replacement

A 46-year-old man after a tricuspid valve replacement due to traumatic severe tricuspid regurgitation developed cavotricuspid isthmus-dependent counterclockwise atrial flutter. During a linear ablation using a contact force-sensing irrigated ablation catheter, the flutter could be terminated by a radiofrequency application within a deep pouch just below the bioprosthetic tricuspid valve.     

Local impedance-guided ablation and ultra-high density mapping versus conventional or contact force-guided ablation with mapping for treatment of cavotricuspid isthmus dependent atrial flutter

Introduction– Local impedance (LI) guided ablation as a method of judging lesion effectiveness for cavotricuspid isthmus dependent atrial flutter (CTI-AFL), and ultra-high density (UHD) mapping when breakthrough occurred across an ablation line has not previously been assessed.MethodsThis retrospective observational study evaluated patients undergoing CTI-AFL ablation using conventional, contact force (CF) and LI guided strategies. Ablation metrics were collected, and in the LI cohort, the use of UHD mapping for breakthrough evaluated.Results30 patients were included, 10 per group. Mean total ablation time was significantly shorter with LI (3.2 ± 1.3min) vs conventional (5.6 ± 2.7min) and CF (5.7 ± 2.0min, p = 0.0042). Time from start of ablation to CTI block was numerically shorter with LI (14.2 ± 8.0min) vs conventional and CF (19.7 ± 14.1 and 22.5 ± 19.1min, p = 0.4408). Mean lesion duration was significantly shorter with LI, but there were no differences in the number of lesions required to achieve block, procedural success, complication rates or recurrence. 15/30 patients did not achieve block following first-pass ablation. UHD mapping rapidly identified breakthrough in the five LI patients, including epicardial-endocardial breakthrough (EEB).Conclusion– The use of LI during ablation for real-time lesion assessment was as efficacious as the conventional and CF methods. UHD mapping rapidly identified breakthrough, including EEB.