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Aims: Contact force (CF) sensing has emerged as a tool to guide and improve outcomes for catheter ablation (CA) for cardiac arrhythmias. The clinical benefit on patient outcomes remains unknown. To study whether CF-guided CA for typical atrial flutter (AFL) is superior to CA not guided by CF.Methods and Results: In a double-blinded controlled superiority trial, we randomized patients 1:1 to receive CA for typical AFL guided by CF (intervention group) or blinded to CF (control group). In the intervention group, a specific value of the lesion size index (LSI), estimating ablation lesions size was targeted for each ablation lesion. Patients underwent electrophysiological study (EPS) after 3 months to assess occurrence of the primary endpoint of re-conduction across the cavo-tricuspid isthmus (CTI). We included 156 patients with typical AFL, median age was 68 [interquartile range (IQR) 61-74] years and 120 (77%) patients were male. At index procedure median LSI was higher in the intervention group [6.4 (IQR 5.1-7) vs. 5.6 (IQR 4.5-6.9), P < 0.0001]. After 3 months, 126 patients (58 in intervention group) underwent EPS for primary endpoint assessment. Thirty (24%) patients had CTI re-conduction, distributed with 15 patients in each treatment group (P = 0.62). We observed no difference between treatment groups with regard to fluoroscopy, ablation, or procedure times, nor peri-procedural complications.Conclusion: Contact force-guided ablation does not reduce re-conduction across the CTI after 3 months, nor does CF-guided ablation shorten fluoroscopy, ablation, or total procedure times. [ABSTRACT FROM AUTHOR]

Aims Radiofrequency ablation (RFA) is the treatment of choice of cavotricuspid isthmus (CTI)-dependent atrial flutter. Procedural time is highly variable due to anatomical structures. This study aimed to characterize CTI anatomy by transesophageal 3D echocardiography imaging (3D-TEE) to identify anatomic structures related to longer ablation time. Methods and results Thirty-one consecutive patients (mean age 67.3± 11.5 years, 22 males) underwent CTI-ablation procedure. Before ablation, TEE was performed and 3D-TEE images were acquired to evaluate CTI anatomy qualitatively as well as perform measures of CTI morphological features. The electrophysiologist performing RFA was blinded to 3D-TEE data. Bidirectional block of CTI was achieved in all patients without procedural complications after a median ablation time of 11 (IQR 7-14) min. Patients with RFA time ≥ 11min (Group 2) presented lower left ventricular ejection fraction (51.1± 17.0 vs. 59.5± 6.6%, P< 0.010), a larger left atrium (46.2± 8.4 vs. 39.9± 9.4mm, P< 0.058), and, more frequently, a right atrial pouch (12/16 patients vs. 4/15, P= 0.012) compared with patients with RFA time< 11min (Group 1); CTI pouch was significantly deeper in Group 2 compared with Group 1: telediastolic (TD) pouch depth was 10.4± 4.5 vs. 6.3± 1.5mm (P= 0.003) and telesystolic (TS) depth 12.8± 4.4 vs. 7.0± 1.4mm (P< 0.001), respectively. TD isthmus length, prominent pectinate muscle, and presence of an Eustachian ridge (ER) did not differ between the two groups. Conclusion Routine pre-procedural 3D-TEE imaging is extremely helpful in qualitative and quantitative evaluation of CTI anatomy in patients undergoing RFA for symptomatic typical atrial flutter. Detection of a deep right atrial pouch was found to be associated with significantly prolonged CTI ablation time to achieve bidirectional block. [ABSTRACT FROM AUTHOR]

Since its first description about one century ago, our understanding of atrial flutter (AFL) circuits has considerably evolved. One AFLP circuit can have variable electrocardiographic (ECG) manifestations depending on the presence of pre-existing lesions, or impaired atrial substrate. Conversely, different (right sided or even left sided) atrial circuits including different mechanisms (macroreentrant, microreentrant, or focal) can present with a very similar surface ECG manifestation. The development of efficient high-resolution electroanatomical mapping systems has improved our knowledge about AFL mechanisms, as well as facilitated their curative treatment with radiofrequency catheter ablation. This article will review ECG features for typical and atypical flutters, and emphasize the limitations for circuit location from the surface ECG. [ABSTRACT FROM AUTHOR]

Aims Chronic obstructive pulmonary disease (COPD) is one of the important underlying diseases of atrial fibrillation (AF). However, the prevalence and electrophysiological characteristics of typical atrial flutter (AFL) in patients with AF and COPD remain unknown. The purpose of the present study was to investigate those characteristics. Methods and results We investigated 181 consecutive patients who underwent catheter ablation of AF. Twenty-eight patients were diagnosed with COPD according to the Global Initiatives for Chronic Obstructive Lung Disease (GOLD) criteria. Forty patients with no lung disease served as a control group. We analysed the electrophysiological characteristics in these groups. Typical AFL was more common in the COPD group (19/28, 68%) than in the non-COPD group (13/40, 33%; P = 0.006). The prevalence of AFL increased with the severity of COPD: 4 (50%) of 8 patients with GOLD1, 13 (72%) of 18 patients with GOLD2, and 2 (100%) of 2 patients with GOLD3. Atrial flutter cycle length and conduction time from the coronary sinus (CS) ostium to the low lateral right atrium (RA) during CS ostium pacing before and after the cavotricuspid isthmus ablation were significantly longer in the COPD group than in the non-COPD group (285 vs. 236, 71 vs. 53, 164 vs. 134 ms; P = 0.009, 0.03, 0.002, respectively). Conclusion In COPD patients with AF, conduction time of RA was prolonged and typical AFL was commonly observed. [ABSTRACT FROM PUBLISHER]

Aims: Although cavotricuspid isthmus (CTI) ablation can cure typical atrial flutter (AFL), it might be difficult to achieve a bidirectional conduction block in the isthmus in some patients. We investigated the usefulness of a steerable sheath for CTI ablation in patients with typical AFL or atrial fibrillation. [ABSTRACT FROM PUBLISHER]

Identification of atypical atrial flutter (AFL) (non-cavo-tricuspid isthmus-dependent) prior to the electrophysiology laboratory is potentially useful because it allows appropriate procedural planning and enables discussion of the likely success rates and risks of the procedure with the patient. Typical counterclockwise AFL has a stereotypic appearance, the electrocardiogram (ECG) is predictive of the diagnosis in the majority of cases, and ablation procedures are associated with a high degree of safety and success. Atypical right atrial and left AFLs have a highly variable flutter wave morphology and may appear atypical, resemble typical flutter or appear to be focal in origin. Targeting these complex and often multiple re-entrant circuits is aided by expertise and use of electroanatomic mapping systems. This review will address whether there are clues from the 12-lead ECG which assist in the localization of AFL circuits. [ABSTRACT FROM PUBLISHER]

Aims: Upper turn-around of the reentry circuit in typical atrial flutter (AF) is classically described to be located in front of the superior vena cava (SVC), but circuits posterior to the SVC as well as lower loop reentry (LLR) involving only the lower part of the right atrium have been described. However, true prevalence of such AF circuits remains unknown. [ABSTRACT FROM PUBLISHER]

Aims: Catheter ablation (CA) has become the treatment of choice for regular supraventricular tachycardia (SVT). The purpose of this study was to investigate whether the current clinical results in a large single centre are as good as success rates quoted to patients from published trials and national cardiology society websites. [ABSTRACT FROM PUBLISHER]

The purpose of this prospective, non-randomized study was to investigate the effectiveness of cooled radiofrequency ablation (cRFA) compared with conventional radiofrequency application (RFA) for ablation of typical atrial flutter (AF).Methods Isthmus ablation was carried out using a system with a circulating fluid path through the ablation tip to control tip temperature in 100 patients with AF. Thirty consecutive AF patients underwent conventional RFA. The number of applications for cRFA was 13·7±6·9 and for RFA 24·0±14·5 (P< 0·0007) at powers between 35 and 50 W and a tip temperature range of 38–43°C. Ablation duration and fluoroscopy time were 9·9±4·9 and 22·8±10·7 min for cRFA, respectively. In contrast, for RFA, ablation duration and fluoroscopy time were 20·6±14·2 (P< 0·0001) and 27·4±12·7 min, respectively. In 93% of the cooled tip group and in 80% of the control group bi-directional block was confirmed. [ABSTRACT FROM PUBLISHER]

Typical atrial flutter is due to a counterclockwise macrore-entry circuit localized in the right atrium with a surface ECG pattern showing predominantly negative F waves in the inferior leads and positive F waves in V1. Recently it has been proposed to classify atrial flutter on the basis of its cavo-tricuspid isthmus dependence rather than on the ECG pattern. Therefore some atrial flutters are considered typical even if the ECG does not exhibit a typical pattern. This is the case for reverse typical atrial flutter, lower loop re-entry and partial-isthmus-dependent short circuit flutter. The term atypical flutter refers to a non-isthmus dependent flutter. Usually these patients have had previous cardiac surgery with a right or left atriotomy. Flutter involving a spontaneous right atrial scar is not uncommon. [ABSTRACT FROM PUBLISHER]