Arrhythmia-specific settings for automated high-density mapping: A multicenter experience.

BACKGROUND: Advancements in electrophysiology 3-D mapping systems facilitate the broadening scope of electrophysiology study and catheter ablation to treat complex arrhythmias. While electroanatomical mapping systems have default settings available for a variety of mapping parameters, significant operator customization driven by arrhythmia type and experience can occur. However, multicenter comprehensive reporting of customized mapping settings is lacking. METHODS: In this prospective, multicenter observational registry, subjects with cardiac arrhythmias underwent electrophysiology study and ablation procedure using the EnSite Precision™ electroanatomical mapping system per standard of care, and associated automated mapping thresholds and procedural characteristics were observed. RESULTS: Cardiac mapping and ablation was performed in 503 patients (64.4% male, 59.6 ± 13.2 years) for a variety of indications including atrial fibrillation (N = 277), atrial flutter (N = 67), other supraventricular tachycardias (N = 96), and ventricular tachycardia (N = 56). Automated electroanatomical mapping was used to generate 88.2% of all maps, and arrhythmia-specific adjustments of mapping thresholds were utilized to collect electrophysiologically relevant data. The most commonly used thresholds for mapping in AF were Distance (average 2.7 ± 3.5 mm) and Signal-to-Noise Ratio (5.2 ± 1.1), while mapping in VT commonly used Score (88.5 ± 6.5%) and Distance (0.6 ± 0.5 mm). Automated mapping collected and utilized 8.8 times more data than manual mapping without increasing mapping time. CONCLUSIONS: This registry revealed arrhythmia-specific automated mapping settings used to generate electroanatomical maps of multiple cardiac rhythms with higher point density than manual mapping without increasing mapping time. Commonly used mapping threshold settings could serve as an important reference for new automated electroanatomical mapping users or those expanding their usage to new indications and arrhythmias.

Elimination of the negative component of the unipolar electrogram as a local procedural endpoint during paroxysmal atrial fibrillation catheter ablation using contact-force sensing: the UNIFORCE study.

PURPOSE: Elimination of the negative component of the unipolar atrial electrogram is a reliable indicator of the creation of a transmural lesion. Contact-force (CF) sensing technology has the potential to increase the durability of pulmonary vein isolation (PVI). In the present multicenter study, we assessed the 2-year sinus rhythm (SR) maintenance rate in patients with paroxysmal atrial fibrillation (PAF) after PVI guided by these two approaches. METHODS: Two hundred fifteen consecutive PAF patients (62.1 ± 10.1 years, 65 women) were prospectively enrolled. All patients underwent PVI under CARTO guidance according to a systematic contiguous "point-by-point" approach, using radiofrequency energy, and a CF externally irrigated ablation catheter with the goal of at least 10g (ideally 20g) of force. The ablation endpoint of each individual lesion was elimination of the negative component of the unipolar atrial signal. The procedural endpoint was PVI with bidirectional block. RESULTS: All PVs were successfully isolated. After 30 min of waiting time, 35 patients (16%) had PV reconnection and in all of them, the PVs were re-isolated. Two years after a single ablation procedure, 187 patients (87%) remained arrhythmia free, without anti-arrhythmic drugs. Of the 28 patients presenting with AF recurrence, 25 had PV reconnection and underwent repeat PVI while in the remaining 3 patients, all four PVs were isolated and extra-PV triggers were identified. There were six groin hematomas and one transient ischemic attack. CONCLUSIONS: Unipolar atrial signal analysis combined with CF sensing ensures a robust 2-year SR maintenance rate in the treatment of PAF. Clinical trial registration-URL: http://www.clinicaltrials.gov . Unique identifier: NCT02520960.

Impact of acute atrial fibrillation termination and prolongation of atrial fibrillation cycle length on the outcome of ablation of persistent atrial fibrillation: A substudy of the STAR AF II trial.

BACKGROUND: Controversy exists about the impact of acute atrial fibrillation (AF) termination and prolongation of atrial fibrillation cycle length (AFCL) during ablation on long-term procedural outcome. OBJECTIVE: The purpose of this study was to analyze the influence of AF termination and AFCL prolongation on freedom from AF in patients from the STAR AF II (Substrate and Trigger Ablation for Reduction of Atrial Fibrillation Trial-Part II) trial. METHODS: Acute changes in AFCL and AF termination were collected during the index procedure of the STAR AF II trial and compared to recurrence of AF at 18 months. Recurrence was assessed by ECG, Holter (3, 6, 9, 12, 18 months), and weekly transtelephonic ECG monitoring for 18 months. RESULTS: AF terminated in 8% of the pulmonary vein isolation (PVI) arm, 45% in the PVI+complex electrogram arm, and 22% of the PVI+linear ablation arm (P <.001), but freedom from AF did not differ among the 3 groups (P = .15). Freedom from AF was significantly higher in patients who presented to the laboratory in sinus rhythm (SR) compared to those without AF termination (63% vs 44%, P = .007). Patients with AF termination had an intermediate outcome (53%) that was not significantly different from those in SR (P = .84) or those who did not terminate (P = .08). AF termination was a univariable predictor of success (P = .007), but by multivariable analysis, presence of early SR was the strongest predictor of success (hazard ratio 0.67, P = .004). Prolongation of AFCL was not predictive of 18-month freedom from AF. CONCLUSION: Acute AF termination and prolongation in AFCL did not consistently predict 18-month freedom from AF. Presence of SR before or early during the ablation was the strongest predictor of better outcome.

Incidence and prognostic significance of sustained ventricular tachycardias in heart failure patients implanted with biventricular pacemakers without a back-up defibrillator: results from the prospective, multicentre, Mona Lisa cohort study.

AIMS: The aim of this study was to investigate the 12-month incidence, predictive factors, and prognosis of sustained ventricular tachycardia (VT) in chronic heart failure patients implanted with biventricular pacemakers without a back-up defibrillator (CRT-P), assessed by continuous intracardiac ventricular electrograms. METHODS AND RESULTS: The Mona Lisa study, a prospective, multicentre, cohort study, designed to determine the incidence of sustained VT and its prognostic impact in CRT-P recipients within the year after implant enrolled 198 patients with moderate or severe chronic heart failure, despite optimal pharmacological therapy. An independent committee reviewed the data from all arrhythmic episodes as well as causes of death according to predefined criteria. During a mean follow-up of 9.8 +/- 3.1 months after implantation, 8 patients experienced at least one episode of sustained VT [4.3%; 95% confidence interval (CI), 1.1-7.5] and 21 deaths occurred, giving a 12-month mortality rate of 11.7% (95% CI, 6.4-16.9). The presence of sustained VT was associated with a high risk of sudden cardiac death (SCD) and the lowest 12-month overall survival (P < 0.0001). CONCLUSION: The incidence of sustained VT remains relatively low in the first year after CRT-P implantation, but when present appears closely associated with short-term adverse outcomes, especially SCD. This emphasizes the possible value of remote monitoring to detect high-risk patients for urgent upgrading.

Clinical examination should not be forgotten when assessing the level of 2/1 AV block.

The authors underline the importance of carrying out a simple clinical examination to assess the level of two-to-one auriculoventricular block before any invasive electrophysiological procedures are performed. Clinical examination can indeed easily distinguish between the two different prognostic entities, represented by nodal and infra-nodal atrioventricular block. This initial evaluation of the severity of conduction disorders, as soon as the patient arrives at the emergency department or attends a consultation, may be greatly helpful in selecting the most appropriate management of those patients.