Pulsed field ablation technology for pulmonary vein and left atrial posterior wall isolation in patients with persistent atrial fibrillation.

INTRODUCTION: Limited data exist on pulsed-field ablation (PFA) in patients with persistent atrial fibrillation (PeAF) undergoing left atrial posterior wall isolation (LAPWI). METHODS: The Advanced TecHnologies For SuccEssful AblatioN of AF in Clinical Practice (ATHENA) prospective registry included consecutive patients referred for PeAF catheter ablation at 9 Italian centers, treated with the FARAPULSETM-PFA system. The primary efficacy and safety study endpoints were the acute LAPWI rate, freedom from arrhythmic recurrences and the incidence of major periprocedural complications. Patients undergoing pulmonary vein isolation (PVI) alone, PWI + LAPWI and redo procedures were compared. RESULTS: Among 249 patients, 21.7% had long-standing PeAF, 79.5% were male; mean age was 63 ± 9 years. LAPWI was performed in 57.6% of cases, with 15.3% being redo procedures. Median skin-to-skin times (PVI-only 68 [60-90] vs. PVI + LAPWI 70 [59-88] mins) did not differ between groups. 45.8% LAPWI cases were approached with a 3D-mapping system, and 37.3% with intracardiac echocardiography. LAPWI was achieved in all patients by means of PFA alone, in 88.8% cases at first pass. LAPWI was validated either by an Ultrahigh-density mapping system or by recording electrical activity + pacing maneuvers. No major complications occurred, while 2.4% minor complications were detected. During a median follow-up of 273 [191-379] days, 41 patients (16.5%) experienced an arrhythmic recurrence after the 90-day blanking period, with a mean time to recurrence of 223 ± 100 days and no differences among ablation strategies. CONCLUSION: LAPWI with PFA demonstrates feasibility, rapidity, and safety in real-world practice, offering a viable alternative for PeAF patients. LAPWI is achievable even with a fluoroscopy-only method and does not significantly extend overall procedural times.

High-density mapping of Koch's triangle during sinus rhythm and typical atrioventricular nodal re-entrant tachycardia, integrated with direct recording of atrio-ventricular node structure potential.

BACKGROUND: The mechanism of typical slow-fast atrioventricular nodal re-entrant tachycardia (AVNRT) and its anatomical and electrophysiological circuit inside the right atrium (RA) and Koch's Triangle (KT) are not well known. OBJECTIVE: To identify the potentials of the compact AV node and inferior extensions and to perform accurate mapping of the RA and KT in sinus rhythm (SR) and during AVNRT, to define the tachycardia circuit. METHODS: Consecutive patients with typical AVNRT were enrolled in 12 Italian centers and underwent mapping and ablation by means of a basket catheter with small electrode spacing for ultrahigh-density mapping and a modified signal-filtering toolset to record the potentials of the AV nodal structures. RESULTS: Forty-five consecutive cases of successful ablation of typical slow-fast AVNRT were included. The mean SR cycle length (CL) was 784.1 ± 6 ms and the mean tachycardia CL was 361.2 ± 54 ms. The AV node potential had a significantly shorter duration and higher amplitude in sinus rhythm than during tachycardia (60 ± 40 ms vs. 160 ± 40 ms, p < .001 and 0.3 ± 0.2 mV vs. 0.09 ± 0.12 mV, p < .001, respectively). The nodal potential duration extension was 169.4 ± 31 ms, resulting in a time-window coverage of 47.6 ± 9%. The recording of AV nodal structure potentials enabled us to obtain 100% coverage of the tachycardia CL during slow-fast AVNRT. CONCLUSION: Detailed recording of the potentials of nodal structures is possible by means of multipolar catheters for ultrahigh-density mapping, allowing 100% of the AVNRT CL to be covered. These results also have clinical implications for the ablation of right-septal and para-septal arrhythmias.

Investigating Deep Sedation With Intravenous Ketamine in Spontaneous Respiration During Pulsed-Field Ablation.

OBJECTIVES: The authors report their experience of a protocol for deep sedation with ketamine in spontaneous respiration during the pulsed-field ablation (PFA) of atrial fibrillation (AF). DESIGN: Observational, prospective, nonrandomized fashion. SETTING: Single-center hospitalized patients. PARTICIPANTS: All consecutive patients undergoing PFA of AF. INTERVENTIONS: Patients undergoing deep sedation with intravenous ketamine. MEASUREMENTS AND MAIN RESULTS: The authors' sedation protocol involves the intravenous administration of fentanyl (1.5 µg/kg) and midazolam (2 mg) at low doses before local anesthesia with lidocaine. A ketamine adjunct (1 mg/kg) in 5-minute boluses was injected about 5 minutes before the first PFA delivery. The authors enrolled 117 patients (age = 59 ± 10 y, 74.4% males, body mass index = 27.6 ± 5 kg/m2, fluoroscopy time = 24 ± 14 minutes, skin-to-skin time = 80 ± 40 minutes and PFA LA dwell time = 24 ± 7 minutes). By the end of the procedure, pulmonary vein isolation had been achieved in all patients using PFA alone. The mean time under sedation was 54.9 ± 6 minutes, with 92 patients (79%) being sedated for <1 hour. A satisfactory Ramsay Sedation Scale level before ketamine administration was achieved in all patients, except one (80.3% of the patients with rank 3; 18.4% with rank 2). In all procedures, the satisfaction level was found acceptable by both the patient and the primary operator (satisfactory in 98.2% of cases). All patients achieved a Numeric Rating Scale for Pain ≤3 (none or mild). No major procedure or anesthesia-related complications were reported. CONCLUSION: The authors' standardized sedation protocol with the administration of drugs with rapid onset and pharmacologic offset at low doses was safe and effective, with an optimal degree of patient and operator satisfaction.

Sedation strategies for pulsed-field ablation of atrial fibrillation: focus on deep sedation with intravenous ketamine in spontaneous respiration.

AIMS: A standardized sedation protocol for pulsed-field ablation (PFA) of atrial fibrillation (AF) through irreversible cellular electroporation has not been well established. We report our experience of a protocol for deep sedation with ketamine in spontaneous respiration during the PFA of AF. METHODS AND RESULTS: All consecutive patients undergoing PFA for AF at our center were included. Our sedation protocol involves the intravenous administration of fentanyl (1.5 mcg/kg) and midazolam (2 mg) at low doses before local anesthesia with lidocaine. A ketamine adjunct (1 mg/kg) was injected about 5 minutes before the first PFA delivery. We enrolled 66 patients (age = 59 ± 9 years, 78.8% males, body mass index = 28.8 ± 5 kg/m2, fluoroscopy time = 21[15-30] min, skin-to-skin time = 75[60-100] min and PFA LA dwell time = 25[22-28] min). By the end of the procedure, PVI had been achieved in all patients by means of PFA alone. The mean time under sedation was 56.4 ± 6 min, with 50 (76%) patients being sedated for less than 1 hour. A satisfactory Ramsey Sedation Scale level before ketamine infusion was achieved in all patients except one (78.8% of the patients with rank 3; 19.7% with rank 2). In all procedures, the satisfaction level was found to be acceptable by both the patient and the primary operator (Score = 0 in 98.5% of cases). All patients reported none or mild pain. No major procedure or anesthesia-related complications were reported. CONCLUSION: Our standardized sedation protocol with the administration of drugs with rapid onset and pharmacological offset at low doses was safe and effective, with an optimal degree of patient and operator satisfaction. CLINICAL TRIAL REGISTRATION: Advanced TecHnologies For SuccEssful AblatioN of AF in Clinical Practice (ATHENA). URL: http://clinicaltrials.gov/Identifier: NCT05617456.

Pulmonary vein isolation by means of a novel cryoballoon technology in paroxysmal atrial fibrillation patients: 1-year outcome from a large Italian multicenter clinical registry.

INTRODUCTION: Recently, a new cryoballoon (CB) technology (POLARx; Boston Scientific) has come onto the market. Preliminary data have shown that its acute safety and efficacy are similar to those of the first-generation CB. The aim of this study was to assess the medium-term outcome of pulmonary vein isolation (PVI) with the POLARxTM CB in a large multicenter registry. METHODS: We prospectively collected data on 125 consecutive patients with paroxysmal atrial fibrillation (AF) who underwent PVI by means of a novel CB system. Two cases of transient phrenic nerve palsy occurred, with full recovery in the 48h post procedure; no major procedure-related adverse events were reported. During the 90-day blanking period, 4 (3.2%) patients experienced an early recurrence. After the blanking period, over a mean follow-up of 411 ± 62 days, 19 patients (15.2%) suffered an AF/atrial tachycardia (AT) recurrence. The 1-year freedom from AF/AT recurrence was 86.4% (n = 17): 10 (8%) patients had an AF recurrence, 6 (4.8%) had an AT occurrence and 1 (0.8%) suffered both events. Patients with AF/AT recurrences had both a shorter deflation time and total deflation time. Moreover, CB ablations with measured TTI < 90 s and TTI < 60 s were more frequent in patients without AF/AT recurrence (88.5% and 77.4%, respectively) than in those who experienced at least one AF/AT recurrence (67.5% and 55.0%, p = .001 and p = .005, respectively). CONCLUSION: The novel POLARx cryo-balloon system is safe and effective for PV isolation, displaying a 1-year freedom from atrial arrhythmia recurrence of 86.4%, which is in line to that reported with AFA-Pro CB or RF ablation. CLINICAL TRIAL REGISTRATION: Catheter Ablation of Arrhythmias with a High-Density Mapping System in Real-World Practice (CHARISMA). URL: http://clinicaltrials.gov/ Identifier: NCT03793998. Registration date: January 4, 2019.

Can specific ECG markers identify a pharmacologically induced type 1 Brugada pattern? Insights from a large, single-center cohort.

BACKGROUND: In patients with a type 2 or 3 Brugada pattern, the pharmacological (IC drugs) induction of a type 1 pattern confirms the diagnosis of Brugada syndrome. OBJECTIVE: To evaluate the value of various ECG markers in predicting IC drug test results. METHODS: We retrospectively analysed 443 consecutive patients referred to our Center (from January 2010 to December 2019) to undergo Ajmaline/Flecainide testing; all had a type 2 or 3 Brugada pattern or were relatives with Brugada syndrome. Clinical parameters and ECG markers (r1V1 and SV6 duration and amplitude, QRSV1/QRSV6 duration, V1 and V2 ST amplitude) were independently evaluated for their association to pharmacological test positivity, and a logistic regression model was applied. RESULTS: The drug test was positive in 151 (34%) patients. On multivariate logistic regression analysis, age > 45 years, female gender, HR >60 bpm, QRSV1/QRSV6 duration >1 and non-isoelectric pattern in V2 were associated with a positive test. The percentage of patients who tested positive increased according to the presence of the above ECG markers (from 11.3% in the absence to 57.6% in the presence of both factors). During long-term follow-up, the clinical event rate was higher in patients with predictive ECG markers and very low in those without. CONCLUSIONS: In our population we confirmed the ability of QRSV1/QRSV6 duration >1 and of a non-isoelectric pattern in V2 to predict a pharmacologically induced type 1 Brugada pattern. Patients with neither of these ECG markers had a rather low event rate during follow-up.

Targeted ablation of residual pulmonary vein potentials in atrial fibrillation ablation through ultra-high-density mapping: Insights from the CHARISMA registry.

INTRODUCTION: Low-voltage activity beyond pulmonary veins (PVs) may contribute to the failure of ablation of atrial fibrillation (AF) in the long term. We aimed to assess the presence of gaps (PVG) and residual potential (residual antral potential [RAP]) within the antral scar by means of an ultra-high-density mapping (UHDM) system. METHODS: We studied consecutive patients from the CHARISMA registry who were undergoing AF ablation and had complete characterization of residual PV antral activity. The Lumipoint™ (Boston Scientific) map-analysis tool was used sequentially on each PV component. The ablation endpoint was PV isolation (PVI) and electrical quiescence in the antral region. RESULTS: Fifty-eight cases of AF ablation were analyzed. A total of 86 PVGs in 34 (58.6%) patients and 44 RAPs in 34 patients (58.6%) were found. In 16 (27.6%) cases, we found at least one RAP in patients with complete absence of PV conduction. RAPs showed a lower mean voltage than PVG (0.3 ± 0.2 mV vs. 0.7 ± 0.5 mV, p < .0001), whereas the mean number of electrogram peaks was higher (8.4 ± 1.4 vs. 3.2 ± 1.5, p < .0001). The percentage of patients in whom RAPs were detected through Lumipoint™ was higher than through propagation map analysis (58.6% vs. 36.2%, p = .025). Acute procedural success was 100%, with all PVs successfully isolated and RAPs completely abolished in all study patients. During a mean follow-up of 453 ± 133 days, 6 patients (10.3%) suffered an AF/AT recurrence. CONCLUSION: Local vulnerabilities in antral lesion sets were easily discernible by means of the UHDM system in both de novo and redo patients when no PV conduction was present.

Optimized radiofrequency lesions through local impedance guidance for effective CTI ablation in right atrial flutter.

BACKGROUND: Although radiofrequency (RF) catheter ablation of cavo-tricuspid isthmus (CTI) is an established treatment for typical right atrial flutter (RAFL), it remains to be established whether local tissue impedance (LI) is able to predict effective CTI ablation and what LI drop values during ablation should be used to judge a lesion as effective. We aimed to investigate the ability of LI to predict ablation efficacy in patients with RAFL. METHODS: RF delivery was guided by the DirectSense™ algorithm. Successful single RF application was defined according to a defragmentation of atrial potentials (DAP), reduction of voltage (RedV) by at least 80% or changes on unipolar electrogram (UPC). The ablation endpoint was the creation of bidirectional conduction block (BDB) across the isthmus. RESULTS: 392 point-by-point RF applications were analyzed in 48 consecutive RAFL patients. The mean baseline LI was 105.4 ± 12Ω prior to ablation and 92.0 ± 11Ω after ablation (p < 0.0001). According to validation criteria, absolute drops in impedance were larger at successful ablation sites than at ineffective ablation sites (DAP: 17.8 ± 6Ω vs. 8.7 ± 4Ω; RedV: 17.2 ± 6Ω vs. 7.8 ± 5Ω; UPC: 19.6 ± 6Ω vs. 10.1 ± 5Ω, all p < 0.0001). LI drop values significantly increased according to the number of criteria satisfied (ranging from 7.5Ω to 19.9). BDB was obtained in all cases. No procedure-related adverse events were reported. CONCLUSIONS: A LI-guided approach to CTI ablation was safe and effective in treating RAFL. The magnitude of LI drop was associated with effective lesion formation and BDB and could be used as a marker of ablation efficacy. CLINICAL TRIAL REGISTRATION: Catheter Ablation of Arrhythmias with a High-Density Mapping System in Real-World Practice (CHARISMA). URL: http://clinicaltrials.gov/ Identifier: NCT03793998.

Pulmonary vein isolation in atrial fibrillation patients guided by a novel local impedance algorithm: 1-year outcome from the CHARISMA study.

BACKGROUND: Highly localized impedance (LI) measurements during atrial fibrillation (AF) ablation have recently emerged as a viable real-time indicator of tissue characteristics and durability of the lesions created. We report the outcomes of acute and long-term clinical evaluation of the new DirectSense algorithm in AF ablation. METHODS: Consecutive patients undergoing AF ablation were included in the CHARISMA registry. RF delivery was guided by the DirectSense algorithm, which records the magnitude and time-course of the impedance drop. The ablation endpoint was pulmonary vein isolation (PVI), as assessed by the entrance and exit block. RESULTS: 3556 point-by-point first-pass RF applications of >10 s duration were analyzed in 153 patients (mean age=59 ± 10 years, 70% men, 61% paroxysmal AF, 39% persistent AF). The mean baseline LI was 105 ± 15 Ω before ablation and 92 ± 12 Ω after ablation (p < .0001). Both absolute drops in LI and the time to LI drop (LI drop/τ) were greater at successful ablation sites (n = 3122, 88%) than at ineffective ablation sites (n = 434, 12%) (14 ± 8 Ω vs 6 ± 4 Ω, p < .0001 for LI; 0.73 [0.41-1.25] Ω/s vs. 0.35[0.22-0.59 Ω/s, p < .0001 for LI drop/τ). No major complications occurred during or after the procedures. All PVs had been successfully isolated. During a mean follow-up of 366 ± 130 days, 18 patients (11.8%) suffered an AF/atrial tachycardia recurrence after the 90-day blanking period. CONCLUSION: The magnitude and time-course of the LI drop during RF delivery were associated with effective lesion formation. This ablation strategy for PVI guided by LI technology proved safe and effective and resulted in a very low rate of AF recurrence over 1-year follow-up.

Early rhythm-control ablation therapy to prevent atrial fibrillation recurrences: Insights from the CHARISMA Registry.

BACKGROUND: An early, comprehensive rhythm-control therapy is needed in order to treat atrial fibrillation (AF) effectively and to improve ablation outcomes. METHODS: A total of 153 consecutive patients from the CHARISMA registry undergoing AF ablation at eight centers were included. Patients with de novo PVI were classified as having undergone early treatment (ET) if the procedure was performed within 6 months after the first AF episode, and as having undergone delayed treatment (DT) if ablation was performed over 6 months after the first AF episode. RESULTS: One-hundred fifty-three patients were enrolled (69.9% male, 59 ± 10 years, 61.4% paroxysmal AF, 38.6% persistent AF). The time from the first AF episode to the ablation procedure was 1034 ± 1483 days. The ET group comprised 36 patients (25.3%), the DT group 60 (39.2%) and Redo cases were 57 (37.3%). During a mean follow-up of 366 ± 130 days, 18 patients (11.8%) suffered an AF/AT recurrence. More DT patients than ET patients suffered recurrences (15.7% vs. 2.2%, p = 0.0452) and the time to AT/AF recurrence was shorter in the group of patients who received an ablation treatment after 6 months (HR = 6.19, 95% CI: 1.7 to 21.9; p = 0.0474). On multivariate Cox analysis, only hypertension (HR = 4.86, 95% CI: 1.6 to 14.98, p = 0.0062) was independently associated with recurrences. Beyond the hypertension risk factor, ET was associated with a low risk of recurrence; recurrence rate ranged from 0% (ET patients without hypertension) to 25.0% (DT patients with hypertension). CONCLUSIONS: An early rhythm-control ablation therapy in the absence of common risk factors was associated with the lowest rate of recurrences.

A novel local impedance algorithm to guide effective pulmonary vein isolation in atrial fibrillation patients: Preliminary experience across different ablation sites from the CHARISMA pilot study.

INTRODUCTION: Recently, a novel technology able to measure local impedance (LI) and tissue characteristics has been made available for clinical use. This analysis explores the relationships among LI and generator impedance (GI) parameters in atrial fibrillation (AF) patients. Characterization of LI among different ablation spots and procedural success were also evaluated. METHODS AND RESULTS: Consecutive patients undergoing AF ablation from the CHARISMA registry at five Italian centers were included. A novel radiofrequency (RF) ablation catheter with a dedicated algorithm (DIRECTSENSE™) was used to measure LI and to guide ablation. The ablation endpoint was pulmonary vein (PV) isolation. We analyzed 2219 ablation spots created around PVs in 46 patients for AF ablation. The mean baseline tissue impedance was 105.8 ± 14 Ω for LI versus 91.8 ± 10 Ω for GI (p < .0001). Baseline impedance was homogenous across the PV sites and proved higher in high-voltage areas than in intermediate- and low-voltage areas and the blood pool (p < .001). Both LI and GI displayed a significant drop after RF delivery, and absolute LI drop values were significantly larger than GI drop values (14 ± 8 vs. 3.7 ± 5 Ω, p < .0001). Every 5-point increment in LI drop was associated with successful ablation (odds ratio = 3.05, 95% confidence interval: 2.3-4.1, p < .0001). Conversely, GI drops were not significantly different comparing successful versus unsuccessful sites (3.7 ± 5 vs. 2.8 ± 4 Ω, p = .1099). No steam pops or major complications occurred during or after the procedures. By the end of the procedures, all PVs had been successfully isolated in all patients. CONCLUSIONS: The magnitude of the LI drop was more closely associated with effective lesion formation than the GI drop.

Real-life outcome of implantable cardioverter-defibrillator and cardiac resynchronization defibrillator replacement/upgrade in a contemporary population: observations from the multicentre DECODE registry.

AIMS: The benefit of prolonged implantable cardioverter-defibrillator (ICD)/cardiac resynchronization therapy defibrillator (CRT-D) therapy following device replacement is hindered by clinical and procedure-related adverse events (AEs). Adverse events rate is highest in more complex devices and at upgrades, as per the REPLACE registry experience, but is changing owing to the improvement in device technology and medical care. We aimed at understanding the extent and type of AEs in a contemporary Italian population. METHODS AND RESULTS: Detect long-term complications after ICD replacement (DECODE) was a prospective, single-arm, multicentre cohort study aimed at estimating medium- to long-term AEs in a large population of patients undergoing ICD/cardiac resynchronization defibrillator replacement/upgrade from 2013 to 2015. We prospectively analysed all clinical and device-related AEs at 12-month follow-up (FU) of 983 consecutive patients (median age 71 years, 76% male, 55% ischaemic, 47% CRT-D) followed for 353 ± 49 days. Seven percent of the patients died (60.6% for cardiovascular reasons), whereas 104 AEs occurred; 43 (4.4%) patients needed at least one surgical action to treat the AE. Adverse events rates were 3.3/100 years lead-related, 3.4/100 years bleedings, and 1.6/100 years infective. The primary endpoint was predicted by hospitalization in the month prior to the procedure [hazard ratio (HR) = 2.23, 1.16-4.29; 0.0169] and by upgrade (HR = 1.75, 1.02-2.99, 0.0441). One hundred and twelve (11.4%) patients met the combined endpoint of death from any cause, cardiac implantable electronic device (CIED)-related infection, and surgical action/hospitalization required to treat the AE. Hospitalization within 30 days prior to the procedure (HR = 2.07, 1.13-3.81; 0.0199), anticoagulation (HR = 1.97, 1.26-3.07; 0.003), and ischaemic cardiomyopathy (HR = 1.67, 95% confidence interval 1.06-2.63; P = 0.0276) were associated with the combined endpoint during FU. CONCLUSIONS: Adverse events following CIED replacement/upgrade are lower than previously reported, possibly owing to improved patients care. Hospitalization in the month prior to the procedure, upgrade, and clinical profile (anticoagulation, ischaemic cardiomyopathy) hint to increased risk, suggesting an individualized planning of the procedure to minimize overall AEs. CLINICAL TRIAL REGISTRATION: URL: http://clinicaltrials.gov/ Identifier: NCT02076789.

Reasons for successful clinical outcome following pulmonary vein isolation despite lack of persistent LA-PV conduction block.

The mechanisms of atrial fibrillation (AF) induction and maintenance, including those involved in paroxysmal atrial fibrillation, are not completely known; this limits our ablation strategies and prevents us from understanding what we are actually doing when performing pulmonary vein isolation. In this report, we focus on the commonly used ablation strategies for AF and question the importance of complete pulmonary vein isolation in achieving lasting success in the ablation of AF. We also discuss in detail the absence of durable pulmonary vein isolation in patients without arrhythmic recurrences after AF ablation and the possibility to cure paroxysmal AF without concomitant pulmonary vein isolation, provocatively questioning the dogma of pulmonary vein isolation as the cornerstone of AF ablation. Finally, a prospective personalized approach in the individual patient is advocated.

Appropriate implantable cardioverter-defibrillator interventions in cardiac resynchronization therapy-defibrillator (CRT-D) patients undergoing device replacement: time to downgrade from CRT-D to CRT-pacemaker? Insights from real-world clinical practice in the DECODE CRT-D analysis.

Aim: Ventricular tachycardia (VT)/ventricular fibrillation (VF) occurrence after cardiac resynchronization therapy-defibrillator (CRT-D) replacement is unknown; hence, there is no practical guideline to recommend either CRT-D or CRT-pacemaker at the time of device replacement. We observed the 1-year VT/VF occurrence after CRT-D replacement in a subanalysis of the Detect Long-term Complications after ICD Replacement (DECODE) registry. Methods and results: A total of 332 consecutive patients who had undergone CRT-D replacement from 2013 to 2015 were enrolled in 36 Italian centres. The primary endpoint was the number of patients with any appropriate implantable cardioverter-defibrillator (ICD) interventions during 12-month follow-up. The secondary endpoint comprised death from any cause and appropriate ICD interventions. At replacement, 214 (64.5%) patients had a left ventricular ejection fraction ≤ 35% and 138 (41.6%) patients had a secondary prevention indication for ICD. Seventy (21.1%) patients had no longer indication to ICD therapy. During a median follow-up period of 406.5 (362-533) days, VT/VF requiring therapy delivery occurred in 57 (17%) patients, specifically in 7% of those who no longer had an ICD indication. On multivariate analysis, number of criteria for ICD replacement independently predicted appropriate ICD intervention during follow-up [hazard ratio (HR) = 1.62, 95% confidence interval (CI) 1.07-2.46; log-rank P = 0.02]. The combined endpoint of death from any cause or appropriate ICD therapy occurred in 76 (23%) patients. Only NYHA class remained associated with this combined endpoint (HR = 1.97, 95% CI 1.23-3.14; P = 0.005). Conclusions: The DECODE registry showed the 'real-world' experience of CRT-D recipients approaching device replacement, in which 7% of patients who no longer had an indication for ICD therapy experienced appropriate ICD interventions.

Feasibility of cathodic-anodal left ventricular stimulation for alternative multisite pacing.

BACKGROUND: Simultaneous cathodic-anodal capture by a bipole of a cardiac resynchronization therapy (CRT) left-ventricular (LV) catheter may depolarize a larger LV area than conventional multipoint pacing. We evaluated the feasibility of cathodic-anodal LV stimulation. METHODS: In 30 patients undergoing CRT with a quadripolar LV lead, we evaluated the cathodic and anodal capture threshold for each LV pole and compared QRS on electrocardiogram (ECG) during single-point cathodic biventricular stimulation (S-BS), multipoint BS (M-BS), and cathodic-anodal BS (CA-BS). RESULTS: Anodal capture was obtained by three poles in 23/30 patients, by two poles in five, and was not feasible in two. The mean single-point anodal threshold was 3.93 V versus single-point cathodic threshold of 1.95 V. On comparing ECGs, M-BS and CA-BS produced similar QRS wavefront activation in 90% of patients. CONCLUSIONS: CA-BS is feasible and may be used in LV pacing to achieve a different wavefront of electrical activation. Further prospective studies are needed in order to verify the clinical impact of this kind of stimulation.

Occurrence of simultaneous cathodal-anodal capture with left ventricular quadripolar leads for cardiac resynchronization therapy: an electrocardiogram evaluation.

AIMS: The occurrence of left ventricular (LV) anodal activation during pacing with modern multipolar cardiac resynchronization therapy (CRT) systems has never been reported. The aim of our study was to demonstrate, by means of electrocardiogram (ECG) analysis, the occurrence of simultaneous cathodal-anodal LV capture with quadripolar LV leads. METHODS AND RESULTS: We studied 10 first-time recipients of a CRT device equipped with a quadripolar LV lead. During follow-up, standard supine 12-lead ECGs were obtained in available cathode-to-anode LV pacing configurations with a pulse amplitude equal to twice the pacing threshold. The occurrence of simultaneous cathodal-anodal LV capture was defined as the presence of variations in electrocardiographic ventricular activation (EVA) when the distal tip (cathode)-to-device can (anode) pacing configuration was compared with the distal tip (cathode)-to-proximal ring (anode) configuration. In eight patients, we found differences in EVA when different LV sites were paced through the unipolar LV tip and unipolar LV ring configurations. In these patients, a difference in EVA was detected in 61.5% (59 of 96) of the ECG leads (marked difference in 31.3%, slight difference in 30.2%). Changes in EVA between unipolar tip-to-can and bipolar tip-to-ring pacing that were suggestive of cathodal-anodal LV capture were found in six patients. In these patients, a total of 30 (41.7%) ECG leads showed a difference in EVA (marked difference in 20.8%, slight difference in 20.8%). CONCLUSION: In our experience, additional anodal capture by the proximal LV ring during LV pacing is provable in most recipients of a resynchronization device equipped with a multipolar LV lead.

Stricter criteria for left bundle branch block diagnosis do not improve response to CRT.

BACKGROUND: Cardiac resynchronization therapy (CRT) has proved to be effective in patients with heart failure and left bundle branch block (LBBB). Recently, new electrocardiography criteria have been proposed for the diagnosis of LBBB. These criteria are stricter than the current American Heart Association (AHA) criteria. We assessed the rate of echocardiographic response to CRT in patients with traditional LBBB versus patients who met the new criteria (strict LBBB). METHODS: Consecutive patients undergoing CRT were enrolled in the CRT MORE registry. Patients with no-LBBB QRS morphology according to AHA criteria, atrial fibrillation, right bundle branch block, and right ventricular pacing were excluded. Strict LBBB was defined as: QRS ≥ 140 ms for men and ≥130 ms for women, QS or rS in V1-V2, mid-QRS notching or slurring in ≥2 contiguous leads. Patients showing a relative decrease of ≥15% in left ventricular end-systolic volume (LVESV) at 12 months were defined as responders. RESULTS: Among 335 patients with LBBB, 131 (39%) had strict LBBB. Patients with and without strict LBBB showed comparable baseline characteristics, except for QRS duration (166 ± 20 ms vs 152 ± 25 ms, P < 0.001). On 12-month evaluation, 205 patients (61%) were responders; 85 of 131 (65%) had strict LBBB and 120 of 204 (59%) had traditional LBBB (P = 0.267). On multivariate analysis, a history of atrial fibrillation, larger LVESV, and the presence of mid-QRS notching in ≥1 lead (odds ratio 2.099; 95% confidence interval 1.061-4.152, P = 0.033) were independently associated with echocardiographic response. CONCLUSION: Stricter definition of LBBB did not improve response to CRT in comparison to the current AHA definition.

Novel cryoballoon technology for atrial fibrillation ablation: Impact of pulmonary vein variant anatomy, cooling characteristics, and 1-year outcome from the CHARISMA registry.

BACKGROUND: No data have been reported on cooling characteristics and the impact of variant pulmonary vein (PV) anatomy on atrial fibrillation (AF) recurrences after POLARx cryoballoon (CB) ablation. OBJECTIVE: The purpose of this study was to analyze the impact of PV anatomy variants and cooling characteristics after CB ablation from a large multicenter prospective registry. METHODS: The primary end point was defined as 1-year absence of any atrial tachyarrhythmias (ATAs: AF/atrial flutter/atrial tachycardia). Correlation between ATA recurrences and anatomy variants/cooling characteristics were evaluated. The secondary outcome was the rate of major periprocedural complications. RESULTS: A total of 429 consecutive patients diagnosed with paroxysmal AF (83.4%) or persistent AF (peAF; 16.6%) were enrolled. Twenty-eight patients (6.6%) exhibited an anatomical variant (common ostium: 4.0%; adjunctive PV: 2.6%). Nadir temperature, thaw time, and total deflation time were different between standard PVs and PV variants. After the blanking period, over a mean of 431 ± 99 days of follow-up, 63 patients (14.7%) suffered an ATA recurrence. Patients with recurrences had both a shorter thaw time (18.5 ± 7 seconds vs 19.8 ± 7 seconds; P = .0012) and a shorter total deflation time, whereas time to isolation was longer (57.4 ± 42 seconds vs 49.1 ± 33 seconds; P = .04). Patients with anatomy variants showed a similar ATA recurrence rate (5 of 28 [17.9%]) to the standard PV anatomy group (58 of 401 [14.5%]) (P = .584), with a hazard ratio (HR) of 1.43 (95% confidence interval [CI] 0.49-4.13; log-rank, P = .4384). After adjusting for confounders, heart failure (HR 4.12; 95% CI 1.75-9.73; P = .0013) and peAF (HR 1.81; 95% CI 1.03-3.18; P = .0433) remained associated with ATA recurrence during follow-up. CONCLUSION: The POLARx CB system demonstrated long-term efficacy, along with a safe profile, in both patients with paroxysmal AF and those with peAF, regardless of the presence PV variants. Time to isolation was longer in patients with ATA recurrences during follow-up. CLINICAL TRIAL REGISTRATION: Catheter Ablation of Arrhythmias with a High-Density Mapping System in Real-World Practice (CHARISMA). CLINICALTRIALS: gov identifier: NCT03793998. Registration date: January 4, 2019.