Predicting ventricular arrhythmia inducibility in ajmaline-induced Brugada type I pattern: Validation of the dST-Tiso interval.

INTRODUCTION: The dST-Tiso is a newly proposed electrocardiographic (ECG) marker during Brugada (BrS) type I pattern, that predicts the likelihood of ventricular arrhythmia (VA) inducibility in patients with ajmaline-induced pattern. The objective of this study was to validate the effectiveness of this criterion using an independent data set. METHODS: Consecutive patients exhibiting a BrS type I ECG pattern following ajmaline administration underwent programmed ventricular stimulation (PVS). dST-Tiso interval was measured in all patients and tested as a predictor for positive VA inducibility. RESULTS: Among 128 patients (median age 43 years, 59% male) with drug-induced BrS type I ECG pattern who underwent PVS, 32 (25.0%) had VA inducibility that required defibrillation. Compared to noninducible subjects, those with positive PVS were more commonly male (81% vs. 51%, p = 0.003), had longer PQ (165 vs. 160 ms, p = 0.016) and dST-Tiso (310 vs. 230 ms, p < 0.001) intervals, and shorter QT interval (412 vs. 420 ms, p = 0.022). When treated as a continuous variable, dST-Tiso confirmed significant association with VA inducibility, with an adjusted odds ratio of 1.02 (95% confidence interval: 1.01-1.03, p < 0.001) for each 1 ms increase in duration. A dST-Tiso interval >300 ms yielded a sensitivity of 75%, a specificity of 86%, and positive and negative predictive values of 69% and 91%, respectively. CONCLUSION: The validation of the model based on the dST-Tiso interval >300 ms confirmed its high accuracy in predicting VA inducibility in drug-induced BrS type I pattern. This straightforward ECG marker might be linked to the extent of the electrical substrate of the disease.

Temperature and ST-segment morphology remote monitoring: new perspectives for implantable cardiac monitors in Brugada syndrome.

INTRODUCTION: Patients with Brugada syndrome (BrS) face an increased risk of ventricular arrhythmias and sudden cardiac death. Implantable cardiac monitors (ICMs) have emerged as effective tools for detecting arrhythmias in BrS. Technological advancements, including temperature sensors and improved subcutaneous electrocardiogram (subECG) signal quality, hold promise for further enhancing their utility in this population. METHODS AND RESULTS: We present a case of a 40-year-old man exhibiting a BrS type 2 pattern on 12-lead ECG, who underwent ICM insertion (BIOMONITOR IIIm, BIOTRONIK) due to drug-induced BrS type 1 pattern and a history of syncope, with a negative response to programmed ventricular stimulation. The device contains an integrated temperature sensor and can transmit daily vital data, such as mean heart rate and physical activity. Several months later, remote alerts indicated a temperature increase, along with transmitted subECGs suggesting a fever-induced BrS type 1 pattern. The patient was promptly advised to commence antipyretic therapy. Over the following days, remotely monitored parameters showed decreases in mean temperature, physical activity, and mean heart rate, without further recurrence of abnormal subECGs. CONCLUSION: ICMs offer valuable insights beyond arrhythmia detection in BrS. Early detection of fever using embedded temperature sensors may improve patient management, while continuous subECG morphological analysis has the potential to enhance risk stratification in BrS patients.

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.

Impact of the third generation cryoballoon on atrial fibrillation ablation: An useful tool?

BACKGROUND: Third-generation cryoballoon (CB3) is characterized by a 40% shorter distal tip designed to increase the rate of pulmonary veins real-time signal recording in order to measure time necessary to isolate veins, the "Time to effect" (TTE). Few data are currently available on clinical follow up of CB3 treated patients. METHODS: Sixtyeight consecutive patients (mean age 57.8 ±â€¯9.6 years, 48 male) with paroxysmal or persistent atrial fibrillation (AF) were enrolled. Thirthyfour (25 paroxysmal AF) underwent to a 28 mmCB3 pulmonary veins isolation and were compared to 34 treated (21 paroxysmal AF) with 28 mmCB2. RESULTS: CB3 use was correlated to significant increase of the possibility to measure TTE in every treated veins (left superior 82,35% vs 23,53%, left inferior 70,59% vs 38,24%, right superior 58,82% vs 14,71%, right inferior 52,94% vs 17,65%). When it is measured, TTE wasn't different between two groups. Higher nadir temperature was observed in CB3 patients (-39.4 ±â€¯5.2 °C vs -43.0 ±â€¯7.2 °C, p = 0.03). CB3 procedures were shorter (91.4 ±â€¯21.7 vs 110.9 ±â€¯31.8 min, p = 0.018), with a significant reduction in cryoenergy delivery time (24.2 ±â€¯8.5 vs 20.3 ±â€¯6.7 min, p < 0.05), and a significant reduction in left atrium dwell time (59.3 ±â€¯9.8 vs 69.3 ±â€¯10.8 min, p = 0.02, p < 0.05). At one year follow up period the Kaplan-Meier curve didn't show any significant difference in AF-free survival (Log p = 0,49). CONCLUSIONS: Novel CB3 is a useful tool in order to simplify AF cryoballoon ablation when compared to second generation cryoballoon, as observed in our experience. Follow up data seem confirm a clinical CB3 efficacy at least comparable CB2.

Delta-wave automatic mapping of the manifest accessory pathway.

Background: Despite the high success rate of radiofrequency catheter ablation (RFCA) in Wolff-Parkinson-White Syndrome (WPW), localizing the successful ablation site can be challenging and may require multiple radiofrequency (RF) applications. Objective: This study aims to evaluate the efficacy of a novel workflow for the automatic and precise identification of accessory pathway ablation site, named Delta Wave Automatic Mapping. Methods: Patients undergoing a first procedure for RF ablation of a manifest accessory pathway were included. Electro-Anatomical Mapping (EAM) was performed with the CARTO 3 system (Biosense Webster, Johnson & Johnson Medical S.p.a., Irvine, CA) leveraging auto-acquisition algorithms already present in the CARTO 3 software. Mapping and ablation were performed with an irrigated tip catheter with contact force sensor. Procedure success was defined as loss of pathway function after ablation. The number of RF applications required and time to effect were measured for each patient. Recurrences were evaluated during follow-up visits. Additionally, at the end of each procedure, historical predictors of ablation success were measured offline to evaluate their relationship with the successful ablation site found with the novel workflow. Results: A total of 50 patients were analysed (62% APs right and 38% APs left). All 50 APs were successfully eliminated in each procedure with a median Time-to-effect (TTE) of 2.0 (IQR 1.2-3.5) seconds. No AP recurrences during a median follow-up of 10 (IQR 6-13) months were recorded. Offline analysis of successful ablation site revealed a pre-ablation delta/ventricular interval of ≤-10 msec in 52% of the patients and in 100% of the patients the signal related to the Kent bundle was identified. Conclusions: The novel workflow efficiently localizes APs without requiring manual annotations. Historical endocardial parameters predicting success were measured offline for each case and they corresponded to the ablation target automatically annotated by the proposed workflow. This novel mapping workflow holds promise in enhancing the efficacy of RFCA in the presence of manifest APs.

Different image integration modalities to guide AF ablation: impact on procedural and fluoroscopy times.

BACKGROUND: Different image integration modalities are available for atrial fibrillation (AF) ablation, but their impact on procedural and fluoroscopy times has not been evaluated yet. METHODS: Sixty patients (mean age 52.2 ± 12.0 years, 48.3% men, 75% paroxysmal AF) undergoing pulmonary vein (PV) encircling with PV disconnection for symptomatic drug-refractory AF were randomized to ablation with CARTO electroanatomical mapping (Biosense Webster, Diamond Bar, CA, USA) integrated with: (1) preprocedural magnetic resonance imaging (MRI; Group 1); (2) intracardiac echocardiography (ICE; Group 2); (3) preprocedural MRI and ICE (Group 3). RESULTS: PV disconnection was achieved in all patients. Total procedural time (Group 1: 124.7 ± 47.0; Group 2: 112.5 ± 30.4; Group 3: 108.6 ± 34.7 minutes) and total ablation time were similar between groups (P = ns). MRI integration alone required a higher fluoroscopy time (23.8 ± 6.9 in Group 1 vs 11.0 ± 2.3 and 13.9 ± 4.2 minutes in Groups 2 and 3, respectively; P < 0.005) and a longer time spent in the left atrium (109.0 ± 43.5 in Group 1 vs 78.2 ± 29.7 and 74.8 ± 34.3 minutes in Groups 2 and 3, respectively; P = 0.03) in comparison to ICE integration. Addition of MRI to ICE integration showed a tendency for a higher fluoroscopy time in comparison to ICE integration alone (P = 0.06). At a mean follow-up of 9.1 ± 2.2 months, there were no significant differences in AF recurrences among the groups (P = ns). CONCLUSION: ICE image integration significantly reduces the fluoroscopy time and the time spent in the left atrium in comparison to MRI integration alone. Addition of MRI to ICE integration does not reduce total procedural time and seems to lead to higher fluoroscopy time in comparison to ICE integration alone.

dST-Tiso Interval, a Novel Electrocardiographic Marker of Ventricular Arrhythmia Inducibility in Individuals With Ajmaline-Induced Brugada Type I Pattern.

The aim of this study was to investigate the reliability of a novel electrocardiographic (ECG) marker in predicting ventricular arrhythmia (VA) inducibility in individuals with drug-induced Brugada syndrome (BrS) type I pattern. Consecutive patients with drug-induced type I BrS pattern underwent programmed ventricular stimulation (PVS) and, according to their response, were divided into 2 groups. Clinical characteristics and 12-lead ECG intervals before and after ajmaline infusion were compared between the 2 groups. A novel ECG marker named dST-Tiso interval consisting in the interval between the onset of the coved ST-segment elevation and its termination at the isoelectric line was also evaluated. Our cohort included 76 individuals (median age 44 years, 75% male). Twenty-five (32.9%) had VA inducibility requiring defibrillation. As compared with not inducible subjects, those with VA inducibility were more frequently male (92% vs 65%, p = 0.013), had longer PQ interval (basal: 172 vs 152 ms, p = 0.033; after ajmaline: 216 vs 200 ms, p = 0.040), higher J peak (0.6 vs 0.5 mV, p = 0.006) and longer dST-Tiso (360 vs 240 ms, p < 0.001). The dST-Tiso showed a C-statistics of 0.90 (95% confidence interval: 0.82 to 0.99) and an adjusted odds ratio for VA of 1.03 (1.01 to 1.04, p < 0.001). A dST-Tiso interval >300 ms yielded a sensitivity of 92.0%, a specificity of 90.2%, positive and negative predictive values of 82.1% and 95.8%. In conclusion, the dST-Tiso interval is a powerful predictor of VA inducibility in drug-induced BrS type I pattern. External validation is needed, but this marker might be useful in the clinical counseling process of these individuals before invasive PVS.

Safety and feasibility of electrical isolation of the superior vena cava in addition to pulmonary vein ablation for paroxysmal atrial fibrillation using the cryoballoon: lessons from a prospective study.

PURPOSE: The purpose of this study was to evaluate the feasibility and safety of superior vena cava (SVC) isolation in addition to standard pulmonary vein isolation (PVI) using the second-generation cryoballoon (CB) in patients with paroxysmal atrial fibrillation. METHODS: Thirty-seven consecutive patients that underwent CB ablation for paroxysmal atrial fibrillation (PAF) were prospectively enrolled in our study. After PVI the SVC was mapped for potentials. If the SVC exhibited electrical activity, isolation was achieved performing a single 180-s balloon application. RESULTS: Regarding SVC isolation, 180-s freeze in the SVC could be completed in 32 (86.4%) patients, and 5 patients had at least 120 s of freezing application (13.5%). Real-time recording during SVC isolation was observed in 30 (81.0%) patients. The mean time to isolation was 36.9 ± 28.7 s and the temperature at isolation was - 33 (- 15 to - 40) °C. No cases developed persistent phrenic nerve palsy (PNP) or any other complication. CONCLUSIONS: Superior vena cava isolation proved to be safe and feasible with the second generation cryoballoon in a prospective series of patients affected by PAF.

Remote monitoring of cardiac implantable devices during COVID-19 outbreak: "keep people safe" and "focus only on health care needs".

BACKGROUND: The COVID-19 pandemic has challenged the ability of health care organisations to provide adequate care. We report the experience of a national tertiary electrophysiology centre in the management of patients with cardiac implantable electronic devices (CIEDs) through the use of a fully remote follow-up model. METHODS: We daily and prospectively collected remote monitoring (RM) relevant findings and following clinical actions performed from March 10th to April 3rd 2020, a period of suspension of routine ambulatory activity due to the national lockdown. RESULTS: During the study period (25 days), we received 2,215 transmissions from 2,955 devices. Among them, 129 patients reported potential clinically actionable RM observations (event rate: 12.0/1000 patient-week). In 77 patients (60%), RM events triggered a clinical action, but only 5 patients needed an urgent in-hospital access (4 urgent procedures and 1 device reprogramming). CONCLUSIONS: In the unprecedented COVID-19 pandemic, RM became an essential tool in healthcare delivery for CIED patients. We observed that RM was effective in "keep people safe" and "focus only on individuals with health care needs".

Noncontact mapping of left ventricle during CRT implant.

INTRODUCTION: Not all candidates for cardiac resynchronization therapy (CRT) are responders at follow-up. Echocardiographic parameters of dyssynchrony do not predict the response. Analysis of electrical properties of left ventricle (LV) by noncontact mapping (NCM) could be useful to better identify candidates for CRT. METHODS AND RESULTS: We studied nine consecutive patients undergoing CRT. An NCM was positioned in the LV via atrial transeptal puncture. LV activation was recorded during sinus rhythm (SR), pacing from RV, from different LV epicardial locations, and in biventricular (BIV) pacing. The corresponding invasive pressure was determined. Heparin, administered during NCM, was reversed and CRT implant was completed. An offline analysis of the data was performed in order to measure transeptal and total LV activation time, to evaluate the site of earliest and latest LV activation, and the pattern of activation. No complications occurred. Mean time of total NCM procedures was 24 + or - 7 minutes. During SR, RV, LV, and BIV pacing, respectively, a "U"-shaped LV activation pattern was found in three, seven, four, and and two patients; mean LV activation time was 58.1 + or - 7.0, 81.7 + or - 15.8, 71.1 + or - 12.4, and 65.6 + or - 7.7 ms; and mean systolic LV peak pressure was 114 + or - 21, 97 + or - 18, 103 + or - 17 and 110 + or - 15 mmHg, respectively. LV activation was influenced by a slow conduction area at the pacing site and by the duration of transeptal time. CONCLUSION: An NCM during CRT is safe and feasible. It provides an additional information on electrical activation in SR and in various modality of pacing. Further studies with larger populations are needed in order to correlate electrical to clinical outcomes.

Contact versus noncontact mapping for ablation of ventricular tachycardia in patients with previous myocardial infarction.

INTRODUCTION: The aim of this study was to compare contact versus noncontact mapping for radiofrequency (RF) ablation of any sustained post-myocardial infarction (MI) ventricular tachycardia (VT). METHODS: Forty patients with tolerated VT post-MI were randomized to RF ablation with contact (group 1) or noncontact (group 2) mapping systems. In both groups ablation of tolerated VT was guided by VT activation map confirmed by concealed entrainment. When untolerated VTs were induced, ablation was performed in group 1 according to pace mapping starting from the scar border zone and in group 2 according to the VT activation map confirmed by pace mapping. RESULTS: No differences were seen between the groups in terms of acute success rate of clinical VT ablation (95% vs 100%, respectively; P = ns) and in the noninducibility of any VT at the end of the procedure (55% vs 85%, respectively; P = 0.08). Moreover, untolerated VTs were eliminated in 30% of group 1 versus 83.3% of group 2 patients (P < 0.05). The mean total procedural and fluoroscopy times were 236.4 +/- 42.7 and 29.0 +/- 7.8 minutes in group 1 and 144.5 +/- 50.8 and 23.4 +/- 5.8 minutes in group 2 (P < 0.001 and < 0.05, respectively). At a mean follow-up of 15.2 +/- 6.7 months no differences were seen in VT recurrences between groups, but noninducibility at the end of the procedure was predictive of freedom from recurrences (P < 0.001). CONCLUSION: Both systems are useful for ablation of tolerated VT. Noncontact mapping is more effective for ablation of untolerated VT and allows the reduction of procedural and fluoroscopy times. Noninducibility at the end of the procedure seems predictive of freedom from recurrences during follow-up.

Paroxysmal atrial fibrillation ablation with the multipolar mapping and ablation catheter (Mesh-Bard).

Pulmonary veins (PVs) ablation is a valid treatment option for atrial fibrillation. The standard approach for PVs isolation usually requires two catheters or an electroanatomical reconstruction of the left atrium. We describe our initial experience with a single device for mapping and ablating in a patient referred to our center for the relapsing of atrial fibrillation 3 years after a previous ablation procedure. The newly available catheter MESH was safe and effective to quickly isolate two reconnected PVs.

Leadless pacemaker implantation after transcatheter lead extraction in complex anatomy patient.

After transvenous lead extraction, leadless pacemaker might be a valid alternative to the traditional two-step strategy including an active fixation leads temporary PM and subsequent contralateral permanent implantation in patients who are pacemaker-dependent. Moreover, leadless PM might be of great importance in patients presenting with congenital vascular or cardiac abnormality.

Acute and chronic haemodynamic effects of biventricular pacing and of switching to different pacing modalities in heart failure patients.

BACKGROUND: In patients with severe heart failure, sinus rhythm and wide QRS complex biventricular (BiV) pacing leads to clinical and haemodynamic improvement, but the immediate reversibility of these changes is not known. METHODS: We assessed the acute and medium-term (3-month) haemodynamic effects of BiV pacing and of switching to other pacing modalities in 21 patients with severe heart failure, sinus rhythm and QRS>or=130 ms. Haemodynamic studies were performed: 1) at the time of implantation of a BiV pacing device, during AAI pacing, atrial synchronous right ventricular (RV) pacing, atrial synchronous left ventricular (LV) pacing and atrial synchronous BiV pacing (all at 100 bpm); 2) after 3 months of continuous BiV pacing--with evaluations being made by switching to RV and the other pacing modalities. RESULTS: At both the acute and medium-term evaluations, BiV pacing provided the greatest improvement in cardiac index. Switching from BiV to RV pacing led to a more marked decrease in the cardiac index at 3 months. No strict correlation was evident between acute and medium-term effects of BiV pacing on cardiac index. CONCLUSION: Cardiac resynchronization by BiV pacing provides acute/medium-term improvements in cardiac index. Sudden, medium-term failure of LV stimulation can lead to an even more pronounced haemodynamic derangement than that inducible by RV pacing at baseline. Acute haemodynamic evaluations do not seem to provide a powerful way for identifying medium-term responders.

Radiofrequency ablation of paroxysmal atrial fibrillation by mesh catheter.

INTRODUCTION: Pulmonary veins isolation usually requires a multielectrode catheter for mapping in addition to the ablation catheter. We describe our experience with a new multipolar catheter designed for simultaneous mapping and ablation (MESH, Bard). METHODS AND RESULTS: We tested the catheter in 15 patients (mean age 61.1 +/- 7.9; eight men) scheduled for paroxysmal atrial fibrillation ablation. The catheter was positioned in front of the pulmonary vein ostia. A pulmonary vein potential was demonstrated in 63.5% of the veins, which were disconnected with a mean of 1.6 radiofrequency applications with a mean time of 351 +/- 125.8 s (range 180-650) for each vein. Mean procedural time was 93 +/- 17.1 min (range 65-120), and fluoroscopy time was 13.7 +/- 4.0 (range 5-15) min. No complications occurred during and after or procedures. CONCLUSION: Pulmonary veins disconnection with MESH ablator catheter is feasible with short procedural and X-ray exposure time. Further studies are needed to compare this new device to standard multipolar mapping catheters in order to evaluate its ability to correctly identify pulmonary vein potentials and to compare its safety and efficacy.

[Cardiac resynchronization therapy and reduction of mortality in heart failure: a proven association]. / Terapia di resincronizzazione e riduzione di mortalità nello scompenso cardiaco: un'associazione provata.

Cardiac resynchronization therapy (CRT) is currently used for treatment of refractory heart failure and is effective in reducing symptoms and increasing quality of life and exercise tolerance. Data from the literature also show that CRT may prolong event-free survival and reduce heart failure mortality. This therapy is also highly cost-effective as compared to optimized medical treatment. The reduction of the risk of death occurs in both nonischemic and ischemic heart failure, although in this latter group CRT benefit seems to be less. It is still controversial whether a back-up defibrillator should be implanted to all patients undergoing CRT. Finally, left ventricular reverse remodeling occurring after 3 to 6 months of treatment predicts long-term benefit of CRT on mortality.