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.

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.

Non-invasive cardiac activation mapping and identification of severity of epicardial substrate in Brugada Syndrome: a case report.

Introduction: It has recently been shown that electrocardiographic imaging (ECGi) can be employed in individuals undergoing an ajmaline test who have Brugada Syndrome (BrS), to evaluate the extent of substrate-involved arrhythmia in the right ventricular overflow tract (RVOT). For the first time, we stratify the risk of sudden cardiac death (SCD) in BrS during ajmaline testing using the dST-Tiso interval (a robust predictor of the inducibility of ventricular arrhythmias (VAs) in the presence of drug-induced BrS type-1 pattern) in combination with ECGi technology. Case presentation: We studied a 48-year-old man with BrS ECG type-2 pattern and presence of J-wave without a family history of SCD but with a previous syncope. Transthoracic echocardiography and cardiac magnetic resonance imaging were performed, showing normal results. The ECG was performed to assess the novel ECG marker "dST-Tiso interval." The 3D epicardial mapping of the RVOT surface was performed with the support of a non-contact cardiac mapping system in sinus rhythm during ajmaline infusion. The examination of the propagation map unveiled the presence of multiple conduction blocks in this pathologic epicardial region, and the conduction blocks were identified within the central part and/or near the boundary separating the normal and slow conduction areas. Conclusion: The dST-Tiso interval, which lies between the onset and termination of the coved ST-segment elevation and serves as a robust predictor of VA inducibility in cases of drug-induced BrS type-1 pattern, was utilized in conjunction with ECGi technology (employed for the non-invasive confirmation and identification of the pathological substrate area). This combined approach was applied to stratify the risk of SCD in BrS during ajmaline testing, alongside clinical scores.

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.

Rhythm- or rate-control strategies according to 4S-AF characterization scheme and long-term outcomes in atrial fibrillation patients: the FAMo (Fibrillazione Atriale in Modena) cohort.

The 4S-AF scheme [Stroke risk, Symptom severity, Severity of atrial fibrillation (AF) burden, Substrate severity] was recently proposed to characterize AF patients. In this post hoc analysis we evaluated the agreement between the therapeutic strategy (rate or rhythm control, respectively), as suggested by the 4S-AF scheme, and the actual strategy followed in a patients cohort. Outcomes of interest were as follows: all-cause death, a composite of all-cause death/any thromboembolism/acute coronary syndrome, and a composite of all-cause death, any thrombotic/ischemic event, and major bleeding (net clinical outcome). We enrolled 615 patients: 60.5% male, median age 74 [interquartile range (IQR) 67-80] years; median CHA2DS2VASc 4 and median HAS-BLED 2. The 4S-AF score would have suggested a rhythm-control strategy in 351 (57.1%) patients while a rate control in 264 (42.9%). The strategy adopted was concordant with the 4S-AF suggestions in 342 (55.6%) cases, and non-concordant in 273 (44.4%). After a median follow-up of 941 days (IQR 365-1282), 113 (18.4%) patients died, 158 (25.7%) had an event of the composite endpoint. On adjusted Cox regression analysis, when 4S-AF score suggested rate control, disagreement with that suggestion was not associated with a worse outcome. When 4S-AF indicated rhythm control, disagreement was associated with a higher risk of all-cause death (HR 7.59; 95% CI 1.65-35.01), and of the composite outcome (HR 2.69; 95% CI 1.19-6.06). The 4S-AF scheme is a useful tool to comprehensively evaluate AF patients and aid the decision-making process. Disagreement with the rhythm control suggestion of the 4S-AF scheme was associated with adverse clinical outcomes.

Key characteristics for effective acute pulmonary vein isolation when using a novel cryoballoon technology: insights from the CHARISMA registry.

PURPOSE: A new cryoballoon (CB) technology (POLARx™; Boston Scientific) for pulmonary vein (PV) isolation in patients with atrial fibrillation (AF) has recently been introduced. The aim of this study was to evaluate procedural and biophysical parameters resulting in acute PV isolation when using this new CB. METHODS: We assessed the first 69 consecutive patients indicated for AF ablation who underwent PV isolation by means of a novel CB system. Procedural metrics were prospectively recorded. RESULTS: A total of 274 PVs were targeted in 69 patients. PV isolation was achieved in all patients by means of cryoablation alone. The median time to isolation (TTI) was 44 [31-68] s (median temperature at TTI = - 49 [- 53 to - 41] °C). The median duration of CB ablation was 180 [180 to 240] s. The median nadir temperature was - 56.0 [- 61 to - 52] °C, and the median thaw time to 0 °C was 18 [15-21] s. The median grade of PV occlusion was 4 [3 to 4]. On the basis of ROC analysis, we defined the following cut-off values for acute PV isolation: - 56 °C for nadir temperature (sensitivity = 73.3%, specificity = 64.6%, AUC = 0.716; positive predictive value = 88.1%), 30 s for TTT (60.2%, 53.3%, 0.578; 79.7%), thaw time > 17 s (65.3%, 70.0%, 0.709; 86.9%), and grade of PV occlusion = 4 (79.4%, 66.7%, 0.738; 88.5%). No major procedure-related adverse events were observed at 30-day post-procedure. CONCLUSIONS: The new POLARx™ CB appears to be effective and safe. A nadir temperature of - 56 °C, a thaw time to 0 °C ≥ 17 s, and complete PV occlusion were the best predictors of acute PV isolation. 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.

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.

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".

Usefulness of Red Cells Distribution Width to Predict Worse Outcomes in Patients With Atrial Fibrillation.

Red cells distribution width (RDW) is a measure of red cell size variability, but little is known about the relation between RDW and outcomes in atrial fibrillation (AF).The aims of our study were to evaluate the association between RDW values, AF patients' profile and outcomes. Consecutive patients with ECG-confirmed AF were divided in 3 groups according to tertiles of RDW values (≤13.5%, 13.6% to 14.6%, >14.6%).We enrolled 457 patients, 61.9% males, median (interquartile range) age 74 (66 to 80). Both CHA2DS2-VASc and HAS-BLED scores increased progressively according to RDW tertiles. During follow-up, there was an increased risk for all-cause death and the composite end point in the highest RDW tertile (p <0.001 for both outcomes). On multivariate Cox regression analysis, the highest RDW tertile was independently associated with all-cause death (hazard ratio [HR] 3.23, 95% confidence interval [CI] 1.04 to 10.00) and the composite end point (HR 2.04, 95% CI 1.12 to 3.70). RDW as a continuous variable was also independently associated with all cause death and the composite outcome (HR 1.16, 95% CI 1.02 to 1.31 and HR 1.16, 95% CI 1.05 to 1.27, respectively). In conclusion, in a real-life AF population, RDW is associated with clinical factors indicating a worse profile and is independently associated with increased risks of all-cause death and other clinical events.