Focal pulsed field ablation in complex atrial tachycardia: First clinical experience and 1- year outcome.

BACKGROUND: Pulsed-field ablation (PFA) has become increasingly important in the treatment of cardiac arrhythmias. In addition to single-shot devices mainly used for pulmonary vein isolation, focal PFA may provide a treatment option increasing the versatility of the technique. OBJECTIVE: The study objective was to provide data on feasibility, safety and long-term outcome of focal PFA for the ablation of complex atrial tachycardia (AT). METHODS: All consecutive patients (n=34) with complex AT treated at our department between 2022 and 2023 with a focal PFA system (CENTAURI™, Galvanize therapeutics, San Carlos, USA) were included. The majority of patients (32/34 pts) had undergone at least one prior radiofrequency ablation. Established contact-force sensing catheters were used for PFA application in combination with a PFA generator. Pulse electric field (PEF) trains were conducted in a R-wave triggered manner. RESULTS: Acute procedural success was accomplished in all patients. PFA included creation of 51 linear lesions and (re)isolation of 12 pulmonary veins. Mean procedure duration was 102.7 ± 30.3 min, with a LA dwell time of 75.0 ± 24.7 min. Mean fluoroscopy duration was 8.7 ± 5.3 min. No complications occurred. After a mean follow-up of 340.9 ± 130.1 days, recurrence of any AT occurred in 15 patients (44.1%). During 9 reablations, 3 gaps in previously created linear lesions were detected whereas the majority of recurrences (n=6) was not related to previous PFA lesion creation. CONCLUSION: Focal pulsed-field ablation of complex AT substrates was safe and efficient. Acute procedural success was 100%; after one year, the majority of patients were in sinus rhythm. A minority of recurrences was caused by insufficient PFA lesion creation.

Radiofrequency ablation-Real-time visualization of lesions and their correlation with underlying parameters.

BACKGROUND: Lesion durability and transmurality are crucial for successful radiofrequency (RF) ablation. This study provides a model of real-time RF lesion visualization and insights into the role of underlying parameters, as local impedance (LI). METHODS: A force-sensing, LI-sensing catheter was used for lesion creation in an ex vivo model involving cross-sections of porcine cardiac preparations. During 60 s of RF application, one measurement per second was performed regarding lesion size and available ablation parameters. In total, 1847 measurements from n = 36 lesions were performed. Power (20-50 W) and contact force (1-5 g, 10-15 g, 20-25 g) were systematically alternated. RESULTS: Lesion formation was most prominent in the first seconds of RF application during which nonlinear lesion growth was observed (max. 1.08 mm/s for lesion depth and 2.71 mm/s for lesion diameter). Power levels determined the extent of lesion formation in the early phase. After 20 s, lesion size growth velocity approaches 0.1 mm/s at all power levels. LI changes were also highest in the first seconds (up to - 12 Ω/s) and decreased to less than - 0.1Ω/s after prolonged application. CONCLUSION: Lesion formation in irrigated RF ablation is a nonlinear process. Final lesion size resulting from an RF application is mainly influenced by high rates of lesion growth in the first seconds of ablation. LI seems to be a good surrogate for differentiating changes in lesion formation.

Pulsed field ablation in patients with cardiac implantable electronic devices: an ex vivo assessment of safety.

BACKGROUND: Pulse field ablation (PFA) is a novel catheter ablation technology with potential safety benefits due to its tissue selectivity. It has the potential to directly damage or interact with the functionality of cardiac implantable electronic devices (CIEDs) in the form of electromagnetic interference (EMI). The aim of our study was to assess the impact of PFA on CIEDs. METHODS: PFA lesions (45 per CIED) were applied from the Farapulse system to CIEDs (< 5 cm from the lead tip and < 15 cm from the generator). All devices were checked before and after PFA application for proper sensing and pacing functionality as well as for integrity of shock circuits in ICDs using a heart simulator. Moreover, devices were then interrogated for any spontaneous reprogramming, mode switching or other EMI effects. RESULTS: In total, 44 CIEDs were tested (16 pacemaker, 21 ICDs, 7 CRT-P/D) with 1980 PFA applications. There was no change in device settings, functionality and electrical parameters, and there was no macroscopic damage to the devices. The risk of damage to the electric components or leads on a patient-based analysis is 0/44 (95% CI 0-8%) and on a PFA pulse-based analysis is 0/1980 (95% CI 0-0.2%). Clinically relevant EMI appeared with oversensing and pacing inhibition but not tachycardia detection. CONCLUSIONS: Bipolar PFA appears safe and does not result in damage to CIEDs or leads. Clinically relevant EMI does occur, but appropriate peri-procedural programming may mitigate this. In vivo studies are needed to confirm our findings.

First clinical data on artificial intelligence-guided catheter ablation in long-standing persistent atrial fibrillation.

INTRODUCTION: Despite advanced ablation strategies and major technological improvements, treatment of persistent atrial fibrillation (AF) remains challenging and the underlying pathophysiology is not fully understood. This study analyzed the multiple procedure outcome and safety of catheter ablation of spatiotemporal dispersions (DISPERS) detected by artificial intelligence (AI)-guided software in patients with long-standing persistent AF. METHODS AND RESULTS: The Volta VX1 software was used for 50 consecutive patients undergoing catheter ablation for persistent AF. First, high-density mapping (78% biatrial) with a multipolar mapping catheter was performed. In addition to pulmonary vein isolation (PVI), ablation of DISPERS was performed aiming at homogenizing, dissecting, isolating, or connecting DISPERS areas to nonconducting anatomical structures. Follow-up contained regular visits at our outpatient clinic at 1, 3, 6, and 12 months including 7-day Holter electrocardiograms. Patients were mainly suffering from long-standing persistent AF (mean AF duration 50.30 ± 54.28 months). Following PVI, ablation of left atrial and right atrial DISPERS areas led to AF cycle length prolongation (mean of 162.0 ± 16.6 to 202.2 ± 21.6 ms after) and AF termination to atrial tachycardia (AT) or sinus rhythm (SR) in 12 patients (24%). No stroke or pericardial effusion occurred; major groin complications (pseudoaneurysm n = 1, atrioventricular fistula n = 1) were detected in two patients. After a blanking period of 6 weeks, recurrence of any atrial arrhythmia was documented in 26 patients (52%). The majority of patients presented with organized AT (n = 15) while AF was present in n = 9 patients and AT/AF was observed in n = 2 patients. Twenty-two patients underwent reablation. During a mean follow-up of 363.14 ± 187.42 days and after an average of 1.46 ± 0.68 procedures, 82% of patients remained in stable SR. CONCLUSION: DISPERS-guided ablation using machine learning software (the Volta VX1 software) in addition to PVI in long-standing persistent AF ablation resulted in high long-term success rates regarding AF and AT elimination. Most arrhythmia recurrences were reentrant AT. After a total of 1.46 ± 0.68 procedures, freedom from AF/AT was 82%. Despite prolonged procedure times complication rates were low. Randomized studies are necessary to evaluate long-term efficacy of dispersion-guided ablation using AI.

Myocardial injury and inflammation following pulsed-field ablation and very high-power short-duration ablation for atrial fibrillation.

INTRODUCTION: Pulmonary vein isolation (PVI) using radiofrequency ablation (RFA) is an established treatment strategy for atrial fibrillation (AF). To improve PVI efficacy and safety, high-power short-duration (HPSD) ablation and pulsed-field ablation (PFA) were recently introduced into clinical practice. This study aimed to determine the extent of myocardial injury and systemic inflammation following PFA, HPSD, and standard RFA using established biomarkers. METHODS: We included 179 patients with paroxysmal AF receiving first-time PVI with different ablation technologies: standard RFA (30-40 W/20-30 s, n = 52), power-controlled HPSD (70 W/5-7 s, n = 60), temperature-controlled HPSD (90 W/4 s, n = 32), and PFA (biphasic, bipolar waveform, n = 35). High-sensitivity cardiac troponin T (hs-cTnT), creatine kinase (CK), CK MB isoform (CK-MB), and white blood cell (WBC) count were determined before and after ablation. RESULTS: Baseline characteristics were well-balanced between groups (age 63.1 ± 10.3 years, 61.5% male). Postablation hs-cTnT release was significantly higher with PFA (1469.3 ± 495.0 ng/L), HPSD-70W (1322.3 ± 510.6 ng/L), and HPSD-90W (1441.2 ± 409.9 ng/L) than with standard RFA (1045.9 ± 369.7 ng/L; p < .001). CK and CK-MB release was increased with PFA by 3.4-fold and 5.8-fold, respectively, as compared to standard RFA (p < .001). PFA was associated with the lowest elevation in WBC (Δ1.5 ± 1.5 × 109 /L), as compared to standard RFA (Δ3.8 ± 2.5 × 109 /L, p < .001), HPSD-70W (Δ2.7 ± 1.7 × 109 /L, p = .037), and HPSD-90W (Δ3.6 ± 2.5 × 109 /L, p < .001). CONCLUSION: Among the four investigated ablation technologies, PFA was associated with the highest myocardial injury and the lowest inflammatory reaction.

Long-Term Follow-Up of Empirical Slow Pathway Ablation in Pediatric and Adult Patients with Suspected AV Nodal Reentrant Tachycardia.

BACKGROUND: The aim of this study was to assess long-term efficacy and safety of empirical slow pathway (ESP) ablation in pediatric and adult patients with a special interest in patients without dual AV nodal physiology (DAVNP). METHODS: A retrospective single-center review of patients who underwent ESP ablation between December 2014 and September 2022 was performed. Follow-up included telephone communication, letter questionnaire and outpatient presentation. Recurrence was based on typical symptoms. RESULTS: 115 patients aged 6-81 years (median age 36.3 years, 59.1% female; 26 pts < 18 years) were included. A typical history was present in all patients (100%), an ECG documentation of narrow complex tachycardia in 97 patients (84%). Patients were divided into three groups: Group 1 without DAVNP (n = 23), Group 2 with AH jump (n = 30) and Group 3 with AH jump and at least one AV nodal echo beat (n = 62). No permanent AV block was observed. During a median follow-up of 23.6 ± 22.7 months, symptom recurrence occurred in 7/115 patients (6.1%) with no significant difference between the groups (p = 0.73, log-rank test). Symptom recurrence occurred significantly more often in patients without (5/18 patients; 27%) as compared to patients with ECG documentation (2/97 patients; 2.1%; p = 0.025). No correlation between age and success rate was found (p > 0.1). CONCLUSIONS: ESP ablation is effective and safe in patients with non-inducible AVNRT. Overall, recurrence of symptoms during long-term follow-up is low, even if no DAVNP is present. Tachycardia documentation before the EP study leads to a significantly lower recurrence rate following ESP ablation.

The influence of electrode-tissue-coverage on RF lesion formation and local impedance: Insights from an ex vivo model.

BACKGROUND: The influence of power, duration and contact force (CF) on radiofrequency (RF) lesion formation is well known, whereas data on local impedance (LI) and electrode-tissue-coverage (ETC) is scarce. The objective was to investigate their effect on lesion formation in an ex vivo model. METHODS AND RESULTS: An ex vivo model was developed utilizing cross-sections of porcine heart preparations and a force-sensing, LI-measuring catheter. N = 72 lesion were created systematically varying ETC (minor/full), CF (1-5 g, 10-15 g, 20-25 g) and power (20 W, 30 W, 40 W, 50 W). In minor ETC, the distal tip of the catheter was in electric contact with the tissue, in full ETC the whole catheter tip was embedded within the tissue. Lesion size and all parameters were measured once per second (n = 3320). LI correlated strongly with lesion depth (r = -0.742 for ΔLI; r = 0.781 for %LI-drop). Lesions in full ETC were significantly wider and deeper compared to minor ETC (p < .001) and steam pops were more likely. Baseline LI, ΔLI, and %LI-drop were significantly higher in full ETC (p < .001). In lesions resulting in steam pops, baseline LI, and ΔLI were significantly higher. The influence of CF on lesion size was higher in minor ETC than in full ETC. CONCLUSIONS: ETC is a main determinant of lesion size and occurrence of steam pops. Baseline LI and LI-drop are useful surrogate parameters for real-time assessment of ETC and ΔLI correlates strongly with lesion size.

Cardiologist-Directed Sedation Management in Patients Undergoing Transvenous Lead Extraction: A Single-Centre Retrospective Analysis.

BACKGROUND: The demand for transvenous lead extraction (TLE) has increased. In line with this, the safety of such procedures has also increased. Traditionally, TLE is performed under resource-intensive general anaesthesia. This study aims to evaluate the safety and outcomes of Cardiologist-lead deep sedation for TLE. METHODS: We retrospectively analysed 328 TLE procedures performed under deep sedation from 2016 to 2019. TLE procedures were performed by experienced electrophysiologists. Sedation was administered by a specifically trained cardiologist (bolus midazolam/fentanyl and propofol infusion). Procedural sedation data including blood pressure, medication administration and sedation time were collected. Complications related to sedation and the operative component of the procedure were analysed retrospectively. RESULTS: The sedation-associated complication rate during TLE was 22.0%. The most common complication (75% of complications) was hypotension requiring noradrenaline, followed by bradycardia requiring atropine (13% of complications). Additionally, the unplanned presence of an anaesthesiologist was needed in one case (0.3%). Deep sedation was achieved with midazolam (mean dose 42.9 ± 26.5 µg/kg), fentanyl (mean dose 0.4 ± 0.6 µg/kg) and propofol (mean dose 3.5 ± 1.2 mg/kg/h). There was no difference in medication dosage between those with a sedation-associated complication and those without. Sedation-associated complications appeared significantly more in patients with reduced LVEF (p = 0.01), renal impairment (p = 0.01) and a higher American Society of Anaesthesiologists (ASA) class (p = 0.01). CONCLUSION: Deep sedation for TLE can be safely performed by a specifically trained cardiologist, with a transition to general anaesthesia required in only 0.3% of cases. We continue to recommend the on-call availability of an anaesthesiologist and cardiac surgeon in case of major complications.

High-power chargers for electric vehicles: are they safe for patients with pacemakers and defibrillators?

AIMS: Battery electric vehicle (BEV) sales and use are rapidly expanding. Battery electric vehicles, along with their charging stations, are a potential source of electromagnetic interference (EMI) for patients with cardiac implantable electronic devices (CIEDs). The new 'high-power' charging stations have the potential to create strong electromagnetic fields and induce EMI in CIEDs, and their safety has not been evaluated. METHODS AND RESULTS: A total of 130 CIED patients performed 561 charges of four BEVs and a test vehicle (350 kW charge capacity) using high-power charging stations under continuous 6-lead electrocardiogram monitoring. The charging cable was placed directly over the CIED, and devices were programmed to maximize the chance of EMI detection. Cardiac implantable electronic devices were re-interrogated after patients charged all BEVs and the test vehicle for evidence of EMI. There were no incidences of EMI, specifically no over-sensing, pacing inhibition, inappropriate tachycardia detection, mode switching, or spontaneous reprogramming. The risk of EMI on a patient-based analysis is 0/130 [95% confidence interval (CI) 0%-2%], and the risk of EMI on a charge-based analysis is 0/561 (95% CI 0%-0.6%). The effective magnetic field along the charging cable was 38.65 µT and at the charging station was 77.9 µT. CONCLUSIONS: The use of electric cars with high-power chargers by patients with cardiac devices appears to be safe with no evidence of clinically relevant EMI. Reasonable caution, by minimizing the time spent in close proximity with the charging cables, is still advised as the occurrence of very rare events cannot be excluded from our results.

Electrical isolation of the right ventricular outflow tract in idiopathic ventricular tachycardia: a case report.

Background: Ventricular tachycardia (VT) originating in the right ventricular outflow tract (RVOT) is the most common form of idiopathic VT. Catheter ablation of right ventricular outflow tract tachycardia (RVOT-VT) is associated with high success rates. However, non-inducibility of VT on electrophysiological (EP) study can severely impact ablation outcome. We describe a novel catheter ablation strategy which proved feasible and safe in a case of highly symptomatic, non-inducible RVOT-VT. Case summary: A 51-year-old male with a history of non-sustained VT (NSVT) was referred to our hospital after two syncopal episodes resulting in collapse. Upon admission, a cluster of monomorphic NSVT (250-270 b.p.m.) resulted in haemodynamic instability and required transfer to the intensive care unit. On twelve-lead electrocardiogram, NSVT showed inferior axis and left bundle branch block, suggestive of RVOT-VT. Diagnostic workup including echocardiography, coronary angiography, and late enhancement computed tomography (CT) revealed no evidence of structural heart disease. On two EP studies, non-inducibility of clinical VT despite repeated ventricular pacing and isoproterenol infusion rendered precise mapping of triggered activity unfeasible. Therefore, a bailout ablation strategy was developed by performing a circumferential electrical RVOT isolation using a 3.5 mm irrigated-tip ablation catheter under the guidance of high-density electroanatomic mapping (CARTO® 3) and CT reconstruction of cardiac anatomy. No procedural complications occurred, and the patient remained arrhythmia-free during a 6-month follow-up period. Discussion: Catheter ablation is a first-line therapy for symptomatic and drug-refractory idiopathic RVOT-VT. Non-inducibility of RVOT-VT represents a relevant limitation for successful ablation which might be overcome by electrical RVOT isolation as a bailout ablation strategy.

["Asymptomatic WPW" : Is treatment necessary?] / "Asymptomatisches WPW" : Bedarf es einer Therapie?

The term "asymptomatic WPW" (Wolff-Parkinson-White) is often used as a synonym for ventricular pre-excitation of the WPW type due to an accessory pathway characterized by a short PR interval and a delta wave on the electrocardiogram (ECG) without the clinical occurrence of paroxysmal tachycardia. Asymptomatic WPW is often diagnosed in young and otherwise healthy people. There is a small associated risk of sudden cardiac death due to rapid antegrade conduction over the accessory pathway during atrial fibrillation. This paper highlights aspects of noninvasive and invasive risk stratification, therapy by catheter ablation, and the ongoing risk-benefit discussion in asymptomatic WPW.

Safety profile and long-term efficacy of very high-power short-duration (60-70 W) catheter ablation for atrial fibrillation: results of a large comparative analysis.

AIMS: This retrospective study sought to compare complication rates and efficacy of power-controlled very high-power short-duration (vHPSD) and conventional catheter ablation in a large cohort of patients with atrial fibrillation (AF). METHODS AND RESULTS: We analyzed 1115 consecutive patients with AF (38.7% paroxysmal, 61.3% persistent) who received first-time catheter ablation at our centre from 2015 to 2021. Circumferential pulmonary vein isolation ± additional substrate ablation using an irrigated-tip catheter was performed with vHPSD (70 W/5-7 s or 60 W/7-10 s) in 574 patients and with conventional power (30-35 W/15-30 s) in 541 patients. Baseline characteristics were well-balanced between groups (mean age 65.1 ± 11.2 years, 63.4% male). The 30-day incidence of cardiac tamponade [2/574 (0.35%) vs. 1/541 (0.18%), P = 0.598], pericardial effusion ≥ 10 mm [2/574 (0.35%) vs. 1/541 (0.18%), P = 0.598] and transient ischaemic attack [1/574 (0.17%) vs. 2/541 (0.37%), P = 0.529] was not significantly different between vHPSD and conventional ablation. No stroke, atrio-esophageal fistula, cardiac arrest or death occurred. Procedure (122.2 ± 46.8 min vs. 155.0 ± 50.5 min, P < 0.001), radiofrequency (22.4 ± 19.3 min vs. 52.9 ± 22.0 min, P < 0.001), and fluoroscopy (8.1 ± 7.2 vs. 9.2 ± 7.4, P = 0.016) duration were significantly shorter in the vHPSD group. At 12 months follow-up, freedom of any atrial arrhythmia was 44.1% vs. 34.2% (P = 0.010) in persistent AF and 78.1% vs. 70.2% in paroxysmal AF (P = 0.068). CONCLUSION: vHPSD ablation is as safe as conventional ablation and is associated with an improved long-term efficacy in persistent AF.

Fetal Bradycardia Caused by Monogenic Disorders-A Review of the Literature.

Introduction: The standard obstetric definition of fetal bradycardia is a sustained fetal heart rate < 110 bpm over at least 10 min. Fetal bradycardia can be the first and only prenatal presentation of a heart disease. We present an overview on different genetic disorders that should be taken into consideration in case of diagnosed fetal bradycardia. Methods: A literature review was conducted using a PubMed- and OMIM-based search for monogenetic disorders causing fetal bradycardia in September 2022. Results: The review on the literature identified nine monogenic diseases that could lead to fetal bradycardia. Four of these disorders can be associated with extracardiac findings. Discussion: Genetic testing should be considered in cases with fetal bradycardia, especially in cases of additional extracardiac findings. Broad sequencing techniques and improved prenatal phenotyping could help to establish a diagnosis in an increasing number of cases.

Ultrasound-Guided Access Reduces Vascular Complications in Patients Undergoing Catheter Ablation for Cardiac Arrhythmias.

Background: Femoral vascular access using the standard anatomic landmark-guided method is often limited by peripheral artery disease and obesity. We investigated the effect of ultrasound-guided vascular puncture (UGVP) on the rate of vascular complications in patients undergoing catheter ablation for atrial or ventricular arrhythmias. Methods: The data of 479 patients (59% male, mean age 68 years ± 11 years) undergoing catheter ablation for left atrial (n = 426; 89%), right atrial (n = 28; 6%) or ventricular arrhythmias (n = 28; 6%) were analyzed. All patients were on uninterrupted oral anticoagulants and heparin was administered intravenously during the procedure. Femoral access complications were compared between patients undergoing UGVP (n = 320; 67%) and patients undergoing a conventional approach (n = 159; 33%). Complication rates were also compared between patients with a BMI of >30 kg/m2 (n = 136) and patients with a BMI < 30 kg/m2 (n = 343). Results: Total vascular access complications including mild hematomas were n = 37 (7.7%). In the conventional group n = 17 (10.7%) and in the ultrasound (US) group n = 20 (6.3%) total vascular access complications occurred (OR 0.557, 95% CI 0.283−1.096). UGVP significantly reduced the risk of hematoma > 5 cm (OR 0.382, 95% CI 0.148, 0.988) or pseudoaneurysm (OR 0.160, 95% CI 0.032, 0.804). There was no significant difference between the groups regarding retroperitoneal hematomas or AV fistulas (p > 0.05). In patients with BMI > 30 kg/m2, UGVP led to a highly relevant reduction in the risk of total vascular access complications (OR 0.138, 95% CI 0.027, 0.659), hematomas > 5 cm (OR 0.051, 95% CI 0.000, 0.466) and pseudoaneurysms (OR 0.051, 95% CI 0.000, 0.466). Conclusion: UGVP significantly reduces vascular access complications. Patients with a BMI > 30 kg/m2 seem to particularly profit from a UGVP approach.

Prevalence and Treatment Outcomes of Arrhythmias in Patients with Single Ventricle Physiology over the Age of 40 Years.

Background: Arrhythmias are a well known complication in patients with single ventricle physiology (SVP). However, there is still a lack of data regarding arrhythmias in older patients. The aim of this study was to analyze arrhythmia type and frequency, treatment and recurrence rates in patients with SVP over the age of 40 years. Methods: Data was obtained retrospectively from clinical records. All patients > 40 years with SVP with arrhythmias between 2005 and 2018 were included in the study. Treatment was classified as medical, interventional (electrophysiological studies (EPS) in combination with catheter ablation) or direct current cardioversion (DCCV). Results: Altogether, 29 patients (11 female; mean 47.5 ± 4.6 years) with 85 arrhythmia episodes were identified. The median follow-up time was 6.3 years. Cavo-tricuspid (CTI) and non-CTI related intra-atrial reentrant tachycardia (IART) and atrial fibrillation (AF) were most common (48.2% and 37.6%, respectively). In total, 18 EPS/ablations were performed in 9 patients and 52 DCCVs in 20 patients. Acute success was 98% for DCCV and 72.2% for EPS/ablation. Recurrence rate was high (70% for DCCV and 55% for EPS). AT recurrences occurred after a median of 8 and 2.5 months, respectively. On multivariate analyses, age was the only risk factor for arrhythmia recurrence (HR 0.58, 95% C.I. 0.43−0.78, p < 0.0001). Pacemaker implantation was necessary in seven patients (AV block n = 4, sinus node dysfunction n = 3) and one patient received an ICD for secondary prophylaxis. Sudden death occurred in three patients. Conclusions: The most common arrhythmias in patients with SVP > 40 years are IART and AF. Arrhythmia recurrence following EPS or DCCV is frequent. Older age is an independent risk factor for arrhythmia recurrence.

Peak Oxygen Uptake on Cardiopulmonary Exercise Test Is a Predictor for Severe Arrhythmic Events during Three-Year Follow-Up in Patients with Complex Congenital Heart Disease.

Patients with congenital heart disease (CHD) are at increased risk for severe arrhythmia and sudden cardiac death (SCD). Although implantable cardioverter defibrillators (ICD) effectively prevent SCD, risk stratification for primary prophylaxis in patients with CHD remains challenging. Patients with complex CHD undergoing CPET were included in this single-center study. Univariable and backwards stepwise multivariable logistic regression models were used to identify variables associated with the endpoint of severe arrhythmic event during three years of follow-up. Cut-off values were established with receiver operating characteristic (ROC) curve analysis. Survival analysis was conducted via Kaplan-Meier plots. Severe Arrhythmia was documented in 97 of 1194 patients (8.1%/3 years). Independent risk factors for severe arrhythmia during follow-up were old age and a low peak oxygen uptake (V.O2peak) on multivariable analysis. Patients with more advanced age and with V.O2peak values of less than 24.9 mL/min/kg were at significantly increased risk for the occurrence of severe arrhythmias during follow-up. The combined analysis of both risk factors yielded an additional benefit for risk assessment. Age at CPET and V.O2peak predict the risk for severe arrhythmic events and should be considered for risk stratification of SCD in patients with complex CHD.

Deep sedation with propofol in patients undergoing left atrial ablation procedures-Is it safe?

Background: Catheter ablation for atrial fibrillation (AF) or left atrial tachycardia is well established. To avoid body movement and pain, sedative and analgesic agents are used. Objective: The aim was to investigate safety of sedation/anti-pain protocol administered by electrophysiology (EP) staff. Methods: A total of 3211 consecutive patients (61% male) undergoing left atrial ablation for paroxysmal AF (37.1%), persistent AF (35.3%) or left atrial tachycardia (27.6%) were included. Midazolam, fentanyl, and propofol were administered by EP staff. In case of respiratory depression, endotracheal intubation (eIT) or noninvasive ventilation (NIV) was implemented. Risk factors for eIT or NIV were analyzed. Results: Mean doses of propofol, midazolam, and fentanyl were 33.7 ± 16.7 mg, 3 ± 11.1 mg, and 0.16 ± 2.2 mg, respectively. Norepinephrine was administered in 396 of 3211 patients (12.3%) because of blood pressure drop (mean arterial pressure <60 mm Hg). NIV was necessary in 47 patients (1.5%) and eIT in 1 patient (0.03%). Procedure duration, high body mass index (BMI), high CHADS2-VASC2 score, high age, low glomerular filtration rate, diabetes mellitus, and low baseline oxygen saturation were associated with NIV or eIT. The only independent predictor for NIV/eIT was high BMI (>30.1 ± 9.0 kg/m2). Therefore, patients with a BMI of ≥30 had a 40% higher risk for the need of NIV/eIT during the procedure in our study. Conclusion: Sedation/anti-pain control including midazolam, propofol, and fentanyl administered by EP staff is safe, with only 1.53% requirement of NIV/eIT. High BMI (>30 kg/m2) emerged as an independent predictor for eIT/NIV.

A prospective case-control validation of procalcitonin as a biomarker diagnosing pacemaker and implantable cardioverter-defibrillator pocket infection.

BACKGROUND: The diagnosis of device infections, especially pocket infections, is challenging and relies primarily on clinical presentation. The prospective DIRT (Device associated Infections Role of new diagnostic Tools) study identified procalcitonin (PCT) as the most promising biomarker among other 14 biomarkers to aid the diagnosis of pocket infection. It also identified an optimized cut-off value of 0.05 ng/ml for a localized generator pocket infection. AIMS: The present study aims to validate the proposed PCT cut-off value of 0.05 ng/ml for the diagnosis of pocket infection in an independent cohort. METHODS: We prospectively enrolled 81 patients with pocket infections and 81 controls matched for age and renal function presenting for elective device exchange or lead revision. Patients with concomitant infectious or inflammatory diseases, end-stage renal failure, current active malignancy, or receiving immunosuppressive therapy were excluded. RESULTS: An elevated PCT over 0.05 ng/ml was found in 68% (n = 55) of pocket infections and 24% (n = 19) of controls, corresponding to a sensitivity of 68% and a specificity of 77% for diagnosing a pocket infection. In receiver operating characteristic (ROC) analysis, PCT showed an area under the curve of 0.75 (95% confidence interval, 0.68-0.83; P < 0.001). Sensitivity remained high with antibiotic pretreatment (65% compared to 69% without pretreatment) and in cases with minimal inflammatory signs (67% compared to 70% with extensive inflammation). CONCLUSION: Our study validates the cut-off value of 0.05 ng/ml PCT for diagnosis of a pocket infection, even in patients pre-treated with antibiotics or with minimal clinical signs of inflammation.

Patient Characteristics, Procedural Characteristics, and Outcomes in Patients Having Lead Extraction in a High-Volume Center.

The rate of transvenous lead extraction (TLE) is increasing, with an increasing rate of complex devices being implanted. TLE is now a routine part of cardiac device management and up-to-date data on the safety and efficacy of TLE with modern tools and techniques is essential to management decisions regarding noninfectious indications for lead extraction. We present a contemporary, prospective review of TLE at our high-volume cardiac center. All patients who underwent TLE from June 2016 to June 2019 were enrolled in our local database, and baseline clinical data, procedural information, and outcome data were collected. In total, 561 leads were explanted (n = 153) or extracted (n = 408) from 341 patients over the study period. Patients were predominantly male (71%), with a mean age of 65 ± 17 years. The most common indication for lead removal was lead failure (45.2%, n = 154), followed by infection of the pocket or device (29.3%, n = 100). In total, complete success was achieved in 96.4% (n = 541) leads, clinical success in a further 2.1% (n = 12), and failure only in 1.4% (n = 8). There was an overall complication rate of 0.9% (3/341) for major complications and 1.5% (5/341) for minor complications. There were no deaths. In conclusion, our data suggest that there are ongoing improvements in the safety profile and success rates of lead extraction undertaken by experienced operators. The major complication rate now is <1%.