Expanded application of wearable cardioverter defibrillators beyond current guidelines: proposal for a European register explained through single clinical scenarios.

The wearable cardioverter defibrillator (WCD) is becoming a more and more widely used instrument for the prevention of sudden cardiac death of patients either with a secondary prevention implantable cardioverter defibrillator indication or with a transient high risk of sudden cardiac death. Although clinical practice has demonstrated a benefit of protecting patients for a period as long as 3-6 months with such devices, the current European guidelines concerning ventricular arrhythmias and sudden cardiac death are still extremely restrictive in the patient selection in part because of the costs derived from such a prevention device, in part because of the lack of robust randomised trials.To illustrate expanded use cases for the WCD, four real-life clinical cases are presented where patients received the device slightly outside the established guidelines. These cases demonstrate the broader utility of WCDs in situations involving acute myocarditis, thyrotoxicosis, pre-excited atrial fibrillation and awaiting staging/prognosis of a lung tumour. The findings prompt expansion of the existing guidelines for WCD use to efficiently protect more patients whose risk of arrhythmic cardiac death is transient or uncertain. This could be achieved by establishing a European register of the patients who receive a WCD for further analysis.

Fusion Imaging of Non-Invasive and Invasive Cardiac Electroanatomic Mapping in Patients with Ventricular Ectopic Beats: A Feasibility Analysis in a Case Series.

In patients with premature ventricular contractions (PVCs), non-invasive mapping could locate the PVCs' origin on a personalized 3-dimensional (3D) heart model and, thus, facilitate catheter ablation therapy planning. The aim of our report is to evaluate its accuracy compared to invasive mapping in terms of assessing the PVCs' early activation zone (EAZ). For this purpose, non-invasive electrocardiographic imaging (ECGI) was performed using the Amycard 01C system (EP Solutions SA, Switzerland) in three cases. In the first step, a multichannel ECG (up to 224 electrodes) was recorded, and the dominant PVCs were registered. Afterward, a cardiac computed tomography (in two cases) or magnetic resonance imaging (in one case) investigation was carried out acquiring non-contrast torso scans for 8-electrode strip visualization and contrast heart acquisition. For the reconstructed epi/endocardial meshes of the heart, non-invasive isochronal maps were generated for the selected multichannel ECG fragments. Then, the patients underwent an invasive electrophysiological study, and the PVCs' activation was evaluated by a 3D mapping system (EnSite NavX Precision, Abbott). Finally, using custom-written software, we performed 3D fusion of the non-invasive and invasive models and compared the resulting isochronal maps. A qualitative analysis in each case showed the same early localization of the dominant PVC on the endocardial surface when comparing the non-invasive and invasive isochronal maps. The distance from the EAZ to the mitral or tricuspid annulus was comparable in the invasive/non-invasive data (36/41 mm in case N1, 73/75 mm in case N2, 9/12 mm in case N3). The area of EAZ was also similar between the invasive/non-invasive maps (4.3/4.5 cm2 in case N1, 7.1/7.0 cm2 in case N2, 0.4/0.6 cm2 in case N3). The distances from the non-invasive to invasive earliest activation site were 4 mm in case N1, 7 mm in case N2, and 4 mm in case N3. Such results were appropriate to trust the clinical value of the preoperative data in these cases. In conclusion, the non-invasive identification of PVCs before an invasive electrophysiological study can guide clinical and interventional decisions, demonstrating appropriate accuracy in the estimation of focus origin.

His bundle pacing guided by automated intrinsic morphology matching is feasible in patients with narrow QRS complexes.

Pace mapping and visual comparison of the local pacing response with the intrinsic QRS morphology form the mainstay of His bundle pacing (HBP). We evaluated the performance of a surface lead morphology match algorithm for automated classification of the pacing response in patients with narrow intrinsic QRS undergoing electroanatomic mapping (EAM)-guided HBP. HBP was attempted in 43 patients. In 28 cases with narrow QRS, the EnSite AutoMap Module was used for automated assessment of the QRS morphology resulting from pace mapping in the His cloud area with either a diagnostic catheter or the His lead. An intrinsic morphology match score (IMS) was calculated for 1.546 QRS complexes and assessed regarding its accuracy and performance in classifying the individual pacing response as either selective HBP (S-HBP), nonselective HBP (NS-HBP) or right ventricular stimulation. Automated morphology comparison of 354 intrinsic beats with the individual reference determined a test accuracy of 99% (95% CI 98.96-99.04) and a precision of 97.99-99.5%. For His-lead stimulation, an IMS ≥ 89% identified S-HBP with a sensitivity, specificity and positive predictive value of 1.00 (0.99, 1.00) and a negative predictive value of 0.99 (0.98, 1.00). An IMS between 78 and < 89% indicated NS-HBP with a sensitivity and specificity of 1.00 (0.99, 1.00) and 0.99 (0.98, 1.00), respectively. IMS represents a new automated measure for standardized individual morphology classification in patients with normal QRS undergoing EAM-guided HBP.Clinical trial registration: NCT04416958.

Clinical valuation of ST changes in a group of patients with ventricular arrhythmias: The inSighT Study.

BACKGROUND: The inSighT study was designed to determine the prevalence of ischemic changes as recorded by implantable cardioverter-defibrillator (ICD) ST deviations in intracardiac electrocardiograms (EGM) over the 24 h preceding malignant ventricular arrhythmias (VT/VF). METHODS: The study enrolled patients with known coronary artery disease (CAD) or high risk of future development of CAD implanted with an ICD equipped with an ST monitoring feature (Ellipse™/Fortify Assura™, St. Jude Medical). Device session records were collected at each in-clinic follow-up. EGM ST levels of the beats over the 15 minutes prior to VT/VF events were compared using a t test with those from a baseline period of 23-24 h prior to the VT/VF event. All events with p < .05 were visually inspected to confirm they were evaluable; additional criteria for exclusion from further analysis included inappropriate therapy, aberrant conduction, and occurrence of VT/VF within 24h prior to the current event. RESULTS: The study enrolled 481 ICD patients (64 ± 11 years, 83% male) in 14 countries and followed them for 15±5 months. A total of 165 confirmed VT/VF episodes were observed, of which 71 events (in 56 patients, 34% of all patients with VT/VF) were preceded by significant (p < .05) ST-segment changes unrelated to known non-ischemic causes. None of the analyzed demographic and clinical factors proved to be associated with greater odds of presenting with ST-segment changes prior to VT/VF episode. CONCLUSION: In this exploratory study, characteristic ST-segment changes, likely representative of ischemic events, were observed in 34% of all patients with VT/VF episodes.

Perioperative Sensor and Algorithm Programming in Patients with Implanted ICDs and Pacemakers for Cardiac Resynchronization Therapy.

BACKGROUND: ICDs and pacemakers for cardiac resynchronization therapy (CRT) are complex devices with different sensors and automatic algorithms implanted in patients with advanced cardiac diseases. Data on the perioperative management and outcome of CRT carriers undergoing surgery unrelated to the device are scarce. METHODS: Data from 198 CRT device carriers (100 with active rate responsive sensor) were evaluated regarding perioperative adverse (device-related) events (A(D)E) and lead parameter changes. RESULTS: Thirty-nine adverse observations were documented in 180 patients during preoperative interrogation, which were most often related to the left-ventricular lead and requiring intervention/reprogramming in 22 cases (12%). Anesthesia-related events occurred in 69 patients. There was no ADE for non-cardiac surgery and in pacemaker-dependent patients not programmed to an asynchronous pacing mode. Post-operative device interrogation showed significant lead parameter changes in 64/179 patients (36%) requiring reprogramming in 29 cases (16%). CONCLUSION: The left-ventricular pacing lead represents the most vulnerable system component. Comprehensive pre and post-interventional device interrogation is mandatory to ensure proper system function. The type of ICD function suspension has no impact on each patient's outcome. Precautionary activity sensor deactivation is not required for non-cardiac interventions. Routine prophylactic device reprogramming to asynchronous pacing appears inessential. Most of the CRT pacemakers do not require surgery-related reprogramming.

Minielectrode catheter technology for near zero-fluoroscopy substrate-guided ablation of typical atrial flutter.

BACKGROUND: MicroFidelity catheter technology may facilitate voltage-guided ablation by high-resolution electroanatomic mapping (HR-EAM) and precisely targeted energy application. OBJECTIVE: To evaluate the performance of minielectrode (ME) technology for zero-fluoroscopy substrate-guided cavotricuspid isthmus (CTI) ablation. METHODS: Eighty-two patients underwent near zero-fluoroscopy substrate-guided CTI ablation using a nonirrigated large-tip catheter with 3 MEs. The CTI was subdivided into 15 electroanatomic segments. Bipolar voltage maps were compared with ME signals. The outcome was compared with a historic cohort of 92 patients who underwent linear ablation. RESULTS: Compared with linear ablation, the substrate-guided approach was associated with an almost halved ablation duration (336 ± 228 vs 649 ± 409 seconds, P < .001), halved radiofrequency energy applied (14.2 ± 10.6 vs 28.6 ± 19.6 kJ, P < .001), and shorter procedure duration (60.8 ± 33.8 vs 76.3 ± 40.9 minutes, P = .008) limiting the extent of energy delivery to 22.7% of the CTI area. HR-EAM visualized 2.03 ± 0.88 conductive pathways with a diameter of 5.35 ± 1.98 mm. A higher number of ME-detected bundles and a larger channel diameter correlated with increased ablation requirements. In 97.6% of the voltage-guided and 88.0% of the linear procedures, fluoroscopy was not used. CONCLUSION: HR-EAM-based substrate-guided CTI ablation may improve procedural outcome compared with the linear approach. Enhanced identification of discrete conductive pathways correlates with ablation efficacy. The electroanatomic subdivision of the CTI into 15 segments was feasible and may improve the understanding and comparability of anatomic variants and ablation results. Independent of the ablation strategy, modern EAM technology enables safe zero-fluoroscopy procedures in the majority of cases.

Evaluation of Mathematical Arterialization of Venous Blood in Intensive Care and Pulmonary Ward Patients.

BACKGROUND: Arterial blood gases are important when assessing acute or critically ill patients. Capillary blood and mathematical arterialization of venous blood have been proposed as alternative methods, eliminating pain and complications of arterial puncture. OBJECTIVES: This study compares the arterial samples, arterialized venous samples, and capillary samples in ICU and pulmonary ward patients. METHOD: Ninety-one adult patients with respiratory failure were included in the analysis. Arterial, peripheral venous, and mathematically arterialized venous samples were compared in all patients using Bland-Altman analysis, with capillary samples included in 36 patients. RESULTS: Overall for pH and PCO2, arterialized venous values, and in the subset of 36 patients, capillary values, compared well to arterial values and were within the pre-defined clinically acceptable differences (pH ± 0.05 and PCO2 ± 0.88 kPa). For PO2, arterialized or capillary values describe arterial with similar precision (PO2 arterialized -0.03, LoA -1.48 to 1.42 kPa and PO2 capillary 0.82, LoA -1.36 to 3 kPa), with capillary values underestimating arterial. CONCLUSIONS: Mathematical arterialization functions well in a range of patients in an ICU and ward outside the country of development of the method. Furthermore, accuracy and precision are similar to capillary blood samples. When considering a replacement for arterial sampling in ward patients, using capillary sampling or mathematical arterialization should depend on logistic ease of implementation and use rather than improved measurements of using either technique.

Impact of Different Geriatric Conditions on Choice of Therapy and In-Hospital Outcomes in Elderly Patients with Acute Coronary Syndrome.

INTRODUCTION: The clinical benefit of invasive therapy in elderly patients with acute coronary syndrome (ACS) remains unclear. Furthermore, the decision-making process to treat this growing patient group is also debatable. The purpose of this study was to assess the association between elderly ACS patients, the treatment choice and their in-hospital outcomes after non-ST-elevation (NSTE)-ACS in a consecutive series of patients >75 years of age. METHODS AND RESULTS: Consecutive patients >75 years presenting with NSTE-ACS in our hospital between July 2017 and July 2018 were included during the first 2 days of hospital admission. Demographic data, prior medical history and present medical condition were documented. During day 0 and day 2, geriatric assessments (Clinical Frailty Scale [CFS], Barthel index, Charlson comorbidity index, "timed up and go" test [TUG], Mini-Mental Status Test [MMS], Geriatric Depression Scale [GDS], SF-36 for quality of life, instrumental activities of daily living [IADL], Killip-score, Grace-score and Euro-score) were conducted. After 6 months, patients were re-evaluated. In 106 patients (mean age 81.9±5.3 years, 57% male gender), 68 patients (64%) were treated interventionally, and 38 patients had conservative treatment (36%). Patients treated with intervention were significantly younger (80.9±4.7 years vs 83.5±6.0 years, p=0.015), had a lower rate of prior cerebral events (17.6% vs 26.3%; p=ns) and suffered more often from chronic obstructive pulmonary disease (17.6% vs 34.2%; p=0.050). All other demographic variables were comparable between both groups. The composite clinical endpoint (death, re-infarction, bleeding) was reached in 7 patients (10.3%) of the invasive and in 2 patients (5.3%) of the conservative group. They were not significantly different between both groups. A frailty index, consisting of commonly used parameters of functional impairment in elderly patients, namely, MMS ≤2 at baseline, IADL ≤7, CFS ≥7 and age ≥85 years, significantly predicted conservative treatment. CONCLUSION: Effective revascularization techniques are still underused in patients of older age in the case of ACS. For decision-making, geriatric tests alone may not predict treatment in those patients, but the combination of different tests may better predict treatment and perhaps the clinical outcomes in those patients. Furthermore, frail patients are at higher risk for not receiving guideline recommended therapy.

High-density mapping-guided corrective HIS bundle pacing after failed CRT upgrade for persistent left superior vena cava.

In patients with persistent left superior vena cava (PLSVC), transvenous device implantation for cardiac resynchronization therapy (CRT) may be challenging. We present a complex case with successful, high-density electroanatomic mapping (EAM) guided corrective His bundle pacing (CHBP) following failed CRT upgrade in a patient with PLSVC, congenital heart disease, and pacing-associated heart failure. CHBP restored physiological conduction in left bundle branch block with complete conduction block leading to clinical improvement and cardiac remodeling. The presented case supports the growing evidence that EAM-guided CHBP may be considered a feasible alternative to conventional CRT when venous anatomy is not favorable for left ventricular lead implantation.

Quinidine-A legacy within the modern era of antiarrhythmic therapy.

Quinidine has a very long history as antiarrhythmic medication. The alkaloid has been used in the treatment of almost all cardiac arrhythmias, especially atrial fibrillation, since the early twentieth century. Despite decreases in clinical prescription over the last two decades, mainly due to side effects like pro-arrhythmia, leading to increased mortality and to the availability of newer anti-arrhythmic drugs and catheter ablation, Quinidine remains an invaluable drug in the modern era of antiarrhythmic therapy. We present a review of the pharmacological properties of quinidine and its pivotal therapeutic role in the treatment of life-threatening arrhythmic storms in patients with congenital arrhythmogenic syndromes like Brugada's syndrome, early repolarization syndrome, short QT syndrome and idiopathic ventricular fibrillation.

Real-world geographic variations in the use of cardiac implantable electronic devices-The PANORAMA 2 observational cohort study.

BACKGROUND: Currently, several geographies around the world remain underrepresented in medical device trials. The PANORAMA 2 study was designed to assess contemporary region-specific differences in clinical practice patterns of patients with cardiac implantable electronic devices (CIEDs). METHODS: In this prospective, multicenter, observational, multinational study, baseline and implant data of 4,706 patients receiving Medtronic CIEDs (Medtronic plc, Minneapolis, MN, USA; either de novo device implants, replacements, or upgrades) were analyzed, consisting of: 54% implantable pulse generators (IPGs), 20.3% implantable cardiac defibrillators (ICDs), 15% cardiac resynchronization therapy -defibrillators, and 5.1% cardiac resynchronization therapy -pacemakers, from 117 hospitals in 23 countries across four geographical regions between 2012 and 2016. RESULTS: For all device types, in all regions, there were fewer females than males enrolled, and women were less likely to have ischemic cardiomyopathy. Implant procedure duration differed significantly across the geographies for all device types. Subjects from emerging countries, women, and older patients were less likely to receive a magnetic resonance imaging-compatible device. Defibrillation testing differed significantly between the regions. European patients had the highest rates of atrial fibrillation (AF), and the lowest number of implanted single-chamber IPGs. Evaluation of stroke history suggested that the general embolic risk is more strongly associated with stroke than AF. CONCLUSIONS: We provide comprehensive descriptive data on patients receiving Medtronic CIEDs from several geographies, some of which are understudied in randomized controlled trials. We found significant variations in patient characteristics. Several medical decisions appear to be affected by socioeconomic factors. Long-term follow-up data will help evaluate if these variations require adjustments to outcome expectations.

Oesophageal injury following magnetically guided single-catheter ablation for atrial fibrillation: insights from the MAGNA-AF registry.

Aims: Oesophagogastroduodenoscopy (OGD) after catheter ablation (CA) of atrial fibrillation (AF) revealed a high rate of procedure related oesophageal lesions. We hypothesized that magnetically guided CA with careful radiofrequency energy titration at the posterior left atrial (LA) wall limits the incidence of oesophageal tissue damage. Methods and results: As a part of the prospective "Remote MAGNetic catheter Ablation for Atrial Fibrillation" (MAGNA-AF) registry, 251 out of 266 consecutive patients underwent OGD after magnetically guided single-CA for AF. All detected pathologies were analysed. Simultaneous pacing and ablation from the tip of the magnetically guided catheter was found to be a safe and feasible method for energy titration. Post-interventional OGD documented midoesophageal tissue damage in four (1.6%) patients. Although a thermal origin of these injuries must be discussed, none of them was located at the anterior oesophageal wall. Risk factors for midoesophageal lesions were female gender and concomitant acetylsalicylic acid (ASA) treatment. Mechanical lesions in 16 patients were attributed to periprocedural transoesophageal echocardiography (TOE). There was no atrio-oesophageal fistula (AOF). Five hundred and one incidental pathologies were found endoscopically, most frequent axial oesophageal herniation (71%), oesophagitis (22%), and gastritis (57%). Conclusion: Magnetically guided CA for AF with careful energy titration at the posterior LA wall and no oesophageal temperature monitoring is not associated with an increased incidence of oesophageal thermal injury. The routine use of periprocedural TOE may cause a low rate of mechanical oesophageal lesions but reliably prevents major complications like transient ischaemic attack, stroke, or cardiac tamponade. An observed high prevalence of upper digestive system inflammation (63%) may further support the recommendation for a routine post-interventional treatment with a proton-pump-inhibitor.

Interventional Laser-assisted Extraction of an Infected Trapped Ventriculoatrial Shunt Based on Techniques for Pacemaker Lead Explantation.

We present a case of successful interventional laser-assisted extraction of an endovascularly trapped long-term implanted ventriculoatrial shunt in a patient with shunt-associated septicemia. This approach is based on modified techniques for explantation of pacemaker leads and might be considered an additional option for extraction of otherwise nonremovable trapped endovascular catheters in experienced centers.

Underdetection of ventricular fibrillation despite ICD testing and high sinus R wave.

Apart from monitoring shock efficacy, proof of flawless detection of induced ventricular fibrillation (VF) is a decisive argument in favor of implantable cardioverter defibrillator (ICD) testing. On the other hand, it has been observed that undersensing of VF is extremely rare with good sensing of the intrinsic R wave of ≥ 5-7 mV. The case presented here shows limitations in both argumentations: Neither optimal R wave sensing during sinus rhythm nor repeated ICD testing could rule out or predict multiple erroneous detections of clinical VF episodes. This must be taken into consideration in the current discussion on the necessity of defibrillation testing. Further optimization of sensing technology should be a focus in the development of modern ICD systems so as to improve the safety and efficacy of ICD therapy.

ICD implantation without intraoperative testing does not increase the rate of system modifications and does not impair defibrillation efficacy tested in follow-up.

AIM: The need for implantable cardioverter-defibrillator (ICD) defibrillation testing (DT) and subsequent intraoperative system modifications is discussed controversially. The study's goal was to prove that consequent abdication of intraoperative DT does not impair defibrillation efficacy and does not increase the rate of postoperative system revisions. METHODS: In a prospective single-center observational study, 609 out of 648 consecutive patients underwent transvenous ICD implantation (left-sided, active can, dual coil lead, and biphasic shock waveform) waiving intraoperative DT. Defibrillation efficacy was validated prior to hospital discharge (PHD) by applying two 10 J safety margin (SM) shocks. RESULTS: Following "schockless" implantation 580 out of 609 patients (95.2 %) met a 10 J SM with default programming. Shock path reversal provided 10 J SM in 13 out of 29 cases with initially failed DT. In four patients (0.7 %) maximum energy shocks were ineffective. There was no morbidity or mortality related to DT. The total rate of surgical ICD revisions was 1.8 %. CONCLUSION: Routine ICD implantation without intraoperative DT does not lead to an increased rate of postoperative system modifications and does not decrease defibrillation efficacy as tested PHD.

Clinical use of automatic pacemaker algorithms: results of the AUTOMATICITY registry.

AIMS: Follow-up of the ever-increasing numbers of patients with implantable cardiac devices places a heavy burden on clinical departments. Device automaticity may alleviate the follow-up burden by minimizing the time for physician involvement. The aim of the prospective, multicentre AUTOMATICITY registry was to examine the performance of a subset of programmed automatic algorithms during patient follow-up and their acceptance by implanting physicians. METHODS AND RESULTS: The clinical use of automatic algorithms from the Insignia pacemakers (PM; Boston Scientific, St Paul, MN, USA) was evaluated: atrial and ventricular AutoSense (sensitivity adjustment), ventricular Automatic Capture (threshold verification and output setting), AutoLifeStyle (sensor settings adjustment). The objective of the study was to assess the reprogramming rates within 12 months of implant, the reasons for reprogramming and relationship to adverse events. A total of 960 patients were enrolled in the study. The proportion of patients free from any algorithm reprogramming at 12 months was 86.1%. A total of 2736 algorithms were activated at enrolment, with 156 (5.7%) being reprogrammed in 115 patients at 12 months for any reason. Forty-nine reprogrammings (1.8%) were unintentional or related to changes in device settings such that the algorithm was no longer available, 33 (1.2%) were due to suspected sensing issues, and 22 (0.8%) were assumed related to the algorithm. The individual 12-month reprogramming-free rates were: ventricular AutoSense 94.3%, Atrial AutoSense 93.3%, AutoLifeStyle 93.9%, and Automatic Capture 95.9%. CONCLUSION: The results of the AUTOMATICITY registry show that automatic measurement of key settings and automatic adjustment to optimal programming is feasible and safe. The simplicity of PM follow-up and avoidance of frequent reprogramming may contribute to a more effective use of hospital time and resources.

Laser extraction of a trapped infected port catheter in a child using existing experience from pacemaker and ICD lead removal.

A 9-year-old girl presented with systemic infection related to a Port-a-Cath system (PAC); therefore, the urgent removal of the PAC was indicated. However, the catheter was trapped and not extractable by conventional means. Using existing comprehensive experience in the removal of pacemaker and implantable cardioverter defibrillator leads, the entrapped PAC was successfully extracted by laser technique, thus avoiding open heart surgery.