ICD Implantation Research Articles

Predictors of ventricular tachyarrhythmia in patients with a wearable cardioverter defibrillator: an international multicenter registry.

Wearable cardioverter defibrillator (WCD) can protect patients from sudden cardiac death due to ventricular tachyarrhythmias and serve as a bridge to decision of definite defibrillator implantation. The aim of this analysis from an international, multicenter WCD registry was to identify predictors of sustained ventricular tachycardia (VT) and/or ventricular fibrillation (VF) in this population. One thousand six hundred seventy-five patients with WCD were included in a multicenter registry from 9 European centers, with a median follow-up of 440days (IQR 120-893). The primary study end point was the occurrence of sustained VT/VF. Sustained VT was detected by WCD in 5.4% and VF in 0.9% of all patients. Of the 30.3% of patients receiving ICD implantation during follow-up, sustained VT was recorded in 9.3% and VF in 2.6%. Non-ischemic cardiomyopathy (HR 0.5, p < 0.001), and medication with angiotensin-converting enzyme inhibitors (HR 0.7, p = 0.027) and aldosterone antagonists (HR 0.7, p = 0.005) were associated with a significantly lower risk of VT/VF. Patients who received WCD due to a transient increased risk of sudden cardiac death have a comparatively lower risk of VT/VF in the presence of non-ischemic cardiomyopathy. Of note, optimal medical treatment for heart failure not only results in an improvement in left ventricular ejection fraction but also in a reduction in the risk for VT/VF.

Evaluation of the prognostic value of papillary muscle-free strain in patients with hypertrophic cardiomyopathy.

The prognosis of hypertrophic cardiomyopathy (HCM) varies from mild disease with a normal life expectancy to heart failure and sudden cardiac death (SCD). The identification of patients who are at high risk for SCD remains challenging. In this study, we evaluated the prognostic value of papillary muscle-free strain in HCM patients. Seventy-nine patients with a diagnosis of HCM were included in this study. Patients were divided into low/intermediate-risk (n=57) and high-risk (n=22) groups. Two-dimensional (2-D) echocardiography and strain imaging were performed for each patient. The mean age of the study population was 53.85±15.88 years; 47 (59.5%) of them were male. During a mean follow-up duration of 74.45±17.03 months, 12 patients died. A comparison of the low-intermediate and high-SCD risk groups revealed that patients in the high-SCD risk group had greater maximal wall thickness, interventricular septum thickness, posterior wall thickness, and left ventricular mass index (LVMI) and lower (less negative) global longitudinal, anterolateral papillary muscle (ALPM) and posteromedial papillary muscle (PMPM) free strain. Additionally, a history of syncope and ICD implantation were found to be more common in patients with high SCD risk scores. The SCD risk score was positively correlated with the global longitudinal strain, ALPM-free strain, and PMPM-free strain (r=.528, r=.658, and r=.600, respectively; p<.001 for all). Our results showed that the LVMI, presence of syncope, global longitudinal strain, and ALPM-free strain were predictors of death. Decreased papillary muscle-free strain values might have prognostic value in patients with HCM.

The Role of TOMM40 in Cardiovascular Mortality and Conduction Disorders: An Observational Study.

Aims: TOMM40 single nucleotide polymorphism (SNP) rs2075650 consists of allelic variation c.275-31A > G and it has been linked to Alzheimer disease, apolipoprotein and cholesterol levels and other risk factors. However, data on its role in cardiovascular disorders are lacking. The first aim of the study is to evaluate mortality according to TOMM40 genotype in a cohort of selected patients affected by advanced atherosclerosis. Second aim was to investigate the relationship between Xg and AA alleles and the presence of conduction disorders and implantation of defibrillator (ICD) or pacemaker (PM) in our cohort. Materials and Methods: We enrolled 276 patients (mean age 70.16 ± 7.96 years) affected by hemodynamic significant carotid stenosis and/or ischemia of the lower limbs of II or III stadium Fontaine. We divided the population into two groups according to the genotype (Xg and AA carriers). We evaluated several electrocardiographic and echocardiographic parameters, including heart rate, rhythm, presence of right and left bundle branch block (LBBB and RBBB), PR interval, QRS duration and morphology, QTc interval, and left ventricular ejection fraction (LVEF). We clinically followed these patients for 82.53 ± 30.02 months and we evaluated the incidence of cardiovascular events, number of deaths and PM/ICD implantations. Results: We did not find a difference in total mortality between Xg and AA carriers (16.3 % vs. 19.4%; p = 0.62). However, we found a higher mortality for fatal cardiovascular events in Xg carriers (8.2% vs. 4.4%; HR = 4.53, 95% CI 1.179-17.367; p = 0.04) with respect to AA carriers. We noted a higher percentage of LBBB in Xg carriers (10.2% vs. 3.1%, p = 0.027), which was statistically significant. Presence of right bundle branch block (RBBB) was also higher in Xg (10.2% vs. 4.4%, p = 0.10), but without reaching statistically significant difference compared to AA patients. We did not observe significant differences in heart rate, presence of sinus rhythm, number of device implantations, PR and QTc intervals, QRS duration and LVEF between the two groups. At the time of enrolment, we observed a tendency for device implant in Xg carriers at a younger age compared to AA carriers (58.50 ± 0.71 y vs. 72.14 ± 11.11 y, p = 0.10). During the follow-up, we noted no statistical difference for new device implantations in Xg respect to AA carriers (8.2% vs. 3.5%; HR = 2.384, 95% CI 0.718-7.922; p = 0.156). The tendency to implant Xg at a younger age compared to AA patients was confirmed during follow-up, but without reaching a significant difference(69.50 ± 2.89 y vs. 75.63 ± 8.35 y, p = 0.074). Finally, we pointed out that Xg carriers underwent device implantation 7.27 ± 4.43 years before AA (65.83 ± 6.11 years vs. 73.10 ± 10.39 years) and that difference reached a statistically significant difference (p = 0.049) when we considered all patients, from enrollment to follow-up. Conclusions: In our study we observed that TOMM40 Xg patients affected by advanced atherosclerosis have a higher incidence of developing fatal cardiovascular events, higher incidence of LBBB and an earlier age of PM or ICD implantations, as compared to AA carriers. Further studies will be needed to evaluate the genomic contribution of TOMM40 SNPs to cardiovascular deaths and cardiac conduction diseases.

Real-world evaluation of the treatment yield of implantable loop recorders (ILR) in the Netherlands

Abstract Background Implantable loop recorders (ILRs) are invasive and expensive diagnostic tools used to determine the underlying arrhythmias associated with syncope and palpitations as well as capture atrial fibrillation (AF). The diagnostic and treatment yield from ILRs is uncertain. Prior studies indicated that 26-52% ILR patients were diagnosed with arrhythmias and 11-30% received subsequent treatment. Purpose Our primary aim was to determine the incidence of pacemaker and ICD implants within 1- and 3- years of ILR implantation. The secondary aims include 1) an evaluation of the incidence of AF ablation, 2) the identification of predictors for treatment, and 3) safety. Methods Adult patients who underwent an ILR implant in the Netherlands Heart Registration (NHR) Pacemaker and ICD registry (2018-2021) were included. The NHR device registry was linked to the ablation registry to determine the incidence of AF ablation after ILR. Incidence rates for pacemaker implants, ICD implants, AF ablations, and complications among ILR patients were reported as a proportion of ILR patients over 1- and 3- years. Predictors for treatment following an ILR were determined from multivariable logistic regression models. Results From 2018 to 2021, 11,961 patients underwent an ILR implant in the Netherlands. Patients who underwent ILR implantation were a median age 69 (IQR 56-77) years, 46.9% female, and 24.9% had AF. The most frequent indication for ILR implantation was syncope (76.2%), followed by palpitations (15.2%). At 1- and 3-years post-ILR implantation, 12.0% and 14.6% of ILR patients underwent a pacemaker implant, respectively (Figure 1). Fewer patients underwent ICD implants (0.9% and 1.3%) and AF ablation (1.3% and 1.8%) at 1- and 3-years post-ILR implantation, respectively (Figure 1). Compared to males, females were 28% and 70% less likely to undergo a pacemaker and ICD implant following ILR, respectively (Figure 2). Additional predictors for pacemaker implantation included older age, AF, and syncope (p&amp;lt;0.05 for all, Figure 2a). In addition to female sex, AF was a predictor of ICD implantation (Figure 2b). The incidence of complications was relatively low (0.3%). Infection was the most frequent complication (0.2%), followed by device dislocation (0.06%), bleeding (0.02%), and device defect (0.01%). Conclusion Despite the benefits of ILRs for long-term remote monitoring, the therapeutic yield of ILRs is relatively low with 14.6%, 1.3%, and 1.8% of ILR patients undergoing implantation for pacemakers, ICDs, and AF ablation at 3-years follow-up. As an expensive and invasive diagnostic tool, a more targeted approach for referrals is warranted to increase the therapeutic yield of the ILRs. Further investigations are warranted to determine the diagnostic yield of ILRs, regardless of subsequent invasive therapy.

Clinical impact of ICD implantation in octogenarians: a longitudinal cohort study

Abstract Background The implantation of defibrillators (ICDs) in patients over 80 years old is becoming increasingly common; however, evidence-based data regarding the actual clinical benefit in this population remain limited and contradictory. While age seems not to affect mortality and arrhythmia risk in octogenarians undergoing secondary prevention, the mortality reduction benefit given by ICD implantation for primary prevention appears to decrease with advancing age, likely due to the high number of non-arrhythmic deaths. Purpose This study aims to assess the long-term incidence of ventricular arrhythmias and mortality in a real-world cohort of octogenarian patients undergoing ICD implants. Methods This was an observational, retrospective, longitudinal cohort study. Demographic, clinical, and radiological data were collected for all patients undergoing ICD implantation between 2014 and 2021. Deaths from all causes and significant arrhythmic events (sustained ventricular tachycardias and ventricular fibrillation) detected during routine device controls and remote monitoring were recorded. Then was performed an univariate Kaplan-Meier analysis, stratifying the population by age in relation to the two study endpoints: ventricular arrhythmias and all-cause mortality. Results Out of a total of 700 patients, 512 underwent ICD implantation before the age of 80 (mean age at implantation 64±12), while 188 underwent ICD implantation after the age of 80 (mean age at implantation 82±3.2). No significant differences were found between these two groups in terms of gender (82% vs. 83% male; p 0.12), indication for implantation (74% vs. 75% primary prevention; p 0.79), and the presence of late gadolinium enhancement (LGE) on cardiac MRI (68% vs. 77%; p 0.14). Octogenarians were more frequently affected by ischemic heart disease (54% vs. 65%; p 0.01) and were more frequently treated with Amiodarone (17% vs. 24%; p 0.02). At the end of the average 8-year follow-up, octogenarians had significantly higher all-cause mortality than younger patients (HR=2.35 [1.88-3.16]; p&amp;lt;0.05), with survival curves diverging from 3 years after implantation. However, ventricular arrhythmic events were significantly reduced in octogenarian patients (HR=0.88 [0.87-0.89]; p&amp;lt;0.05). Conclusions In a real-world population of octogenarian patients, the clinical benefit of ICD implantation for primary prevention appears diminished, considering the trade-off between ventricular arrhythmias and mortality, in both ischemic and non-ischemic cardiomyopathy patients.

Near-zero fluoroscopy technique for cardiac electronic device implantation: long-term outcomes

Abstract Introduction Radiation hazards are a major concern for both patients and staff. We have previously described a near-zero fluoroscopy technique for cardiac electronic device implantation. In this study, we aimed to investigate the long-term safety of this technique and compare outcomes and procedural metrics with a conventional approach in a larger population. Methods Low-dose fluoroscopy technique. Radiation exposure during fluoroscopy is directly proportional to the time the unit is activated. Typically, the pedal switch is depressed for at least a few seconds per imaging sequence in order to visualize "live" movements of either the leads during their positioning or the needle during a fluoroscopy-guided puncture of the subclavian vein. Our technique consists of setting a low frame rate per second (0.5-3.75fps) and momentarily triggering the foot pedal switch only to obtain screenshots of the position of the leads/needle. Use of live electrograms to assist spatial awareness of lead position (e.g. Atrial, Coronary Sinus, Ventricular signals) acts as an adjunct to guidance. Study design We included consecutive patients undergoing permanent pacemaker (PPM) or cardiac defibrillator (ICD) implant at our center from July 2018 to December 2022 using the near-zero fluoroscopy technique. Procedures were performed by three operators (AC, MD, MF). Cumulative radiation dose was measured using dose-area product (DAP). We assessed procedure success and complication rate during long-term follow-up. We compared the procedural metrics and outcomes with a cohort of patients with PPM or ICD implanted in our centre by senior operators, using a traditional fluoroscopic approach. Propensity score was adopted to match baseline characteristics between the study and control group. Results The total population consisted of 412 patients (74.2±13.9 years, 60.9% male). We included 206 who underwent PPM or ICD implantation using the low-dose fluoroscopy technique, and 206 matched-control. A PPM or ICD was successfully implanted in all patients. Fluoroscopy time and DAP were significantly lower in the low-dose fluoroscopy group, mean 2.3±2.0 seconds versus 258.4±252.1 seconds (P&amp;lt;0.001) and 3.4±3.5 µGym2 versus 29.8±55.4 µGym2 (P&amp;lt;0.001), respectively. Mean procedure time was 49.0±20.8 minutes in the low fluoroscopy group and 65.7±26.8 minutes in the control group (P&amp;lt;0.001). Median frame per second setting was 0.5 in the low-dose cohort. After a mean follow-up of 441±470 days, the rate of complications was identical across groups (2.4%, p = 1.0). Conclusion This near-zero dose fluoroscopy technique is effective and safe, enabling a 10x reduction in radiation exposure during device implant. Modification of traditional implant and imaging techniques can provide material reductions in fluoroscopy dose to even below that for a standard PA chest radiograph.

Swiss national cardiac device registry: changing trends in pacemaker and ICD procedures over the last two decades

Abstract Background The Swiss National Device and Ablation Registry (SwissEPnet) provides a comprehensive database for cardiac pacemaker and ICD procedures. All Swiss centers performing device implantations are obliged to provide their data in this web-based platform. The purpose of this study was to provide an in-depth look at pacemaker and Implantable -defibrillator (ICD) statistics and changing trends over the course of the last 20 years. Methods and Results We analyzed the database of pacemaker and ICD procedures between January 1, 2003, and December 31, 2022. During the study period, a total of 124 458 pacemaker and cardiac resynchronization (CRT) procedures (mean age 77.7 years; 59.7% male) were performed in 73 centers while 29 133 ICDs and CRT-D procedures (mean age 63.63 years; 80.2 % male) were performed in 56 centers in Switzerland. While the number of pacemaker procedures doubled in 20 years and there has been a constant increase in the mean age of patients receiving a pacemaker, the number of ICD procedures has more than tripled and now plateaued with a mean age which remained stable over time. Throughout the study period, the main indications for de novo pacemaker implantations were AV block in 41.7% of patients, followed by sick sinus syndrome combined with tachy-bradycardia syndrome (29.6%) and atrial fibrillation (AF) with slow ventricular conduction (13.7%). The main indication for ICD implantation was primary preventive (66.7%). Since 2016 there has been a decline in primary preventive interventions. Fluoroscopy and procedure durations remained stable over time in pacemaker and ICD procedures. Newer technologies, such as leadless pacemakers and CRT procedures required more fluoroscopy time, but this has also decreased over time. While regular battery changes remained stable (80% in pacemakers, 68% in ICDs), the proportion of DDD and CRT upgrades has increased. The overall reintervention rate due to device-associated infections was 2.4% in pacemaker- and 2.8% in ICD procedures. Since 2013, there has been a steady increase in lead removals/extractions, which were performed mainly due to device-related infections, but also because of lead dysfunctions and worsening electrical parameters. Conclusions In the last 20 years, there was a pronounced increase in the number of pacemaker procedures and a marked increase in the number of ICD procedures which has plateaued now. In younger technologies there is decreasing trend in fluoroscopy time by stable procedure times. Overall, there is a constant increase in mean age of patients receiving a pacemaker, while the mean age of patients receiving an ICD did not change during follow up. Female patients are constantly younger and undergo ICD implantation significantly less often than men. Despite of a stable infection rate, there has been a significant increase in lead removal and extractions in Switzerland.

Cardiac tumors with life threatening arrhythmia, an eight year single centre experience

Abstract Background Cardiac tumors are rare cardiac disorders which occur either as primary or secondary tumors. They have a wide variety of clinical presentations from accidental discovery till sudden cardiac death. Manifestations are mainly due to mass effect, local invasion, embolization, or constitutional symptoms. (1) Cardiac tumor related arrhythmias are more often incessant, especially in younger children, and the mechanism can be reentry or triggered automaticity. (2) Arrhythmia management depends on its clinical impact as well as tumor size, site, and nature. Surgical resection is preferred in life threating arrhythmias however, the decision should be tailored. Purpose To describe our institution’s tailored approach in treatment of cardiac tumors presenting with life threatening ventricular arrhythmias (VAs), including surgical resection, coiling of feeding vessels or even ICD implantation with long term rhythm monitoring. Methods We reviewed patients with primary cardiac tumors presenting to our center from 2015 to 2023 with emphasis on those with life threatening VAs. Patient records were examined for clinical presentation, ECGs, imaging modalities, histopathological analysis of the resected tumors and interrogation data for those with cardiac implantable electronic devices (CIEDS). Results Over 8 years, 64 patients were diagnosed to have primary cardiac tumors. Of those, 3.8% (6 patients) presented with life threatening monomorphic VT, half of them were pediatrics. Tissue characterization by CMR and histopathological analysis for the resected tumors revealed: 4 fibromas, one lipoma and one hemangioma. Surface ECGs during VT showed exit at, or close to, the site of the tumor (Table). Total surgical resection was performed in four cases (3 fibromas and one lipoma), one of them (the youngest, 6 months old) died during the postoperative period due to refractory heart failure. Partial resection was done in one patient with fibroma as the tumor involved the majority of RV free wall while the patient with hemangioma underwent coiling of the feeding vessels twice with marked decrease in the tumor size however he had one further episode of VT, so ICD was implanted. Over a mean follow up period of 3 years, four patients had no recurrence of tachycardia as confirmed with implantable loop recorders (ILRs) while the patient with ICD had infrequent episodes. Conclusion Total surgical resection, albeit risky, is highly effective in eliminating life threatening VAs caused by cardiac tumors. Other modalities like partial resection or coiling of the feeding vessels could be effective in high-risk patients. Devascularization, in our hemangioma case was not totally protective. Finally, ILRs were highly beneficial in confirming long-term freedom of arrhythmia after resection.Table: VT exit, tumor site and typeECG, CMR, angiogram&amp; surgical view

The safety and feasibility of same-day discharge after subcutaneous implantable cardioverter defibrillator implantation

Abstract Introduction Subcutaneous Implantable cardioverter defibrillators (S-ICDs) are now progressively administered as a day-case procedure. While existing data supports the feasibility and safety of same-day discharge after transvenous ICD implantation, comparable evidence for S-ICDs is not well established. This study addresses this by presenting data from the most extensive population documented in the medical literature. We seek to evaluate the feasibility and safety of same-day discharge after S-ICD implantation. Purpose To investigate the feasibility and safety of same-day discharge following S-ICD implantation. Methods A retrospective analysis was conducted, encompassing data from all patients who underwent S-ICD implantation at our institution between January 2011 to April 2023 (n=240). The cohort was stratified into two groups: those discharged on the same day of the procedure (SD, n=124) and those subject to at least overnight hospital observation (OD, n=116). The medical records were reviewed during this period aiming to identify potential complications. Complications were categorized as device-related complications or inappropriate shock. Specific events, such as inappropriate shocks; lead revision; infection necessitating lead or generator extraction; pocket hematoma requiring drainage, blood transfusion, or prolongation of hospitalization; and other complications related to the lead or generator prompting medical or surgical intervention were documented. An inappropriate shock was defined as one delivered for any rhythm other than ventricular fibrillation or ventricular tachycardia. Results Among the 240 patients included in the study, 123 were scheduled for a day case procedure, while the remaining 117 underwent S-ICD implantation as in-patients. Notably, 112(91%) out of 123 planned-day patients and 12 in-patients (SD, total n=124) were successfully discharged on the same day. A substantial proportion (84%) of SD group had undergone the procedure for primary prevention. Patients with congenital heart disease were predominantly observed overnight. Defibrillation testing (DFT) is routine in our practice to ensure S-ICD integrity and was conducted in all S-ICD patients unless contraindicated. The success rate of DFT among attempted patients was high, standing at 72% and 78% in the SD and OD groups, respectively. The incidence of device-related complications was comparable between the two groups. The SD group displayed a slightly higher superficial infection rate but the incidence of inappropriate shocks was lower in the SD groups. Conclusion Based on our findings, same-day discharge following S-ICD implantation emerges as an appropriate practice. Our data strongly supports the assertion that same-day discharge in this context is safe and feasible, offering valuable insights into the optimal post-procedural management of S-ICD patients.Table 1ComplicationsTable 2Defibrillation Test

Preserving active lifestyle: subcutaneous defibrillators in young patients engaged in recreational sports. Insights from a multicenter study

Abstract Background Leading an active lifestyle and participating in recreational sports are crucial for overall well-being and cardiovascular health. Many young patients with implantable defibrillators engage in these activities, but the safety for subcutaneous defibrillator (S-ICD) recipients is unknown. Purpose Evaluate how lifestyle and recreational sports affect the risk of appropriate (AS) and inappropriate shocks (IAS) in S-ICD recipients. Methods We enrolled consecutive young S-ICD recipients (14-65 years) from 19 Italian centers and assessed their physical activity with the International Physical Activity Questionnaire (IPAQ). During follow-up, we analyzed the impact of lifestyle and recreational sports on AS and IAS. Results We enrolled 602 S-ICD recipients (77% males; age: 46±14 years). Common diagnoses included hypertrophic cardiomyopathy (24%), ischemic heart disease (20%), and idiopathic dilated CM (17%). IPAQ was administered 47 months (IQR: 26-68) post-SICD implantation. According to the IPAQ, patients were categorized as inactive subjects (IS; 27.9%), minimally active subjects (MAS; 43.7%), or highly active subjects (HAS; 28.4%). Patients with progressively higher activity levels had, in parallel, younger age (48±14 vs. 45±13 vs. 44±13 years; p=0.02) and higher ejection fraction (EF, %) (46±16 vs. 48±15 vs. 49±16; p=0.09). 163 patients (27.1%) regularly participated in recreational sports, with fitness/gym (25.2%), walking (20.9%), and cycling (14.1%) as the most common choices. As compared to patients not engaged in sports, recreational athletes were younger (43±13 vs 47±14 years; p&amp;lt;0.01) and had higher EF (52±14 vs 46±16; p&amp;lt;0.01). During follow-up (32 months; IQR 19-54), there were 77 discrete VT/VF episodes and 10 storms in 44 patients treated with AS. Also, there were 38 discrete IAS and 7 inappropriate shock storms in 39 patients. IS, MAS and HAS had similar rates of AS (9.5% vs 6.8% vs 5.8%, respectively; p=0.39) and IAS (4.8% vs 6.5% vs 8.2%, respectively; p=0.44). Kaplan-Meier curves showed similar cumulative rate of first AS (p= 0.12) or IAS (p= 0.74) for the 3 groups (Figures 1 and 2). Recreational athletes and non-athletes were propensity matched for age, sex, heart disease, EF, and primary/secondary prevention ICD implantation. Non-athletes and recreational athletes had similar risk of AS (HR: 1.78; 95% CI: 0.75-4.41; p=0.20) and IAS (HR: 1.20; 95% CI: 0.55-2.64; p=0.64). Out of 163 recreational athletes, 7 (4.3%) experienced 12 distinct AS, of which 3 (25%) occurred during sport activities. There were no arrhythmic storms while engaging in sports. Additionally, 15 patients (9.2%) had 17 episodes of IAS, with 3 (17.6%) occurring during sport practice. Conclusions In young S-ICD recipients, those leading more active lifestyle and commonly engaged in recreational sports were not exposed to a higher risk neither of appropriate, nor of inappropriate shocks. However, shocks related to sport practice were not uncommon.AS-free survival according to IPAQIAS-free survival according to IPAQ

The use of left bundle branch pacing as a bail-out in case of CRT pacing failure: a case series

Abstract Introduction LBBB pacing has emerged as a novel alternative to CS pacing for cardiac resynchronization therapy in patients with heart failure. Purpose We hereby present a series of four cases wherein the use of LBB pacing, although not initially planned as first choice, was able to overcome a variety of different limitations of traditional CRT pacing. Presentation Patient #1 was an 81-year old man with a history of ischemic HF and AF who was admitted with recurring episodes of sustained ventricular tachycardia (VT) below the detection zone of the CRT-D that had been implanted 11 years ago. Interrogation of the device revealed fracture in the RV lead, intact values of the RV defibrillation coil and inability to capture from an LV lead in an anterior vein. Following initial stabilization the patient underwent successful LBB lead implantation combined with a new RV pace-sense lead as backup due to acceptable but non-optimal LBB lead values attributed to ischemic septal scarring. We were able to retain the previous CRT-D device by relegating the LBB lead to the atrial port and with the use of DDDR programming with custom AV delay values in order to achieve LBB pacing with RV pacing as backup. Patient #2 was a 51-year old man with a history of ischemic HF and permanent AF with a previously implanted CRT-D who was also admitted due to episodes of VT. Device interrogation revealed high threshold of an LV lead located in an anterior vein. The patient underwent supplementary LBB lead implantation which was then connected to the atrial port of the pre-existing CRT-D device, providing primarily LBB pacing with RV pacing backup through the use of custom DDDR programming same as in the previous case. Patient #3 was a 71–year old man with newly-diagnosed ischemic cardiomyopathy and multiple episodes of hemodynamically unstable VT that persisted even after successful reperfusion, necessitating VT ablation. The patient had narrow QRS at baseline and was not eligible for CRT-D, however after medical therapy to suppress ventricular arrhythmias the patient seemed prone to developing LBBB-like QRS widening. The decision was made to proceed with standard ICD implantation and combine a standard defibrillation lead with an LBB lead through the use of a DF1 port, so as to be able to provide LBB pacing as needed in the future. Patient #4 was a 62-year old man with a history of hypertrophic cardiomyopathy and HF with extensive apical scar scheduled for CRT-D implantation. CS venography during implantation revealed a single lateral vein draining the apical LV, lead was implanted but with no capture. An LBB pacing lead was successfully implanted and used instead of the LV lead in the conventional CRT-D set up. Conclusion In this case series we demonstrate that LBB pacing is a viable option as a bail-out in various cases of CRT pacing failure, including both septal scar and hypertrophy, as well as different anatomical substrates and CRT status.LBB pacing characteristics summary

Feasibility of left bundle branch area defibrillator implantation using three-dimensional delivery systems and traditional high voltage leads

Abstract Background Left bundle branch area (LBBA) pacing is an innovative cardiac pacing technique that provides physiological stimulation, which is useful in patients affected by atrioventricular block (preventing pacing-induced cardiomyopathy), and could be an alternative strategy to traditional cardiac resynchronization therapy. Recently, Huybrechts el al. have reported a proof-of-concept study concerning left bundle branch area defibrillator (LBBAD) implantation, evaluating the feasibility of positioning a standard high-voltage (HV) lead by manually pre-shaped delivery systems to achieve LBBAD. No follow-up data were available because the leads were moved to standard positions after testing. Purpose This study aimed to assess the safety and feasibility of definitively implanting a traditional HV lead, using novel three-dimensional delivery systems, to stimulate the LBBA and the lead performance in 1-month follow-up. Methods This is a single-center, non-randomized, prospective study. The study population consisted of consecutive patients referred for an ICD implantation between September and October 2023. LBBAD was attempted by exploiting three-dimensional delivery systems to reach the target transseptal location. After positioning an active fixation HV lead in the LBBA, acute pacing measurements were collected. Defibrillation testing was performed using either patient-tailored (DeFT Response) or fixed-tilt waveform. Echocardiographic evaluation using speckle tracking was performed after implantation. A short-term follow-up was planned in order to verify the stability of electrical parameters in one month. Results LBBAD was performed in 9 consecutive patients (mean age 69±11 years, 56% male). The mean time to implant the HV lead was 20 minutes. The HV lead was successfully implanted in 100% of patients, reaching LBBA in 6 (67%) patients at the first attempt and in 3 (33%) at the second attempt. LBBA pacing exhibited a mean QRS duration and V6 R-wave peak time of 128±9 ms and 64±12 ms. Acute LBBA pacing threshold, R-wave amplitudes, and pacing/shock impedances were 0.88±0.22 V at 0.5 ms, 8.4±2.8 mV, and 637±210 Ω/ 75±20 Ω. The defibrillation test (78% patient-tailored and 22% fixed-tilt waveform) was successful in 6 (75%) of patients at the first shock (~22J) and in 2 (25%) at the second shock (~33J)(test aborted in 1 patient due to respiratory issues during sedation). The mean peak strain dispersion of 31.7ms confirmed global synchrony during pacing. The electrical measurements remained stable, and no lead-related complications were observed at 1-month follow-up. Conclusion We performed for the first time ever LBBAD definitive implantation. This study proves the feasibility and safety of using three-dimensional delivery tools for LBBAD procedures and shows optimal results at the implant for up to one month. Nevertheless, a larger and long-term evaluation is needed to evaluate the performance of LBBAD implants.

LINAC-Based STereotactic Arrhythmia Radioablation (STAR) for paroxysmal atrial fibrillation in elderly: a prospective phase II trial

Abstract Background and aims Stereotactic arrhythmia radioablation (STAR) is a novel therapeutic approach for cardiac arrhythmias. The aim of this trial is to investigate the feasibility of STAR for the treatment of paroxysmal atrial fibrillation (AF) in elderly patients. Method inclusion criteria were: age &amp;gt; 70 years, symptomatic AF, antiarrhythmic drugs failure or intolerance. All patients underwent to 4D cardiac Computed Tomography simulation. The clinical target volume was identified in the area around pulmonary veins (PV). STAR was performed with a total dose of 25 Gy (single fraction) delivered in 3 minutes. Results Twenty patients were enrolled and 18 underwent STAR. One patient withdrew informed consent before treatment and 1 patient was excluded due to unfavorable esophagus position. With a median follow-up (FU) of 16 months (range 12-23), no acute toxicity more than grade 3 was reported. Five patients had a grade 1 esophagitis 24 hours after STAR; eight patients had an asymptomatic grade 1 pericardial effusion, one patient had a torsade de pointes treated effectively by electrical cardioversion and subsequent cardiac ICD implantation. Most patients had a significant reduction in AF episodes. Five patients, due to arrhythmias recurrences after STAR, performed electrophysiological study documenting successful PV isolation. Finally, a significant improvement of quality of life was documented (48 ± 15 at enrollment vs 75 ± 15 at 12 months FU; p &amp;lt; 0.001). Conclusion The present phase II trial demonstrated the feasibility of STAR in paroxysmal AF elderly patients and its potential role in increasing the quality of life. Surely, more robust data are needed about safety and efficacy.

The effect of bachmann bundle pacing on diastolic function in patients with non-obstructive HCM

Abstract Background and Objective Patients with non-obstructive HCM (nHCM) have advanced diastolic dysfunction and atrial remodeling, leading to increased heart failure hospitalisations. The objective of this study was to evaluate the role of Bachmann bundle pacing (BBP) in diastolic filling compared to right atrial appendage pacing (RAAP). Methods Forty patients with symptomatic nHCM and normal LV function were prospectively enrolled from January 2021 to June 2023. Inclusion criteria included electrocardiographic evidence of inter-atrial delay, E/e’ &amp;gt; 15, and an indication for ICD implantation. BBP was attempted in twenty patients, others underwent RAAP. A Biotronik Selectra 3D 40-S sheath was used for BBP in patients in whom initial lead implantation was unsuccessful. BBP was defined based on P-wave morphology and fluoroscopic lead position. The RV lead was implanted in the RV apex in all patients and the AV delay was optimized based on diastolic filling period and E/e’. Devices were programmed in DDD mode. During follow up, diastolic function, functional capacity, atrial fibrillation, and heart failure hospitalisations were assessed in both groups. Results Among the forty patients (age 48.2+7.8 yrs, males 75%, ESC-SCD Risk 4.3+0.6%), the baseline P wave duration, E/A, E/e’ were 138.4+16.4 ms, 2.5+0.5, and 17.5+2.4, respectively. Six patients (15%) had a history of paroxysmal AF (3 each in BBP and RAAP groups). Of the 16 patients (80%) who underwent successful BBP, the Selectra 3D 40-S sheath was used in 8 patients (Figure 1, Panel A). During BBP, a bachmann bundle potential was recorded in 7 of 16 patients (43.8%) (Figure 1, Panel C). The pacing threshold (1.5+0.5@0.4ms vs. 0.9+0.3@0.4ms, p=0.026) was higher and the atrial sensing (1.8+0.4 vs. 3.3+0.6, p=0.002) was lower in the BBP group compared to the RAAP group at 4 weeks and 6 months of follow up. There was an acute rise in threshold (2.1@0.4 ms) in 1 BBP patient at 4 weeks of follow up. Patients in the BBP group had a reduction in P wave duration compared to the patients in the RAAP group (-22.5 + 5.4 vs. +5.6 + 3.2 ms, p&amp;lt;0.001). During follow up (11.4 + 3.4 months), there was a significant improvement in diastolic function (E/e’), functional capacity (NYHA Class) and reduction in NT-proBNP in the BBB group compared to the RAAP group (Figure 1). The percentage of atrial pacing was similar in both groups (BBP 73.2 + 7.8 vs. RAAP 78.5 + 9.1 %, p=0.219). The risk of atrial fibrillation/tachycardia (12.5% vs. 35.0%, p=0.022) and heart failure hospitalisations (6.3% vs. 20%, p=0.042) was lower in the BBP group compared with RAAP during follow up. Conclusions BBP is safe and effective in improving diastolic function, functional capacity and heart failure hospitalizations in patients with nHCM.BBP Pacing using Selectra 3D 40-S SheathChange in E/e', NYHA, and NT-pro BNP

Repolarization dynamics stability in Brugada type-1 pattern subjects with positive and negative genetics

Abstract Background Brugada type-1 pattern (Brgd1) risk stratification in asymptomatic subjects and its repolarization dynamics are complex. Purpose This study aims to analyze, from alternative standpoints, superficial 12-lead ECG V1 repolarization patterns (repol.). This method diverges from standard ECG pattern characterization. It rather exploits nonlinear dynamics and stability of ECG repol. to assess stability driving cardiac dynamics. This work consists in analyzing 2 subjects with Brgd1: Subject1 with negative genetics and negative EP study. Subect2 with positive genetics. Target To deepen knowledge/insight and applications of control-and-stability-theory applied to 12-lead ECG, aiming to eventually diminish the number of invasive EP studies. Methods A stability control closed loop system has been designed to model electrophysiology dynamics of cardiac conduction: ECG segments being the input-output of the system. (Figure). A sequence of V1 repol. have been scanned, digitized, and quantitatively processed yielding stability parameters (poles in S-plane). Scanning and signal processing performed by Matlab R_2023b. Results Figures. Conclusions Based on our data, 12-lead-ECG repol. seem to be associated with increasing stability in Subject1, exhibiting negative genetics. On the other hand, less stability seems to be associated with Subject2, reporting positive genetic tests. In conclusion, furthering control-and-stability-theory applied to 12-lead ECGs aims to deeper comprehension of physiological and pathological substrates of malignant arrhythmias, and to focus on noninvasive risk stratification strategies for ICD implantation indication in BrS. Further development of this technique will be largely facilitated by the implementation of AI methodologies in the near future.

Impact of phase-correction of late-gadolinium enhancement images on quantification of scar metrics and in-silico VT-modelling in patients with an ischemic cardiomyopathy

Abstract Background Late gadolinium enhancement (LGE) is used to perform tissue characterization and has become the cornerstone to guide treatment of ventricular tachyarrhythmia (VT). Traditionally, LGE acquisition is reconstructed in two distinct forms: non-phase corrected magnitude (MIR) and phase-corrected inversion recovery (PSIR) images. However, the influence of MIR vs. PSIR on the quantification of scar metrics and the repercussion on estimating myocardial arrhythmogenicity have not been comprehensively explored. Aim This study investigated the influence of PSIR and MIR LGE on the quantification of scar metrics in a randomly selected cohort of patients with ischemic cardiomyopathy who had undergone imaging prior to ICD implantation and had received device therapy during follow-up. In addition, this study assessed how these image variations affect functional estimation of arrhythmogenicity using computational modelling. Methods ADAS 3D LV was used to generate scar maps from 2D PSIR and MIR LGE images in 10 patients. The extent of variation in scar-characteristics was evaluated by quantifying the borderzone (BZ), scar core, and conduction corridors. Electrical simulations were performed on the patient-specific anatomical models using the Virtual Induction and Treatment of Arrhythmias (VITA) framework. VITA was used to assess the electrical vulnerability of potential reentrant channels and provided the number of inducible VTs and their corresponding round-trip-time (RTT), an equivalent of VT cycle-length. Results Scar quantification using PSIR LGE resulted in a significantly larger BZ (22.1±23.7g vs. 6.2±2.7g, p &amp;lt;.001) and scar core (43.5±21.5g vs. 10.5±4g, p =.047). Furthermore, both the absolute number (6.8±4 vs. 3.4±1.5, p = .031) and weight (13±13.1g vs. 1.4±0.8g, p =.018) of conduction corridors were also higher using PSIR. VTs were inducible in 8 PSIR-models and 7 MIR-models. Despite large differences in scar characteristics, VITA metrics were not significantly different between PSIR and MIR derived models. Although, the absolute number of inducible VTs were larger for PSIR (6.2±5.4 vs. 3.4±3.1), non-parametric testing using Wilcoxon signed-rank test did not demonstrate a significant difference (Z = -1.334, p =.139). A comparable, non-significant difference was observed for mean- (117±78 vs. 79±60, p =.257) and max-RTT (181±141 vs. 120±103, p =.294) between PSIR and MIR derived models. Conclusion PSIR resulted in significantly larger BZ, scar core area, and conduction corridors. While the absolute, VITA-derived estimation of myocardial arrhythmogenicity, including inducible VTs and RTT, were higher in the PSIR-based quantification, these differences did not reach statistical significance. These results highlight important differences between two clinically applied image reconstruction techniques for the assessment of arrhythmogenic substrate, emphasizing the need for additional investigation and refinement of scar quantification techniques.

Association between Preeclampsia and Long-term Risk of Arrhythmias.

Preeclampsia (PE), a pregnancy-induced hypertensive disorder, affects 4-5% of pregnancies worldwide. It is well known that hypertension is associated with an increased risk of arrhythmias; however, data on the association between PE and arrhythmias are sparse. In this observational cohort study, we identified all primiparous women who gave birth in Denmark (1997-2016) using Danish nationwide registries. The women were stratified on whether they developed PE during primiparous pregnancy, and followed from primiparous pregnancy to incident arrhythmia, emigration, death, or end of study (December 31, 2018). A total of 523,271 primiparous women with a median age of 28 years were included and 23,367 (4.5%) were diagnosed with PE. During a median follow-up of 10.1 years, women with vs without PE were associated with a higher incidence of arrhythmias (1.42% vs 1.02%): 1) Composite of cardiac arrest, ventricular tachycardia/fibrillation, or ICD implantation (adjusted HR 1.60 [95% CI 1.14-2.24]), 2) Composite of advanced 2nd degree or 3rd degree atrioventricular block, sinoatrial dysfunction, or pacemaker implantation (adjusted HR 1.48 [95% CI 0.97-2.23]), 3) Composite of supraventricular tachyarrhythmias or extra systoles (adjusted HR 1.34 [95% CI 1.19-1.51]), 4) Composite of all the above-mentioned arrhythmias (adjusted HR 1.37 [95% CI 1.23-1.54]). Preeclamptic women were associated with a significantly and at hitherto unknown long-term increased rate of arrhythmias. This finding suggests that women with PE may benefit from cardiovascular risk assessment, screening, and preventive education.

FEAR OF SUDDEN DEATH ‘INTERRUPTED‘ BY WEARABLE DEFIBRILLATOR: CASE REPORT

Abstract A male patient (pt) 49y,grade II familiarity for sudden cardiac death (SCD).He arrived in the emergency department for worsening dyspnea and he underwent ECG:sinus rhythm and left bundle branch block(QRS duration 170 msec);color Doppler echocardiogram (CDE)showing:Dilated left ventricle, severely and globally hypocontractile(EF30%).Negative cardiac enzymes on laboratory tests.The coronary arteries were normal at angiographic control.The pt did not undergo to cardiac MRI because of claustrophobia.Blood samples were sent for genetic screening for cardiomyopathy.The pt started drug therapy following ESC guidelines.He was transferred to cardiopulmonary rehabilitation department.At the end of the 2 weeks of the rehabilitation cycle, left ventricular systolic dysfunction persisted.The pt was discharged with a wearable defibrillator (WCD) to continue therapy optimization following ESC heart failure guidelines.At the end of 3 months,the pt underwent an echocardiographic recheck which confirmed dilated,severely,and globally hypocontractile left ventricle(EF35%).ICD implantation was indicated, but the pt refused it.Therefore,was prescribed the continuation of SCD protection by WCD.The pt underwent monthly followups,for the next 6 months,reporting no improvement in left ventricular contractile capacity measured by CDE and continuing to refuse biventricular ICD implantation.We noted a correct and consistent wearing of the WCD.After 177 days of wearing,the pt had an episode of loss of consciousness and WCD shock.A remote device check documented ventricular fibrillation at 200 bpm,which was correctly recognized and discontinued.The pt accepted biventricular ICD implantation.At follow–up at 1 month CDE documented improvement in left ventricular contractile capacity(EF 40%),and no arrhythmic events in the absence of symptoms.WCDs have been used extensively in Italy since 2015.This technology provides temporary protection from SCD for pts with an evolving risk profile who are not yet eligible for an ICD.WCD is an effective therapy for the treatment of SCD with a very low complication rate and high pt compliance over time.Our case demonstrates how WCD enabled optimal titration of drug therapy following guidelines and prevented sudden death in young high–risk pts.In addition, our case shows that reduced compliance for definitive ICD implantation due to non–acceptance of the disease,fear of surgery,or subsequent lifestyle changes are not barriers to saving patients from SCD.

AN UNUSUAL LEFT VENTRICULAR APICAL MASS COMPLICATING ACUTE MYOCARDIAL INFARCTION

Abstract An 34–year–old man presented to the emergency department of our hospital with palpitations and presyncope. He was a smoker but had no others known cardiovascular risk factors. At admission, his electrocardiogram (ECG) showed sustained monomorphic ventricular tachycardia (VT) at a rate of 187 beats per minute. The VT was successfully treated with synchronized direct current cardioversion. The ECG in sinus rhythm showed Qs from V1 to V6 with ventricular repolarization anomalies in the same site suspicious for previous anterior necrosis. A transthoracic echocardiogram revealed akinetic apex, akinesia of middle segments of the interventricular septum, anterior and lateral walls, Left Ventricular (LV) ejection fraction of 30% and a large apical mass suspicious for LV thrombus. The patient was admitted to the coronary care unit and taken to the Cath lab that showed total left anterior descending mid–segment occlusion. Due to the chronicity of the condition, the patient was recommended to optimal medical therapy. Suspecting LV thrombus, the patient began treatment with unfractionated heparin i.v. and subsequently imbricate therapy with enoxaparin s.c. and warfarin. Additionally, the patient underwent subcutaneous implantable cardioverter defibrillator (S–ICD) implantation for secondary prevention of sudden cardiac death. At echocardiographic follow–up one week after discharge, the apical mass remained unchanged despite warfarin therapy with INR at target. For this reason, the patient was recommended to perform a Cardiovascular magnetic resonance (CMR). Three months after S–ICD implantation, a CMR was performed which showed transmural areas of late gadolinium enhancement involving all apical segments and middle segments of the interventricular septum which allowed the diagnosis of a large intramyocardial dissecting hematoma (IDH) of left ventricle. IDH is a rare complication of ST–elevation myocardial infarction (STEMI), it is an unusual form of subacute cardiac rupture and could be fatal. It usually consists of a cavity or channels within the myocardium. Its prognosis varies according to its location, but generally apical IDH have more favorable outcome with a higher likelihood of spontaneous retraction. We report this case because the IDH is a diagnostic challenge and it represents an extremely rare and poorly described event in the literature.

THE CONUNDRUM OF DRUG INTERACTIONS AND HOLTER MONITORING: LAMIN GENE MUTATION DISCOVERED BY A TORSADE DE POINTES EPISODE FOLLOWED BY OUT–OF–THE–HOSPITAL RESUSCITATION

Abstract The prolongation of the QTc interval on the electrocardiogram is known to be associated with an increased risk of developing life–threatening ventricular arrhythmias such as torsades de pointes (TdP). QTc values exceeding 500 ms can double or even triple the risk of TdP. Many drugs, including amiodarone and some SSRI antidepressants like paroxetine, can prolong the QTc interval. A 57–year–old patient experienced cardiac arrest during an overnight Holter recording prescribed to exclude brady–tachy syndrome in the presence of persistent atrial fibrillation. ECG ambulatory monitoring revealed significant bradycardia with the onset of idioventricular rhythm, followed by TdP triggered by premature ventricular contractions, subsequently degenerating into ventricular fibrillation. The patient was resuscitated by family members and later by emergency medical personnel using 3 DC shocks, leading to the restoration of spontaneous circulation. The patient was transferred to the cardiology intensive care unit where a coronary angiography showed normal results. Blood tests indicated low potassium levels (3.3 mEq/L), with a moderately reduced left ventricular ejection fraction at 45%. The patient was discharged after ICD implantation and during the diagnostic follow–up the genetic testings for long QT syndrome were negative, but showed a mutation of the LMNA lamin A/C gene. During the two months previous to hospital admission, the patient had complained of fatigue in the presence of atrial fibrillation with a low ventricular response. Nonetheless, she had been prescribed oral amiodarone to optimize the chances of successful electrical cardioversion, in combination with paroxetine that the patient was already taking at home. The combination of these two drugs and the patient‘s idiopathic bradycardia contributed to a marked prolongation of the QT interval, leading to TdP degenerated into ventricular fibrillation. This case, notable for the prolonged recording of ventricular fibrillation and subsequent resuscitation chest compressions during a Holter monitoring, suggests caution in the use of antiarrhythmic drugs unless strongly indicated in the presence of potentially ominous drug interactions. It is encouraging to note how the widespread adoption of cardiopulmonary resuscitation culture has enabled individuals who might not have otherwise received medical attention to be effectively resuscitated.