Nonsustained Ventricular Tachycardia Research Articles

Cardiac magnetic resonance for ventricular arrhythmias: a systematic review and meta-analysis

BackgroundCardiac magnetic resonance (CMR) allows comprehensive myocardial tissue characterisation, revealing areas of myocardial inflammation or fibrosis that may predispose to ventricular arrhythmias (VAs). With this study, we aimed to estimate...

Excess of high-caffeinated energy drinks causing ventricular arrhythmias

ABSTRACT A young male patient had palpitations after consumption of few high caffeinated energy drinks which he took after his office hours to relieve fatigue. He immediately seeked medical help. Electrocardiogram showed multiple runs of non-sustained ventricular tachycardia and ventricular bigeminy and trigeminy. Echocardiography was normal. The patient was admitted to intensive care unit and treated with anti-arrhythmic drugs to which the arrhythmias responded and subsided. Cardiac magnetic resonance imaging of heart did not reveal any structural heart abnormality and treadmill stress test was negative ruling out significant coronary artery disease. High caffeinated energy drinks can produce serious ventricular arrhythmias if taken beyond safe doses. These ventricular arrhythmias are known to be causative factor for sudden cardiac arrest and therefore a caution & regulation is needed in widespread unrestricted used of these drinks.

A novel tool for arrhythmic risk stratification in desmoplakin gene variant carriers.

Pathogenic desmoplakin (DSP) gene variants are associated with the development of a distinct form of arrhythmogenic cardiomyopathy known as DSP cardiomyopathy. Patients harbouring these variants are at high risk for sustained ventricular arrhythmia (VA), but existing tools for individualized arrhythmic risk assessment have proven unreliable in this population. Patients from the multi-national DSP-ERADOS (Desmoplakin SPecific Effort for a RAre Disease Outcome Study) Network patient registry who had pathogenic or likely pathogenic DSP variants and no sustained VA prior to enrolment were followed longitudinally for the development of first sustained VA event. Clinically guided, step-wise Cox regression analysis was used to develop a novel clinical tool predicting the development of incident VA. Model performance was assessed by c-statistic in both the model development cohort (n = 385) and in an external validation cohort (n = 86). In total, 471 DSP patients [mean age 37.8 years, 65.6% women, 38.6% probands, 26% with left ventricular ejection fraction (LVEF) < 50%] were followed for a median of 4.0 (interquartile range: 1.6-7.3) years; 71 experienced first sustained VA events {2.6% [95% confidence interval (CI): 2.0, 3.5] events/year}. Within the development cohort, five readily available clinical parameters were identified as independent predictors of VA and included in a novel DSP risk score: female sex [hazard ratio (HR) 1.9 (95% CI: 1.1-3.4)], history of non-sustained ventricular tachycardia [HR 1.7 (95% CI: 1.1-2.8)], natural logarithm of 24-h premature ventricular contraction burden [HR 1.3 (95% CI: 1.1-1.4)], LVEF < 50% [HR 1.5 (95% CI: .95-2.5)], and presence of moderate to severe right ventricular systolic dysfunction [HR 6.0 (95% CI: 2.9-12.5)]. The model demonstrated good risk discrimination within both the development [c-statistic .782 (95% CI: .77-.80)] and external validation [c-statistic .791 (95% CI: .75-.83)] cohorts. The negative predictive value for DSP patients in the external validation cohort deemed to be at low risk for VA (<5% at 5 years; n = 26) was 100%. The DSP risk score is a novel model that leverages readily available clinical parameters to provide individualized VA risk assessment for DSP patients. This tool may help guide decision-making for primary prevention implantable cardioverter-defibrillator placement in this high-risk population and supports a gene-first risk stratification approach.

Oral amiodarone and propranolol in maintenance therapy of postimplantation tachycardia: An observational study.

Left ventricular assist devices (LVADs) are widely used as end-stage therapy in patients with advanced heart failure, whereas implantation increases the risks of development of sustained ventricular tachycardia at the later postimplantation stage. Therefore, this study aimed to evaluate the clinical efficacy of orally administered amiodarone and propranolol in 3 patients with ventricular tachycardia (VT) after LVAD implantation who were resistant to initial anti-antiarrhythmic drugs. This retrospective cohort study consisted of the initial evaluation of the clinical data of 14 adult patients who underwent implantation of LVAD between January 2019 and March 2021. A total of 3 patients with resistant VT were finally included. In all cases, the patients were initially administered amiodarone in the different doses intravenously to stabilize the critical condition, whereas its oral form along with that of propranolol was used as maintenance therapy in the first 2 cases. In the third case, amiodarone was withdrawn because of the risk of development of hyperthyroidism, while oral propranolol was used in the treatment. The assessment in the 16-month follow-up period after discharge did not show presence of non-sustained and sustained VT in all 3 cases. In the ventricular arrhythmia-free group, the total mortality rate within the follow-up period was 11.1 ± 7.78 months in the 3 patients. We suggest that maintenance oral therapy of propranolol and amiodarone can significantly decrease the risks of complications in patients with VT after implantation of ventricular assist device in the long term.

Design of a Low-area Hardware Architecture to Predict Early Signs of Sudden Cardiac Arrests

Sudden cardiac arrest (SCA) results in an unexpected and untimely death within minutes, and its early prediction can alert cardiac patients to a timely medical diagnosis. To detect early symptoms of an SCA, the detection and classification of ventricular tachycardias (VT) are of utmost importance. In this work, a low-area yet highly accurate hardware architecture for VT classification is proposed based on the detection of premature ventricular contraction (PVC) beats. After pre-processing of the ECG signals using a wavelet-based pre-processing unit, a characteristics-matching algorithm is used to detect the PVC beats, and a low-complexity adaptive decision-based logic classifier is used to classify them into four types of VTs, namely monomorphic, polymorphic, non-sustained VT (NSVT), and sustained VT (SVT). FPGA verification of the hardware architecture for the VT classifier using the Nexys 4 DDR Artix-7 board utilizes 10.4% of the total available resources and displays the type of VT and the number of PVCs detected to help in determining the severity of SCA and the need for medical attention. The ASIC implementation of the proposed PVC-based VT classification using the SCL 180 nm CMOS technology results in an area overhead of 0.02 mm2 and a power consumption of 3.47 μW for a high accuracy rate of 98.2%. When compared to the existing CA detection systems for wearable devices, the proposed one consumes the least area while achieving high detection rates.

Ventricular arrhythmia events in patients with implantable cardioverter-defibrillator before and after the treatment with sodium-glucose co-transporter 2 inhibitors

Abstract Background The role of sodium-glucose co-transporter 2 inhibitors (SGLT2i) in the treatment of chronic heart failure is expanding. However, the timing of implantable cardioverter-defibrillator (ICD) implantation for primary prevention in relation to the use of SGLT2i remains unclear. A small case series has described appropriate shocks from ICD in two patients following the initiation of SGLT2i, but a comprehensive analysis is lacking in the literature. Methods This study aimed to investigate the rate of ventricular arrhythmic burden and appropriate anti-tachycardia therapy from ICD before and after the initiation of SGLT2i therapy. We conducted a retrospective single-center analysis, comparing ventricular events from home monitoring reports three months before and three months after SGLT2i therapy initiation. Results Seventeen patients were enrolled in the study. At baseline, clinical characteristics were as follows: 13 (76%) were male, 9 (53%) had ischemic, 2 (12%) had valvular, and 6 (35%) had idiopathic cardiomyopathy. The mean end-diastolic volume (EDV) was 203 ± 90 ml, and the mean left ventricular ejection fraction was 0.36 ± 0.09. All patients were treated with beta-blockers, 14 (82%) with sacubitril-valsartan, 13 (76%) with aldosterone antagonists, 16 (94%) with furosemide, and 5 (29%) with amiodarone. SGLT2i started with dapagliflozin for 13 patients (76%), empagliflozin for 3 patients (18%), and canagliflozin for 1 patient (6%). Ten patients (59%) had single-chamber or dual-chamber ICDs, and 7 had implantable cardiac resynchronization therapy (CRT) defibrillators. In the three months before SGLT2i treatment, 4/17 patients had non-sustained ventricular tachycardia (NSVT), compared to 8/17 (23% vs. 47%, p-value 0.23) patients with NSVT after treatment. Seven patients (41%) experienced an increase in the rate of NSVT events, with one patient having 28 NSVT events after treatment versus none before treatment. No patients had anti-tachycardia therapy in the three months before treatment, while in the three months after SGLT2i treatment, 1 patient had ventricular tachycardia treated with anti-tachycardia pacing (110 days after the beginning of the treatment), and 2 patients had ventricular tachycardia treated with appropriate shocks (2 and 25 days after the initiation of SGLT2i treatment). Conclusion This small retrospective analysis revealed an increase in ventricular arrhythmic events in the three months following the initiation of SGLT2i. These findings highlight the need for a more extensive analysis to establish a stronger statistical correlation.

Catheter ablation of papillary muscle arrhythmias: procedural characteristics and long term outcome

Abstract Background Ventricular arrhythmias (VA) originating from the papillary muscles can occur both in patients with and without structural heart disease. Although catheter ablation is the treatment of choice, ablation success remains challenging and long-term outcomes for this origin of VA are still unsatisfactory. Methods and Results All patients undergoing catheter ablation for premature ventricular contractions or ventricular tachycardia between june 2009 and november 2022 were analyzed. 66 patients (26 female (39%), mean age 60±15 years) undergoing catheter ablation of VA originating from the papillary muscle were identified. 21/66 (32%) patients had a reduced or mildly reduced left ventricular ejection fraction at time of initial presentation. While mitral valve regurgitation was present in 32/66 (48%) patients, mitral valve prolapse was observed in only 2/66 (3%) patients. 6/66 (9%) patients presented with non-sustained ventricular tachycardia (VT) and 1/66 (2%) patient presented with sustainend VT prior to catheter ablation. 61/66 (92%) patients underwent ablation of PVCs of the left ventricular papillary muscles (22/66 (33%) patients anterolateral; 39 (59%) patients posteromedial). 5/66 patients underwent ablation of premature ventricular complex (PVC) originating from the papillary muscles of the right ventricle. In 13/66 (19.7%) patients only a retrograde approach was used, in 26/66 (39.5%) patients a retrograde and an additional transeptal approach and in only 10/66 (15.2%) patients solely a transeptal approach. Mean PVC QRS duration was 152.5 ± 3.5 msec. Ablation was acutely successful in 44/66 (67%) patients. Mean procedure time was 145.8 ± 63.7 minutes and mean number of radiofrequency applications was 21.3 ± 16.7 (25 to 55 Watts, 37764.2 ± 27824.1 Joules). Overall, procedural complications occurred in 4/66 (6%) patients Follow up data were obtained from Holter ECGs, review of medical records, patient consultation, or via structured follow-up within the prospective TRUST registry. All information was combined to assess recurrence of PVC/VT. Recurrence of VA originating from the papillary muscles occurred in 11/66 (17%) patients. 9/66 patients (14%) underwent re-ablation due to recurrence of VA originating from the papillary muscles after previous ablation procedures. Conclusion Catheter ablation of papillary muscle arrhythmias is associated with a single procedural success rate of 67% with a procedural complication rate of 6%. 14% of patients underwent re-ablation due to recurrence of papillary muscle arrhythmias.

Long-term prognostic role of pre-ICD implantation magnetic resonance: a longitudinal cohort study

Abstract Background While it's has already been demonstrated that cardiovascular mortality increases in patients with reduced ejection fraction (EF), there is no evidence that this parameter identifies with high sensitivity those who will experience sudden cardiac death (SCD). Cardiac magnetic resonance (CMR), through myocardial scar characterization, could enhance risk stratification for arrhythmic events in such patients. Purpose The study's objective was to identify factors, independent of EF, capable of stratifying arrhythmic risk in a population of patients undergoing implantable cardioverter-defibrillator (ICD) placement. Methods This is 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 (non-sustained ventricular tachycardia, sustained ventricular tachycardia, ventricular fibrillation) were recorded during routine device controls and remote monitoring. To define the prognostic value of various factors was performed an univariate Kaplan-Meier analysis in relation to the composite primary endpoint, consisting of ventricular arrhythmias [VA] and all-cause mortality. Results Among 700 patients (82% males, mean age 69 ± 13 years) who underwent ICD implantation (46% single-chamber, 15% dual-chamber, 36% cardiac resynchronization therapy, 3% subcutaneous ICD) pre-implantation CMR was available in 354 of the total, with 69% of them implanted for primary prevention and 52% with non-ischemic cardiomyopathy. Late gadolinium enhancement (LGE) was present in 67% of them; and 30% of these patients had it in fewer than 5 segments. At the end of the mean 8-year follow-up, 30.6% of patients died. Patients with LGE showed increased all-cause mortality and incidence of VA compared to those without LGE (HR=2.17 [1.78-2.60]; p&amp;lt;0.05); this data was mainly driven by the difference in mortality, as the incidence of VA alone did not exhibit significant variation between the two groups (HR=0.7 [0.65-1.02]; p=0.23). In patients with fewer than 5 cardiac segments involved by LGE, the risk of all-cause death and significant VA was higher than in those with more than 5 segments involved (HR=2.46 [2.09-9.07]; p&amp;lt;0.05). Conclusions The presence of LGE emerged as a significant prognostic factor for both arrhythmic events and overall mortality. This suggests the possibility that assessing myocardial fibrosis serves as a comprehensive predictor of the patient's future clinical outcome, extending beyond merely predicting arrhythmic events. Notably, the relevance of LGE is heightened when observed in fewer than 5 segments, indicating a focal substrate, making it a crucial prognostic factor for anticipating arrhythmic events. In patients with reduced EF, pre-implantation CMR proves valuable in effectively stratifying arrhythmic risk and all-cause mortality.

Genetic characterization of drug-induced long QT syndrome in a large prospective cohort

Abstract Introduction Drug-induced long QT syndrome (DI-LQTS) is a clinical entity with a poorly defined etiopathogenesis. Purpose The objective of the study was to determine the genetic basis of a prospective cohort of patients with DI-LQTS in the setting of a tertiary hospital center. Methods Prospective observational study with consecutive inclusion of patients with the diagnosis of DI-LQTS according to standard criteria, in a tertiary hospital, between 2018 and 2022. A genetic study was performed through massive DNA sequencing to identify variants in known genes associated with cardiopathy, arrhythmogenic and cardiomyopathy. Results 86 patients (age 65±15 years, 59% men) were included. The mean corrected QT interval (QTc) of the entire cohort was 543±56 ms. The drugs associated with QTc interval prolongation were: psychotropics 51%, antiarrhythmics 38%, anesthetics 30%, antibiotics 16%, antineoplastics 5%, others 4%. Twenty-one patients (24%) presented with ventricular arrhythmias at the time of drug-induced QTc prolongation: 10 (12%) ventricular fibrillation, 7 (8%) sustained ventricular tachycardia, 3 (3%) non-sustained ventricular tachycardia, 1 (1%) frequent ventricular premature beats. Genetic information was obtained in 83 (97%) patients. 17 pathogenic mutations associated with heart disease were identified in 15 (18%) patients: 4 (5%) patients with 5 mutations in ion channel genes (KCNE1, KCNE1B, KCNH2, RYR1, RYR2), and 12 (14%) patients with 12 mutations in genes associated with cardiomyopathy (NF1, PKD2, ABCC6, TTN, FHOD3, MYO6, COL11A1, CCDC40, CRELD1, COL4A1). Two patients had 2 pathogenic mutations each, one of them with both mutations associated with channelopathy, and another with a mutation associated with channelopathy and a second mutation related to cardiomyopathy. Only 1 patient carrying a pathogenic mutation related to cardiomyopathy had a clear phenotype, while in 3 carrier patients there was a history of transient systolic dysfunction, 2 due to tachycardiocardiopathy and 1 due to peripartum cardiomyopathy. The identification of a pathogenic mutation was not related to significant differences in QTc interval prolongation (544±63 vs 542±55 ms) or risk of ventricular arrhythmias (26% vs 24%). Conclusions The genetic basis of drug-induced long QT syndrome is essentially different from that of the congenital form of the disease. The identification of pathogenic mutations in genes associated with cardiomyopathy is relatively frequent, while those associated with ion channel genes are uncommon.

Arrhythmic mitral valve prolapse with versus without prior mitral valve repair: clinical profiles, electrophysiological substrates, and long-term clinical outcomes

Abstract Background Arrhythmic mitral valve prolapse (AMVP) is characterized by an arrhythmogenic left ventricular substrate, with high prevalence of myocardial scar. Whether patients with prior mitral valve repair for mitral valve prolapse (MVP) and new-onset complex ventricular arrhythmias (VAs) after cardiac surgery have different electroanatomical substrate and arrhythmic outcomes compared with AMVP patients without prior mitral valve surgery is currently unknown. Purpose We sought to compare the electroanatomical substrate and long-term clinical outcomes of patients with new-onset complex VAs after mitral valve surgery to AMVP patients without prior surgery. Methods We conducted a multicenter, prospective, observational study, enrolling MVP patients with prior mitral valve repair and new-onset complex VAs (&amp;gt;1000 premature ventricular contractions [PVCs]/day, nonsustained ventricular tachycardia [NSVT], and sustained VT) after cardiac surgery (group A,n=9), and patients with MVP, complex VAs and no prior surgery (group B,n=20). Each patient underwent a comprehensive diagnostic workup, including left ventricular electroanatomical mapping. Clinical-imaging data, as well as the location and segmental extension of both low-voltage areas and late potentials were assessed and compared between the two groups. The primary outcome was the occurrence of sustained VT or ventricular fibrillation(VF) during follow-up. Results In group A, complex VAs were first diagnosed after a median of 30(8-56) months following mitral valve repair. The characteristics of patients from the two study groups are presented in the Table. Patients from group A were older, sustained VT was nonsignificantly more common at baseline, the PVC count nonsignificantly higher, and LVEF nonsignificantly lower. Mitral annular disjunction was never observed in group A, while it was found in 7 patients from group B (p=0.066). At LV electroanatomical voltage mapping, bipolar and unipolar low-voltage areas (LVAs) were equally common in the two groups overall, and typically involved basal perimitral regions. However, patients from group B had concomitant bipolar and unipolar LVAs 50% of times, with larger unipolar LVAs, while patients from group A mostly showed isolated bipolar LVAs. Over a median follow-up of 15 (12-41) months, patients from group A (n=3, 33%) had slightly higher incidence of sustained VT or VF (HR: 1.91; 95% CI, 1.06-42.65; log-rank p=0.02, Figure) than patients from group B (n=2, 10%). Conclusion Compared to patients with AMVP and no prior cardiac surgery, patients with new-onset complex VAs after mitral valve repair for MVP have a slightly different clinical profile and electroanatomical substrate, characterized by predominant bipolar LVAs in the perimitral region. The long-term risk of major ventricular arrhythmias appears slightly higher in MVP patients with prior mitral valve surgery, mandating at least an equally careful risk assessment in both groups.

Premature ventricular contractions increase with heart rate in patients with mitral valve prolapse

Abstract Background A subset of patients with mitral valve prolapse (MVP) are at risk of life-threatening ventricular arrhythmias (VAs), and a high burden of premature ventricular contractions (PVCs) is associated with increased mortality in patients with MVP. Previous studies indicate that PVC burden could either increase with increasing heart rate (HR), decrease with increasing HR, or with no relationship to HR. The association between PVC burden and HR in MVP is not known, nor if there is an association with VAs. Purpose We aimed to explore the relationship between PVC burden and HR in patients with MVP. Furthermore, we aimed to explore whether the different PVC profiles were associated with severe VA. Methods In this cross-sectional ambispective outcome study, we included patients with MVP and available Holter monitorings with &amp;gt;100 PVCs per 24-hours seen at our tertiary centre. The Holter monitoring with the highest PVC burden was used in case of multiple recordings. We investigated the relationship between hourly PVC burden and hourly mean HR by univariable mixed linear regression. We defined PVC profiles as (1) fast-HR-dependent-PVC (F-HR-PVC) when there was a significant positive correlation, (2) slow-HR-dependent-PVC (S-HR-PVC) when there was a significant negative correlation, and (3) independent-HR-PVC (I-HR-PVC) when no correlation between PVC and HR was found. The significance was set to 0.05. Severe VA was defined as sustained ventricular tachycardia, non-sustained ventricular tachycardia with haemodynamic instability, ventricular fibrillation, aborted cardiac arrest, or appropriate shock by a primary preventive implantable cardioverterefibrillator. Severe VA was recorded from retrospective medical history, prospective ICD interrogation or monitoring with implantable loop recorder. Results We included 75 patients with &amp;gt;100 PVCs at Holter monitoring (median age 48 years [IQR 35-58], 58% female). The median PVC burden was 1.9% per 24-hours (IQR 0.4-7.2). We found F-HR-PVC in 49 patients (65%), S-HR-PVC in 1 (1%), and I-HR-PVC in 25 (33%). Twelve (16%) patients had severe VA and these had higher PVC burden compared to those without severe VA (7.3% per 24-hours [IQR 4.2-10.4] vs 1.1% per 24-hours [IQR 0.3-5.3], p=0.004). The median PVC burden was 1.5% (IQR 0.3-8.0) for F-HR-PVC, 5.7% for S-HR-PVC and 1.5% (IQR 0.3-8.0) for I-HR-PVC. We found no association between different PVC profiles and the presence of severe VA (F-HR-PVC 65% vs 67%, S-HR-PVC 2% vs 0%, I-HR-PVC 33% vs 33%, p&amp;gt;0.05 for all groups). Conclusion Fast-HR-dependent-PVC was most common in MVP patients, and slow-HR-dependent-PVC were rare. A higher PVC burden was associated with severe VA. However, different PVC profiles did not infer higher risk of severe VA in our study. Further studies are needed to explore whether distinct PVC profiles can predict severe VA in larger patient populations.

High incidence of inappropriate alarms due to artifact sensing and misclassification of episodes in patients with wearable cardioverter-defibrillators

Abstract Background The wearable cardioverter-defibrillator (WCD) has become a useful tool used for temporary protection from sudden cardiac death. However, since the WCD uses surface electrodes to detect arrhythmias, it is prone to inappropriate detection. Although shock conversion rates for the WCD are high for detected events, its efficacy in clinical practice tends to be degraded by patient noncompliance. Reasons include wear discomfort and frequent false alarms, that may interrupt sleep and generate anxiety. Data on the incidence of false alarms emitted by the WCD and their predictors are rare. Purpose The aim of our study was to assess both artifact and misclassification burden and wear compliance in patients with a WCD. Methods and Results We conducted a single-centre retrospective observational study analyzing patients with a WCD prescribed at our institution. In total, in 134 patients (mean age 51.7 ± 13.8 ys, 79.1% male) provided with a WCD, arrhythmia recordings were analyzed and categorized as either non-sustained ventricular tachycardia, sustained ventricular tachycardia / fibrillation, and artifact sensing or misclassified episodes. Indication for WCD prescription was both primary and secondary prophylactic. All patients received optimal medical therapy. Baseline evaluation in all patients included transthoracic echocardiography, 12-lead electrocardiogram, and baseline laboratory values. A total of 3019 false WCD alarms were documented in 134 patients (average number of false alarms 22.5 ± 130.4 episodes per patient) over a mean WCD wearing time of 71.5 ± 70.9 days (daily wearing time 20.2 ± 5.9 hs). In total, in 78 patients (58.2%), either artifact sensing (41.8%), misclassified episodes (3.7%) or both (9.7%) occurred. Misclassified episodes included sinus tachycardias, atrial flutter, atrial fibrillation, ventricular extrasystoles, and intermittent bundle branch block. At multivariate analysis, WCD wearing time (HR 1.02; 95% CI 1.01-1.02; P &amp;lt; 0.001) and loop diuretics (HR 0.16; 95% CI 0.06-0.44; P &amp;lt; 0.001) were identified as independent predictors of artifact episode occurrence. In terms of the frequency of artifact episodes, loop diuretics (HR -0.11; 95% CI interval -0.21-0.0001; P = 0.049), angiotensin receptor-neprilysin inhibitors (ARNIs) (HR -0.11; 95% CI -0.22-0.01; P = 0.03), and the R-amplitude (HR -0.17; 95% CI -0.27-0.07; P = 0.01) of the WCD baseline electrocardiogram (ECG) were independent predictors. In addition, WCD wearing time (HR 1.00; 95% CI 1.00-1.01; P = 0.04), atrial fibrillation (HR 4.03; 95% CI 1.15-14.11; P &amp;lt; 0.001), and ARNIs (HR 3.17; 95% CI 1.05-9.52; P &amp;lt; 0.001) were significantly associated with the occurrence of misdetected / misclassified episodes. Conclusions In conclusion, In WCD patients with a ZOLL LifeVest system, false alarms emitted by the device were frequent and most common caused by artefacts.

Long-term outcome after catheter ablation for fascicular ventricular tachycardia in a single high-volume center in Germany

Abstract Background Idiopathic Fascicular Ventricular Tachycardia (IFVT) accounts for less than 10% of all VTs and represents the most common idiopathic ventricular tachycardia of the left ventricle. This study reports on clinical and procedural characteristics and the long-term outcome of patients undergoing catheter ablation of premature ventricular complexes (PVC) and ventricular tachycardias (VTs) arising in proximity of the left ventricular conduction system. Methods and results This study includes 27 patients (17 male, 45 ± 17 years; 10 females, 50 ± 11 years) who underwent electrophysiological examinations at a tertiary ablation center over a period of 14 years (2009 to 2022). Follow-up was performed via regular Holter-ECGs and clinical evaluations, or via structured follow-up within the prospective TRUST registry. In 21/27 patients (77.8%), the left posterior fascicle (LPF) was involved in the IFVT. In 4 (14.8%) the left anterior fascicle (LAF) was involved and in 2 (7.4%) patients an origin in the upper septal (US) area was demonstrated. 22/27 (81.5%) patients had a preserved left ventricular ejection fraction (LVEF) and only 5 (18.5%) patients had a LVEF less than 50% at the time of presentation. 14/27 (51.9%) patients presented with PVC or non-sustained VTs with the following distribution: 10 (71.4%) originating from the LPF, 3 (21.4%) from the LAF and 1 (7.1%) from the US. 21/27 (77.8%) patients presented with sustained VTs: 16 (76.2%) arising from the LPF, 4 (19%) from the LAF and 1 (4.8%) from the US. However, only 2 (7.4%) patients presented in sustained VT at the beginning of the EP procedure. In 16 (59.3%) patients a sustained VT was induced during the EP study via isoprenaline and/or programmed ventricular stimulation. Mean QRS duration of the VT was 124.5 ± 14.6 msec. In 21 (77.7%) patients only a retrograde approach was used, in 3 (11.1%) patients a retrograde and an additional transeptal approach and in only 3 (11.1%) patients solely a transeptal approach. Mean number of radiofrequency applications was 11.8 ± 12.6 (30 to 40 Watts, 27545.6 ± 30524.4 Joules). FVT ablation was acutely successful in 24 patients (88.9%). In 2 patients (7.4%) no ablation was performed due to inability to induce VT under sedation. 3/27 patients (11.1%) underwent re-ablation due to FVT recurrence after previous ablation procedures. Moreover, 3 (11.1%) additional patients underwent repeated VT ablations during follow-up, but the arrhythmia originated from a different LV area. No procedure-related complication occurred. In 4 patients (14.8%) left fascicular posterior block was caused by ablation and in 3 (11.1%) patients a complete left bundle block. Mean procedure time was 130 ± 48.9 minutes. Conclusion Ablation of FVT in a tertiary ablation center is associated with a high single procedural success rate of 88.9% during long-term follow-up, with a mild risk of fascicular injury. 11.1% of patients underwent re-ablation due to FVT recurrence.

Catastrophic implantable cardioverter-defibrillator misclassification of ventricular tachycardia

Inappropriate therapy is a frequent adverse consequence of implantable cardioverter-defibrillator. Inappropriate therapy often occurs due to the misinterpretation of sinus tachycardia or atrial fibrillation/flutter with rapid atrioventricular conduction by the device. Current implantable cardioverter-defibrillator (ICD) mechanisms integrate various discriminators into algorithms to differentiate supraventricular tachycardia (SVT) from ventricular tachycardia (VT), to prevent such occurrences. A 40-year-old man suffered seizures and cardiac arrest abruptly, without prior complaints of chest pain. Without delay, he initiated cardiopulmonary resuscitation (CPR), resulting in the regaining of spontaneous circulation. The patient had previously received a single-chamber ICD due to recurring VT and a prior episode of cardiac arrest. The patient had a medical background of coronary artery disease with complete revascularisation and no previous occurrence of SVT. Interrogating the ICD revealed captured non-sustained ventricular tachycardia (NSVT) and SVT events but no VT episode or shock therapy. During the specified time period, the patient underwent an electrophysiological study, and no SVT was induced with the normal function of the atrioventricular and sinoatrial nodes. Various causes can lead to errors in morphology discrimination criteria in single-chamber ICDs. Extending the detection interval is highly recommended to avoid misclassification of ICDs.

Prognostic relevance of ventricular arrhythmias in surgical patients with gastrointestinal tumors.

Individuals diagnosed with gastrointestinal tumors are at an increased risk of developing cardiovascular diseases. Among which, ventricular arrhythmia is a prevalent clinical concern. This suggests that ventricular arrhythmias may have predictive value in the prognosis of patients with gastrointestinal tumors. To explore the prognostic value of ventricular arrhythmias in patients with gastrointestinal tumors receiving surgery. We retrospectively analyzed data from 130 patients undergoing gastrointestinal tumor resection. These patients were evaluated by a 24-h ambulatory electrocardiogram (ECG) at the Sixth Affiliated Hospital of Sun Yat-sen University from January 2018 to June 2020. Additionally, 41 general healthy age-matched and sex-matched controls were included. Patients were categorized into survival and non-survival groups. The primary endpoint was all-cause mortality, and secondary endpoints included major adverse cardiovascular events (MACEs). Colorectal tumors comprised 90% of cases. Preoperative ambulatory ECG monitoring revealed that among the 130 patients with gastrointestinal tumors, 100 (76.92%) exhibited varying degrees of premature ventricular contractions (PVCs). Ten patients (7.69%) manifested non-sustained ventricular tachycardia (NSVT). The patients with gastrointestinal tumors exhibited higher PVCs compared to the healthy controls on both conventional ECG [27 (21.3) vs 1 (2.5), P = 0.012] and 24-h ambulatory ECG [14 (1.0, 405) vs 1 (0, 6.5), P < 0.001]. Non-survivors had a higher PVC count than survivors [150.50 (7.25, 1690.50) vs 9 (0, 229.25), P = 0.020]. During the follow-up period, 24 patients died and 11 patients experienced MACEs. Univariate analysis linked PVC > 35/24 h to all-cause mortality, and NSVT was associated with MACE. However, neither PVC burden nor NSVT independently predicted outcomes according to multivariate analysis. Patients with gastrointestinal tumors exhibited elevated PVCs. PVCs > 35/24 h and NSVT detected by 24-h ambulatory ECG were prognostically significant but were not found to be independent predictors.

Phenotype and Clinical Outcomes in Desmin-Related Arrhythmogenic Cardiomyopathy

BackgroundDesmin (DES) pathogenic variants cause a small proportion of arrhythmogenic cardiomyopathy (ACM). Outcomes data on DES-related ACM are scarce. ObjectivesThis study sought to provide information on the clinical phenotype and outcomes of patients with ACM caused by pathogenic variants of the DES gene in a multicenter cohort. MethodsWe collected phenotypic and outcomes data from 16 families with DES-related ACM from 10 European centers. We assessed in vitro DES aggregates. Major cardiac events were compared to historical controls with lamin A/C truncating variant (LMNA-tv) and filament C truncating variant (FLNC-tv) ACM. ResultsOf 82 patients (54% males, median age: 36 years), 11 experienced sudden cardiac death (SCD) (n = 7) or heart failure death (HFd)/heart transplantation (HTx) (n = 4) before clinical evaluation. Among 68 survivors, 59 (86%) presented signs of cardiomyopathy, with left ventricular (LV) dominant (50%) or biventricular (34%) disease. Mean LV ejection fraction was 51% ± 13%; 36 of 53 had late gadolinium enhancement (ring-like pattern in 49%). During a median of 6.73 years (Q1-Q3: 3.55-9.52 years), the composite endpoint (sustained ventricular tachycardia, aborted SCD, implantable cardioverter-defibrillator therapy, SCD, HFd, and HTx) was achieved in 15 additional patients with HFd/HTx (n = 5) and SCD/aborted SCD/implantable cardioverter-defibrillator therapy/sustained ventricular tachycardia (n = 10). Male sex (P = 0.004), nonsustained ventricular tachycardia (P = 0.017) and LV ejection fraction ≤50% (P = 0.012) were associated with the composite endpoint. Males with DES variants had similar outcomes to historical FLNC-tv and LMNA-tv controls. However, females showed better outcomes than those with LMNA-tv. In vitro experiments showed the characteristic finding of DES aggregates in 7 of 12 variants. ConclusionsDES ACM is associated with poor outcomes which can be predicted with potentially successful treatments, underscoring the importance of familial evaluation and genetic studies to identify at risk individuals.

Serial Cardiac Magnetic Resonance Imaging in Patients with Mitral Valve Prolapse-A Single-Center Retrospective Registry.

Background: Mitral valve prolapse (MVP) and mitral annular disjunction (MAD) are common valvular abnormalities that have been associated with ventricular arrhythmias (VA). Cardiac magnetic resonance imaging (CMR) has a key role in risk stratification of VA, including assessment of late gadolinium enhancement (LGE). Methods: Single-center retrospective analysis of patients with MVP or MAD who had >1 CMR and >1 24 h Holter registration available. Data are presented in detail, including evolution of VA and presence of LGE over time. Results: A total of twelve patients had repeated CMR and Holter registrations available, of which in four (33%) patients, it was conducted before and after minimal invasive mitral valve repair (MVR). After a median of 4.7 years, four out of eight (50%) patients without surgical intervention had new areas of LGE. New LGE was observed in the papillary muscles and the mid to basal inferolateral wall. In four patients, presenting with syncope or high-risk non-sustained ventricular tachycardia (VT), programmed ventricular stimulation was performed and in two (50%), sustained monomorphic VT was easily inducible. In two patients who underwent MVR, new LGE was observed in the basal inferolateral wall of which one presented with an increased burden of VA. Conclusions: In patients with MVP and MAD, repeat CMR may show new LGE in a small subset of patients, even shortly after MVR. A subgroup of patients who presented with an increase in VA burden showed new LGE upon repeat CMR. VA in patients with MVP and MAD are part of a heterogeneous spectrum that requires further investigation to establish risk stratification strategies.

Characteristics Associated with Ventricular Tachyarrhythmias and Their Prognostic Impact in Heart Failure with Mildly Reduced Ejection Fraction.

Background: The occurrence of ventricular tachyarrhythmias represents an established risk factor of mortality in heart failure (HF). However, data concerning their prognostic impact in heart failure with mildly reduced ejection fraction (HFmrEF) is limited. Therefore, the present study aims to investigate patient characteristics associated with ventricular tachyarrhythmias and their prognostic impact in patients with HFmrEF. Methods: Consecutive patients hospitalized with HFmrEF (i.e., left ventricular ejection fraction 41-49% and signs and/or symptoms of HF) were retrospectively included at one institution from 2016 to 2022. The prognosis of patients with HFmrEF and different types of ventricular tachyarrhythmias (i.e., non-sustained ventricular tachycardia (nsVT), sustained VT (sVT), and ventricular fibrillation (VF) was investigated for the primary endpoint of long-term all-cause mortality at 30 months. Secondary endpoints included in-hospital all-cause mortality and long-term HF-related rehospitalization at 30 months. Results: From a total of 2184 patients with HFmrEF, 4.4% experienced ventricular tachyarrhythmias (i.e., 2.0% nsVT, 0.7% sVT, and 1.6% VF). The occurrence of nsVT was associated with higher New York Heart Association (NYHA) functional class, whereas the incidence of sVT/VF was associated with acute myocardial infarction and ischemic heart disease. However, nsVT (25.0%; HR = 0.760; 95% CI 0.419-1.380; p = 0.367) and sVT/VF (28.8%; HR = 0.928; 95% CI 0.556-1.549; p = 0.776) were not associated with a higher risk of long-term all-cause mortality compared to patients with HFmrEF without ventricular tachyarrhythmias (31.5%). In-hospital cardiovascular mortality was more frequently observed in patients with HFmrEF and sVT/VF compared to those with HFmrEF but without sustained ventricular tachyarrhythmias (7.7% vs. 1.5%; p = 0.004). Finally, the risk of rehospitalization for worsening HF was not affected by the presence of ventricular tachyarrhythmias. Conclusions: The occurrence of ventricular tachyarrhythmias in patients hospitalized with HFmrEF was low and not associated with long-term prognosis.

Long-term Monitoring to Detect Risk of Sudden Cardiac Death in Inherited Arrhythmia Patients

BackgroundRisk stratification in inherited arrhythmia syndromes is challenging. Implantable cardioverter defibrillators (ICDs) are effective in the prevention of sudden cardiac death but are associated with significant complications. We aimed to determine the value of long-term implantable loop recorder (ILR) monitoring to determine risk factors for arrhythmias in inherited arrhythmia patients. MethodsWe conducted a prospective multicentre study between 2015 and 2020 recruiting inherited arrhythmia probands and family members at intermediate arrhythmic risk, with no class 1 indication for ICD implantation. The primary endpoint was the detection by ILR of nonsustained ventricular tachycardia over ≥ 10 consecutive beats. Secondary endpoints included ICD insertion during follow-up, all-cause mortality, and ILR complication rates. ResultsA total of 45 individuals (30 female participants) were enrolled in the study. The most common diagnoses were long-QT syndrome (28%), Brugada syndrome (26%), and arrhythmogenic cardiomyopathy (11%). Following ILR insertion (mean follow-up 633 days; range, 387-969), cardiac symptoms occurred in 19 of 45 patients (42%), 5 of whom had nonsustained ventricular tachycardias (11%), which were symptomatic in 3 individuals. This situation led to ICD implantation based on ILR in 5 of 45 patients (11%). Fifty percent of symptomatic events occurred in ARVC patients. The median time from ILR insertion to ICD implantation was 152 days (interquartile range (25th, 75th percentiles) 55 of 209). No patient experienced sudden cardiac death. ConclusionsILRs enable the detection of high-risk arrhythmic features and facilitate selection of ICD candidates in inherited arrhythmia patients with borderline indications.

The Spatial Ventricular Gradient Is Associated With Inducibility of Ventricular Arrhythmias During Electrophysiology Study

BackgroundMyocardial electrical heterogeneity is critical for normal cardiac electromechanical function, but abnormal or excessive electrical heterogeneity is proarrhythmic. The spatial ventricular gradient (SVG), a vectorcardiographic measure of electrical heterogeneity, has been associated with arrhythmic events during long-term follow-up, but its relationship with short-term inducibility of ventricular arrhythmias (VAs) is unclear. ObjectiveThis study was designed to determine associations between SVG and inducible VAs during electrophysiology study. MethodsA retrospective study was conducted of adults without prior sustained VA, cardiac arrest, or implantable cardioverter-defibrillator who underwent ventricular stimulation for evaluation of syncope and nonsustained ventricular tachycardia or for risk stratification before primary prevention implantable cardioverter-defibrillator implantation. The 12-lead electrocardiograms were converted into vectorcardiograms, and SVG magnitude (SVGmag) and direction (azimuth and elevation) were calculated. Odds of inducible VA were regressed by logistic models. ResultsOf 143 patients (median age, 69 years; 80% male; median left ventricular ejection fraction [LVEF], 47%; 52% myocardial infarction), 34 (23.8%) had inducible VAs. Inducible patients had lower median LVEF (38% vs 50%; P < .0001), smaller SVGmag (29.5 vs 39.4 mV·ms; P = .0099), and smaller cosine SVG azimuth (cosSVGaz; 0.64 vs 0.89; P = .0007). When LVEF, SVGmag, and cosSVGaz were dichotomized at their medians, there was a 39-fold increase in adjusted odds (P = .002) between patients with all low LVEF, SVGmag, and cosSVGaz (65% inducible) compared with patients with all high LVEF, SVGmag, and cosSVGaz (4% [n = 1] inducible). After multivariable adjustment, SVGmag, cosSVGaz, and sex but not LVEF or other characteristics remained associated with inducible VAs. ConclusionAssessment of electrical heterogeneity by SVG, which reflects abnormal electrophysiologic substrate, adds to LVEF and identifies patients at high and low risk of inducible VA at electrophysiology study.