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Heart Rhythm Jun 2024
PubMed: 38848861
DOI: 10.1016/j.hrthm.2024.06.001 -
Heart Rhythm Jun 2024Where activation wavefront curvature is convexly shaped, functional conduction block can occur.
BACKGROUND
Where activation wavefront curvature is convexly shaped, functional conduction block can occur.
OBJECTIVE
The purpose of this study was to determine whether left ventricular (LV) wall thickness determined from contrast-enhanced computed tomography (CT) is useful in localizing such areas in clinical postinfarction reentrant ventricular tachycardia (VT).
METHODS
We evaluated data from 6 patients who underwent catheter ablation for postinfarction VT. CT imaging with inHEART processing was conducted 1-3 days before electrophysiological (EP) study to determine LV wall thickness (T). Activation wavefront curvature was approximated as ΔT/T, where ΔT represents wall thickness change. During EP study, bipolar LV VT electrograms were acquired using a high-density mapping catheter, and activation times were determined. Maps of T, ΔT/T, and VT activation were subsequently compared using statistical analyses.
RESULTS
Two of 6 cases exhibited dual circuit morphologies, resulting in a total of 8 VT morphologies analyzed. The LV wall near the VT isthmus location tended to be thin, on the order of a few hundred micrometers. Regions of largest ΔT/T partially coincided with the lateral isthmus boundaries where electrical conduction block occurred during VT. ΔT/T at the boundaries, measured from imaging, was significantly larger compared to values at the isthmus midline and to the global LV mean value (P <.001).
CONCLUSION
Wavefront curvature measured by ΔT/T and caused by source-sink mismatch is dependent on ventricular wall thickness. Areas of high wavefront curvature partly coincide with and may be helpful in locating the VT isthmus in infarct border zones using preprocedural imaging analysis.
PubMed: 38848858
DOI: 10.1016/j.hrthm.2024.05.056 -
Heart Rhythm Jun 2024Recurrent ventricular tachycardia (VT) can be treated by substrate modification of the myocardial scar by catheter ablation during sinus rhythm without VT induction....
RIPPLE-VT study: Multicenter prospective evaluation of ventricular tachycardia substrate ablation by targeting scar channels to eliminate latest scar potentials without direct ablation.
BACKGROUND
Recurrent ventricular tachycardia (VT) can be treated by substrate modification of the myocardial scar by catheter ablation during sinus rhythm without VT induction. Better defining this arrhythmic substrate could help improve outcome and reduce ablation burden.
OBJECTIVE
The study aimed to limit ablation within postinfarction scar to conduction channels within the scar to reduce VT recurrence.
METHODS
Patients undergoing catheter ablation for recurrent implantable cardioverter-defibrillator therapy for postinfarction VT were recruited at 5 centers. Left ventricular maps were collected on CARTO using a Pentaray catheter. Ripple mapping was used to categorize infarct scar potentials (SPs) by timing. Earliest SPs were ablated sequentially until there was loss of the terminal SPs without their direct ablation. The primary outcome measure was sustained VT episodes as documented by device interrogations at 1 year, which was compared with VT episodes in the year before ablation.
RESULTS
The study recruited 50 patients (mean left ventricular ejection fraction, 33% ± 9%), and 37 patients (74%) met the channel ablation end point with successful loss of latest SPs without direct ablation. There were 16 recurrences during 1-year follow-up. There was a 90% reduction in VT burden from 30.2 ± 53.9 to 3.1 ± 7.5 (P < .01) per patient, with a concomitant 88% reduction in appropriate shocks from 2.1 ± 2.7 to 0.2 ± 0.9 (P < .01). There were 8 deaths during follow-up. Those who met the channel ablation end point had no significant difference in mortality, recurrence, or VT burden but had a significantly lower ablation burden of 25.7 ± 4.2 minutes vs 39.9 ± 6.1 minutes (P = .001).
CONCLUSION
Scar channel ablation is feasible by ripple mapping and can be an alternative to more extensive substrate modification techniques.
PubMed: 38848856
DOI: 10.1016/j.hrthm.2024.05.046 -
Medicine Jun 2024In recent years, significant advancements in radiofrequency ablation technology have notably enhanced arrhythmia treatment in cardiology. Technological advancements and...
In recent years, significant advancements in radiofrequency ablation technology have notably enhanced arrhythmia treatment in cardiology. Technological advancements and increasing clinical adoption have made radiofrequency ablation a key therapy in improving life quality for patients with conditions like atrial fibrillation (AF). Consequently, there has been a marked increase in research output, underscoring the technology's significance and its potential in cardiology. Aims to comprehensively analyze cardiology's radiofrequency ablation research trends, identifying leading countries and institutions in international collaborations, key researchers' contributions, and evolving research hotspots. The study, based on the Web of Science Core Collection database, reviewed the literatures from 2004 to 2023. CiteSpace 6.2.R7 Basic was used for bibliometric analysis, which examined annual publication trends, international collaboration networks, key authors, leading research institutions, major journals, keyword co-occurrence and clustering trends. Analyzing 3423 relevant articles, this study reveals a consistent growth in cardiology radiofrequency ablation research since 2004. The analysis shows that the United States, Germany, and France hold central roles in the international collaboration network, with leading authors from premier US and European institutions. Keyword cluster analysis identifies "atrial flutter" and "ventricular tachycardia" as current research focal points. Cardiology radiofrequency ablation research shows a growth trend, led by the United States and European countries. Research hotspots are concentrated on the diverse applications of radiofrequency ablation technology and the treatment of AF. Future studies may increasingly focus on technological innovation and the deepening of clinical applications.
Topics: Bibliometrics; Humans; Cardiology; Radiofrequency Ablation; Biomedical Research; Atrial Fibrillation; Catheter Ablation
PubMed: 38847657
DOI: 10.1097/MD.0000000000038498 -
Circulation. Heart Failure Jun 2024The immune systems and chronic inflammation are implicated in the pathogenesis of dilated cardiomyopathy (DCM) and heart failure. However, the significance of neutrophil...
BACKGROUND
The immune systems and chronic inflammation are implicated in the pathogenesis of dilated cardiomyopathy (DCM) and heart failure. However, the significance of neutrophil extracellular traps (NETs) in heart failure remains to be elucidated.
METHODS
We enrolled consecutive 62 patients with heart failure with idiopathic DCM who underwent endomyocardial biopsy. Biopsy specimens were subjected to fluorescent immunostaining to detect NETs, and clinical and outcome data were collected. Ex vivo and in vivo experiments were conducted.
RESULTS
The numbers of NETs per myocardial tissue area and the proportion of NETs per neutrophil were significantly higher in patients with DCM compared with non-DCM control subjects without heart failure, and the numbers of NETs were negatively correlated with left ventricular ejection fraction. Patients with DCM with NETs (n=32) showed lower left ventricular ejection fraction and higher BNP (B-type natriuretic peptide) than those without NETs (n=30). In a multivariable Cox proportional hazard model, the presence of NETs was independently associated with an increased risk of adverse cardiac events in patients with DCM. To understand specific underlying mechanisms, extracellular flux analysis in ex vivo revealed that NETs-containing conditioned medium from wild-type neutrophils or purified NET components led to impaired mitochondrial oxygen consumption of cardiomyocytes, while these effects were abolished when PAD4 (peptidyl arginine deiminase 4) in neutrophils was genetically ablated. In a murine model of pressure overload, NETs in myocardial tissue were predominantly detected in the acute phase and persisted throughout the ongoing stress. Four weeks after transverse aortic constriction, left ventricular ejection fraction was reduced in wild-type mice, whereas PAD4-deficient mice displayed preserved left ventricular ejection fraction without inducing NET formation.
CONCLUSIONS
NETs in myocardial tissue contribute to cardiac dysfunction and adverse outcomes in patients with heart failure with DCM, potentially through mitochondrial dysfunction of cardiomyocytes.
Topics: Cardiomyopathy, Dilated; Humans; Extracellular Traps; Heart Failure; Male; Female; Middle Aged; Animals; Myocardium; Neutrophils; Stroke Volume; Myocytes, Cardiac; Ventricular Function, Left; Mice; Aged; Mitochondria, Heart; Mice, Inbred C57BL; Biopsy
PubMed: 38847093
DOI: 10.1161/CIRCHEARTFAILURE.123.011057 -
European Journal of Case Reports in... 2024Cardiac sarcoidosis can cause a wide range of symptoms, including shortness of breath, chest pain, oedema, and fatal arrhythmias such as ventricular tachycardia (VT)....
BACKGROUND
Cardiac sarcoidosis can cause a wide range of symptoms, including shortness of breath, chest pain, oedema, and fatal arrhythmias such as ventricular tachycardia (VT). Because the symptoms can be nonspecific, diagnosing cardiac sarcoidosis can be challenging. Treatment options may include corticosteroids to reduce inflammation, immunosuppressive drugs to prevent further damage, medications to control symptoms, ablation procedures, and defibrillators to prevent cardiac arrest.
CASE
A 60-year-old woman who has sarcoidosis affecting multiple organs including cardiac sarcoidosis, non-ischemic cardiomyopathy with reduced ejection fraction, and hypertension, was admitted with tachycardia, shortness of breath, and a recently fired automatic implantable cardioverter defibrillator (AICD). Three months prior, the patient was admitted for a syncopal episode and diagnosed with cardiac sarcoidosis through cardiac magnetic resonance imaging (MRI) and positron emission tomography (PET), which demonstrated active inflammation, and an AICD was implanted. During this admission, the patient had an episode of ventricular tachycardia and was treated with amiodarone and lidocaine. The patient received steroids, sacubitril/valsartan, and methotrexate. After 48 hours of observation, the patient was discharged without further events.
CONCLUSION
Cardiac sarcoidosis is a rare but serious disease that can lead to life-threatening cardiac complications such as ventricular tachycardia. Early diagnosis and aggressive management are crucial for improving outcomes and preventing sudden cardiac death. AICD implantation as a secondary prevention in cardiac sarcoidosis might prevent cardiac arrest."
LEARNING POINTS
Cardiac sarcoidosis can present with non-specific symptoms and lead to life-threatening arrhythmias such as ventricular tachycardia, emphasising the importance of early diagnosis and aggressive management to prevent sudden cardiac death.A multidisciplinary approach involving imaging modalities such as cardiac magnetic resonance imaging (MRI) and positron emission tomography (PET) scans, along with histological findings, is crucial for accurately diagnosing cardiac sarcoidosis, as endomyocardial biopsy alone has low sensitivity.Implantation of an automatic implantable cardioverter defibrillator (AICD) as a secondary prevention measure should be considered in cardiac sarcoidosis patients, even in elderly individuals with mildly to moderately reduced ejection fraction, to prevent fatal arrhythmias and sudden cardiac death.
PubMed: 38846646
DOI: 10.12890/2024_004469 -
Europace : European Pacing,... Jul 2024
PubMed: 38845561
DOI: 10.1093/europace/euae149 -
Journal of Cardiovascular... Jun 2024Prior studies have indicated that the frequency of premature ventricular complexes (PVC) increases after catheter ablation for atrial fibrillation (AF). However, these...
INTRODUCTION
Prior studies have indicated that the frequency of premature ventricular complexes (PVC) increases after catheter ablation for atrial fibrillation (AF). However, these studies have primarily focused on patients whose PVC burden increased rather than including the full spectrum of outcomes.
METHODS AND RESULTS
We performed a single-center retrospective cohort study of consecutive patients who underwent first-time AF ablation from 1/2018 to 12/2022 for paroxysmal or persistent AF and had both preablation and postablation rhythm monitoring within 6 months of the procedure. Patients were excluded if they had prior AF or PVC ablation or were prescribed a class I or III antiarrhythmic medication. Among 2945 patients who underwent AF ablation during the study period, 130 patients underwent first-time AF ablation and received both pre and post ambulatory monitoring. The median PVC burden before ablation was <1%. Most patients (63%) had no change in PVC burden after AF ablation compared with preablation, and patients who had an increase in PVC burden were offset by those with reductions in PVCs. A paired analysis pre- and post-AF ablation showed no significant change in PVC burden (p = .495).
CONCLUSION
Although an elevated PVC burden after AF ablation may be seen clinically, the majority of patients have no change in burden. Studies that suggest an increase in PVC burden after AF ablation may suffer from incomplete sample selection and thus omit the important effect of regression to the mean.
PubMed: 38845147
DOI: 10.1111/jce.16333 -
Cell Reports Jun 2024The choroid plexus (ChP) produces cerebrospinal fluid (CSF). It also contributes to brain development and serves as the CSF-blood barrier. Prior studies have identified...
The choroid plexus (ChP) produces cerebrospinal fluid (CSF). It also contributes to brain development and serves as the CSF-blood barrier. Prior studies have identified transporters on the epithelial cells that transport water and ions from the blood vasculature to the ventricles and tight junctions involved in the CSF-blood barrier. Yet, how the ChP epithelial cells control brain physiology remains unresolved. We use zebrafish to provide insights into the physiological roles of the ChP. Upon histological and transcriptomic analyses, we identify that the zebrafish ChP is conserved with mammals and expresses transporters involved in CSF secretion. Next, we show that the ChP epithelial cells secrete proteins into CSF. By ablating the ChP epithelial cells, we identify a reduction of the ventricular sizes without alterations of the CSF-blood barrier. Altogether, our findings reveal that the zebrafish ChP is conserved and contributes to the size and homeostasis of the brain ventricles.
Topics: Animals; Zebrafish; Choroid Plexus; Homeostasis; Cerebral Ventricles; Zebrafish Proteins; Cerebrospinal Fluid; Epithelial Cells; Biological Evolution; Blood-Brain Barrier
PubMed: 38843394
DOI: 10.1016/j.celrep.2024.114331 -
JACC. Clinical Electrophysiology May 2024There is limited information on the mode of arrhythmia initiation in idiopathic ventricular fibrillation (IVF). A non-pause-dependent mechanism has been suggested to be...
BACKGROUND
There is limited information on the mode of arrhythmia initiation in idiopathic ventricular fibrillation (IVF). A non-pause-dependent mechanism has been suggested to be the rule.
OBJECTIVES
The aim of this study was to assess the mode and characteristics of initiation of polymorphic ventricular tachycardia (PVT) in patients with short or long-coupled PVT/IVF included in THESIS (THerapy Efficacy in Short or long-coupled idiopathic ventricular fibrillation: an International Survey), a multicenter study involving 287 IVF patients treated with drugs or radiofrequency ablation.
METHODS
We reviewed the initiation of 410 episodes of ≥1 PVT triplet in 180 patients (58.3% females; age 39.6 ± 13.6 years) with IVF. The incidence of pause-dependency arrhythmia initiation (prolongation by >20 ms of the preceding cycle length) was assessed.
RESULTS
Most arrhythmias (n = 295; 72%) occurred during baseline supraventricular rhythm without ambient premature ventricular complexes (PVCs), whereas 106 (25.9%) occurred during baseline rhythm including PVCs. Nine (2.2%) arrhythmias occurred during atrial/ventricular pacing and were excluded from further analysis. Mode of PVT initiation was pause-dependent in 45 (15.6%) and 64 (60.4%) of instances in the first and second settings, respectively, for a total of 109 of 401 (27.2%). More than one type of pause-dependent and/or non-pause-dependent initiation (mean: 2.6) occurred in 94.4% of patients with ≥4 events. Coupling intervals of initiating PVCs were <350 ms, 350-500 ms, and >500 ms in 76.6%, 20.72%, and 2.7% of arrhythmia initiations, respectively.
CONCLUSIONS
Pause-dependent initiation occurred in more than a quarter of arrhythmic episodes in IVF patients. PVCs having long (between 350 and 500 ms) and very long (>500 ms) coupling intervals were observed at the initiation of nearly a quarter of PVT episodes.
PubMed: 38842971
DOI: 10.1016/j.jacep.2024.03.036