BACKGROUND: While the guidelines acknowledge the anticipated benefits of using an implantable cardioverter defibrillator (ICD) in individuals with catecholaminergic polymorphic ventricular tachycardia (CPVT). However, the potential adverse effects have received less attention.
METHODS: To address this issue comprehensively, we will explore various databases such as the Cochrane Library, Web of Science, EMBASE and PubMed. Our study will include CPVT patients, both with and without ICD implantation. Two researchers will evaluate the eligible studies independently and gather pertinent data. The quality of the studies included will be assessed using either the Newcastle-Ottawa Scale or the Cochrane Risk of Bias Tool. Data analysis will be conducted using RevMan.
BACKGROUND: Because this research depends exclusively on existing studies, obtaining patient informed consent and ethics approval is unnecessary. The results of this meta-analysis will be shared at conferences or in peer-reviewed journals.
UNASSIGNED: CRD42022370824.

BACKGROUND: Idiopathic ventricular arrhythmias (IVAs) arising from different portions of the communicating vein of the left ventricular summit (summit-CV) are not a rare phenomenon. Whereas its electrocardiographic (ECG) and electrophysiological characteristics are not fully investigated.
OBJECTIVE: This study aimed to identify distinct ECG and electrophysiological features of IVAs originating from different portions of summit-CV.
METHODS: Nineteen patients confirmed arising from summit-CV were included in this study.
RESULTS: The 19 patients were divided into proximal and distal portion groups based on their target sites in summit-CV. In the proximal portion group, 100% (11/11) VAs showed dominant negative (rs or QS) waves in lead I, while in the distal portion group, 87.5% (7/8) showed dominant positive waves (R, Rs or r) (p < 0.000). In lead V1, 100% (11/11) of the proximal portion group showed dominant positive waves (R or Rs), while 62.50% (5/8) of the distal portion group showed positive and negative bidirectional or negative waves (RS or rS) (p < 0.005). RI>4mV, SI<3.5mV, RV1<13mV, SV1>3.5mV, RI/SI>0.83, and RV1/SV1< 2.6 indicated a distal portion of summit-CV with the predictive value of 0.909, 1.000, 0.653, 0.972, 0.903, 0.966, respectively. A more positive wave in lead I and a more negative wave in lead V1 indicated more distal origin in summit-CV. Target sites in proximal and distal summit-CV groups showed similar electrophysiological characteristics during mapping.
CONCLUSIONS: There were significant differences in ECG characteristics of VAs at different portions of summit-CV, which could aid pre-procedure planning and facilitate radiofrequency catheter ablation (RFCA) procedures.

This article describes the case of a 40-year-old individual who presented with fulminant myocarditis. Initial ECG displayed sinus tachycardia with a heart rate of 117 bpm, QS complexes in leads V1-V3, ST-segment depression in leads II, III, aVF, V5-V6, and ST-segment elevation >0.2 mV in leads V1 through V3. The initial clinical assessment suggested an acute anteroseptal myocardial infarction. However, subsequent diagnostic evaluation through coronary angiography disclosed that the coronary arteries were normal. Therefore, clinicians should carefully consider the differential diagnosis between these conditions, as their management strategies differ markedly. Two hours after admission, the patient unexpectedly developed syncope. The ECG findings were consistent with the typical characteristics of bidirectional ventricular tachycardia. Our report described the appearance and morphology as well as mechanism of bidirectional ventricular tachycardia in detail. Additionally, we delineate differential diagnoses for disease that can cause bidirectional ventricular tachycardia, such as aconite poisoning, digoxin overdose, immune checkpoint inhibitor (ICI), myocardial ischemia, and hereditary channelopathies, such as catecholaminergic polymorphic ventricular tachycardia (CPVT) and Andersen-Tawil syndrome. Therefore, clinicians should recognize this ECG finding immediately and initiate appropriate treatment promptly as these measures may be vital in saving the patient\'s life.

In this systematic review and meta-analysis, we aim to evaluate the efficacy and safety of catheter ablation as the first-line treatment of ventricular tachycardia (VT) in patients with structural heart disease (SHD) and preserved left ventricular ejection fraction (LVEF). Patients with SHD are particularly susceptible to VT, a condition that increases the risk of sudden cardiac death (SCD). Implantable cardioverter-defibrillators (ICDs) can terminate VT and prevent SCD but do not prevent VT recurrence. The efficacy and safety of CA as a first-line treatment in SHD patients with preserved LVEF remain unclear. We searched PubMed/Medline, EMBASE, Web of Science, and Cochrane CENTRAL for studies reporting the outcomes of CA therapy in patients with VT and preserved LVEF, published up to January 19, 2023. The primary outcome was the incidence of SCD following catheter ablation as the first-line treatment of VT in patients with SHD and preserved LVEF. Secondary outcomes included all-cause mortality, VT recurrence, procedural complications, CA success rate, and ICD implantation after catheter ablation. We included seven studies in the meta-analysis, encompassing a total of 920 patients. The pooled success rate of catheter ablation was 84.6% (95% CI 67.2-93.6). Complications occurred in 6.4% (95% CI 4.0-9.9) of patients, and 13.9% (95% CI 10.1-18.8) required ICD implantation after ablation. VT recurrence was observed in 23.2% (95% CI 14.8-34.6) of patients, while the rate of sudden cardiac death (SCD) was 3.1% (95% CI 1.7-5.6). The overall prevalence of all-cause mortality in this population was 5% (95% CI 1.8-13). CA appears promising as a first-line VT treatment in patients with SHD and preserved LVEF, especially for monomorphic hemodynamically tolerated VT. However, due to the lack of direct comparisons with ICDs and anti-arrhythmic drugs, further research is needed to confirm these findings.

Cardiac electrophysiology involves the diagnosis and management of arrhythmias. CT and MRI play an increasingly important role in cardiac electrophysiology, primarily in preprocedural planning of ablation procedures but also in procedural guidance and postprocedural follow-up. The most common applications include ablation for atrial fibrillation (AF), ablation for ventricular tachycardia (VT), and for planning cardiac resynchronization therapy (CRT). For AF ablation, preprocedural evaluation includes anatomic evaluation and planning using CT or MRI as well as evaluation for left atrial fibrosis using MRI, a marker of poor outcomes following ablation. Procedural guidance during AF ablation is achieved by fusing anatomic data from CT or MRI with electroanatomic mapping to guide the procedure. Postprocedural imaging with CT following AF ablation is commonly used to evaluate for complications such as pulmonary vein stenosis and atrioesophageal fistula. For VT ablation, both MRI and CT are used to identify scar, representing the arrhythmogenic substrate targeted for ablation, and to plan the optimal approach for ablation. CT or MR images may be fused with electroanatomic maps for intraprocedural guidance during VT ablation and may also be used to assess for complications following ablation. Finally, functional information from MRI may be used to identify patients who may benefit from CRT, and cardiac vein mapping with CT or MRI may assist in planning access. ©RSNA, 2024 Supplemental material is available for this article.

The first symptoms of catecholaminergic polymorphic ventricular tachycardia (CPVT) usually occur in childhood and adolescence. 60% of patients experience syncope before the age of 40. Sudden cardiac death (SCD) is the first symptom of the disease in 30-50% of patients with CPVT. Early diagnosis is therefore crucial for the patient\'s prognosis. The diagnosis of CPVT is confirmed by a normal resting ECG, exclusion of structural heart disease, detection of bidirectional or polymorphic ventricular tachycardia (VT) in the stress ECG and/or detection of a pathogenic mutant in a gene associated with CPVT. Up to 60% of CPVT patients carry changes in the RYR2 gene. This gene encodes the cardiac ryanodine receptor, the most important Ca2+-releasing channel of the sarcoplasmic reticulum, which plays a central role in the contraction and relaxation of the heart muscle. If the function of the ryanodine receptor is impaired, too much calcium enters the cells, which triggers life-threatening arrhythmias. The overactive ryanodine receptor is therefore the main target for gene therapy methods. Even though the development of gene therapy is progressing, there is still no causal therapy available and it is all the more important to make a diagnosis as early as possible, which enables appropriate behavior and adequate symptomatic therapy. The decisive factor here is the evaluation of the genetic analysis in the context of the clinical findings. Based on this, recommendations can be made for preventive measures and the avoidance of specific triggers that could lead to life-threatening arrhythmias.
Die ersten Symptome der katecholaminergen polymorphen ventrikulären Tachykardie (CPVT) treten meist im Kindes- und Jugendalter auf. 60% der Patienten haben Synkopen vor dem 40. Lebensjahr. Der plötzliche Herztod (PHT) ist bei 30-50% der Patienten mit CPVT das erste Symptom der Erkrankung. Die rechtzeitige Diagnosesicherung ist daher entscheidend für die Prognose der Patienten. Gesichert wird die Diagnose CPVT bei unauffälligem Ruhe-EKG, Ausschluss einer strukturellen Herzerkrankung, Nachweis einer bidirektionalen oder polymorphen ventrikulären Tachykardie (VT) im Belastungs-EKG und/oder Nachweis einer pathogenen Variante in einem Gen, das mit einer CPVT assoziiert ist. Bis zu 60% der CPVT-Patienten tragen Veränderungen im RYR2-Gen. Dieses Gen kodiert für den kardialen Ryanodinrezeptor, den wichtigsten Ca2+-freisetzenden Kanal des sarkoplasmatischen Retikulums, der eine zentrale Rolle bei der Kontraktion und Entspannung des Herzmuskels spielt. Ist die Funktion des Ryanodinrezeptors gestört, gelangt zu viel Kalzium in die Zellen, was lebensbedrohliche Arrhythmien auslöst. Der überaktive Ryanodinrezeptor ist daher der Hauptansatzpunkt für die gentherapeutischen Methoden. Auch wenn die Entwicklung der Gentherapie voranschreitet, steht bisher noch keine ursächliche Therapie zur Verfügung und eine möglichst frühzeitige Diagnose, die ein angepasstes Verhalten und eine adäquate symptomatische Therapie ermöglicht, ist umso wichtiger. Entscheidend ist dabei die Bewertung der genetischen Analyse im Kontext mit den klinischen Befunden. Darauf aufbauend können Empfehlungen für präventive Maßnahmen und die Meidung spezifischer Trigger, die zu lebensbedrohlichen Rhythmusstörungen führen könnten, ausgesprochen werden.Schlüsselwörter: Kardiale Ionenkanalerkrankung, plötzlicher Herztod, unklare Synkope, Arrhythmie, Herzgenetik, RyanodinrezeptorEingereicht am 19. März 2024 - Revision akzeptiert am 25. Juni 2024.

BACKGROUND: For many patients, sudden cardiac arrest (SCA) risk is elevated temporarily. Wearable cardioverter-defibrillators (WCDs) can monitor and treat SCA during these temporary periods. Traditional WCDs can be uncomfortable, require frequent maintenance, and cannot be used when showering, resulting in poor compliance and avoidable SCA deaths. The Jewel is a novel, water-resistant patch-wearable cardioverter-defibrillator (P-WCD) with a machine learning detection algorithm designed to improve compliance and protection against SCA.
OBJECTIVE: This study aims to demonstrate the safety and clinical effectiveness of a novel P-WCD.
METHODS: The Jewel IDE Study, a prospective, single-arm study conducted at 30 U.S. sites, enrolled patients at SCA risk due to ventricular tachycardia/ventricular fibrillation who were not candidates for or refused an implantable defibrillator. The primary safety endpoint was <15% patients with clinically significant cutaneous adverse device effects and the primary effectiveness endpoint was <2 inappropriate shocks/100 patient-months. Secondary endpoints were ≥1 successful ventricular tachycardia/ventricular fibrillation conversion and wear time compliance of >14.1 h/d.
RESULTS: A total of 305 patients (mean age: 57.9 years; 30.2% female, 27.9% non-White) were enrolled, of which 290 had available device data. The clinically significant cutaneous adverse device effect rate was 2.30% (upper 1-sided 98% CI: 4.80); none were severe. No device-related deaths or serious adverse events were reported. The inappropriate shock rate was 0.36/100 patient-months (upper 1-sided 98% CI: 1.53). Of 11 shocks in 9 patients, 9 shocks were adjudicated to be appropriate. Eight of 9 shocks were successful with a single shock. Median wear time compliance was 23.5 (20.7-23.9) h/d.
CONCLUSIONS: The novel P-WCD is a safe and effective WCD with high patient compliance. There were no deaths due to noncompliance and a high number of successful conversions (Jewel IDE study [A Clinical Evaluation of the Jewel P-WCD in Subjects at High Risk for Sudden Cardiac Arrest]; NCT05201495).

暂无摘要。

OBJECTIVE: Wearable cardioverter-defibrillators (WCDs) are indicated in patients at risk of sudden cardiac arrest who are not immediate candidates for implantable defibrillator therapy. Limitations of existing WCDs include poor compliance and high false alarm rates. The Jewel is a novel patch-WCD (P-WCD) that addresses these limitations with an adhesive-based design for near-continuous wear and a machine learning algorithm designed to minimize inappropriate detections. This was a first-in-human study of the Jewel P-WCD conducted in an electrophysiology (EP) lab to determine the safety and effectiveness of the device in terminating ventricular tachycardia/ventricular fibrillation (VT/VF) with a single shock. The aim was to evaluate the safety and effectiveness of terminating VT/VF with a single shock using the Jewel P-WCD.
RESULTS: This was a first-in-human, prospective, single-arm, single-centre study in patients scheduled for an EP procedure in which VT/VF was expected to either spontaneously occur or be induced. The Jewel P-WCD was placed on consented patients; upon confirmation of VT/VF, a single shock (150 J) was delivered via the device. A group sequential design and Pocock alpha spending function was used to measure the observed proportion of successful VT/VF single-shock terminations. The endpoint was achieved if the lower confidence limit exceeded the performance goal of 62%, using a one-sided lower 97.4% exact confidence bound. Of 18 eligible subjects, 16 (88.9%, 97.4% confidence bound: 65.4%) were successfully defibrillated with a single shock, exceeding the primary endpoint performance goal with no adverse events.
CONCLUSIONS: This first-in-human evaluation of the Jewel P-WCD demonstrated the safety and effectiveness of terminating VT/VF.
BACKGROUND: URL: https://clinicaltrials.gov/; Unique identifier: NCT05490459.

OBJECTIVE: Successful ventricular arrhythmia (VA) ablation requires identification of functionally critical sites during contact mapping. Estimation of the peak frequency (PF) component of the electrogram (EGM) may improve correct near-field (NF) annotation to identify circuit segments on the mapped surface. In turn, assessment of NF and far-field (FF) EGMs may delineate the three-dimensional path of a ventricular tachycardia (VT) circuit.
RESULTS: A proprietary NF detection algorithm was applied retrospectively to scar-related re-entry VT maps and compared with manually reviewed maps employing first deflection (FDcorr) for VT activation maps and last deflection (LD) for substrate maps. Ventricular tachycardia isthmus location and characteristics mapped with FDcorr vs. NF were compared. Omnipolar low-voltage areas, late activating areas, and deceleration zones (DZ) in LD vs. NF substrate maps were compared. On substrate maps, PF estimation was compared between isthmus and bystander sites. Activation mapping with entrainment and/or VT termination with radiofrequency (RF) ablation confirmed critical sites. Eighteen patients with high-density VT activation and substrate maps (55.6% ischaemic) were included. Near-field detection correctly located critical parts of the circuit in 77.7% of the cases compared with manually reviewed VT maps as reference. In substrate maps, NF detection identified deceleration zones in 88.8% of cases, which overlapped with FDcorr VT isthmus in 72.2% compared with 83.3% overlap of DZ assessed by LD. Applied to substrate maps, PF as a stand-alone feature did not differentiate VT isthmus sites from low-voltage bystander sites. Omnipolar voltage was significantly higher at isthmus sites with longer EGM durations compared with low-voltage bystander sites.
CONCLUSIONS: The NF algorithm may enable rapid high-density activation mapping of VT circuits in the NF of the mapped surface. Integrated assessment and combined analysis of NF and FF EGM-components could support characterization of three-dimensional VT circuits with intramural segments. For scar-related substrate mapping, PF as a stand-alone EGM feature did not enable the differentiation of functionally critical sites of the dominant VT from low-voltage bystander sites in this cohort.