The occurrence of ventricular tachycardia (VT) in patients with acute myocardial infarction (AMI) is associated with poor prognosis. Drug therapy and implantable cardioverter-defibrillators (ICDs) are effective methods to prevent sudden death. Radiofrequency (RF) catheter ablation can map the matrix and mechanism of VT, thereby effectively reducing the occurrence of ICD discharge. This paper reports on the case of a middle-aged man who underwent emergency percutaneous coronary intervention for AMI and developed VT and ventricular fibrillation on day 7 after reperfusion. An ICD was implanted. On day 19, he received catheter ablation because of refractory monomorphic ventricular tachycardia and frequent discharge of the ICD. After three months, the patient had not experienced any further ventricular tachycardia attacks. The conclusion is that RF catheter ablation can resolve the ES after myocardial infarction and significantly reduce the occurrence of ICD discharges.

Radiofrequency ablation (RFA) has been a central therapeutic strategy for ventricular tachycardia (VT). However, concerns about its long-term effectiveness and complications have arisen. Pulsed field ablation (PFA), characterized by its nonthermal, highly tissue-selective ablation technique, has emerged as a promising alternative. This comprehensive review delves into the potential advantages and opportunities presented by PFA in the realm of VT, drawing insights from both animal experimentation and clinical case studies. PFA shows promise in generating superior lesions within scarred myocardial tissue, and its inherent repetition dependency holds the potential to enhance therapeutic outcomes. Clinical cases underscore the promise of PFA for VT ablation. Despite its promising applications, challenges such as catheter maneuverability and proarrhythmic effects require further investigation. Large-scale, long-term studies are essential to establish the suitability of PFA for VT treatment.

UNASSIGNED: Cardiac sympathetic nerve system (SNS) might play an important role in arrhythmogenesis of arrhythmogenic cardiomyopathy (ACM). This study aims to assess the activity of cardiac SNS in ACM patients by heart rate variability (HRV), and to investigate its predictive value for sustained ventricular tachycardia (sVT).
UNASSIGNED: A total of 88 ACM patients and 65 sex- and age- matched healthy participants were enrolled. The time domain measures were used to evaluate the activity of cardiac SNS. An independent cohort with 48 ACM patients was as the validation cohort.
UNASSIGNED: ACM patients had lower levels of standard deviation of all NN intervals (SDNN) [118.0 (90.3, 136.8) vs. 152.0 (132.5, 174.5) ms, p < 0.001] compared with healthy participants. Further analysis showed ACM patients with sVT had lower levels of SDNN than those without sVT (105.0 ± 28.1 vs. 131.8 ± 33.1 ms, p < 0.001). Multivariate logistic regression analysis showed SDNN was independently associated with sVT in ACM patients [odds ratio (OR) 0.59, 95% confidence interval (CI) (0.45-0.78), p < 0.001]. Receiver operating characteristics curve demonstrated SDNN had clinical values in predicting sVT in ACM patients [area under the curve (AUC) = 0.73, 95% CI (0.63-0.84), p < 0.001], which was verified in the validation cohort.
UNASSIGNED: The present study suggests that HRV is impaired in patients with ACM, and the SDNN level has a moderate value in risk stratification for sVT in ACM patients. In addition, the finding might provide new target for the further management of ACM with integrated traditional Chinese and western medicine.

BACKGROUND: At present, the overall number of cardiac storms is small, there is a paucity of published literature describing cardiac storms in patients undergoing superficial surgery under general anesthesia (GA). In recent years, cardiac storm has attracted much clinical attention due to its high mortality, difficult management and poor prognosis.
METHODS: This paper reports a 57-year-old male with cardiac electrical storm. He presented with clinical symptoms such as exudation, bad breath, restricted mouth opening, and mucous leukoplakia on local skin, without history of cardiac disease and cardiovascular disease, undergoing superficial face surgery under GA. At 2 hours after anesthesia induction, several premature ventricular beats were detected on monitoring. Hematocrit and plasma potassium were found to be markedly decreased. The patient subsequently experienced a cardiac electrical storm, with repeated episodes of polymorphic ventricular tachycardia (VT) not degenerating to ventricular fibrillation (VF). Combining these clinical symptoms and examinations, we made the diagnosis of cardiac electrical storm. At the first occurrence of bradycardia, we administered atropine, which resolved bradycardia. However, this was followed 10 minutes later by VT, which we treated with atropine and epinephrine. Epinephrine and amiodarone were given in the second episode; epinephrine and lidocaine were used to treat the third episode. Finally, he was treated successfully with pharmacologic therapy and chest compressions. No abnormal electrocardiograph events occurred in the patient after surgery.
CONCLUSIONS: This case highlights the possibility of anesthesia-induced autotransfusion and cardiac electrical storm occurring in patients without known cardiac disease. For this kind of case needs as soon as possible electric defibrillation and electric cardioversion, timely intravenous application effective anti-arrhythmic drugs and other treatment measures. We expect that this case report adds to the existing literature on this subject.

OBJECTIVE: To explore the characteristics of optimal ablation site and its surrounding tissue in terms of unipolar and bipolar voltage mapping in idiopathic arrythmias from right ventricular outflow tract (RVOT) to understand if there is any difference between the two arrhythmias in matrix.
METHODS: A total of 40 patients with idiopathic arrhythmias originated from RVOT (28 PVCs/12 VT) were enrolled in the study group. The control group consisted of five patients with supraventricular tachycardia (SVT). Before ablation, the CARTO system was applied to establish a detailed three-dimensional electroanatomic voltage map (EVM) of RVOT during the sinus rhythm.
RESULTS: A band-like LVA of similar size was observed under the pulmonary valve on not only the bipolar map, but also unipolar map, for every patient. Both unipolar and bipolar voltage values in areas within 5 mm were significantly different from those in other areas above ablation targets, whereas similar differences were observed only in unipolar voltage values below the optimal ablation site for either of the two arrhythmias. Significant difference was present between VT group and VPCs group in voltage values for every area including target site. In terms of the overall LVA areas and the scar areas displayed on the unipolar and bipolar voltage maps, there was a significant difference between the unipolar value and bipolar value for the LVA areas and the scar areas in the VT or PVC group (P<0.05).
CONCLUSIONS: There was focal micro-scarring around the optimal ablation site. The ectopic focus is probably located in mid- or epi-myocardium. The distributions of majority of optimal ablation sites were regular especially at the noteworthy border of the band-like LVA on bipolar voltage map, or in the band-like LVA on unipolar voltage map.

Ventricular tachycardia (VT) causes sudden cardiac death, however, the majority of risk genes for VT remain unknown. SCN4B encodes a β-subunit, Navβ4, for the voltage-gated cardiac sodium channel complex involved in generation and conduction of the cardiac action potential. We hypothesized that genomic variants in SCN4B increase the risk of VT. We used high-resolution melt analysis followed by Sanger sequencing to screen 199 VT patients to identify nonsynonymous variants in SCN4B. Two nonsynonymous heterozygous variants in SCN4B were identified in VT patients, including p.Gly8Ser in four VT patients and p.Ala145Ser in one VT patient. Case-control association studies were used to assess the association between variant p.Gly8Ser and VT in two independent populations for VT (299 VT cases vs. 981 controls in population 1 and 270 VT patients vs. 639 controls in population 2). Significant association was identified between p.Gly8Ser and VT in population 1 (P = 1.21 × 10-4, odds ratio or OR = 11.04), and the finding was confirmed in population 2 (P = 0.03, OR = 3.62). The association remained highly significant in the combined population (P = 3.09 × 10-5, OR = 6.17). Significant association was also identified between p.Gly8Ser and idiopathic VT (P = 1.89 × 10-5, OR = 7.27). Functional analysis with Western blotting showed that both p.Gly8Ser and p.Ala145Ser variants significantly reduced the expression level of Navβ4. Based on 2015 ACMG Standards and Guidelines, p.Gly8Ser and p.Ala145Ser can be classified as the pathogenic and likely pathogenic variant, respectively. Our data suggest that SCN4B is a susceptibility gene for common VT and idiopathic VT and link rare SCN4B variants with large effects (OR = 6.17-7.27) to common VT.