Prognostic significance of nonsustained ventricular tachycardia in patients receiving cardiac resynchronization therapy for primary prevention: Analysis of the Japan cardiac device treatment registry database

BackgroundWhether nonsustained ventricular tachycardia (NSVT) is a marker of increased risk of sustained ventricular tachyarrhythmias (VTAs) remains to be established in patients receiving cardiac resynchronization therapy with a defibrillator (CRT‐D) for primary prevention.MethodsAmong the follow‐up data of the Japan cardiac device treatment registry (JCDTR) with an implantation date between January 2011 and August 2015, information regarding a history of NSVT before the CRT‐D implantation for primary prevention had been registered in 269 patients. Outcomes were compared between two groups with and without NSVT: NSVT group (n = 179) and No NSVT group (n = 90).ResultsThere was no significant difference with regard to age, gender, and NYHA class between the two groups. Left ventricular ejection fraction (LVEF) was 25.6% in the NSVT group and 28.0% in the No NSVT group (P = .046). The rate of appropriate therapy at 24 months was 26.0% and 18.4% in the NSVT and No NSVT groups (P = .22), respectively. Survival free from heart failure death was reduced in the NSVT group, as compared with the No NSVT group, with the rate of 90.2% vs 97.2% at 24 months (P = .030). A multivariate analysis identified a history of NSVT, anemia, and no use of angiotensin‐converting enzyme inhibitor (ACEI) or angiotensin‐receptor blocker (ARB) as predictors of heart failure death.ConclusionsNSVT appears to be a surrogate marker of severe heart failure rather than a substrate for subsequent sustained VTAs in patients with CRT‐D for primary prevention

Effect of Tea Catechins on Influenza Infection and the Common Cold with a Focus on Epidemiological/Clinical Studies

Influenza and the common cold are acute infectious diseases of the respiratory tract. Influenza is a severe disease that is highly infectious and can progress to life-threating diseases such as pneumonia or encephalitis when aggravated. Due to the fact that influenza infections and common colds spread easily via droplets and contact, public prevention measures, such as hand washing and facial masks, are recommended for influenza prophylaxis. Experimental studies have reported that tea catechins inhibited influenza viral adsorption and suppressed replication and neuraminidase activity. They were also effective against some cold viruses. In addition, tea catechins enhance immunity against viral infection. Although the antiviral activity of tea catechins has been demonstrated, the clinical evidence to support their utility remains inconclusive. Since the late 1990s, several epidemiological studies have suggested that the regular consumption of green tea decreases influenza infection rates and some cold symptoms, and that gargling with tea catechin may protect against the development of influenza infection. This review briefly summarizes the effect of tea catechins on influenza infection and the common cold with a focus on epidemiological/clinical studies, and clarifies the need for further studies to confirm their clinical efficacy

Concomitant abnormalities in Brugada syndrome

Brugada syndrome (BS) is characterized by ST-segment elevation in the right precordial leads and is associated with sudden cardiac death secondary to polymorphic ventricular tachycardia (PVT)/ventricular fibrillation (VF) in the absence of structural heart disease. Vasospastic angina (VSA) and neurally mediated syncope (NMS) are observed occasionally in BS patients, although their associations with BS remain controversial. The incidence of concomitant VSA and BS is 11–13%, and there might be an increased risk of VF when BS and VSA coexist, as reported in several previous studies. Whether the manifestation or augmentation of a coved-type electrocardiography (ECG) pattern is associated with coronary artery vasospasm is unclear. The significance of increased coved-type ST-segment elevation and its relation to arrhythmogenesis in BS is an important issue that needs to be resolved in future studies of concomitant BS and VSA. The coexistence of BS and VSA should always be taken into account in the management of both conditions, particularly when calcium antagonists are used. Previous reports suggest a high incidence of NMS in BS patients, and it is often difficult to differentiate between NMS and high-risk syncopal episodes due to ventricular tachyarrhythmias. Therefore, the identification of a therapeutic strategy to treat syncope in BS patients is often problematic. The autonomic nervous system is involved in arrhythmogenesis and may precipitate cardiac events in BS patients. To investigate BS, it may be useful to consider VSA and NMS as concomitant abnormalities. Future studies are needed to understand the relationship between BS and the autonomic nervous system

Radiofrequency catheter ablation of macroreentrant ventricular tachycardia after corrective surgery for tetralogy of Fallot

Ventricular tachycardia (VT) may occur in patients after corrective surgery for tetralogy of Fallot (ToF), and this can be a cause of sudden cardiac death. Macroreentrant VT is a unique mechanism in these patients, although other mechanisms are involved in VT development. Owing to advances in electrophysiological knowledge and medical technology, macroreentrant VT after corrective surgery for ToF can be treated by catheter ablation. In the macroreentrant circuit of VT, several critical isthmuses (types 1–4) could be included, and these are supported by anatomical obstacles and operative interventions in the right ventricle. Linear radiofrequency (RF) application through the critical isthmus can terminate and prevent the recurrence of macroreentrant VT. Among the critical isthmuses, the type 1 isthmus (between the right ventricular outflow scar and tricuspid annulus) is the most common, but compared with the other types of isthmuses, it is longer so and has a thicker myocardium. Therefore, higher-energy RF application using irrigation and/or large-tip ablation catheters is usually required to complete the linear conduction block. Since other isthmuses may simultaneously work as critical components of the macroreentrant circuit, detailed mapping is encouraged before starting RF application in the type 1 isthmus. Since long-term evidence of the effectiveness of catheter ablation for VT in patients after ToF repair is limited, hybrid treatment with implantable cardioverter defibrillators (ICDs) would be a reasonable strategy for secondary prevention of cardiac events, such as that in patients with other underlying heart diseases. Indications of electrophysiological study, catheter ablation, and/or ICD therapy for primary prevention of sudden cardiac death should be further examined in high-risk patients after ToF repair

Effects of Tea Catechins on Alzheimer’s Disease: Recent Updates and Perspectives

Alzheimer’s disease (AD) is one of the most common neurodegenerative disorders worldwide. Its incidence is gradually increasing because of an aging demographic. Therefore, AD prevention and modification is important to improve the health status of older adults. Oxidative stress is a component of the pathological mechanisms underlying AD. It is caused by a disruption of the balance between reactive oxygen species and antioxidant molecules. This imbalance also causes neuroinflammation. Catechins, which are bioactive components of tea, have antioxidative and anti-inflammatory effects. Moreover, other potential properties related to AD prevention and modification have been reported in in vitro and in vivo studies. Several clinical studies have also been conducted to date. The current review summarizes recent updates and perspectives of the effects of catechins on AD based on the molecular mechanisms and related clinical studies