Nifekalant in the treatment of life-threatening ventricular tachyarrhythmias

The aim of the present study is to review the literature and discuss nifekalant's potential use as a first aid drug in an emergency care setting.The PubMed database was used to identify papers,using Keywords nifekalant,MS-551,amiodarone and lidocaine.Nifekalant hydrochloride,formally known as MS-551,is a classⅢ antiarrhythmic agent which acts only by increasing the time course of myocardial repolarization.It was developed and is currently being used only in Japan for the treatment of ventricular tachyarrhythmias.It is a non-selective K+channel blocker without any β-blocking actions.Administration of nifekalant suppressed sustained ventricular tachyarrhythmias in acute coronary syndrome patients,and in cardiac arrest victims as well as during or after cardiac surgery.The major adverse effect of nifekalant is QT interval prolongation and occurrence of torsades de pointes which requires frequent monitoring of the QT interval during nifekalant infusion with adequate dose adjustment.Nifekalant is a possible effective antiarrhythmic agent for refractory ventricular tachyarrhythmias.Further clinical studies are required before nifekalant is routinely used in the emergency care setting.

Use of the impedance threshold device in cardiopulmonary resuscitation

Although approximately one million sudden cardiac deaths occur yearly in the US and Europe,cardiac arrest (CA)remains a clinical condition still characterized by a poor prognosis.In an effort to improve the cardio- pulmonary resuscitation(CPR)technique,the 2005 American Heart Association(AHA)Guidelines for CPR gave the impedance threshold device(ITD)a Class IIa recommendation.The AHA recommendation means that there is strong evidence to demonstrate that ITD enhances circulation,improves hemodynamics and increases the likelihood of resuscitation in patients in CA.During standard CPR,venous blood return to the heart relies on the natural elastic recoil of the chest which creates a transient decrease in intrathoracic pressure.The ITD further decreases intrathoracic pressure by preventing respiratory gases from entering the lungs during the decompression phase of CPR. Thus,although ITD is placed into the respiratory circuit it works as a circulatory enhancer device that provides its therapeutic benefit with each chest decompression. The ease of use of this device,its ability to be incor- porated into a mask and other airway devices,the absence of device-related adverse effects and few requirements in additional training,suggest that ITD may be a favorable new device for improving CPR efficiency.Since the literature is short of studies with clinically meaningful outcomes such as neurological outcome and long term survival,further evidence is still needed.

Hypertrophic cardiomyopathy and sudden cardiac death

Hypertrophic cardiomyopathy (HCM) is a common genetic cardiovascular disease that affects the left ventricle. HCM can appear at any age, with the majority of the patients remaining clinically stable. When patients complain of symptoms, these include: dyspnea, dizziness, syncope and angina. HCM can lead to sudden cardiac death (SCD), mainly due to ventricular tachyarrhythmia or ventricular tachycardia. High-risk patients benefit from implantable cardioverter-defibrillators. Left ventricular outflow tract obstruction is not a rare feature in HCM, especially in symptomatic patients, and procedures that abolish that obstruction provide positive and consistent results that can improve longterm survival. HCM is the most common cause of sudden death in young competitive athletes and preparticipation screening programs have to be implemented to avoid these tragic fatalities. The structure of these programs is a matter of large debate. Worldwide registries are necessary to identify the full extent of HCMrelated SCD.