br Materials and methods This study included

Materials and methods This study included WCD patients with high risk of SCD but did not meet the eligibility criteria for immediate orexin receptor antagonist of an implantable cardioverter defibrillator (ICD). Current guidelines endorse indications for WCD therapy [5]. Patients with low left ventricular ejection fraction (LVEF; ≤35%) or therapy-refractory nonsustained ventricular tachycardias are at high risk of SCD. However, the guidelines recommend ICD implantation only after waiting at least 40 days or 3 months, depending on whether the patient had undergone revascularization or not. In patients who experience lethal ventricular arrhythmia after MI, ICD implantation is considered after assessment of the efficacies of revascularization, catheter ablation, and anti-arrhythmic therapy. If these therapies fail, ICD implantation is recommended. We analyzed the characteristics and outcomes of patients with ventricular tachyarrhythmia in the early post-MI phase who received a WCD. All of the patients were followed up between August 2010 and November 2014 at the University Hospital of Bonn, Germany. Details of the WCD and the arrhythmia detection algorithm were described elsewhere [1,2]. Variables were reported as mean±standard deviation, median (25–75 percentiles), or n (%). The patients׳ characteristics were compared by using the Fisher exact test for categorical variables and the t test for continuous variables. Statistical significance was established at P<0.05.
Results
Discussion Currently, ICD therapy represents a cornerstone of cardiology practice for reducing the incidence of SCD after MI [6–9]. However, previous randomized trials [10,11] could not show a mortality benefit of early ICD implantation in post-MI patients. Hence, in patients with LV dysfunction in acute MI, current guidelines in the United States and Europe [5] recommend ICD implantation only after waiting at least 40 days or 3 months, depending on whether the patient had undergone revascularization or not. In this study, the median time from MI to WCD prescription was 10 days (range, 5–31 days) and the median length of use was 33 days (range, 20–67 days). Compared with the current guidelines, actual practice uses the mean waiting period. A proportion of the post-MI population eventually recovered LV function without further risk of SCD (i.e., crossing the EF threshold of 35–40%). The present study reveals that the median LVEF improved with WCD therapy (30% [range, 20–36%] vs. 35% [range, 25–40%], P<0.01). Thus, ICD implantation was prevented in 10 patients (42%). The use of WCD contributed to the prevention of an unnecessary ICD implantation. Inappropriate shock is rare, occurring in only 0–3% of WCD patients [12,13]. A WCD is a unique tool designed to avoid an unnecessary shock therapy. If persistent arrhythmia is detected, the WCD notifies the patient via a responsiveness test, allowing a conscious patient to prevent treatment by holding the Response buttons. Therefore, education and medical information have been provided to patients in order to optimize their understanding and acceptance of WCD therapy. Most of our patients agreed that the device was easy to handle after sufficient training before receiving the device.
Conclusion
Conflict of interest
Introduction Congenital long QT syndrome (LQTS) is an inheritable cardiac condition that may lead to fatal cardiac arrhythmia (e.g., torsades de pointes, ventricular fibrillation). Typical presentation consists of syncope, seizure, or even sudden death in otherwise healthy young people. A large neonatal screening study from Italy reported the prevalence of long QT syndrome to be at least 1 in 2500 [1], but the true prevalence of LQTS in other populations is still unknown. Some studies suggest that LQTS might be an underrecognized rather than a rare disease [2]. This underestimation might be the result of a large number of silent-mutation carriers in the total population.