notch signaling In conclusion a rare KCNE D N
In conclusion, a rare KCNE1-D85N polymorphism may modify the LQTS phenotype in combination with other pathogenic LQTS-related gene mutations.
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Introduction Atrial fibrillation (AF) is observed in 10–30% of patients with symptomatic notch signaling failure, and the incidence is increased to about 50% in New York Heart Association (NYHA) class IV patients with severely decompensated hear failure [1,2]. The Studies of Left Ventricular Dysfunction (SOLVD) trial evaluated moderate or severe heart failure patients with NYHA class II and III symptoms and found that all-cause mortality, deaths from heart failure, and the frequency of hospitalization were increased by concomitant AF . Moreover, all-cause mortality was increased by about 35% in patients with heart failure complicated by AF as compared to that in non-complicated heart failure patients . AF aggravates hemodynamics and cardiac function by causing a rapid ventricular rate, loss of atrial kick, irregular RR interval, and loss of physiological atrioventricular synchrony . When hemodynamics are exacerbated, cardiac function declines further and enhances the persistence of AF, forming a vicious cycle. When AF occurs in the acute phase of heart failure (AHF), the heart rate rapidly increases and blood pressure decreases, resulting in cardiogenic shock in some patients. This situation necessitates emergency action, but electrical cardioversion done in such a setting is often ineffective, and even if AF is terminated, recurrence of arrhythmia is immediate in many cases. In terms of acute phase drug therapy for AF complicating AHF, no drug with proven efficacy and safety has been approved in Japan, and digoxin has been used empirically in such cases. For rate control during AF with AHF, a beta-blocker and additional administration of digoxin are recommended as Class I pharmacological therapy in the Japanese Circulation Society (JCS 2010) Guidelines and the European Society of Cardiology (ESC) Guidelines . However, in hemodynamically unstable patients with AHF and low left ventricular function, the use of sufficient beta-blocker doses is often difficult due to the negative inotropic effect of this drug class. Although amiodarone is recommended as a beta-blocker alternative in the JCS 2010 Guidelines, the method of administration is not specified. In 2010, oral amiodarone was approved for AF accompanied by left ventricular dysfunction in Japan. Oral amiodarone seems to be effective in AF patients with AHF; however, its effect is not immediate and oral intake is problematic in some severely unstable patients. Thus, intravenous administration is desirable, as recommended by Guidelines in Western countries. In japan, intravenous amiodarone was approved for the treatment of ventricular tachycardia (VT) and ventricular fibrillation (VF), but not for AF even in patients with AHF. The use of intravenous amiodarone was reportedly safe even in the presence of severe organic heart diseases . However, only a few prospective studies have investigated its effects on rhythm and rate control and its safety for the acute phase treatment of AF complicating severe heart failure. In this study, we prospectively investigated the safety and efficacy of intravenous amiodarone, including the resolution of AF, maintenance of sinus rhythm, and rate control during AF, as an acute phase treatment of AF in patients with AHF using a unified protocol.
Material and methods
Results Before amiodarone administration, the heart rate in the overall patient group was 137±15beats/min. However, the heart rate before amiodarone administration was significantly greater in the 9 patients with persistent/long-standing persistent AF than in the 11 patients with recent-onset/transient/paroxysmal AF (145±11 versus 130±16beats/min, P<0.05).
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