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Background and aims Pathophysiological roles of monocytes in atrial fibrillation (AF), particularly for the progression of structural remodeling of the left atrium (LA), remain elusive. This study examined the association between the characteristics of circulating and local monocytes and extent of structural remodeling in LA, gauged by LA size, in AF patients.

Amiodarone is a widely used agent for life-threatening arrhythmias. Although amiodarone-induced thyrotoxicosis (AIT) is a major adverse effect that can cause recurrence of arrhythmias and exacerbation of heart failure, risk factors for AIT among amiodarone-treated Japanese patients have not been elucidated. Here, we investigated the prevalence and predictive factors for AIT. The study subjects were 225 patients treated with amiodarone between 2008 and 2012, who were euthyroid before amiodarone therapy. All patients with AIT were diagnosed by measurement of thyroid hormones and ultrasonography. Among the 225 subjects, 13 patients (5.8%) developed AIT and all the patients were classified as Type 2 AIT. Baseline features of patients with AIT were not different from those who did not develop AIT, except for age (AIT, 55.1 ± 13.8, non-AIT, 68.1 ± 12.0 years, P < 0.001). Multivariate analyses using the Cox proportional hazard model identified age as the sole determinant of AIT (hazard ratio: 0.927, 95% confidence interval: 0.891–0.964). Receiver operating characteristic curve analysis identified age of 63.5 years as the cutoff value for AIT with sensitivity of 70.3% and specificity of 69.2%. In summary, this study showed that the prevalence of AIT is 5.8% in Japanese patients treated with amiodarone and that young age is a risk factor for AIT.

icturition syncope (MS) is a type of situational syncope in the neurally mediated syncopal syndrome. 1 MS has been described classically as a stereotype occurring in healthy men after recumbency or sleep. 2,3 Kapoor et al have proposed that the clinical features of MS may differ according to on age, 4 but information about MS is so far very limited. The purpose of this study was to clarify the age-dependent clinical characteristics of MS. MethodsThe study population consisted of 37 consecutive patients with MS referred to 3 institutions (Juntendo University Hospital, Juntendo University Shizuoka Hospital, and University Hospital of Occupational and Environmental Health) for syncope during the period August 1995 and December 2006. The mean age of the patients was 52.2± 16.8 years (range 19-76 years, median 55; 26 men, 11 women). According to the median age of the study population, we divided them into 2 groups: a younger group (YG) consisting of 18 patients aged <55 years (range 19-54 years, average 38.2 years) and an older group (OG) consisting of 19 patients aged ≥55 years (range 55-76 years, average 65.5 years). Clinical characteristics including gender, number of syncope episodes, association with other types of neurally mediated syncope and cardiovascular disease, predisposing factors, time of MS occurrence, and response to head-up tilt testing (HUT) were compared between the YG and OG. All patients underwent a standardized, basic evaluation consisting of the following: complete medical history, physical and neurologic examinations, baseline laboratory examinations, 12-lead electrocardiogram (ECG), ambulatory ECG monitoring of at least 24 h, and an echocardiographic examination. HUT was performed if informed consent was given. Other cardiac or neurologic investigations, including exercise stress test, electrophysiologic study, cardiac catheterization, coronary angiography, a computed tomographic brain scan, and electroencephalography, were performed only when clinically indicated. In all patients other causes of syncope or presyncope were excluded before performing a tilt test. Clinical information was collected retrospectively from medical records. None of the patients was administered any medication or underwent cardiac pacemaker implantation for MS.After written informed consent was given, HUT was performed in a quiet room after at least a 5-h fast. A peripheral intravenous catheter was inserted 30 min before the tilt test, and a saline solution of 4.3% glucose was started at a rate of 60 ml/h. The ECG was monitored continuously during the test, and arterial blood pressure was monitored noninvasively by a tonometry system (BP-508, Colin Electronics, Komaki, Japan). After at least 15 min resting in the supine position, each patient was positioned upright at an 80-degree angle for a maximum of 30 min on the tilt table equipped with a footboard for weight bearing (passive tilt). Age-Dependent Clinical Characteristics of Micturition Syncope

Electrocardiographic changes were evaluated retrospectively in five patients without previous episodes of syncope or ventricular fibrillation who developed abnormal ST segment elevation mimicking the Brugada syndrome in leads V1-V3 after the administration of class Ic antiarrhythmic drugs. Pilsicainide (four patients) or flecainide (one patient) were administered orally for the treatment of symptomatic paroxysmal atrial fibrillation or premature atrial contractions. The QRS duration, QTc, and JT intervals on 12 lead surface ECG before administration of these drugs were all within normal range. After administration of the drugs, coved-type ST segment elevation in the right precordial leads was observed with mild QRS prolongation, but there were no apparent changes in JT intervals. No serious arrhythmias were observed during the follow up periods. Since ST segment elevation with mild QRS prolongation was observed with both pilsicainide and flecainide, strong sodium channel blocking effects in the depolarisation may have been the main factors responsible for the ECG changes. As the relation between ST segment elevation and the incidence of serious arrhythmias has not yet been sufficiently clarified, electrocardiographic changes should be closely monitored whenever class Ic drugs are given.

BackgroundRisk factors for atrial fibrillation (AF) recurrence in patients who have undergone AF catheter ablation have not been fully clarified. The objective of this study was to assess whether the left atrium (LA) and LA appendage (LAA) volumes, and cardio-metabolic markers such as polyunsaturated fatty acids (PUFAs) levels were associated with AF recurrence.MethodsSeventy-seven consecutive patients with AF (mean age, 59 ± 8 years; male, 81%; paroxysmal AF, 64%) undergoing catheter ablation were enrolled. Using contrast-enhanced cardiac multi-detector computed tomography (MDCT) scan, the LA and LAA volume and orifice area were assessed. Radiofrequency ablation was performed by an irrigation catheter, initially targeting the pulmonary veins with a wide area circumferential ablation.ResultsPatients with AF recurrence (36%) exhibited both larger LAA volumes and an LAA orifice area than those without AF recurrence, whereas the LA diameter and LA volumes were not significantly different. Notably, AF recurrence occurred in all patients with a large LAA (≥ 25 mL), and the LAA volume was significantly and negatively associated with docosahexaenoic acid (DHA) levels (β = -0.33, P = 0.003). A multiple regression analysis revealed that the log N-terminal proB-type natriuretic peptide and plasma DHA levels were independent factors for the LAA volume when adjusted for age, AF detected age, left ventricular (LV) ejection fraction, end-systolic LV diameter.ConclusionsThese results suggest that the association between LAA volume and low plasma DHA levels may be an important factor for post-ablation AF recurrence.

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