consumed ≥ 1 drink per day. The CHA2DS2- VASc score was calculated for each patient by assigning 2 points for the history of stroke/transient ischemic attack or age ≥ 75 years and 1 point for each of the following parameters: age ≥ 65 years, history of congestive heart failure, hypertension, diabetes mellitus, female sex, and vascular diseases. Transthoracic echocardiography (Vivid 7, GE healthcare, Horten, Norway) was performed for all patients by an expert on cardiovascular imaging. Left atrial antero-posterior (LA-AP), left ventricular end-diastolic (LVEDD) and end-systolic (LVESD) diameters, and left atrium volume (LAV) were measured and recorded as outlined by the current guidelines of chamber quantification by the American Society of Echocardiography(11). Left ventricular ejection fraction was calculated using the modified Simpson’s method. All patients were implanted dual chamber PM, which was programmed to the DDDR mode. The atrial tachycardia detection mode was enabled, and the AF suppression feature was programmed off by performing atrial overdrive pacing. Bipolar atrial leads sensitivity and post ventricular atrial blanking period was interrogated properly to reduce P-wave sensitivity and farfield R-wave over-sensing to identify atrial activities and prevent ventricular Rwave sensing during AHRE detection. Six months after the PM implantation, devices were interrogated to detect and categorize the patients on the basis of occurrence of AHRE. AHRE was defined as atrial high rates faster than 220 bpm and lasting longer than 5 minutes based on previous studies indicating its significance concerning the increased rate of stroke and to exclude slower atrial tachycardias and Rwave over-sensing episodes that were identified frequently at periods shorter than 5 minutes(12,13). The onset detection 232 Koşuyolu Heart J 2018;21(3):230-235 ● Increased Body Mass Index is Associated with Device Detected Silent Atrial Fibrillation number of consecutive beats was 10, and the termination of AHRE was defined as occurrence of 20 consecutive beats below the AHRE detection rate to exclude short episodes of atrial premature beats. Patients were divided into 2 groups on the basis of presence (AHRE [+]) or absence (AHRE [-]) of AHRE at the time of device interrogation. All data were evaluated using the Number Cruncher Statistical System (NCSS, Kaysville, Utah, USA). Mean and standard deviations were used for quantitative variables. Student T test was used for normally distributed variables in both groups and Mann-Whitney U test was used for variables that were not normally distributed. Qualitative variables were evaluated using the Pearson Chi-square and Continuity (Yates) correction. The backward stepwise logistic regression analysis was used for multivariate analysis to identify risk factors for the occurrence of AHRE. A p value of < 0.05 was accepted statistically significant. RESULTS A total of 535 patients were enrolled in the study between January 2015 and February 2016. Of these, 3 patients had BMI < 18 kg/m2 , 27 patients had previous diagnosis of atrial arrhythmias, 39 patients had more than mild valvular heart disease, 18 patients had a previous valve replacement operation or valvuloplasty procedure. The final cohort consisted of 449 (mean age: 67.0 ± 9.0, men: 61.7%, mean BMI: 27.36 ± 3.60 kg/m2 ) patients. There were 117 patients with BMI in the range 18-25 kg/m2 group, 230 patients with BMI in the range 25-30 kg/m2 group, and 102 patients with BMI > 30 kg/m2 group. AHRE was detected in 128 (28.5%) patients during the device interrogation at clinical visit 6 months after implantation. Baseline demographic and clinical characteristics of the study population according to presence of AHRE are listed in Table 1. Patients in the AHRE (+) group were older (65.5 ± 8.9 years vs 70.8 ± 8.1 years, p< 0.01) and had greater BMI (26.84 ± 3.41 kg/m2 vs 28.65 ± 3.75 kg/m2 , p< 0.01) compared to patients in DISCUSSION The major findings of the present study were as follows: First, patients with higher BMI had a higher incidence of AHRE during their device interrogation. There was no significant difference in terms of AHRE detection in overweight (BMI > 25-30 kg/m2 ) patients. In contrast, patients with BMI > 30 kg/m2 were more likely to have AHRE during their device interrogation. Second, patients with AHRE had higher mean resting heart rate, LA-AP diameter, LAV, and CHA2DS2-VASc score. Despite significant progress in the management of patients with AF, the common arrhythmia is still considered to be one of major causes of stroke and heart failure. This can be partly attributed to increased prevalence and associated comorbid conditions of AF in the aging population and relatively high recurrence rates following contemporary medical and ablation therapies once AF develops. Recently, advances in the diagnosing techniques for asymptomatic AF particularly in patients with CIEDs led to the emergence of the term “silent AF”. Technological advances in CIED systems allowed clinicians to detect and store AHRE. Several studies have identified AHRE as a harbinger of future atrial arrhythmias, stroke, and death(3,5). In the MOST trial, authors concluded that AF is a progressive condition (AF begets AF) and has an intermediate stage during which AF recurs and may be permanent.