['Interatrial block which is defined as P wave duration longer than 120 milliseconds is underappreciated but highly prevalent electrocardiographic abnormality and associated with atrial tachyarrhythmias and ischemic stroke. Impaired left atrial mechanics and atrial fibrillation are potential mechanisms contributing to the embolic events associated with interatrial block. Detection of atrial high rate episodes by cardiac implantable electronic devices provides clinicians to diagnose asymptomatic atrial fibrillation. The relation between interatrial block and asymptomatic atrial fibrillation can provide an insight to the increased risk of ischemic stroke in patients with interatrial block.', 'We prospectively evaluated 367 patients who were implanted dual chamber pacemaker due to sinus node dysfunction (SND) between January 2015 and December 2015. Twelve lead electrocardiograms were analyzed to diagnose interatrial block before pacemaker implantation. Six months after the implantation, pacemakers were interrogated to detect atrial high rate episodes. Patients were divided into two groups in terms of presence or absence of atrial high rate episodes.', 'Atrial high rate episodes were detected in 107 (30.1%) patients during their device interrogation. Interatrial block was found in 115 (32.4%) patients out of total study population. Sixty-seven (27.0%) patients in AHRE (-) group had interatrial block while 48 (44.9%) patients had in AHRE (+) group. Prevalence of interatrial block was statistically significantly higher in AHRE (+) patients (P<0.01).'] Does interatrial block predict atrial high rate episodes detected by cardiac implantable electronic devices?