Heart rhythm : the official journal of the Heart Rhythm Society
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Concern exists regarding the potential electromagnetic interaction between pacemakers, implantable cardioverter-defibrillators (ICDs) and digital music players (DMPs). A preliminary study reported interference in 50% of patients whose devices were interrogated near Apple iPods. ⋯ Contrary to a prior report, we did not identify any evidence for electromagnetic interference between a selection of DMPs and intrinsic function of PM/ICDs. The DMPs did sometimes interfere with device-programmer communication, but not in a way that compromised device function. Therefore, we recommend that DMPs not be used during device interrogation, but suggest that there is reassuring counterevidence to mitigate the current high level of concern for interactions between DMPs and implantable cardiac rhythm devices.
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Ventricular arrhythmias (VAs) may arise from the aortic sinuses and have electrocardiographic and electrophysiological characteristics that suggest a left (LCC) or right coronary cusp (RCC) origin. However, VAs that arise near the junction of those two cusps (L-RCC) may have unusual features. ⋯ This study revealed that a qrS pattern in leads V1-V3 suggests a site of origin at the L-RCC.
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Advances in multidetector computed tomography (MDCT) technology now permit three-dimensional cardiac imaging with high spatial and temporal resolution. Historically, transesophageal echocardiography (TEE) has been the gold standard for assessment of the left atrial appendage (LAA) in patients with atrial fibrillation and other atrial arrhythmias. Findings on TEE, including demonstration of LAA thrombus and dense nonclearing spontaneous echocardiographic contrast (SEC), predict future fatal and nonfatal thromboembolic events. ⋯ Current-generation MDCT successfully identifies LAA thrombus and dense nonclearing SEC with high sensitivity and moderate specificity. Importantly, LAA/AscAo HU ratios >0.75 demonstrate 100% negative predictive value for exclusion of LAA thrombus or dense nonclearing SEC. These results suggest that in patients undergoing pulmonary vein isolation procedures, MDCT examinations that demonstrate LAA/AscAo HU ratios >0.75 may preclude the need for preprocedural TEE.
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Twin AV nodes and resulting supraventricular tachycardia (SVT) have been described in right atrial isomerism (RAI). ⋯ This study showed that twin AV nodes in RAI patients could be disclosed by serial electrocardiograms and that SVT, most likely a twin node tachycardia, was common and tended to recur but could be managed by ablation or medication.