Heart rhythm : the official journal of the Heart Rhythm Society
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Transesophageal echocardiography (TEE) is routinely used to exclude atrial thrombus prior to cardioversion of atrial fibrillation (AF). Because the TEE probe lies adjacent to the atria, cardioversion using an electrode attached to the TEE probe should allow for immediate low-energy transesophageal cardioversion. ⋯ Atrial thrombus exclusion and transesophageal cardioversion of AF via a disposable cardioversion sheath offers the opportunity to perform transesophageal cardioversion and TEE thrombus exclusion during one sedation. It may not be suitable for use in patients with gastroesophageal reflux disease. Transesophageal cardioversion may establish sinus rhythm in selected patients refractory to transthoracic cardioversion.
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Randomized Controlled Trial
Increased impedance to inspiration ameliorates hemodynamic changes associated with movement to upright posture in orthostatic hypotension: a randomized blinded pilot study.
Movement to upright posture may result in marked drop of blood pressure with susceptibility to injury from syncope and falls in patients with orthostatic hypotension. ⋯ Enhancing impedance to inspiration may prove useful as adjunctive therapy for diminishing symptoms associated with movement to upright posture in individuals with orthostatic hypotension.
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Magnetic fields may interfere with the function of cardiac pacemakers and implantable cardioverter-defibrillators (ICDs). Neodymium-iron-boron (NdFeB) magnets, which are small in size but produce strong magnetic fields, have become widely available in recent years. Therefore, NdFeB magnets may be associated with an emerging risk of device interference. ⋯ Small NdFeB magnets may cause interference with cardiac pacemakers and ICDs. Patients should be cautioned about the interference risk associated with NdFeB magnets during daily life.
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Brugada and long QT type 3 syndromes are linked to sodium channel mutations and clinically cause arrhythmias that lead to sudden death. We have identified a novel threonine-to-isoleucine missense mutation at position 353 (T353I) adjacent to the pore-lining region of domain I of the cardiac sodium channel (SCN5A) in a family with Brugada syndrome. Both male and female carriers are symptomatic at young ages, have typical Brugada-type electrocardiogram changes, and have relatively normal corrected QT intervals. ⋯ The clinical presentation of patients carrying the T353I mutation is that of Brugada syndrome and could be explained by a cardiac Na(+) channel trafficking defect. However, when the defect was ameliorated, the mutated channels had biophysical properties consistent with long QT syndrome. The lack of phenotypic changes associated with the long QT syndrome could be explained by a T353I-induced trafficking defect reducing the number of mutant channels with persistent currents present at the sarcolemma.