Safety of Implantable Pacemakers and Cardioverter Defibrillators in the Magnetic Field of a Novel Remote Magnetic Navigation System

Safety of Pacemakers and ICDs . Introduction: Electromagnetic interference with pacemaker and implantable cardioverter defibrillator (ICD) systems may cause temporary or permanent system malfunction of implanted devices. The aim of this study was to evaluate potential interference of a novel magnetic navigation system with implantable rhythm devices. Methods: A total of 121 devices (77 pacemakers, 44 ICDs) were exposed to an activated NIOBE II® Magnetic Navigation System (Stereotaxis, St. Louis, MO, USA) at the maximal magnetic field strength of 0.1 Tesla and evaluated in vitro with respect to changes in parameter settings of the device, changes of the battery status/detection of elective replacement indication, or alterations of data stored in the device. Results: A total of 115 out of 121 (95%) devices were free of changes in parameter settings, battery status, and internally stored data after repeated exposition to the electromagnetic field of the remote magnetic navigation system. Interference with the magnetic navigation field was observed in 6 pacemakers, resulting in reprogramming to a power‐on‐reset mode with or without detection of the elective replacement indication in 5 devices and abnormal variance of battery status in one device. All pacemakers could be reprogrammed to the initial modes and the battery status proved to be normal some minutes after the pacemakers had been removed from the magnetic field. Conclusion: Interference of a remote magnetic navigation system (at maximal field strength) with pacemakers and ICDs not connected to leads with antitachycardic detection and therapies turned off is rare. Occurring functional abnormalities could be reprogrammed in our sample. An in vitro study will give information about interference of devices connected to leads. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1136‐1141)     

Flow cytometric analysis of intracellular CD6 8 molecule expression in normal and malignant haemopoiesis

Summary. CD68 molecules are heavily glycosylated lysosomal membrane constituents of unknown function with strong expression in monocytes and macrophages. Using flow cytometry, we quantified expression levels of CD68 molecules in normal and malignant haemopoietic cells. CD68 molecules are intensely expressed in the cytoplasm and weakly on the surface of mature CD14⁺ monocytes. CD68 expression seems to start very early during granulo-monopoietic differentiation. Virtually all myeloperoxidase (MPO)⁺ bone marrow cells coexpress CD68 and similar proportions of CD34⁺ progenitor cells weakly express CD68 or MPO molecules. During further differentiation, CD68 expression is strongly up-regulated in early MP0⁺ precursor cells which lack lactoferrin (LF) and CD14 molecules. Compared to these, more mature MPO⁺LF⁺ bone marrow and peripheral blood granulocytes express considerable lower levels of CD68. In-line with this broad expression, all investigated acute myeloid leukaemia (AML) cases, classified as FAB M1-M5, were CD68 positive, and compared to normal CD34⁺ bone marrow cells, CD34⁺ AML blast cells expressed increased levels. CD68 expression is, however, not restricted to cells of myeloid origin, because a subset (40 – 15%, n = 6) of CD19⁺ peripheral blood B-lympho-cytes and 50% of B-ALL are also weakly positive. In contrast, normal CD3+ lymphocytes lack (<3%. n = 6) CD68 and only low proportions (6 – 3%, n= 6) of CD56⁺ NK cells are CD68⁺. Also, all investigated T-ALL cases (n = 6) lacked CD68.     

Importance of Sinus Rhythm as Endpoint of Persistent Atrial Fibrillation Ablation

Endpoint of Persistent AF Ablation . Background: The endpoint of persistent atrial fibrillation (AF) ablation is still a matter of debate. The purpose of this study was to evaluate if sinus rhythm (SR) as endpoint of persistent AF ablation has a better long‐term outcome compared to atrial tachycardia (AT) or AF at the end of the procedure. Methods and Results: Between 2008 and 2011, 191 consecutive patients undergoing de novo catheter ablation for symptomatic persistent and long‐standing persistent AF using a sequential ablation approach (including pulmonary vein isolation, ablation of complex fractionated electrograms and linear lesions) were included in the study. According to the result at the end of ablation procedure, patients were classified into 3 groups: patients with termination of AF into SR (Group 1, n = 62), patients with AT undergoing cardioversion (CV) (Group 2, n = 47), or patients with AF undergoing CV (Group 3, n = 82). The primary endpoint was freedom from any atrial tachyarrhythmia off antiarrhythmic drugs at 12 months. At 12 months, estimated proportions of patients free from any arrhythmia recurrence were 42% for Group 1, 13% for Group 2, and 25% for Group 3 (P = 0.002). In a Cox regression analysis only termination into SR was associated with a lower risk of arrhythmia recurrence (HR: 0.62; P = 0.04). Conclusion: If SR is achieved as endpoint of persistent and long‐standing persistent AF ablation using a sequential ablation approach it is associated with the highest long‐term single procedure success rate compared to AT or AF at the end of the procedure. (J Cardiovasc Electrophysiol, Vol. 24, pp. 388‐395, April 2013)     

Lucid dreaming: an age‐dependent brain dissociation

The current study focused on the distribution of lucid dreams in school children and young adults. The survey was conducted on a large sample of students aged 6–19 years. Questions distinguished between past and current experience with lucid dreams. Results suggest that lucid dreaming is quite pronounced in young children, its incidence rate drops at about age 16 years. Increased lucidity was found in those attending higher level compared with lower level schools. Taking methodological issues into account, we feel confident to propose a link between the natural occurrence of lucid dreaming and brain maturation.     

Very Late Relapse of Atrial Fibrillation after Pulmonary Vein Isolation: Incidence and Results of Repeat Ablation

Background: There are few data about the incidence of very late (>12 months) arrhythmia relapse after pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) and about the success rate of repeat ablation procedures in this population. Methods: All patients treated with PVI for paroxysmal AF were screened in the institution's electrophysiology database. Follow‐up data at 1, 3, 6, and 12 months and yearly thereafter including repetitive (7 days or 1 day) Holter electrocardiograms were assessed as well as the technique and success rate of repeat ablations. Results: Overall, 24 of 356 (6.7%) patients experienced their first AF recurrence more than 12 months after PVI. Of these 24 patients, 14 underwent reablation for paroxysmal (11 patients) or persistent AF (three patients). Repeat ablation included re‐PVI in all 14 patients (43 of 48 initially isolated PVs with recovered left atrial–PV conduction). Ablation of complex fractionated atrial electrograms or left/right atrial lines was performed in eight patients, including the three patients with persistent AF. During follow‐up of 15.1 ± 9 months after the second ablation, 10 of 14 (71%) reablated patients remained in sinus rhythm. Conclusions : After PVI for paroxysmal AF, very late arrhythmia recurrence occurs in less than 10% of patients. The success rate of the repeat procedure is high. (PACE 2010; 33:1258–1263)