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  • The insulation defect has resulted in dramatic inside out

    2019-04-15

    The insulation defect has resulted in dramatic “inside-out” extrusion of the inner cables, [2–5] observed in up to 33% of patients in one series, [6] and electrical failure in other leads with normal fluoroscopic appearance. Parvathaneni et al. also observed that of those leads with cable extrusion, 31% showed electrical failure. Preservation of electrical function in remaining leads with extruded cables is attributed to their protective cable ethylenetetrafluoroethylene (ETFE) coating. Lead failure manifests in several ways. Oversensing of non-physiologic signal has resulted in inappropriate therapy, [7] and a short-circuit (between the can and coil or between opposing HV electrodes by “outside-in” cable extrusion) has resulted in device failure [8] and death [9]. A recent case report describes the loss of two brand new generators connected to an incumbent SJM Riata lead at the time of generator replacement [8]. In our case the Medtronic generator was saved by aborting purchase diazoxide delivery, a mechanism incorporated to protect the device if low impedance is detected, but it failed to deliver appropriate therapy for VF. An evidence-based strategy for Riata lead follow-up is not yet established. Fluoroscopic examination of all Riata leads may be considered, however some electrical failures occur in fluoroscopically “normal” leads and it is not clear that all insulation breaches will result in lead failure. In a study examining 133 deaths by lead failure, 22 deaths were caused in Riata or Riata ST leads none of which showed lead externalisation [9]. Increased surveillance of electrical parameters may be warranted, yet up to 30% of those with normal electrical data may demonstrate insulation breach and cable extrusion [6]. There are at least two other reports of Riata lead failure in which prior electrical parameters were within acceptable limits [5,10].
    Conclusion
    Conflict of Interest
    Acknowledgements
    Introduction Atrial fibrillation (AF) has been gaining much attention as one of the major causes of cerebral infarction [1]. For practitioners to effectively manage this risk, pseudopodia is imperative to establish an antithrombotic treatment for AF patients. To date, guidelines for antithrombotic treatment in the management of AF patients have been published in the United States [2,3], Europe [4,5], Australia [6], Canada [7,8], and Japan [9], which include verification of the efficacy of direct thrombin and factor Xa inhibitors. A look at the needs of patient populations in the Asia-Pacific region shows that antithrombotic treatment has not yet been defined and no such guidelines exist. The Asia Pacific Heart Rhythm Society (APHRS)—Practice Guideline Subcommittee conducted a Web-based survey from June 2011 to August 2011 to elucidate the current status of antithrombotic treatment in 9 countries. When research was completed, the APHRS published a report entitled, “Fact-finding survey of antithrombotic treatment for prevention of cerebral and systemic thromboembolism in patients with non-valvular atrial fibrillation in 9 countries of the Asia-Pacific region” in the Journal of Arrhythmia[10]. The survey revealed substantial differences in antithrombotic treatments among the 9 surveyed countries. Although the overall survey size was small, in that only 50 physicians per country participated, and further research is still necessary, we believe that the results provide a good foundation to continue the process of creating usable, safe antithrombotic treatment guidelines for patients in Asia-Pacific countries. Among the many results noted in the survey are as follows: (1) there were large differences in the stance of using antiplatelet agents for low-risk patients with a CHADS2 score of 0–1; (2) warfarin was markedly underused in some countries; and (3) warfarin was quickly replaced by dabigatran, such that dabigatran was more frequently used than warfarin in some countries.