br Case report A year old patient

Case report A 38-year-old patient with pectus excavatum received a dual chamber ICD after resuscitated cardiac arrest due to ventricular fibrillation during myocardial infarction following vasculitis (Fig. 1, Panel A). He developed fever and chill after the ICD implantation, consistent with the growth of methicillin-sensitive Staphylococcus aureus in blood cultures. This suggests that the patient had occult bacterial infection with septic shock. Sixteen days after the primary ICD implantation, the device and the lead were explanted under local anesthesia. As there were no signs of infection in the subcutaneous ICD pocket, we decided to implant the ICD subcutaneously. Prior to implantation, the patient passed a pre-implant screening with two vectors. Thirty-four days following the ICD device removal, he Dorsomorphin manufacturer received a second-generation subcutaneous ICD. The pulse generator was placed dorsally between the anterior surface of the serratus and the posterior surface of the latissimus dorsi over the left sixth rib and below the mid-axillary line. Via two parasternal incisions, a 3-mm tripolar parasternal electrode was positioned parallel to and 1cm to the left of the sternal midline with the distal sensing electrode localized adjacent to the manubriosternal junction and the proximal sensing electrode positioned 2cm above the xiphoid process. At the end of the procedure, ventricular fibrillation (50Hz stimulation between shock coil and generator) was induced and successfully terminated by a 65J shock (15J safety margin). The generator automatically selected the optimal sensing and gain selection configuration. The time from initial detection to the shock delivery was about 11.5 seconds (Fig. 2). Post-operative chest radiography confirmed the lead position (Fig. 1, Panels B and C), as evident from an uneventful post-operative recovery and complete healing of wounds (Fig. 1, Panels D and E).
Discussion The cardiac implantable electronic device infection rate in Japan was similar to that previously reported in the USA and Europe [2]. Complete subcutaneous ICD was developed to provide an alternative to the transvenous ICD system, as it is implanted without any transvenous or epicardial leads. Infection rates involving this new device resulting in explant or revision were not lower than those previously reported in the ICD registries. However, it should be emphasized that no systemic infections were recorded with the use of any of the documented devices [3]. In recent studies, the simplicity of implantation that avoided vascular access was reflected in the very low rates (2%) of major and acute complications, such as the device system infection [4]. The first pilot phase of human studies of the subcutaneous ICD commenced in 2008, followed by subsequent regulatory and post-market studies. Approved by the FDA in September 2012 to provide defibrillation therapy for the treatment of ventricular tachyarrhythmias, the Subcutaneous ICD system was developed over 10 years of defibrillation and sensing research, acute human feasible studies, and chronic clinical studies [1,4–6]. This system demonstrated a very high shock efficacy for spontaneous ventricular arrhythmias and a decreasing incidence of inappropriate shocks [4]. The second-generation subcutaneous ICD System (EMBLEM™, Boston Scientific Corp., Marlborough, MA, USA), which is 20% thinner and is projected to last 40% longer than previously described subcutaneous ICD System, is available in Japan from February 2016. The limitations of the current subcutaneous ICD include its inability to provide antitachycardia pacing (ATP) for ventricular tachycardia, limited bradycardia pacing support (only 30s post-shock pacing) and the absence of endovascular monitoring ability for collateral data gathering, such as the impedance monitoring for chronic heart failure. Magnetic resonance imaging (MRI) scans in patients with the current system are still an off-label procedure. One estimate of potential candidates for the subcutaneous ICD might include every patient, especially the younger patients indicated for the primary and secondary sudden cardiac death prevention without a pacing indication.