The implantable cardiac pacemaker was first developed about 60 years ago, and its technology has been evolving remarkably ever since. Recently, newer cardiac devices have become available, including MR-conditional pacemakers, leadless cardiac pacemakers, subcutaneous implantable cardioverter defibrillator (S-ICD), and wearable cardioverter defibrillator (WCD). Although MR-conditional pacemakers are spreading, there are some detailed conditions that need to be paid attention to the time of MR imaging examinations. Leadless cardiac pacemakers and S-ICD are new devices that reduce or eliminate pocket-related complications (e.g., infection and hematoma) and lead-related complications (e.g., fracture, venous thrombosis and tricuspid valve regurgitation). The choice of device, whether old-type or new-type devices, should be made by comparing the advantages and disadvantages. WCD is a unique device that can be used until ICD implantation. The cardiac devices are expected to continue to evolve with more and more innovations and lead to better therapy.

Introduction: The new cardiopulmonary resuscitation (CPR) guideline introduced in 2015 established a new definition for chest compressions: compression rate of 100-120 /min and compression depth of 5-6 cm. These are more difficult to comply with than the former guideline, and we hypothesized that mechanical CPR could comply with the guidelines better than manual CPR. Materials and methods: Participants of the immediate cardiac life support (ICLS) course were recruited, and manual chest compressions performed after the completion of the course were evaluated. The LUCAS^®2 chest compression system was used for mechanical chest compressions. Results: The compression depth and rate in manual CPR (n=18) were 3.65-6.13 cm (median: 5.40 cm) and 98-128 /min (median: 115 /min), respectively, which slightly deviated from levels recommended by the new guidelines, whereas those in mechanical CPR with LUCAS^®2 were 5.13 cm and 101 /min, respectively, which were both within the levels recommended by the new guidelines. Conclusion: Compliance with the new guidelines for the chest compressions may be difficult using manual CPR.

Implantable cardioverter defibrillators (ICDs) are commonly-used devices for secondary prevention of sudden death in patients who have recovered from cardiac arrest. However, challenges arise when patients are travelers from countries where ICDs are not available. A wearable cardioverter defibrillator (WCD) can be a useful alternative in this situation. A 72-year-old Tajikistani woman with a history of ischemic cardiomyopathy had ventricular fibrillation during her stay in Japan. She was successfully resuscitated after immediate cardiopulmonary resuscitation and transferred to our hospital. Emergent coronary angiography revealed chronic total occlusion (CTO) of the left anterior descending artery (LAD) and subtotal occlusion of the right coronary artery (RCA). Primary percutaneous coronary intervention (PCI) to the RCA was successfully performed and the patient fully recovered after targeted temperature management at 34°C for 24 hours. However, ventricular arrhythmia recurred after rewarming and PCI was also performed on the CTO of LAD. Secondary prevention for ventricular fibrillation was indicated, however the patient had to return to Tajikistan, where the appropriate ICD management is not available. In addition, the patient could not pay for the cost as she had no health insurance in Japan. A WCD was indicated as an alternative to ICD implantation. After receiving permission to wear a WCD during air travel, the patient was able to safely return to Tajikistan. WCD might be a useful option for foreign travelers who require secondary prevention for lethal ventricular arrhythmias, to enable them to return to their home country.

Severe sepsis-induced cardiomyopathy (SICM) is a reversible cardiac dysfunction, but can increase the rate of mortality. A 35-year-old man with sepsis caused by streptococcal toxic shock syndrome developed multi-organ failure. SICM with subsequent cardiogenic shock resulted in hemodynamic instability that was unresponsive to conservative medical treatment. We decided to initiate veno arterial extracorporeal membrane oxygenation (VA-ECMO) and intra-aortic balloon pumping. Cardiac function gradually improved and the patient was eventually weaned from mechanical support. Over time, his cardiac function normalized. For patients with severe SICM, VA-ECMO may be an effective bridge to recovery.

We encountered a patient who suffered from multiple organ failure with cardiogenic shock due to myocardial infarction, and was implanted with an extracorporeal ventricular assist device (e-VAD), which was subsequently replaced by an implantable ventricular assist device (i-VAD), and discharged. A 28-year-old man, presented with acute myocardial infarction due to very late stent thrombosis in the left anterior descending coronary artery (LAD) and diagonal branch. Although emergent balloon angioplasty was performed and reperfusion was achieved, stent thrombosis recurred. Because of preexisting chronic total occlusion of the left circumflex artery, the patient underwent coronary artery bypass surgery for complete revascularization. However, postoperative course was complicated with multiple organ failure due to cardiogenic shock, an e-VAD was placed. Subsequently, although he recovered from the multiple organ failure, the cardiac functions were not improved, precluding removal of the ventricular assist device. Thus, after registration for cardiac transplantation, the e-VAD was replaced by an i-VAD. Since then, he made satisfactory progress and was discharged from the hospital, and is currently waiting for cardiac transplantation at home.

We report on two cases of sepsis caused by Corynebacterium striatum (C. striatum) . Case 1 was of a 76-year-old man. He had received 10 mg/day prednisolone for about 2 years. He was diagnosed with pneumonia and was mechanically ventilated. After extubation, his respiratory condition worsened, and C. striatum was detected in the sputum obtained by bronchofiberscopy. We diagnosed sepsis caused by C. striatum pneumoniae. Case 2 was of a 74-year-old woman. She underwent percutaneous coronary intervention for acute myocardial infarction. She had a complicated ventricular septal perforation, and seven days after surgery for repair of the perforation, she developed septic shock. C. striatum was isolated on blood culture and from the drainage fluid from the mediastinum. We diagnosed sepsis shock caused by C. striatum mediastinitis. When C. striatum is isolated from cultures in patients we should not only consider colonization or contamination but also the possibility that C. striatum-induced infection.