The number of patients with asymptomatic and transient atrial fibrillation（AF）has recently increased, and some of these cases are found to have extensive cerebral embolism of sudden onset. Therefore, the usefulness of performing 24-hour Holter electrocardiograms obtained from routine medical offices for the discovery of AF was investigated. Among a total of 2,041 cases, AF was observed in 333 cases（16.3％）and compared with 330 non-AF cases. In male and high-aged patients with AF, hypertension and congestive heart failure ware significantly higher than in patients without AF. Only 31％ of cases have been diagnosed as AF before, but more than twice as many were found to have asymptomatic or paroxysmal type by this monitoring. Anticoagulant therapy was prescribed in only 9.3％ of cases, but Holter monitoring showed that this medication was needed in 24.6％ of cases. In this manner, 24-hour Holter monitoring was found to be useful for the detection of silent and transient type AF as well as anticoagulant-required AF.

An 80-year-old man had been diagnosed with sick sinus syndrome, for which he underwent dual chamber pacemaker implantation via the left subclavian vein 17 years previously. Atrial fibrillation was sustained and changed to the VVI mode at the time of generator replacement 6 years previously. The area that capped the atrial lead connector was stimulated, and skin fistula and pus were observed. The lead removal technique was then performed. Using a 12Fr Excimer laser sheath, the ventricular and atrial leads were peeled off alternately. There was resistance in the subclavian vein area and a mechanical sheath was used. The laser sheath was 14Fr, but it was difficult to remove at the superior vena cava site. Although transvenous lead extraction has a high success rate, it is more likely to have complications because of the long duration of implantation. Both of the leads in our case were fragile because of a long implantation time and difficult to remove using only an Excimer laser sheath. By grasping the lead with a snare from the femoral approach, pulling the snare and the locking device of the collarbone at the same time from both sides simultaneously allowed passage of the laser sheath and both leads could be removed. We experienced a case in which the bi-directional approach of an Excimer laser sheath and snare was effective for transvenous extraction of old leads.

There are few reports on the use of wearable cardioverter-defibrillators（WCDs）in children. Case 1 was a naturally healthy 9-year-old boy. Ventricular fibrillation（VF）developed during a marathon and he was resuscitated. He was diagnosed with vasospastic angina and took a Ca antagonist, but developed VF again. After that, coronary CT revealed an abnormality in the left coronary artery, coronary artery repair surgery was performed, an implantable loop recorder was implanted, and WCD was introduced. Case 2 was a 12-year-old boy with severe aortic valve stenosis who, developed VF while playing football. After resuscitation, aortic valve replacement surgery was performed and WCD was introduced. Both cases showed good wearing compliance and understanding of the equipment. There was no arrhythmia event during wearing, and an electrophysiological study and an exercise stress test were conducted before finishing wearing, and it was thought that the risk of recurrence of VF was low, and the implantable cardioverter-defibrillator was avoided. The chest circumference of case 1 was lower than the minimum size, but the belt was sewed shorter and he was able to wear it. The use of WCD by children after cardiopulmonary arrest resuscitation was very useful in determining treatment.