Therapeutic Research

Case：We experienced 49 year‒old Japanese male with hypertrophic cardiomyopathy and sustained ventricular tachycardia. He was treated with VT ablation and ICD （Boston Scientific, INCEPTA）. The therapy of VT‒1 zone above 140 bpm was ATP Burst 10 times and ATP Ramp 5 times. The therapy of VT zone above 180 bpm was ATP Bust twice, Ramp twice, and Cardioversion. This patient experienced palpitation and ICD shock, which analysis revealed a repeated inappropriate cessation of ATP therapy. He had VT three times detected at VT‒1 zone. During every VT therapy, ATP was terminated at sixth ATP every time, although ATP was supposed to be conducted 15 times（Burst 10 times and Ramp 5 times）. ICD of Boston Scientific have time limit of ATP therapy, called ATP timeout, which default setting is one minute. Because of the ATP timeout setting, this patient had ATP therapy stopped at sixth ATP which reached one minute every time. We elongated ATP timeout setting from one minute to ten minutes. Since ICD of Boston Scientific has ATP timeout set one minuet by default, we should be careful when we set multiple ATPs.

A sixty‒six man complained dyspnea and syncope because of complete AV block. He was implanted a DDD pacemaker（MR‒conditional pacing lead；Medtronic Advisa DR MRI SureScan）. Ten days after the operation, he felt illness and suddenly fell into shock. We diagnosed his clinical condition was cardiac tamponade by the transthoracic echocardiography. We suspected ventricular lead perforation by CT imaging and he underwent the operation. The operation finding was the atrial lead perforation at the bottom of the right appendage. MR conditional leads have stronger rigidity than traditional leads and different torque speed characteristics. Firstly, we have to adequately understand the characteristics of these leads. In addition, we have to be careful avoiding over torque and implanting surely at the tip of the right appendage.

The patient was a 63‒year‒old man. In October 2008, he underwent CRTD implantation for chronic heart failure and ventricular tachycardia associated with old myocardial infarction. During a visit to the pacemaker clinic in December 2010, pacing waves and spontaneous waves appeared in an alternating fashion on a 12‒lead ECG. Intracardiac ECG revealed T wave over sensing after ventricular pacing, followed by atrial waves （sensing during the refractory period）, resulting in failed ventricular pacing. This phenomenon could not be avoided by resetting the threshold for ventricular sensing. When the AV delay was shortened to 150 ms, the T wave amplitude decreased on intracardiac ECG, and the T wave over sensing disappeared. In this case, shortening of AV delay modified conduction, which in turn decreased the T wave amplitude and prolonged the ventricular refractory period, probably resulting in disappearance of the T wave over sensing. Considering sensing threshold characteristics, the ventricular sensing threshold probably explains the failure to avoid T wave over sensing prior to the intervention in this case.

症例：心房細動，三尖弁閉鎖不全の既往のある82 歳，男性。2001 年に徐脈性心房細動，房室ブロックによる失神を生じ，VVI ペースメーカーを挿入した。2004 年，リード不全を生じたため心室リード追加挿入を行い経過観察を行っていたが，2007 年に高度の三尖弁閉鎖不全による右心不全に発展し薬剤治療困難となったため，三尖弁生体弁置換術を施行した。このとき経静脈的挿入を行った心室リード抜去も行い，新たに腹部に心外膜リードによるペースメーカー植え込みを行うことで良好に経過していた。2009 年，交通事故で腹部打撲。他院に搬送されたが打撲以外の外傷なく，事故後約2 ヵ月経過してから頻回に失神を生じるようになった。事故直後のペースメーカーチェックでは異常を認めなかったが，心室刺激閾値は従来の1.25 V/0.4 ms から徐々に上昇し3.5 V/0.4 ms で単極，双極ともに心室捕捉不可能となった。胸腹部X線撮影で明らかなリードの位置異常，損傷は認めなかった。失神の再発，出力を上げても心室捕捉不可能となったため，リード追加も考慮し加療の方針とした。幸いにも三尖弁生体弁置換術時に心外膜リードを2 本挿入してあり，未使用リードが存在したため刺激閾値を計測したところ1.75 V/0.4 ms であり，このリードに新規ペースメーカーを接続し再度腹部にペースメーカー植え込みを行うことで，以後，失神発作は消失した。デバイス自体に外傷による損傷は認めなかった。結語：腹部交通外傷の打撲により，ペーシング閾値の上昇をきたした1 例を経験した。心外膜リードは体外からのショックに脆弱な可能性も考えられ報告した。

An 87‒year‒old man with past medical history of polymorphic ventricular tachycardia, a left sided ICD generator was placed at 72 years old and tunneled ICD lead implanted from the right side for the lead fracture at 75 years old. Generator replacement was undergone by the battery depletion at 85 years old. The left precordial chest pain was observed since the beginning of August, 2013 and the patient made urgent hospitalization with finding of the accidentally exposure of ICD generator when the patient visited hospital for general fatigue. Although the systemic signs of infection including fever were absent, the explantation of the entire system was required if the device pocket infection was evident. However, the ICD generator was removed without extraction of the leads for considering elder, lowering activity of daily life and request of patient and family. The explantation of ICD generator, cover to the cut surface of leads and sterilizing wound were undergone by our department and collaboration with the plastic and reconstructive surgery department at August. The patient was treated with antibiotics for 3 weeks although the bacteriological cultures of the edge of leads were absent. The epidermis of device pocket was poor healing after surgery and the capsule of hypodermis was resected. Then, the sign of infection disappeared. The ICD system was not re‒implanted by the request of patient and family and patient was discharged at September. There have been no sign of inflammation for 10 months and observed as the outpatient. In generally, the explantation of entire system was recommended when the device infection was evident. Although the ultimate treatment seemed to be impossible without the explantation of entire system, we experienced that the patient was selected the palliative approaches to treatment of device pocket infection without extraction of leads, and the recurrence and complication were not observed.

Background：Many patients with L‒looped transposition of the great arteries（L‒TGA）develop refractory heart failure and sustained ventricular tachycardia. We report a case of successful implantation of cardiac resynchronization therapy defibrillator（CRT‒D）in a patient with L‒TGA, who was later found to be a non‒responder to CRT. Case：The patient was diagnosed with L‒TGA and dextrocardia at birth. At 10 years of age, he had complete atrioventricular block after tricuspid valve replacement and was implanted a permanent pacemaker（VVI）via a transvenous approach. There after he underwent repeated exchange of pacemaker leads and implantation of pacemaker on the other chamber. At age 38, ventricular fibrillation occurred during the perioperative period, but upgrade to implantable cardioverter defibrillator（ICD）was not performed due to foreseen difficulties. Amiodarone was initiated and the course was observed. Two years later, the patient developed sustained ventricular tachycardia. At first, ICD implantation was planned but eventually a CRT‒D（ConcertoTM, Medtronic）was implanted because of reduced cardiac function and dyssynchrony detected by tissue Doppler imaging （TDI）. CRT‒D was successfully implanted in spite of the unusual anatomy of his coronary sinus. However, he developed heart failure after the procedure and was assessed as non‒responder to CRT. Then CRT was discontinued and DDI with prolonged AV delay（A pace＋V sense or fusion）was adopted instead. After that, his condition improved dramatically. He received ICD implantation（ProtectaTM XT DR by Medtronic）with MVP‒mode at 39 years of age, and has been doing well without hospitalization. Conclusion：CRT is efficient in most patients with congenital heart disease with reduced cardiac function, but some patients may be non‒responders. Careful consideration of indication for CRT is needed.

背景：早期ステージの保存期慢性腎臓病（CKD）患者では，血清リン（P）値は正常範囲内に保たれているが，骨・ミネラル代謝の異常がステージの進行に伴い出現することから，P制限食やP 吸着薬によりCKD ステージにかかわらず各施設の基準値内にP 値を保つことが推奨されている。従来使用されてきたカルシウム（Ca）含有P 吸着薬は，Ca 非含有P 吸着薬よりも血管石灰化への影響が大きいことが問題視されている。2013 年からCa 非含有P 吸着薬である炭酸ランタンが使用可能となったことから，炭酸Caからの切替え例も含め，保存期CKD 患者に対する炭酸ランタンの有用性について検討した。方法：2013 年10 月から2014 年2 月の間に炭酸ランタンの投与を開始した，血清P 値4 mg/dL 以上のP 吸着薬新規投与患者19 例，および炭酸Ca からの切替え例4 例の保存期CKD 患者計23 例を対象に，血清P，Ca，腎機能のパラメータを測定し，6 ヵ月後までの推移を検討した。結果：観察期間の平均値は245±35 日，中央値は252 日であった。CKD ステージは，G5 が69.6％を占め，炭酸ランタン投与開始時の血清P 値は4.5±0.5 mg/dL，血清Ca 値は8.4±0.8mg/dL であった。炭酸ランタンの開始時投与量は，全例750mg/日で，6 ヵ月後の平均投与量は1370±583mg/日であった。血清P 値は，2 ヵ月後には4.1±0.8 mg/dLへと有意に低下し，6 ヵ月後まで低下を維持する傾向が認められた。CKD ガイドラインが推奨する基準値2.5～4.5 mg/dLを達成した患者は，投与開始時には56.5％であったが，6 ヵ月後には73.9％に達した。血清Ca 値も5 ヵ月後には8.1±0.7 mg/dL へと有意に低下した。血清クレアチニン（Cr）値は投与開始時の3.79±1.36 mg/dL から6 ヵ月後には4.4±2.1mg/dL と有意に増加，eGFR 値は投与開始時の13.9±6.0 mL/min/1.73 m2から6 ヵ月後には12.6±6.3 mL/min/1.73 m2と有意な低下が認められた。尿蛋白/Cr 値を測定しえた8 例では，開始時の6.50±7.99 mg/gCr から大きな変動は認められなかった。炭酸Ca からの切替え例と炭酸ランタン新規投与例との比較では，血清P 値は，炭酸Ca からの切替え例では有意な低下は認められなかったが，新規投与例では1 ヵ月後に有意な低下が認められ，以降低下が持続した。血清Ca 値は，炭酸Ca からの切替え例，新規投与例のいずれも有意な低下が認められた。血清P 値低下例と非低下例の比較では，非低下例で血清Cr 値の有意な増加，およびeGFR 値の有意な低下が認められた。観察期間中，4 例に嘔気が認められた以外には特記すべき有害事象は認められなかった。結論：6 ヵ月間の使用経験から，炭酸ランタンは保存期CKD 患者の血清P 値の管理に有用と思われ，なかでも血清P 値を厳格にコントロール可能であった患者ではCKD の進展を抑制できる可能性が示唆された。

The present study aimed to examine the attitudes of athletes in their teens toward anti –doping, and identify recent problems in relation to education for drug prevention. The subjects were 468 male and 254 female junior high school students who had competed at national judo meets. A survey was conducted, and the students were asked whether or not they had received anti –doping education as well as their opinions on drug violations. The results of the survey suggest that these promising judo athletes had few opportunities to increase their awareness of anti –doping and receive education for it, and that a few students would consider using banned substances to significantly enhance their performance. It is necessary to initiate early anti –doping education in as many settings as possible in order to train competitive athletes with a healthy mind and body, and trainers and other people in charge of training them have a responsibility to promote such anti –doping education.

The present study aimed to examine the awareness of anti –doping among athlete support personnel for students who had competed at national junior high school judo meets, including their trainers and parents, and discuss anti –doping education for these adults. The subjects were 426 trainers and 658 parents of students who had competed at national junior high school judo meets. A survey was conducted, and the trainers and parents were asked whether or not: they had received education on doping, anti –doping education should be implemented for junior high school students, as well as their opinions on drug violations. The results of the survey suggest that these athlete support personnel for junior high school judo athletes had little knowledge of the principles of anti –doping and their level of awareness was low. To train athletes with a healthy mind and body, it is necessary to provide these supporters of athletes with information on anti –doping in a more effective way. Furthermore, they are required to exert increased efforts to improve themselves as role models..