心室中隔欠損兼肺動脈弁下部狭窄術後25年目に持続性心室頻拍および洞結節機能低下を来した1例

A Case of Sustained Ventricular Tachycardia and Dysfunction of the Sinus Node 25 Years after, Patch Closure for Ventricular Septal Defect and Reconstruction for Infundibular Pulmonary tenosis

　症例は47歳，男性．25年前に心室中隔欠損症，肺動脈弁下部狭窄に対し心室中隔パッチ閉鎖，肺動脈再建術を施行された．1998年4月26日から動悸が出現し，28日に心室頻拍に伴う右心不全にて入院となった．心室頻拍はlidocaineの静注で停止し，その後右心不全も改善した．電気生理学的検査では心室頻拍は誘発されなかったが，高位心房刺激にて非通常型心房粗動が誘発された．また，洞結節回復時間の延長があり洞結節機能低下も認められた．右室造影では右室流出路のパッチ形成部位が確認できた．12誘導心電図波形から心室頻拍の起源は流出路前中隔と推測され，パッチの瘢痕，パッチ周囲由来である可能性が示唆された．今回，われわれは治療とたてaprindineを選択したが，今後洞不全症候群の出現・増悪があれば恒久的ペースメーカの適応を，心室頻拍が再発する場合にはカテーテルアブレーション，amiodarone，手術療法，植込み型除細動器の適応を考慮する必要がある．

　This is a case of a 47-year-old man. He had an operation 25 years previously for ventricular septum patch closure of ventricular septal defect, and pulmonary artery reconstruction for infundibular pulmonary stenosis. He was admitted in April, 1998, for heart failure with ventricular tachycardia (VT). After injection of lidocaine (50mg), VT was stopped. Signs of heart failure disappeared for about 10 days. We carried out an electrophysiologic study. Atrial pacing showed the sinus node recovery time was 7880 msec. The function of the sinus node was abnormal, but the function of the atrioventricular node was normal. During incremental ventricular pacing and programmed extrastimuli, VT did not occur. but an uncommon type of atrial flutter (2: 1 conduction) occured under programmed extrastimuli at the high right atrial wall. After injection of disopyramide (50mg), its conduction became 1:1 and it's electrocardiogram was different from the VT at the time of admission. Angiographic study was carried out and showed a portion of the patch reconstruction for the outflow of the right ventricule. We suspected that this sustained VT originated from the outflow of the right1 ventricle or from scar around the VSD patch. We selected aprindine as medication for this patient. If sick sinus syndrome had occurred or if VT were recurrent, we would have considered implanting a permanent pacemaker, catheter ablation, the administration of amiodarone or the implantation of ICD.