ペースメーカ植込み6カ月後に心室リードによる右室穿孔を来した1例

A Case Report of Right Ventricular Perforation 6 Months after Permanent Pacemaker Implantation

要旨　ペースメーカの心筋リード穿孔は，多くは植込み周術期に生じる合併症であるが，今回われわれは植込み6カ月後に心室リードによる右室穿孔を来した1例を経験した．患者は88歳，男性．洞不全症候群の診断でスクリューインリードを用いてDDDペースメーカ植込み術を施行した．植込み時は閾値・リード抵抗とも良好であったが，植込み7日後に心室リード抵抗の低下，18日後に心室リード先端の屈曲，1カ月後にペーシング閾値の上昇を認めた．植込み6カ月後に突然左胸痛を自覚し，来院時心電図でペースメーカ不全を認め，心エコー・胸部CTで心室リードの右室穿孔が確認されたが，心囊液の貯留は認めなかった．入院6日後，全身麻酔下・胸骨正中切開で心室リード切断・抜去術を施行した．穿孔したリードの先端を切断し，同時に右室穿孔部を閉鎖した．リードと心血管組織との癒着は認めなかったため，ジェネレーター側から容易にリード抜去が可能であった．

　An 88-year-old man with sinus node dysfunction underwent dual-chamber pacemaker implantation with screw-in leads. The sensing and pacing thresholds for the right ventricular lead were good at the time of implantation. Seven-day postoperative assessment revealed a decrease in the impedance of the ventricular lead and at one month after implantation, the ventricular pacing threshold was elevated. Six months after implantation, the patient presented with sudden left chest pain and an electrocardiogram showed failure of the ventricular sensing and pacing. A computed tomography and an echocardiogram revealed right ventricular lead perforation without pericardial effusion. A midline skin incision was performed followed by median sternotomy under general anesthesia. After the pericardiotomy, the ventricular lead was found to have perforated the apex of the right ventricle. There was no bloody pericardial fluid and no sign of myocardial degeneration around the perforated region. Immediately after the lead tip was cut, the perforation was surgically closed. The lead was removed easily from the generator side without firm adhesion to heart or vessels. He was discharged 19 days after surgery and has been free from any syncopal episodes with AAI pacing mode.