大動脈弁人工弁（機械弁）置換術後遠隔期に生じたOMI-VT stormに対し経心房中隔的に施行したカテーテルアブレーションが著効した１例

A ６８-year-old woman with VT storm and frequent appropriate ICD therapy was referred for catheter ablation. Her past history was notable for aortic valve replacement by mechanical valve due to infectious endocarditis １７ years prior to presentation and left ventricular apical old myocardial infarction with unknown onset. At ６７ years old, She admitted to the prior hospital due to ventricular tachycardia with LBBB and superior axis at heart rate of ２１０ per minutes. Administration of amiodarone and magnesium sulfate was ineffective and cardioversion of ２００J was successfully terminated the tachycardia. Intra-cardiac defibrillator was implanted and the administration of amiodarone and mexiletine was started. ５ months after, she admitted to the hospital due to the frequent appropriate shock against the same ventricular tachycardia. Administration of lidocaine, sotalol, pilsicainide, and magnesium sulfate could not control the tachycardia and she was referred to our hospital for catheter ablation. During the first session, ventricular tachycardia was easily induced and electroanatomical mapping was performed both during tachycardia and during sinus rhythm. Late diastolic potential preceding the onset of QRS wave by ４５ms was detected at the infero-septal side of the apical aneurysm. ７．５s of the RF energy application at this site could terminate the tachycardia and thereafter no ventricular tachycardia was induced. But after dose-reduction or cessation of some anti-arrhythmic drugs, ventricular tachycardia was recurred and second session was performed. This time, no ventricular tachycardia was induced, then we performed isthmus transection and core isolation against the apical aneurysm. Thereafter no ventricular tachycardia was occurred in spite of dose-reduction or cessation of some anti-arrhythmic drugs.