心室頻拍症における心房細動および心房受攻性についての検討

Atrial Fibrillation and Atrial Vulnerability in Ventricular Tachycardia

　心室頻拍（VT）患者における心房細動（af）および心房受攻性をみる目的で，VT患者54例（VT群）を対象に電気生理学的検査を施行した．VT群では13例（24.1％）と高頻度にafが誘発され（対照群107例中9例，8.4％，p＜0.01），うち12例は持続性VT群（39例，30.8％）であった．VT群，持続性VT群では対照群に比し心房不応期，FRPA／PAは有意に小で，PA時間，心房波の持続時間の最大延長率max D₂／D₁, fragmented atrial activityzone, repetitive atrial firing（RAF）の出現頻度，RAF zoneは有意に大であった．afの誘発頻度は基礎心疾患の有無で差はなかったが，陳旧性心筋梗塞に多かった（9例中6例）．af（＋）群ではaf（−）群に比しRAF出現頻度，RAF zoneは大であった．以上，持続性VTにおいてはafが比較的よく誘発され，特に陳旧性心筋梗塞では高頻度であった．af（＋）群では心房受攻性の指標と考えられるRAFの出現頻度が高かった．

We examined by electrophysiological examination atrial fibrillation (af) inducibility in patients with ventricular tachycardias (VT). There were fifty four subjects with VT (VT group) and 107 patients without VT, WPW syndrome or paroxysmal af (control group). In the VT group, 39 patients had sustained VT, 15 patients had non-sustained VT, 24 patients had organicheart diseases and 30 patients were free of such heartdiseases. Af was induced in 13 of 54 patients (24.1%) in the VT group and in 9 of 107 patients (8.6%) in the control group (p＜0.01). In the 13 af induced patients, 12 had sustained VT (30.8%), one had non-sustained VT (6.7%), 7 had organic heart diseases (29.2%) and 6 were without such heart diseases (20%). Af was induced in 6 of 9 patients with old myocardial infarction of whom 8 patients had sustained VT. Effective and func-tional atrial refractory periods (FRP_A) and FRP,_A/PA were shorter in the VT group than in the control group. The PA intervals, the maximum increased ratio of the high right atrial wave duration by extrastimuli, the fragmented atrial activity (FAA) zone, the repetitive atrial firing (RAF) zone, the high atrial conduction delay zone and the frequency of patients with RAF in the VT group and the sustained VT group were significantly more increased than in the control group. There were no significant differences in the electrical and hemodynamic parameters between the sustained and non-sustained VT groups. RAF was higher in patients with af than in patients without af. Conclu-sions : Af was induced more frequently (30.8%) in the sustained VT group, especially in patients with old myocardial infarction.