複数のwide QRS tachycardiaにより心室内解離をきたした1例

A case of intra-ventricular dissociation with dual ventricular tachycardia

　複数のwide QRS tachycardiaを同時にきたすことは極めて稀であり，従来このような頻拍は二方向性頻拍（bidirectional tachycardia）としてdigitalis中毒，僧帽弁逸脱症候群，心停止後に起こるとされている^1〜3）。しかしながら，各々のQRS波が個々の周期を形成し，心電図上QRS波が個々の周期を形成し，心電図上QRSが完全解離を示した報告はない。

　今回，我々は，経過中同時に複数のwide QRS tachy-cardiaをきたし，両頻拍の解離を示した慢性反復性心不全の1例を経験したので報告する。

A 63 years old woman with chronic heart failurewas admitted to our hospital for palpitation attack on 26th Apr 1988. The patient was died by cardio-genic shock and recurrent ventricular fibrillation 12 hours after admission. The autopsy revealed diffuse myocardial fibrosis and disarray which was compa-tible with dilated cardiomyopathy.

The electrocardiogram on admission showed a peculiar wide QRS tachycadia with atrioventricular dissociation. After intravenous injection of 400 mg of procainamide, the QRS was separated into two types. The one type was left bundle branch blook (LBBB) type with right axis deviation (type A), which was similar as that documented on Jan 1985, and the other was LBBB with normal axis (type B). Each wide QRS tachycardias were sustained indepen-dently and simultaneously either with RR 440 msec. or with RR 600 msec as if they were dissociated intraventricularly. The different wide QRS tachy-cardia documented on Feb 1986 was suspected as the fusion beats with type A and the QRS resembling type B.

Although ventricular tachycardia with beat-to-beat changes of ORS morphology was generally regarded as bidirectional tachycardia, double foci were con-sidered as origins of the two types of wide QRS tachycardia simultaneously observed in this patient.