Prenylamine失神（tosades de pointes）の1例

A case report of prenylamine syncope (torsades de pointes)

　Picardの報告^1）以来，prenylamine投与中に，QT時間の延長をきたし，torsades de pointes^2〜5）を生じて失神発作に至る症例は内外の文献^6〜18）に散見される。われわれも，prenylamine 90mg服用中にQT時間が著明に延長し，short runs型の多形性心室頻拍を生じて失神発作をくりかえし，lidocaineが奏効したと思われる症例を経験したので報告する。

A 67 year-old woman with hypertension, coro-nary insufficiency, aortic stencsis and chronic hepa-titis, admitted to a hospital for syncopal attacks. She had been recieved prenylamine 90 mg/day and her ECG showed marked prolongation of the QT inter-val and torsades de pointes. She was successfully treated with lidocaine, even though prenylamine was not withdrawn. Similar episodes repeated four times, and finally prenylamine was stopped.

As far as we know, there are 26 cases of preny-lamine syncope, including the present case. The mean age is 69.3 year-old and the sex ratio is M : F=1:3.4. All cases showed QT prolongation and 87% of them showed QT intervals not less than 0.60 sec.

Concerning the therapeutic measures, we propose a classification of torsades de pointes into three types. Type 1 may result from pure QT prolongation, type 2 may be due to the interaction of the delay and non-uniformity of ventricular repolarization and local conduction defects and type 3 may result from pure local conduction defects.