三段脈—定義と分類に関する1考察

Reappraisal of Trigeminy:Proposed Definition and Classification

　三段脈（Trigeminy）の定義はあいまいである^1）。1拍の洞心拍に2拍の期外収縮が続く場合（図1上段）のみをさすもの^2,3），2拍の洞心拍に1拍の期外収縮が続く場合（図1下段）をさすもの^4〜6）とがあり，この両方をさすもの^7〜8）もある。更に広義に，3個の心拍がグループを成して出現するものと定義するもの^9〜12）もある。著者はこれら4つの立場を踏まえて，三段脈を厳密に定義し，自験例，文献例を整理して三段脈の分類を試みたので報告する。

The definition of trigeminy has not been clearly defined and is still controvertial. The authers proposed its definition as follows; Three consecu-tive beats repeating as a group at least three times. Three consecutive beats may consist of escape beat (E), reciprocal beat (R), bundle branch block (B), ventricular pre-excitation (W) as well as sinus beat (S) or premature beat (P). Furthermore, the premature beats and escape beats are subdivided into atrial, atrioventricular junctional and ventricular ones.

Thus, the trigeminy was glossly classified as follows; 1) S-S-S trigeminy, 2) S-S-P trigeminy, 2') S-P-P trigeminy, 3) E-S-S trigeminy, 3') E-E-S trigeminy, 4) E-S-P trigem iny, 5) E-P-P tri-geminy, 6) S-S-B trigeminy, 6') S-B-B trigeminy, 7) Trigeminyi ncluding the ventricular pre-excitation, 8) miscellaneous.

As a result of reviewing our own cases as well as the cases in the literatures, 30 kinds of trigeminy were found, and another 40 possible kinds of trigeminy were listed up theoretically.