心搏周期と脈波伝達時間

Cardiac Interval and Transmisson Time of Pulse Wave.

　脈波伝達速度の研究には脈波伝達時間の測定が必要である。脈波伝達速度に関しては，従来比較的多数の論文があるにも拘らず，心搏周期と脈波伝達時間との関係については全く報告が無い。

　Sands^1）及びHaynes^2）は脈波伝達速度が血管壁の弾力性，血管の径，血圧（effective pressure）及び血管の蛇行等種々の因子に依り影響されることを指摘した。而してこれ等の因子についてはBramwell, Hill　＆　Mc Swiney^3），Bramwell　＆　Hill^4），Sands^1），加藤等^5）の研究報告がある。

Simultaneous recordings of electrocardiogram and radial pulse wave were performed in patients with arrhythmia absoluta (seven cases), interpolated premature beats (one case) and respiratory arrhythmia (five cases) in order to determine the transmission time of the pulse wave from the heart to the wrist.

A relationship was observed between the preceding cardiac interval and the transmission time of pulse wave in the blood vessel, that the transmission was constant when the preceding cardiac interval was longer than 0.5—0.6sec. and that it prolonged abruptly as the interval became shorter than 0.5—0.6sec.

In regard to the relation of the preceding cardiac interval to the height of the pulse wave (mm), the height increased exponentially with the increase of the interval, and the height was zero at the interval of 0.3—0.4sec. As zero mm in height of pulse wave means an infinite prolongation of the transmission time, the cardiac interval is considered to be 0.3—0.4sec. when the time of transmission prolonged infinitely. The fact that the length of the cardiac interval has a good correlation with the cardiac output may account for these relatioships.