Abstract
In order to see possible changes of blood pressure and electrocardiographic findings during actual labor, an investigation was made on 218 male workers over 40 years of age showing no abnormalities of electrocardiograms in the resting state. The investigation was measurement of the blood pressure and tracing of electrocardiograms on completion of Master's double load test. As to the change of the blood pressure, no difference was ascertained either between age-group of 40∼44 years and 50∼54 years or between groups of hypertension and normal blood pressure. But, as to the posstive findings on the electrocardiogram, while no age-difference was found in the group of normal blood pressure of which the rate of positive cases was lower than the hypertensive group, among hypertensive workers higher rate of positive findings was found in those of the age of 50∼59 than those of 40∼49. From this it was considered that coronary sclerosis was taking part for such positive findings due to continued hypertension. The rate of positive findings was higher in laborers than in clerical workers. No sign of cardiac adaptation for labor was found among the former. From the above, it may be concluded that measurement of blood pressure is of little use and the dynamic circulatory state must be checked by means of electrocardiography.
