電気的収縮期間に関する研究(第5報) : 第3編 心臓仕事量とQT時間との関係に就ての臨床的験証

Abstract

In order to verify the experimental results on the relation between the heart work and the QT interval, reported in the preceding articles, in clinical cases, the author studied 53 hypertensive patients and 48 hypotensive patients, which were considered under no influence of digitalis, quina alkaloid and abnormal conditions of any electrolyte.(1) In the hypertensive instances without demonstrable myocardial damage (26 cases), the QT interval was longer than the normal average QT interval in all cases, moreover abnormally prolonged in the majority of cases. But in the hypertensive instances with myocardial damage (27 cases), in general, the QT interval was shortened in comparison with the QT interval in the hypertensive group without myocardial damage.(2) In the hypotensive instances without demonstrable myocardial damage (48 cases), the QT interval tended to be shortened in comparison with the normal QT interval, in general.(3) The above-mentioned clinical data are agreed with the experimental results on the toad heart reported in the preceding articles. Namely, also in the clinical cases under no influence of special medicaments, (i) when the heart function is not damaged, the QT interval is prolonged at increased heart work and is shortened at decreased heart work, and (ii), when the heart function is damaged, the QT interval is shorter than the QT interval which the healthy heart would show when it would work out the same load.(4) Consequently, it is not reasonable, either that the QT interval outside the normal limits is always interpreted to mean that the heart is functionally damaged, or that the QT interval within the normal limits is always interpreted to mean that the heart function is not damaged.The meaning of the QT interval should be interpreted in the relation to the heart work.