1Watt/体重1kg運動負荷法による循環機能の評価
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概要
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In 14 young, 6 middle-aged and 14 senile normal healthy, 18 patients with compensated ischemic heart diseases, 9 cases of hypertensive cardiac disease and 7 patients with mitral valvular disorders, a total of 68 subjects, by means of the quantitative work load ergometer by bicycle type devised by Yaguchi (1967), one of our collaborators, loading 1 watt per kilo, body weight for six minutes in recumbency, some of parameters indicative of cardiovascular functions were observed ; thus under the consideration of the severity classified by the A.M.A. code, the problems on the assay of cardiovascular functions were discussed. 1. In the patients with severity of the third grade, there could hardly be obtained the maximal ergostasis in the sense of Reindell and Klepzig, so that further observation could not be helped to discontinue in normal health. It was limited to attain the relative steady state in normal health, patients with the severity of the first or the second grade only. 2. When the work load is set by kilo, per body weight, there exists the necessity to correct the oxygen uptake determined in the steady state with kilo, body weight. The oxygen uptake corrected with body weight had no relationship to age and the same matter could be ascertained also in the cases of diseased groups. 3. The heart rates in the steady state ranged from 82 to 138 per minute in normal health; among young, middle-aged and senile normal groups there could not been seen any significant difference. A tachycardic tendency was found more frequently in diseased groups than in normal health, and more markedly in the group of the severity of the second grade in that of the first; thus the heart rates proved a good indicator to circulatory functions. 4. The oxygen pulse must be also corrected with kilo, body weight. Among three subdivisions of normal health classified according to ages, there was not found any significant difference in the oxygen pulse a kilo, per body weight.These corrected oxygen pulse was observed significantly smaller in ischemic heart diseases as well as in mitral valvular disease than in normal health. 5. The recovery quotient (E.Q.) was in the close inverse proportion to age; the correlation index was -0.643 (significance level 99.5%), the regressive formula was determined, y=-0.0188x+3.3486. In the majority of diseased group, E.Q. were seen in lower half of the normal range, but there existed no significant difference from E.Q. in normal health. The ratio of E.Q. to heart rates was influenced by age, despite of not so close relationship as in case E.Q. alone. This ratio was significantly smaller in the diseased groups than in normal health, so that this ratio proved also to be one of good indications of circulatory functions. 6. If an interpretation were made by R.M.R. alone, leaving the oxygen debt out of account, there might rise a risk of missunderstanding that an apparent improvement of the circulatory efficiency could be concluded in cardiac diseases. In order to avoid such a mistake, using E.Q. an indirect expression of the oxygen debt, an index E.Q./R.M.R. was calculated; in this way a supplementary explanation representing R.M.R. was made an attempt. When besides E.Q., heart rates (H.R.) is also used as one of denominators of circulatory functions, an index (E.Q./H.R.×R.M.R.)×10^4 becomes more indicative of the efficiency in exercise test. The efficiency decreases with age; though most of the efficiency in the former existed within normal range, yet the efficiency in diseased groups was found smaller than that in normal health. 7. By means of the exercise test within work load of 1 watt per kilo, body weight for six minutes there existed hardly any change in pHac (=pH of the arterialized capillary blood), PacO_2 and PacCO_2 among normal young subjects. In the normal senile or the diseased groups there could be often the reduction of pHac.In more than half of the subjects there appeared a slight tendency to metabolic acidosis; though these values were only of short duration, yet they proved also the available indicators for the exercise test. 8. There were observed no marked variation in the increasing rate of systolic pressure (Ps) due to this work load among young and senile normal subjects as well as patients; and also there existed no marked difference of the mode of response of Ps between most of the hypertensive as well as normal senile and normal young subjects. The response of Ps during this work load in the normal middle-aged approximated to that in the normal senile; this suggests some possibility of the existence of the latent aging change. The problem upon the determination of diastolic pressure (Pd) during exercise test by Korotkow's method was discussed. 9. By the use of our newly devised ergometer, it was able to determine the normal range of QII, QT, ASZ (tension time duration), ATZ (ejection time duration), and ATZ/ ASZ during exercise. The heart in normal function showed the volume reaction type due to the marked diminution of ASZ, whereas the abnormal heart showed the pressure reaction type, missing such a shortening of ASZ as being seen in the normal heart. The normal senile heart showed a intermediate reaction between the normal young or middle-aged and the patients with ischemic or hypertensive heart disease. The relative prolongation of ASZ in the normal senile heart, emphasized by Harrison or Lange, could be assured only during exercise test, though this change in ASZ missed at the rest; in addition, there could not be observed any diminution of ATZ. 10. Respecting heart rates, oxygen pulse/body weight, (E.Q./H. R.)×10^4, (E.Q./H. R. ×R.M.R.)×10^4, cardiodynamics of pressure reaction type and pHac as indicators of the determination of cardiac functions in exercise, there was presented an ergometric classification of the severity of cardiovascular diseases.[table] The discrimination made by sum up of the respective score was showed the good agreement with the A. M. A. classification of the severity of cardiovascular diseases.
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