いわゆるジギタリスEcgにかんする臨床的ならびに実験的研究
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Part I. Digitalis Ecg. in Goldberger's Augmented Unipolar Limb Leads and Wilson's Unipolar Chest Leads. There were analyzed the electrocardiograms of selected 37 cases which were scrupulously observed under the digitalis therapy on account of cardiac insufficiency. 1. P. a) Goldberger's leads: The changes of P are generally not striking, only 2 cases showed the significant transformation in aV_R and aV_L, respectively. b) Wilson's chest leads: The changes of P in V_1〜V_6 were found only in 4 cases. 2. Cardiac position and rotation. a) Goldberger's leads: No more than 2 cases gave the disjtinct changes of the cardiac position in aV leads. b) At the early stage of digitalization the clockwise rotation was more frequently seen than the anticlockwise one. 3. ST. a) Goldberger's leads: ST in aV_R were tend upward and ST in aV_F downward. ST in aV_L was either raised or lowered according to the cardiac position, but these changes were for the most part within normal limits. b) Wilson's chest leads: Except for the extreme right ventricular strain curve, the digitalis ST depression was markedly observed in those leads which showed the largest upward deflection of QRS. Digitalis depresses ST of the levogram, and elevates ST of the dextrogram. However both in the excessive right ventricular strain curve and in the case with vivid "Halb-seiten Effekt," digitalis does not raise ST of the dextrogram. 4. T. a) Goldberger's leads: T in aV_F relatively often decreases in its positivity, becomes negative, and increases in its negativity. The characteristic changes due to digitalization are not clearly recognized in aV_R and aV_L. b) Wilson's chest leads: T frequently decreases in its positivity, becomes negative or diphasic, and increases in its negativity. These changes are in special measure repeatedly found in the levogram. 5. Under the digitalization ventricular premature beats, auricular flutter and fibrillation appeared in several cases. Ventricular bigeminy and atrioventricular block were observed in each of two cases.On the contrary, there were found some cases in which the digitalization extinguished ventricular extrasystoles or bigeminy and auricular fibrillation persisted so long. Even in the presence of the ventricular bigeminy which is as a rule considered to be the indication to stop the digitalis use, yet digitalis can be administered under the closed notice. 6. Among 25 cases which showed sinus full rhythm, the prolongation of PR complicated with ST depression was observed in 6 cases (24 %). 7. Among 36 cases in which QT was estimated satisfactorily, the shortening of QT was found in 17 cases (47 %); 59 % of cases with shortened QT were accompanied by ST depression. 8. The digitalis bradycardia was recognized in 18 cases (49 %) and 65 % of bradycardic cases showed ST depression. 9. In the electrocardiograms of 7 cases suffered from the side effects of digitalis, i. e. vomitting, visual disturbance and so on, there could be often found arrhythmia and distinguished ST depression. The outburst of clinical side, effects was preceded by the clear-cut ST depression in two cases, so that it may possibly be taken the onset of the remarkable ST depression granted for an alarming sign of the threatening side effects. 10. The characteristic patterns of digitalis ecg. can be recognized even in the cases with digitalis refractoriness, the extent of such changes is, however, generally less striking and becomes as slighter as near death. Part II. Experimental Studies on so-called Digitalis Ecg. The experiments were carried on the dog's hearts which were relatively resistive against digitalis Cdorsal fixation, isomytal anesthesia). a) the drip infusion of 1.0 mg of Strophosid intravenously. b) 5 times of the intravenous injections of 0.25 mg of Strophosid every 20 minutes. c) 3 times of the intravenous injection of 0.6 mg of Digicorin (AD-1), in total 1.8 mg. d) the intravenous injection of 1.0 mg of Acetylcholine before and after 1.8 mg of Digicorin.e) 2 times of the intravenous injection of 0.25 mg of Strophosid after the injection of 3.6 mg of Digicorin intravenously. f) the intravenous injection of 300 mg of Pronestyl at the event ventricular tachycardia due to over dosage of digitalis. The timepoint of every observation after the various digitalis injections is always the same; at each observation, besides registration of ecg., blood pressure and respiration, Wezler's analysis was performed. 1) Either Strophosid or Digicorin, which is the limit of calculated therapeutic dosage, do not bring ST-T depression, whereas the calculated toxic doses of two drugs lower ST-T distinctly. There are found some cases in which the extrasystoles are preceded by the appearance of ST-T depression; therefore it cannot be concluded that changes of ST-T pattern can be possible for guide of the digitalis bioassay. 2) In the cases injected with Strophosid fractionatedly, ST-T depression can be recognized earlier at the smaller dosis than that in the cases treated by the drip intravenous infusion. Undiluted Strophosid does often elevate the blood pressure, chiefly due to increase in output. 3) The negative chronotropic action of both Strophosid and Digicorin is more or less weak. 4) The stimulation immediately after the cervical vago-sympathectomy prolongs PR, moreover occasionally elicits atrioventricular dissociation. 5) Even in the toxic stage of Strophosid the essential pattern of carotid sinus pressor reflex can be observed, although the degree 'of reflexibility becomes smaller than that before the injection, and the reflex tachycardia becomes more vague. From these results it may be safe to say that the effect of reflexly augmented sympathicotonia by means of Hering's second stimulation is difficult to take place because of the inhibitory vagal action of Strophosid. 6) The intravenous injection, of 1.0 mg of Acetylcholine administered before the use of Digicorin lowers the blood pressure range abruptly, and there develops apnea instantly after temporal hyperpnea.Electrocardiographically after ventricular arrest due to atrioventricular block followed tachycardic auricular impure flutter, there occured initially bradicardic, thereafter tachycardic auricular fibrillation, sinus complete rhythm, temporal atrioventricular dissociation in turn untill the complete sinus rhythm was recovered. The tachycardia which breaks out at the beginning, is considered to depend upon sinocarotid or cardioaortic chemoreceptor reflex, whereas the intravenous injection of 1.0 mg of Acetylcholine after Digicorin does not cause such an initial tachycardia, so that it may be appropriate to say that Digicorin does exert influence upon these reflex arcs. 7) The intravenous injection of Acetylcholine after application of Digicorin reveals quite the same extent of the reactivity with merely one half dosis, therefore it may be concluded that Digicorin is sure to promote the vagal tonisity. 8) The intravenous injection of Acetylcholine after the administration of Tropin brings out the inverse reaction of blood pressure, whereas the hyperventilation of short duration appears. The former phenomenon may be concerned with suppression of muscarinlike action of Acetylcholine, the latter with the deficiency of the paralytic action against visceroafferent fibre. 9) After the saturation accomplished with Digicorin the intravenous injection of Strophosid depresses ST-T and further there occurs ventricular tachycardia. Even after the saturation of Digicorin, of which toxity is very slight, the injection of Strophosid proves dangerous. 10) After the, saturation by the application of Digicorin, the ventricular tachycardia due to the intravenous injection of Strophosid cannot be prevented with the administration of 300 mg of pronestyl intravenously, so the arterial depression develops. But there appeared the reduction of QRS interval which can be thought to be improvement of intraventricular conduction disturbance; therefore in such event Pronestyl proves necessary.11) All instances injected with Strophosid as above mentioned may show subendocardial haemorrhage which was observed more markedly in the outflow area beneath aortic valves than in the inflow area under mitral valves. The subendocardial haemorrhage lacked in inflammation histologically. The cases treated with the singular use of Digicorin do not show the subendocardial haemorrhage even if ST-T depressed remarkably.
- 千葉大学の論文