摘要:

The efficacy of electrical countershock, cardiac massage, epinephrine and procaine in stopping ventricular fibrillation and restoring a competent ventricular contraction was studied in anesthetized dogs. It was found that countershock is a reliable means of stopping fibrillation. However, it must be preceded by cardiac massage if not applied promptly after the initiation of fibrillation. Epinephrine helps restore a competent ventricular contraction once fibrillation has been stopped by countershock but it increases the incidence of recurrence of fibrillation. The doses of procaine which constitute a reliable means of stopping fibrillation depress the rhythmicity of the heart to such an extent that the cessation of fibrillation is followed by prolonged periods of cardiac standstill.

ISSN:0009-7322    

出版商:OVID    

年代:1953

数据来源: OVID

摘要:

Eight cases of patent ductus arteriosus associated with marked pulmonary hypertension are presented with complete cardiac catheterization studies in six patients and autopsy studies in three cases. Four patients had clear evidence of a "reversed" shunt through the ductus, three presenting the clinical picture of cyanotic congenital heart disease. The authors discuss the nature of the increased resistance of the pulmonary vascular bed which is the basis of the circulatory changes in these cases.

ISSN:0009-7322    

出版商:OVID    

年代:1953

数据来源: OVID

摘要:

Wear and tear degenerative patterns of the arterial system of the lower extremities have been studied in an age series. The intensity of these alterations has been correlated with the distribution of the atheromatous plaques and thrombosis as well as with the effective tension at various levels as calculated by Burton's formula. Evidence is presented for the concept that the lipids in atheromatous plaques arise as a product of these degenerative reactions within the vessel wall, rather than by diffusion from the circulation through the endothelial barrier.

ISSN:0009-7322    

出版商:OVID    

年代:1953

数据来源: OVID

摘要:

This paper describes results obtained during the last three years with special emphasis on those secured since the development of the technic which permits us to employ compatible blood as perfusion fluid. Using the method of paired experiments, data have been obtained on the effects on the pulse wave and the ballistocardiogram which follow changes in the total energy of the simulated systole, changes in the way that energy is applied during the systole, changes in resistance as measured by diastolic pressure, and differences in the amount of arteriosclerosis present in various subjects.

ISSN:0009-7322    

出版商:OVID    

年代:1953

数据来源: OVID

摘要:

Observations on the hemodynamic properties of a thiophanium derivative (Arfonad) have been made on normotensive nonpregnant and pregnant subjects and on patients with hypertensive complications of pregnancy. The drug was given by single intravenous injections and by intravenous drip infusion. The hypotensive effects of single injections where compared with those of a standard tetraethylammonium chloride (TEAC) test. The authors observed that the hemodynamic effects of Arfonad were similar in some respects to those of tetraethylammonium chloride or spinal anesthesia. A fall in the cardiac output occurred when the blood pressure fell following Arfonad administration. The authors discuss these hemodynamic effects in terms of differences in response to ganglionic blocking agents of the various groups of subjects studied.

ISSN:0009-7322    

出版商:OVID    

年代:1953

数据来源: OVID

摘要:

Use of cuvette and earpiece oximeters facilitates the recording of the immediate dilution pattern of the dye T-1824 (Evans blue) in the arterial blood. In patients with venoarterial shunts the pattern of the dilution curves differs from normal. Quantitative analysis of such curves from patients with cyanotic congenital heart disease has been undertaken to establish the proportion of blood which bypassed the pulmonary circulation. The results obtained have been compared with estimates of the volume of the shunt from cardiac catheterization data and related to the arterial oxygen saturation.

ISSN:0009-7322    

出版商:OVID    

年代:1953

数据来源: OVID

摘要:

Tetraethylammonium (TEA) given intravenously decreases peripheral vascular resistance. The magnitude of the decrement is related directly to the prevailing level of neurogenic vasomotor tone. TEA was administered to hypertensive and normotensive subjects. The decrements in resistance of the foot did not differ between the two groups. The decrements of the forearm also did not differ. These findings suggest that the prevailing level of neurogenic vasomotor tone in the extremities is not increased in hypertension.

ISSN:0009-7322    

出版商:OVID    

年代:1953

数据来源: OVID

摘要:

The radiosodium clearance technic was used to measure the effect of Priscoline given intraarterially on the effective blood flow in muscle and skin of normal subjects and patients with peripheral vascular disease. The only clinically significant increase in the clearance rate of radiosodium (Na24) occurred in the skin; the clearance rate in muscle showed small increases which were constantly present but not considered to be clinically significant.

ISSN:0009-7322    

出版商:OVID    

年代:1953

数据来源: OVID

摘要:

The spectrum of frequencies making up the cardiac potential has not been fully explored. Limitation in the high frequency response of most electrocardiographs suppresses in some tracings QRS components whose significance is at present obscure. Using the cathode ray oscillograph it was found that frequencies as high as 1300 cycles per second reveal characteristics not shown at lower frequencies. Frequencies as high as 6400 cycles per second are under investigation. Limitation of the low frequency response by the use of a condenser-resistor network to abolish extraneous potentials produces serious distortions of the RS-T segment.

ISSN:0009-7322    

出版商:OVID    

年代:1953

数据来源: OVID

摘要:

The following brief summary seems justified from the large volume of accumulated data dealing with the reaction of the cardiovascular system in the anemic patient.There are four mechanisms operating in the anemic patient which may increase the supply of oxygen to the tissues when the oxygen carrying capacity of the blood is reduced. Under conditions of rest, a rapid velocity flow and tachycardia with an increase in minute volume of cardiac output is the first response to anemia. As compensation develops, tachycardia and increased velocity flow are largely replaced by selective shunting of blood and the removal of an increasing percentage of oxygen in the tissue capillaries from each gram of circulating hemoglobin.These later physiologic mechanisms are best illustrated by patients with chronic parasitic anemias. Under conditions of physical stress each of the four physiologic mechanisms contribute in meeting the demands for increased oxygen requirements. Compensation is, however, never perfect; the status of the patient is determined by the reduction in hemoglobin, the tissue oxygen requirements, the presence of physical changes in the cardiovascular and pulmonary systems, degree of oxygen abstraction from the blood, and the selective shunting of blood.In relatively acute anemia, dyspnea readily occurs on physical exercise. Reduction in the ventilatory capacity of the lung occurring in some anemic patients results from an over-all reduction in physical fitness due to the anemic state rather than to physical changes in the lung. In well compensated, chronic anemia, the vital capacity of the lungs is frequently above normal and similar to that observed in athletes and completely acclimatized, high altitude inhabitants.In the absence of cardiovascular disease or physical or metabolic factors requiring increased cardiac output, true congestive heart failure rarely results from the anemic state.Effort angina is uncommon in anemic patients and when present is usually related to underlying coronary artery disease.Cardiac hypertrophy under certain conditions results from prolonged anemia. Since cardiac hypertrophy is rightly placed in the category of organic heart disease, one is justified in classifying chronic anemia as one of the etiologic factors in the production of heart disease.

ISSN:0009-7322    

出版商:OVID    

年代:1953

数据来源: OVID