摘要:

By means of small intramural electrodes, potentials at multiple depths within the ventricular wall were recorded in myocardial infarction and in normal hearts. In 41 animals with coronary artery occlusion, electrocardiographic and histologic correlations indicated that coronary QS waves may represent negative potentials transmitted from viable intramural muscle as well as from the cavity. Coronary QR waves were obtained over transmural infarcts containing a mixture of viable and dead tissue, but not over purely subendocardial lesions. In the normal ventricle, positive depolarization potentials greatly predominated over negative potentials. Clinical applications are discussed.

ISSN:0009-7322    

出版商:OVID    

年代:1953

数据来源: OVID

摘要:

Dyspnea has many characteristics, differing from one clinical state to another. In pulmonary diseases the immediate cause is usually a disproportion between actual ventilation (breathing requirement) and breathing capacity. The hyperventilation of organic pulmonary disease is often mistakenly diagnosed as psychoneurosis. In early cardiac dyspnea, muscular fatigue associated with inadequate cardiac output may be a factor. True pulmonary congestion becomes important in more advanced left ventricular failure.

ISSN:0009-7322    

出版商:OVID    

年代:1953

数据来源: OVID

摘要:

The selection of patients for mitral commissurotomy must be made after considering all manifestations of the rheumatic state. A conservative approach is urged and no patients should be operated upon without evidences of increasing pulmonary hypertension and right heart strain. The preparation of the patient, the management of the arrhythmias during surgery and the postoperative care are the full responsibilities of the physician. A team composed of physiologists, cardiologists and surgeons must work together.

ISSN:0009-7322    

出版商:OVID    

年代:1953

数据来源: OVID

摘要:

The effect of the addition of dihydrocholesterol to a high cholesterol diet has been studied in the chicken. It is shown that in this species the elevated plasma cholesterol and resulting atherosclerosis can be reduced to normal levels by such a procedure.

ISSN:0009-7322    

出版商:OVID    

年代:1953

数据来源: OVID

摘要:

Gross and microscopic studies of the auriculoventricular conduction system were performed in 60 human hearts. A unique technic is introduced which will produce a photographic record of undistorted serial sections through a block containing the auriculoventricular node, auriculoventricular bundle and branches. By projecting the completed film as a motion picture, the course and changing relationships of component structures can be followed from level to level in uninterrupted sequence. The neurogenic versus the myogenic concept of cardiac conduction is reviewed at length.

ISSN:0009-7322    

出版商:OVID    

年代:1953

数据来源: OVID

摘要:

Patients with severe essential hypertension have been carefully studied periodically in an attempt to group them as to probable life expectancy. Forty such patients have been observed while on oral 1-hydrazinophthalazine and a low salt diet. Nineteen of the 33 patients in the groups having a relatively good prognosis for survival had some decrease in diastolic pressure. Only one of seven patients in Smithwick group IV had a satisfactory reduction in blood pressure.

ISSN:0009-7322    

出版商:OVID    

年代:1953

数据来源: OVID

摘要:

The effect of carotid sinus pressure on the duration and character of attacks of angina pectoris induced by exercise under controlled conditions has been studied in 13 patients. Observations are presented which are consistent with the hypothesis that stimulation of the carotid sinus induces relief of cardiac pain by interruption of sympathetic reflex arcs or sensory pathways. The usefulness of carotid sinus pressure as a diagnostic test and a therapeutic measure in angina pectoris is discussed.

ISSN:0009-7322    

出版商:OVID    

年代:1953

数据来源: OVID

摘要:

It has been known that exercise causes an increase in the coronary blood flow in animals. The present work has been carried out to study the effect of exercise on coronary blood flow and myocardial oxygen consumption of the human heart in vivo. The results indicate that the heart responds to the increased load of exercise with a rise in coronary blood flow. Since the arteriovenous coronary oxygen difference shows little change, the increase in oxygen consumption of the heart muscle is primarily the result of an increased coronary blood flow. As the cardiac work rises more than the myocardial oxygen consumption, the left ventricular efficiency increases. The response of the failing heart muscle to acute increases in load produced by exercise does not differ from that of the normal heart or of the isolated heart.

ISSN:0009-7322    

出版商:OVID    

年代:1953

数据来源: OVID

摘要:

Normal retinal arteries and veins will constrict when the arterial blood oxygen tension is increased and dilate when it is lowered. A technic, employing fundus photography, is described for measuring this reaction. The amount of constriction on breathing oxygen, and its trend with age, have been measured in normal subjects. The arteries of persons with well-established hypertension and diabetes usually show marked impairment of this constrictor reaction, presumably because of sclerotic changes. It is suggested that measurements of this reaction may prove to be a useful, quantitative extension of present retinal vascular grading technics.

ISSN:0009-7322    

出版商:OVID    

年代:1953

数据来源: OVID

摘要:

It has been found that retinal arterial reactivity to oxygen is diminished in persons with retinal arteriosclerosis, and that cerebral blood flow and the increment in cerebral flow upon inhalation of carbon dioxide are diminished in persons with cerebral arteriosclerosis. The present study demonstrates that there is a significant positive correlation between retinal arterial reactivity on the one hand, and cerebral blood flow and reactivity, on the other. This finding is taken to mean that arteriosclerosis severe enough to affect measurements of this sort is apt to involve retinal and cerebral vessels together.

ISSN:0009-7322    

出版商:OVID    

年代:1953

数据来源: OVID