摘要:

Pulmonary blood volume was measured in five hemodynamically normal subjects and 37 patients with heart disease. Mean pulmonary blood volume in 25 of these patients with moderate to severe mitral stenosis, alone or complicated by other valvular lesions, was 359 ml. per M.2(SE = ±24 ml. per M.2), which was significantly higher than the average value of 230 ml. per M.2(SE = ±14 ml. per M.2) in the five normal subjects (p< 0.025).Multiple correlation of pulmonary blood volume with left atrial mean pressure, pulmonary vascular resistance, and stroke volume showed that each of these factors was significantly related to pulmonary blood volume, independently of the others. Increased left atrial pressure or stroke volume was associated with relatively high, and increased pulmonary vascular resistance with relatively low pulmonary blood volume.In seven subjects 10 to 20 mg. of isoproterenol administered sublingually led to a marked increase in pulmonary blood volume and a small decrease in pulmonary vascular resistance. The average increase in pulmonary blood volume was 78 ml. per M.2, or 35 per cent of the control value (SE = ±15 ml. per M.2), while the average drop in pulmonary vascular resistance was 1.3 R.U.M.2(SE = ±0.5 R.U.M.2). Since the change in volume was too large to be accounted for by arteriolar dilatation alone, and there was a simultaneous decrease in pulmonary arterial and left atrial pressures, isoproterenol apparently increased the distensibility of a large but as yet unidentified segment of the pulmonary vascular bed.

ISSN:0009-7322    

出版商:OVID    

年代:1963

数据来源: OVID

摘要:

A case history of a 46-year-old Negro male was presented with rheumatic aortic insufficiency, angina pectoris, and possible subacute bacterial endocarditis. While hospitalized, the patient developed angina pectoris associated with micturition. This was not accompanied by a change in blood pressure, pulse, or increase in respiratory rate. The striking similarity to a description of a case approximately 300 years ago is pointed out and possible mechanisms of this association of angina and micturition are considered.

ISSN:0009-7322    

出版商:OVID    

年代:1963

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1963

数据来源: OVID

摘要:

The fourth case of right ventricular myxoma is reported, the first one in which the tumor was removed surgically. The clinical picture was that of pulmonic stenosis with some unusual features: effort syncope, changing hemodynamic pattern, and a rapidly progressive clinical course of irreversible congestive heart failure. The importance of early diagnosis, the angiocardiographic findings, and the necessity of operation before development of serious myocardial damage are stressed.

ISSN:0009-7322    

出版商:OVID    

年代:1963

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1963

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1963

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1963

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1963

数据来源: OVID

摘要:

A number of studies have revealed that perceived emotional stress can produce various transient cardiovascular responses. The reactions may include changes in heart rate and cardiac output. They may include abnormalities in heart rhythm, changes in blood pressure, peripheral resistance, blood viscosity, blood clotting time, and serum cholesterol levels. A hypothesis suggested by the findings which requires further research follows: If these cardiovascular responses were sustained for a period of time, they would ultimately influence the onset or course of coronary artery disease. These studies also suggest that emotional tension at one's work may place an additional strain on an already diseased heart.In patients whose cardiovascular system is already impaired, investigators have traced the sequence from emotional upset to heart disease. Since the reported evidence has been based on cardiac subjects, it is still possible that “gradual increase in tension” is perceived only after illness occurs, but not necessarily perceived as stressful before beart disease. Owing to the lack of prospective studies in which the life stress factors are studied prior to heart disease, emotion as a cause or contributory factor to heart disease has not been fully accepted. These studies suggest that certain personality traits may be common to certain forms of heart disease. Most of this evidence has been observed from time-consuming, detailed personality analysis, and the evidence depends on studies of relatively few patients and poor or no controls.It is important to note that these studies on personality type and heart disease were conducted after heart disorders developed. This raises the question of whether the reported personality characteristics preceded or followed the heart disease. The investigations to date assume that the personality structure occurred before the appearance of the heart disease, but before we can answer this question, a longitudinal study of the personality of individuals prior to cardiovascular disease would be necessary.

ISSN:0009-7322    

出版商:OVID    

年代:1963

数据来源: OVID

摘要:

The present status and future prospects of cardiovascular research have been evaluated in terms of a series of axioms that may serve to summarize this report and to guide our efforts in the future.Axiom I. An important objective of cardiovascular physiology is elucidation of the mechanisms of function and control in animals and human subjects under normal conditions.Axiom II. The use of ambiguous and poorly defined terms tends to obscure ignorance and impede progress.Axiom III. Ideally, investigation of physiologic mechanisms should be conducted with minimal disturbances of either the organ system or its controls.Axiom IV. Experimental data are applicablewithout reservationonly to the specific conditions under which they were collected.Axiom V. Extrapolation in the applicationof experimental data to species or to conditions of function different from those in which the information was collected should be based on knowledge of the kind and extent of deviation of the experimental from the normal.Axiom VI. The circulation of anesthetized animals must be regarded as experimental models of normal cardiovascular function.Axiom VII. Experimental models are frequently desirable and useful, but their validation requires quantitative comparison of the specific model with the physiologic mechanism or condition it is designed to represent.Axiom VIII. With the development of technics for comprehensive analysis of cardiovascular function in alert, active animals, general anesthesia, thoracotomy, and heart-lung preparations should be less frequently employed for studies of cardiovascular responses.Axiom IX. The use of general anesthesia to perform on animals the same procedures that are routinely accomplished on human subjects with nothing more than topical anesthesia (venipunctures, catheterization, etc.) may complicate interpretation of experimental observations without contributing significantly to the humane treatment of animals.Axiom X. Before extrapolating from one species to another, an investigator has a responsibility to determine to the best of his ability the extent to which appropriate correspondences have been established for the functions or control mechanisms under study.Axiom XI. A scientific term is most useful when it has a unique definition that immediately indicates what characteristics or properties must be quantitatively measured to determine its existence or change in its status.Axiom XII. Changes in function induced by an investigator during physiologic experiments indicate potential rather than actual mechanisms. The responses to artificially induced loads indicate whatcanhappen rather than whatdoeshappen during normal spontaneous reactions.Axiom XIII. Although newly discovered natural laws may frequently bring order and clarity out of chaos, simplicity is not a reliable criterion for the validity of postulates regarding physiologic function or control mechanisms.

ISSN:0009-7322    

出版商:OVID    

年代:1963

数据来源: OVID