A method for measuring quantitatively the volume of cerebral blood flow in man by inhalation of nitrous oxide (1) found its first application in a study of the cerebral circulatory effects of low CO2 tension achieved by hyperventilation; of high CO2 tension, and of high and low 02 tensions obtained by inhalation of appropriate gas mixtures (2). Only the first part of this study, the effects of active and passive hyperventilation, has been published in detail (3). The purpose of the present paper is to present the remainder of these findings and to derive from them, together with those of the hyperventilation experiments, evidence bearing on the intrinsic control of the human cerebral circulation as revealed by quantitative measurements.

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The effects of altered arterial tensions of carbon dioxide and oxygen on cerebral blood flow and cerebral oxygen consumption of normal young men

Rupture or laceration of the aorta is a more common result of nonpenetrating traumatic injury than is generally appreciated. Approximately 15 per cent of individuals with traumatic rupture survive temporarily. If the lesion is promptly diagnosed appropriate surgical treatment may be life-saving. Diagnosis may be difficult and at times the rupture may remain clinically silent for variable periods. The natural course from aortic rupture to false aneurysm formation with secondary rupture of the aneurysm may be brief or extend over many years. Surgical treatment of a false aneurysm that has remained stable for a prolonged period has been successful, but in some instances conservative management may be the treatment of choice.

Nonpenetrating Traumatic Injury of the Aorta

SUMMARYSixty-eight convergent dorsal horn neurones have been recorded at the lumbar level in anaesthetized intact rats. All cells received prominent Aα and C fibre afferents and correspondingly could be activated by high and low threshold stimuli applied to the peripheral excitatory receptive field.

Diffuse noxious inhibitory controls (DNIC). I. Effects on dorsal horn convergent neurones in the rat.

Knowledge about the role of the right ventricle in health and disease historically has lagged behind that of the left ventricle. Less muscular, restricted in its role to pumping blood through a single organ, and less frequently or obviously involved than the left ventricle in diseases of epidemic proportions such as myocardial ischemia, cardiomyopathy, or valvulopathy, the right ventricle has generally been considered a mere bystander, a victim of pathological processes affecting the cardiovascular system. Consequently, comparatively little attention has been devoted to how right ventricular dysfunction may be best detected and measured, what specific molecular and cellular mechanisms contribute to maintenance or failure of normal right ventricular function, how right ventricular dysfunction evolves structurally and functionally, or what interventions might best preserve right ventricular function. Nevertheless, even the proportionately limited information related to right ventricular function, its impairment in various disease states, and its impact on the outcome of those diseases suggests that the right ventricle is an important contributor and that further understanding of these issues is of pivotal importance.

For this reason, the National Heart, Lung, and Blood Institute convened a working group charged with delineating in broad terms the current base of scientific and medical understanding about the right ventricle and identifying avenues of investigation likely to meaningfully advance knowledge in a clinically useful direction. The following summary represents the presentations and discussions of this working group.

The right ventricle is affected by and contributes to a number of disease processes, including perhaps most notably pulmonary hypertension caused by a variety of lung or pulmonary vascular diseases (cor pulmonale). Other diseases affect the right ventricle in different ways, including global, left ventricular–, or right ventricular–specific cardiomyopathy; right ventricular ischemia or infarction; pulmonary or tricuspid valvular heart disease; and left-to-right shunts.

The right ventricle pumps the same …

Right Ventricular Function and Failure Report of a National Heart, Lung, and Blood Institute Working Group on Cellular and Molecular Mechanisms of Right Heart Failure

Diffuse noxious inhibitory controls (dnic) .1. effects on dorsal horn convergent neurons in the rat

The vertical ballistocardiograph; experiments on the changes in the circulation on arising; with a further study of ballistic theory

An improved method for the determination of cardiac output in man by means of ethyl iodide

In a previous communication experiments have been described (1) in which, when systole was simulated in cadavers, the size of the ballistocardiogram proved to be dependent on two major factors: First, on the energy of the systolic blow; and second, on a factor which may be thought of as determining the hardness or softness of the blow, a factor varied in our experiments by changing the padding on the mallet whose strokes provided the energy for the simulation of systole. In this paper we seek to unite these two major factors in the genesis of the ballistocardiogram into a single conception and to ascertain its relation to more familiar aspects of cardiac function. Put another way we have asked ouselves the question whether there is a single aspect of cardiac performance which is driving the ballistocardiogram and if so, how changes in that aspect are related to changes in the size of this record. In making this study we shall take full advantage of the curves which record both cardiac output and blood pressure at each instant, which are the chief features of our experimental preparation, and which permit us to estimate many aspects of \"cardiac\" performance with an accuracy not as yet approached in measurements made on living men or animals. In this paper we will present our data in detail. The results show that there is indeed a single aspect of cardiac function, related to the heart's force, so closely correlated with the amplitude of the ballistocardiogram under such a great variety of conditions that the magnitude of the one can properly be thought of as determining that of the other.

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Studies made by simulating systole at necropsy. III. On the genesis of the systolic waves of the ballistocardiogram.

In a previous publication we defined the relation between cardiac work and blood pressure measurements by means of multiple regression equations. In this communication we seek a simple method of estimating cardiac work from observations any doctor could make in the clinic.

Isaac Starr

Papers

The vertical ballistocardiograph; experiments on the changes in the circulation on arising; with a further study of ballistic theory

An improved method for the determination of cardiac output in man by means of ethyl iodide

Studies made by simulating systole at necropsy. III. On the genesis of the systolic waves of the ballistocardiogram.

Studies Made by Simulating Systole at Necropsy VIII. Significance of the Pulse Pressure

Progress Towards a Physiological Cardiology: A Second Essay on the Ballistocardiogram