THE EFFECTS OF ACTIVE AND PASSIVE HYPERVENTILATION ON CEREBRAL BLOOD FLOW, CEREBRAL OXYGEN CONSUMPTION, CARDIAC OUTPUT, AND BLOOD PRESSURE OF NORMAL YOUNG MEN

Renal Excretion of Sodium in Arterial Hypertension

Patients with arterial hypertension excrete a sodium load more rapidly than do individuals with normal blood pressure. The relationship of this abnormal sodium excretory response to blood pressure and such extrarenal factors as the central nervous system, dietary salt intake, body fluid volume and sodium content, and the adrenal glands has been studied. On the basis of this and other evidence, it is suggested that the exaggerated natriuresis is the result of a renal tubular defect which occurs after the development of hypertension.

Vasodepressor syncope; factors influencing cardiac output

Vasodepressor syncope is characterized hemodynamically by a sudden fall in total peripheral resistance with little associated change in cardiac output. The failure of the cardiac output to compensate for the fall in peripheral resistance is a striking feature of the fainting reaction. Possible explanations for this phenomenon are the presence of neurogenic myocardial inhibition or markedly limited volume of blood available to the heart. The effects of atropine injections, inflation of antigravity suit, negative pressure breathing, and albumin infusions on the syncopal reaction were studied. Results favor the causative role of limited venous inflow in the cardiac output response.

The effect of hyperventilation on various arrhythmias

The influence of hyperventilation on various cardiac arrhythmias is examined. Auricular and ventricular extrasystoles disappear temporarily, paroxysmal auricular and ventricular tachycardias aswell as attacks of short paroxysmal auricular fibrillation are abolished by hyperventilation. An attempt is made to explain these phenomena.

The hyperventilation syndrome

The hyperventilation syndrome is the name given to a distinctive group of symptoms and signs which are caused by an increase in the depth and rate of breathing. This abnormal breathing is nearly always the result of emotional stress.

Cheyne-Stokes respiration: an oximeter study

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The role of carbon dioxide in anaesthesia

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Studies of the cerebral circulation and metabolism in congestive heart failure

In a study of the cerebral circulation and metabolism in congestive heart failure, using Kety's nitrous oxide technic, it was found that no significant alterations of the cerebral circulation were present when the quantities measured were compared with values determined for a control group. A decrease in cerebral blood flow and oxygen consumption below values established for normal young individuals was demonstrated to be secondary to the presence of arteriosclerosis and not to cardiac decompensation as had previously been concluded. It was also found that in the series studied the increased venous and cerebrospinal fluid pressures were not of sufficient magnitude to affect the cerebral circulation. The factor of a decreased arterial carbon dioxide tension as a cause for diminished cerebral blood flow in cardiac decompensation was similarly considered and dismissed.

Observations on the Dynamics of the Systemic Circulation in man

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