摘要:

This investigation attempts to demonstrate the mechanism by which substances that block autonomic ganglionic transmission increase the pressor and depressor activities of a variety of drugs. Short-lived hypertension and a high degree of vascular responsiveness is induced by combining cord destruction, inactivation of the carotid sinus mechanism and nephreetomy. The increased responsiveness is found to be due to removal of the compensatory nervous mechanisms which tend to oppose changes in blood pressure. It may be reduced or abolished by hepatectomy, severe hypotension and shock.

ISSN:0009-7322    

出版商:OVID    

年代:1950

数据来源: OVID

摘要:

In Ebstein's anomaly the tricuspid valve is displaced downward so that the upper portion of the right ventricle is incorporated in the right auricle. This imipairs the efficiency of the right side of the heart and produces a distinctive syndrome, which is described here for the first time. Diagnosis is important because this malformation, which is not amenable to surgery, may be confused with the tetralogy of Fallot.

ISSN:0009-7322    

出版商:OVID    

年代:1950

数据来源: OVID

摘要:

Experiments were performed on the anesthetized dog to determine the accuracy of the widely used Fick procedure. Cardiac output values, recorded by an optical rotameter, served as a reliable standard for comparison. Under the conditions of these experiments, comparisons showed excellent agreement. The average variation between the two series of the measurements was ±5 per cent. Twelve of thirteen comparisons agreed within less than ±8 per cent. This small deviation was within the range of error which might have existed on the basis of known technical inaccuracies.

ISSN:0009-7322    

出版商:OVID    

年代:1950

数据来源: OVID

摘要:

Flicker fusion threshold (F.F.T.) means the frequency with which successive flashes of light must occur to just appear to the eye free from flicker. A simple portable machine is described which will deliver flashes of light at any required interval. Patients with hypertension or anemia have a lower than normal F.F.T.; furthermore, administration of nitroglycerin, 0.4 mg. sublingually, or papaverine, intravenously, raises the threshold in patients with hypertension and coronary disease and lowers it in normal individuals. It is suggested that this test may be of use in the diagnosis of equivocal cases and for the evaluation of therapeutic measures.

ISSN:0009-7322    

出版商:OVID    

年代:1950

数据来源: OVID

摘要:

Both organic occlusion and vasospasm are usually present in peripheral arterial vascular diseases. The degree of occlusion and the probable effectiveness of treatment designed to relax vasospasm can both be determined by measurement of the maximum increase in cutaneous blood flow produced by suitable vasodilator procedures. These studies included warming the torso and/or injections of tetraethylammonium chloride or benzylimidazoline, and administration of spinal anesthetic. The effects obtained with all three methods were closely comparable. Cutaneous blood flow was estimated from recordings of skin, room and body temperatures.

ISSN:0009-7322    

出版商:OVID    

年代:1950

数据来源: OVID

摘要:

The direction of blood shunts between abnormally communicating ventricles or large vessels is dependent upon blood pressure differences in the adjacent structures, and upon the respective vascular resistance in both circulating systems distal to the communication. In a case of patent ductus arteriosus, physiologic measurements suggested that the direction of blood flow through the ductus was reversed intermittently during the systolic phase of the cardiac cycle. Pathologic studies confirmed the hypothesis by demonstrating the presence of "impingement" plaques on the aortic as well as on the pulmonary artery walls opposite the lumen of the ductus. They also gave information concerning the lesions in the pulmonary vascular bed which might be held responsible for the considerable increase in resistance, the pulmonary systolic hypertension and, attendant to it, the cyclic reversal of blood flow.

ISSN:0009-7322    

出版商:OVID    

年代:1950

数据来源: OVID

摘要:

The occurrence of 59 cases of acute coronary insufficiency among 103 patients with acute hemorrhage, chiefly from the gastrointestinal tract, emphasizes the frequency and gravity of this generally unrecognized complication of bleeding. Clinical, electrocardiographic and anatomic manifestations of myocardial ischemia and subendocardial necrosis are prone to appeal in previously diseased hearts, although they may develop in otherwise normal hearts. Consequently, prompt and adequate blood replacement is required in patients with coronary arteriosclerosis, enlarged hearts, valvular heart disease, etc. to prevent as well as to treat coronary insufficiency secondary to hemorrhage.

ISSN:0009-7322    

出版商:OVID    

年代:1950

数据来源: OVID

摘要:

Following aseptic occlusion of the anterior descending artery of the dog's heart ectopic ventricular tachycardia develops after a latency of four and one-half to eight hours, and persists for two to four days. Large gross infarcts are found in all hearts. The duration of latency of onset of major ectopic activity approximates the minimal period of ischemia required to produce histologic signs of necrosis. It is suspected that products or processes of necrosis have excitatory effects on tissues bounding the ischemic zone. Evidences concerning various possible excitatory factors are briefly reviewed.

ISSN:0009-7322    

出版商:OVID    

年代:1950

数据来源: OVID

摘要:

Because of renewed clinical interest in the Q-T interval and because of a need of normal values for an accompanying investigation in rheumatic fever, the Q-T was studied in 517 normal infants and children from birth to 13 years of age. A meanKof 0.404 for Bazett's formula and of 0.378 for Ashman and Hull's formula was obtained. With Bazett's curve approximating the data more closely, a Bazett's scattergram of the normal Q-T at varying heart rates was constructed. Although no difference inKvalue was noted between the sexes, significant differences were observed in certain age groups.

ISSN:0009-7322    

出版商:OVID    

年代:1950

数据来源: OVID

摘要:

In 143 rheumatic children the Q-T interval was found to be normal in those with quiescent rheumatic heart disease. In 29 with fatal pancarditis the average Q-T was above the average normal, though not beyond the upper limit of normal. Although parallel changes in the Q-T interval and the clinical manifestations of rheumatic fever occurred in about 66 to 75 per cent of cases, there were significant number of instances where changes in the Q-T and in the clinical course of the disease were in opposite directions.

ISSN:0009-7322    

出版商:OVID    

年代:1950

数据来源: OVID