ABSTRACT
The aim of this work is to define, on the basis of impedance rheography, a method to record arterial section variations without either inertia or the production of wall-strain. High frequency current (2 MHz) is employed to measure the impedance variations of the deforming artery. The modulating envelope is representative of arterial section variations. This method permits the recording of arterial section variations by a peri-arterial method or an external method on superficial arteries (without denudation). A comparison between arterial section variations and arterial pressure variations at the same point shows that the arterial wall behaves as a non-linear pressure gauge: Rheogram-pressure curves are similar to volume-arterial pressure curves. The great precision with which this method describes the chronology of arterial deformations is of great interest in defining viscous properties of the arterial wall and following their evolution during pathologic alterations such as atherosclerosis.
Subject(s)
Arteries/physiopathology , Plethysmography, Impedance/methods , Animals , Dogs , Plethysmography, Impedance/instrumentation , Pressure , Vascular Diseases/physiopathologyABSTRACT
A new hardware device has been constructed to detect QRS and P complexes for the purpose of automatic arrhythmia interpretation. This apparatus can operate in noisy conditions and provide synchronized pulses representative of P complex, QRS complex, wide QRS, and premature QRS to different output channels. P wave identification is achieved with a high degree of reliability through a specially designed bipolar electrode catheter. The device could minimize demands on central processor time and core storage computer.
Subject(s)
Arrhythmias, Cardiac/diagnosis , Electrocardiography/instrumentation , Computers , Humans , Monitoring, Physiologic/instrumentation , Tachycardia, Paroxysmal/diagnosisABSTRACT
The authors carried out an enquiry in 32 patients as part of a more extensive study which permitted them to show the necessity of early physical rehabilitation after myocardial infarction which should be gradual and as prolonged as possible under permanent medical control. Subjects under training usually adhere enthusiastically to this program of progressively complete and rapid social reinsertion, by the development of new relationships, whether personal, familial or professional.
Subject(s)
Exercise Therapy , Myocardial Infarction/rehabilitation , Adult , Aftercare , Family , Female , France , Humans , Male , Middle Aged , Professional-Patient Relations , Rehabilitation Centers , Rehabilitation, Vocational , Self Concept , Social Adjustment , Surveys and QuestionnairesABSTRACT
A total cardiac supplementation through a simple by-pass of the left ventricle was performed on hearts in ventricular fibrillation on 51 dogs not treated with heparin. The right-sided circulation was passive to avoid introducing added disturbing parameters. A bi-valved supple prosthesis was set in motion by a pneumatic pump regulated on the left atrial pressure and the arterial tree proper rate. The 44 cases which survived from 7 to 27 hours were limited by a slow and regular lowering of the blood pressure without notable decrease of the output. This lowered pressure was due to the action of the atrial and pulmonary mechanical receptors responding to a left atrial hypertension, secondary to a mild leak of the inflow valve. The mild haemolysis and the total absence of thrombosis should be related with the rate-regulation of the pump on the arterial tree rate, thus providing a maximal yield.
