Some Effects of Electrical Stimulation on Impulse Initiation in Cardiac Fibers; its Relevance for the Determination of the Mechanisms of Clinical Cardiac Arrhythmias

1978 ◽  
pp. 163-181 ◽  
Author(s):  
Andrew L. Wit ◽  
Jay R. Wiggins ◽  
Paul F. Cranefield
Keyword(s):  
Electrical Stimulation ◽  
Cardiac Arrhythmias ◽  
Cardiac Fibers

ADENOHYPOPHYSEAL LH CONTENT IN NORMAL, ANDROGEN-STERILIZED AND PROGESTERONE-PRIMED STERILE FEMALE RATS

1962 ◽  
Vol 39 (1) ◽  
pp. 13-21 ◽  
Author(s):  
Roger A. Gorski ◽  
Charles A. Barraclough
Keyword(s):  
Ascorbic Acid ◽  
Electrical Stimulation ◽  
Quantitative Determination ◽  
Median Eminence ◽  
Hypothalamic Stimulation ◽  
Female Rats ◽  
Rat Pituitary ◽  
Gland Content ◽  
Stimulation Of

ABSTRACT We have previously suggested that the failure of the androgen-sterilized, persistent-oestrous rat to ovulate, following electrical stimulation of the median eminence structures of the hypothalamus, is due to an insufficiency in adenohypophyseal LH concentration. Using the ovarian ascorbic acid technique for quantitative determination of pituitary LH content, the present studies have demonstrated that the sterile rat pituitary gland contains one-third the LH content of the normal prooestrous gland. Furthermore, not only does progesterone priming of this persistent-oestrous rat result in a 75 % increase in LH concentration, but on hypothalamic stimulation sufficient LH is released to induce ovulation. The decrease in LH concentration which accompanies ovulation in the progesterone-primed, sterile rat is approximately 45 % of the total gland content as compared with a 51 % decrease in pituitary content in the normal cyclic rat.

The effect of transcranial magnetic stimulation on the excitability of the motor neuron pools of the muscles of the lower extremities

2021 ◽  
Author(s):  
S.S. Ananiev ◽  
D.A. Pavlov ◽  
R.N. Yakupov ◽  
V.A. Golodnova ◽  
M.V. Balykin
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Magnetic Stimulation ◽  
Primary Motor Cortex ◽  
Lower Extremities ◽  
Transcutaneous Electrical Stimulation ◽  
Stimulation Of

The study was conducted on 22 healthy men aged 18-23 years. The primary motor cortex innervating the lower limb was stimulated with transcranial magnetic stimulation. Using transcutaneous electrical stimulation of the spinal cord, evoked motor responses of the muscles of the lower extremities were initiated when electrodes were applied cutaneous between the spinous processes in the Th11-Th12 projection. Research protocol: Determination of the thresholds of BMO of the muscles of the lower extremities during TESCS; determination of the BMO threshold of the TA muscle in TMS; determination of the thresholds of the BMO of the muscles of the lower extremities during TESCS against the background of 80% and 90% TMS. It was found that magnetic stimulation of the motor cortex of the brain leads to an increase in the excitability of the neural structures of the lumbar thickening of the spinal cord and an improvement in neuromuscular interactions. Key words: transcranial magnetic stimulation, transcutaneous electrical stimulation of the spinal cord, neural networks, excitability, neuromuscular interactions.

Comparison Between Isotropic and Anisotropic Electrical Properties of a DTI-Based Cardiac Model

2008 ◽  
Author(s):  
Ana Maria Saaibi ◽  
Isaac Chang ◽  
Min-Sig Hwang ◽  
Malisa Sarntinoranont
Keyword(s):  
Electrical Properties ◽  
Ventricular Fibrillation ◽  
Cardiac Function ◽  
Cardiac Arrhythmias ◽  
Three Dimensional ◽  
Delicate Balance ◽  
Cardiac Model ◽  
Myocardial Fibers ◽  
Fiber Organization ◽  
Cardiac Fibers

Cardiac function is influenced by the three-dimensional organization of the myocardial fibers. Cardiac fibers are arranged in a circumferential, longitudinal, and a sheet-like fashion, forming counter-wound helices from the base to the apex of the heart. This fiber organization is responsible for the delicate balance between mechanical and electrical functioning of the heart. When electrical disruption of this coordinated function occurs, this is associated with cardiac arrhythmias which may lead to more serious conditions like ventricular fibrillation.

Recognition and Management of Cardiac Arrhythmias: Part II. Ventricular Arrhythmias and Bradyarrhythmias

1998 ◽  
Vol 13 (2) ◽  
pp. 68-77
Author(s):  
Simon Chakko ◽  
Raul Mitrani
Keyword(s):  
Myocardial Infarction ◽  
Heart Failure ◽  
Congestive Heart Failure ◽  
Ventricular Tachycardia ◽  
Ventricular Fibrillation ◽  
Cardiac Arrhythmias ◽  
Ventricular Arrhythmias ◽  
Qrs Complex ◽  
Implantable Defibrillators

This review discusses the treatment of ventricular arrhythmias and bradyarrhythmias. Recent studies addressing the management of nonsustained ventricular arrhythmias in patients with congestive heart failure and those recovering from myocardial infarction are discussed. Determination of the origin of wide QRS complex tachycardia is usually possible at the bedside and the diagnostic criteria are provided. Therapy to prevent recurrent ventricular tachycardia or ventricular fibrillation is difficult and controversial. A widely accepted approach based on electrophysiologic testing and implantable defibrillators appears to be the most effective. Recognition and management of common bradyarrhythmias including the indications for pacemakers are discussed.

Electrical Stimulation as a Substitute for the Tail Clamp in the Determination of Minimum Alveolar Concentration

1993 ◽  
Vol 76 (6) ◽  
pp. 1310-1312 ◽  
Author(s):  
Michael J. Laster ◽  
Jin Liu ◽  
Edmond I. Eger ◽  
Shahram Taheri
Keyword(s):  
Electrical Stimulation ◽  
Minimum Alveolar Concentration

Determination of current density distributions generated by electrical stimulation of the human cerebral cortex

1993 ◽  
Vol 86 (3) ◽  
pp. 183-192 ◽  
Author(s):  
Surendar S. Nathan ◽  
Saurabh R. Sinha ◽  
Barry Gordon ◽  
Ronald P. Lesser ◽  
Nitish V. Thakor
Keyword(s):  
Cerebral Cortex ◽  
Electrical Stimulation ◽  
Current Density ◽  
Human Cerebral Cortex ◽  
Density Distributions ◽  
Stimulation Of
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