PMID: 7519406Jul 1, 1994Paper

Aftereffects of high-intensity DC stimulation on the electromechanical performance of ventricular muscle

The American Journal of Physiology
I KodamaJ Toyama

Abstract

To clarify the mechanisms underlying cardiac dysfunction after electrical defibrillation, we investigated the effects of direct current field stimulation (10 ms, 1-80 V/cm) on isolated guinea pig papillary muscles. Shocks (S2) > 15 V/cm lowered the plateau height of the S2-induced action potential and inhibited its terminal repolarization. Subsequent responses to basic stimuli (S1, 1.0 Hz) for 1-3 min were characterized by a decrease in the maximum diastolic potential, a shortening of action potential duration, and an increase of the developed tension. With S2 > 30 V/cm, a marked delay in repolarization of the S2-induced action potential was followed by oscillation of membrane potential, resulting in repetitive spontaneous activity and often refractoriness to S1 stimulation. The aftereffects were independent of the phase of S2 application. Most of the aftereffects were preserved in the presence of nifedipine (1 microM) or ryanodine (1 microM). Only sodium channel blockade by tetrodotoxin (10 microM) modified the aftereffects by depressing the generation of spontaneous activity. These findings suggest that strong shocks (> 15 V/cm) will produce abnormal arrhythmogenic responses probably through a transient rupture of sarcolemmal...Continue Reading

Citations

Feb 28, 2006·American Journal of Physiology. Heart and Circulatory Physiology·Crystal M RipplingerIgor R Efimov
Aug 9, 2008·Annals of Biomedical Engineering·Fei Yang, Robert Patterson
Jun 26, 2012·American Journal of Physiology. Heart and Circulatory Physiology·Yves T WangYuanna Cheng
Jan 17, 2004·American Journal of Physiology. Heart and Circulatory Physiology·Aleksandre T SambelashviliIgor R Efimov
Jun 3, 2021·International Journal of Molecular Sciences·Nicolas ClementyDominique Babuty

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.