| Keywords [eng] |
Microcurrency, Microcurrent, Electrical stimulation (ES), Electrical current (EC), Direct current (DC), Electric field (EF), Applied electric field, Endogenous electric current/field |
| Abstract [eng] |
Background: Heart failure is a complex disease of the heart´s cellular and molecular components, lacking efficient long-term treatment possibilities and reducing the quality of life of many patients. Today, we know a lot about the pathological changes that occur, but little is known about the complex interactions that guide those regenerative processes after cellular damage. Its mediators are possibly under the influence of endogenous electrical fields and, in particular, injury currents that are established immediately upon membrane disruption. These electrical signals may enable intercellular, bidirectional transport of ions, metabolites, second messengers, and other smaller molecules during the process of regeneration. Endogenous electric fields may introduce, guide, and regulate the regenerative cascade in cardiomyocytes after injury. Purpose: This systematic review examined the effects of exogenous subthreshold microcurrent stimulation on cardiomyocytes/ progenitor cells, or the whole heart, and investigated whether these effects can improve cardiac function in failing hearts. Methods: Using the keywords listed below, online databases like Medline, Google Scholar, Epistemonikos, Scopus, and Cochrane Databases were searched for abstracts or full articles that used applied subthreshold electrical stimulation on cardiomyocytes for therapeutic purposes. Results: 21 studies, including full text articles and abstracts, using exogenous subthreshold microcurrent stimulation on cardiomyocytes have been analyzed. The study types involved were preclinical in vitro trials, small case preclinical animal trials and non-randomised clinical phase I pilot studies. Different parameters, intensities, and durations of microcurrent application have been used in all studies reviewed. Preclinical in vitro studies have shown that exogenous subthreshold microcurrent application modulates the extracellular matrix, the inflammatory cascade, as well as promotes ATP production and leads to cardiogenesis if stimulated. Preclinical in vivo results have also confirmed that microcurrent modulates the extracellular matrix and the inflammatory cascade but also demonstrated an influence on angiogenesis, influencing capillary density. Clinical phase I trials have shown short-term rapid improvements in clinical ejection fraction and left ventricular end-diastolic diameter. Conclusion: The evidence of effects of microcurrent application on cardiomyocytes, their progenitors, or the whole heart is convincing and promising to justify further research as an innovative treatment approach in regenerative medicine. |
