Atlantis Institut des Sciences Fictives

Resumen: Ventricular repolarization dynamics are crucial to arrhythmogenesis. Low-frequency oscillations of repolarization have recently been reported in humans and the magnitude of these oscillations proposed to be a strong predictor of sudden cardiac death. Available evidence suggests a role of the sympathetic nervous system. We have used biophysically detailed models integrating ventricular electrophysiology, calcium dynamics, mechanics and ß-adrenergic signaling to investigate the underlying mechanisms. The main results were: (1) Phasic beta-adrenergic stimulation (ß-AS) at a Mayer wave frequency between 0.03 and 0.15 Hz resulted in a gradual decrease of action potential (AP) duration (APD) with concomitant small APD oscillations. (2) After 3-4 minutes of phasic ß-AS, the mean APD adapted and oscillations of APD became apparent. (3) Phasic changes in haemodynamic loading at the same Mayer wave frequency (a known accompaniment of enhanced sympathetic nerve activity), simulated as variations in the sarcomere length, also induced APD oscillations. (4) The effect of phasic ß-AS and haemodynamic loading on the magnitude of APD oscillations was synergistic. (5) The presence of calcium overload and reduced repolarization reserve further enhanced the magnitude of APD oscillations and was accompanied by afterdepolarizations and/or spontaneous APs. In conclusion, low-frequency oscillations of repolarization recently reported in humans were induced by phasic ß-AS and phasic mechanical loading, which acted synergistically, and were greatly enhanced by disease-associated conditions, leading to arrhythmogenic events.
Idioma: Inglés
DOI: 10.1016/j.yjmcc.2016.05.003
Año: 2016
Publicado en: JOURNAL OF MOLECULAR AND CELLULAR CARDIOLOGY 97 (2016), 93-105
ISSN: 0022-2828
Factor impacto JCR: 5.68 (2016)
Categ. JCR: CELL BIOLOGY rank: 42 / 189 = 0.222 (2016) - Q1 - T1
Categ. JCR: CARDIAC & CARDIOVASCULAR SYSTEMS rank: 20 / 126 = 0.159 (2016) - Q1 - T1
Factor impacto SCIMAGO: 2.536 - Molecular Biology (Q1) - Cardiology and Cardiovascular Medicine (Q1)

Financiación: info:eu-repo/grantAgreement/ES/MINECO/TIN2012-37546-C03-03
Financiación: info:eu-repo/grantAgreement/ES/MINECO/TIN2013-41998-R
Tipo y forma: Article (PostPrint)
Área (Departamento): Área Teoría Señal y Comunicac. (Dpto. Ingeniería Electrón.Com.)
Exportado de SIDERAL (2020-02-21-13:51:52)


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