Disordered myocardial Ca2+ homeostasis results in substructural alterations that may promote occurrence of malignant arrhythmias

Title:

Disordered myocardial Ca2+ homeostasis results in substructural alterations that may promote occurrence of malignant arrhythmias

Creator:

Narcisa Tribulová, Knezl, V., Szeiffova Bačová, B., Egan Beňová, Viczenczova, C., Eva Gonsalvesová, and Ján Slezák

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:016e74d9-0863-4a6d-b55c-b13950736762
uuid:016e74d9-0863-4a6d-b55c-b13950736762
issn:0862-8408

Subject:

Fyziologie člověka a srovnávací fyziologie, fyziologie, morčata, prasata, physiology, Guinea pigs, pigs, Ca2+ overload, heart ultrastructure, malignant arrhythmias, rat, 14, and 612

Type:

article, články, model:article, and TEXT

Format:

print, bez média, and svazek

Description:

We aimed to determine the impact of Ca2+-related disorders induced in intact animal hearts on ultrastructure of the cardiomyocytes prior to occurrence of severe arrhythmias. Three types of acute experiments were performed that are known to be accompanied by disturbances in Ca2+ handling. Langedorffperfused rat or guinea pig hearts subjected to K+-deficient perfusion to induce ventricular fibrillation (VF), burst atrial pacing to induce atrial fibrillation (AF) and open chest pig heart exposed to intramyocardial noradrenaline infusion to induce ventricular tachycardia (VT). Tissue samples for electron microscopic examination were taken during basal condition, prior and during occurrence of malignant arrhythmias. Cardiomyocyte alterations preceding occurrence of arrhythmias consisted of non-uniform sarcomere shortening, disruption of myofilaments and injury of mitochondria that most likely reflected cytosolic Ca2+ disturbances and Ca2+ overload. These disorders were linked with non-uniform pattern of neighboring cardiomyocytes and dissociation of adhesive junctions suggesting defects in cardiac cell-to-cell coupling. Our findings identified heterogeneously distributed high [Ca2+]i-induced subcellular injury of the cardiomyocytes and their junctions as a common feature prior occurrence of VT, VF or AF. In conclusion, there is a link between Ca2+-related disorders in contractility and coupling of the cardiomyocytes pointing out a novel paradigm implicated in development of severe arrhythmias., N. Tribulova, V. Knezl, B. Szeiffova Bacova, T. Egan Benova, C. Viczenczova, E. Gonçalvesova, J. Slezak., and Obsahuje bibliografii

Language:

English

Rights:

http://creativecommons.org/publicdomain/mark/1.0/
policy:public

Source:

Physiological research | 2016 Volume:65 | Number:Suppl 1

Harvested from:

CDK

Metadata only:

false