What question did this study set out to answer?

To investigate whether impairment of mitochondrial function generates cellular conditions that favor the occurrence of proarrhythmic calcium alternans in cardiac myocytes.

January 1, 2010Frontiers in PhysiologyOpen Access

The Role of Mitochondria for the Regulation of Cardiac Alternans

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Why the study?

Does impairment of mitochondrial function increase the occurrence of Ca alternans in single cat atrial myocytes?

Population

Single cat atrial myocytes

Comparison

Impairment of mitochondrial function (using… vs Normal mitochondrial function (implied baseline)

Design

Preclinical

Authors

SFStela FloreaUniversity of Cincinnati Medical Center LBLothar A. BlatterElectrophysiology

Discussion

Member takes

Implication

Mitochondrial impairment may promote proarrhythmic Ca alternans in atrial myocytes; hypothesis-generating in isolated cells and requires in vivo validation.

Key Points

To investigate whether impairment of mitochondrial function generates cellular conditions that favor the occurrence of proarrhythmic calcium alternans in cardiac myocytes.
Isolated single cat atrial myocytes and induced alternans via electrical pacing at frequencies exceeding 1 Hz.
Measured intracellular calcium transients using the fluorescent indicator Indo-1 and quantified the degree of alternans via the alternans ratio.
Pharmacologically inhibited mitochondrial membrane potential (FCCP), ATP synthase (oligomycin), electron transport chain complexes (rotenone, antimycin, cyanide), dehydrogenases, and calcium transport pathways.
Dissipation of mitochondrial membrane potential and inhibition of F1/F0-ATP synthase or the electron transport chain consistently enhanced the alternans ratio.
Disrupting mitochondrial calcium uptake, extrusion, and calcium-dependent dehydrogenases lowered the pacing threshold required to trigger calcium alternans.
Mitochondrial functional impairment compromised intracellular calcium cycling, establishing conditions that facilitate proarrhythmic beat-to-beat alternations.

Structured PICO

Does impairment of mitochondrial function increase the occurrence of Ca alternans in single cat atrial myocytes?

Population

Single cat atrial myocytes

Intervention

Impairment of mitochondrial function (using FCCP, oligomycin, rotenone, antimycin, CN(-), inhibition of Ca-dependent dehydrogenases, and mitochondrial Ca uptake or extrusion) combined with electrical pacing (>1 Hz)

Comparator

Normal mitochondrial function (implied baseline)

Outcome

Degree of alternans quantified as the alternans ratio (AR = 1 - S/L) and threshold for the occurrence of Ca alternanssurrogate

Impairment of mitochondrial function adversely affects cardiac calcium cycling, creating conditions that favor proarrhythmic calcium alternans.

Cite This Study

Florea et al. (2010) studied this question.

synapsesocial.com/papers/6a7950e8bdf697b3de022e3e https://doi.org/10.3389/fphys.2010.00141

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Implication

Mitochondrial impairment may promote proarrhythmic Ca alternans in atrial myocytes; hypothesis-generating in isolated cells and requires in vivo validation.

The Role of Mitochondria for the Regulation of Cardiac Alternans

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

The Role of Mitochondria for the Regulation of Cardiac Alternans

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider