What question did this study set out to answer?

To determine the concentration- and voltage-dependent effects of volatile anesthetics (halothane, isoflurane, and sevoflurane) on the fast inward sodium current (INa) in mammalian ventricular myocytes.

February 1, 1997Anesthesia & Analgesia

Voltage-Dependent Effects of Volatile Anesthetics on Cardiac Sodium Current

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Why the study?

Do volatile anesthetics reduce cardiac sodium current in isolated ventricular myocytes?

Population

Single ventricular myocytes isolated enzymatically from adult guinea pig hearts

Comparison

Volatile anesthetics: halothane, isoflurane, and… vs Baseline/control (pre-exposure measurements)

Design

Preclinical

Authors

HWHenry U. WeigtSLK-Kliniken Heilbronn WKWai‐Meng KwokMedical College of Wisconsin GRGeorg C. RehmertHeidelberg University

Discussion

Member takes

Implication

Halothane's stronger INa depression in animal myocytes may inform arrhythmia risk; leaves open human translation and clinical relevance.

Key Points

To determine the concentration- and voltage-dependent effects of volatile anesthetics (halothane, isoflurane, and sevoflurane) on the fast inward sodium current (INa) in mammalian ventricular myocytes.
Isolated single ventricular myocytes enzymatically from adult guinea pig hearts.
Recorded fast inward Na+ currents (INa) via whole-cell patch-clamp techniques during exposure to clinical concentrations of halothane (0.6, 1.2 mM), isoflurane (0.5, 1.0 mM), and sevoflurane (0.6, 1.2 mM).
Halothane produced significant (P < 0.05) concentration-dependent depressions of peak INa of 12.3% ± 1.8% at 0.6 mM and 24.4% ± 4.1% at 1.2 mM (mean ± SEM, n = 12).
Isoflurane and sevoflurane showed lower potency than halothane, decreasing peak INa by 4.8% ± 1.1% (0.5 mM, n = 12) and 11.4% ± 1.4% (1.0 mM, n = 15), and 3.0% ± 0.7% (0.6 mM, n = 14) and 10.7% ± 3.9% (1.2 mM, n = 12), respectively.
Inhibition was reversible across all agents, exhibited greater blockade at more depolarizing potentials, and shifted steady-state activation and inactivation toward hyperpolarizing potentials.

Structured PICO

Do volatile anesthetics reduce cardiac sodium current in isolated ventricular myocytes?

Population

Single ventricular myocytes isolated enzymatically from adult guinea pig hearts

Intervention

Volatile anesthetics: halothane (0.6 mM and 1.2 mM), isoflurane (0.5 mM and 1.0 mM), and sevoflurane (0.6 mM and 1.2 mM)

Comparator

Baseline/control (pre-exposure measurements)

Outcome

Depression of the fast inward Na+ current (INa) measured via patch clamp techniquesurrogate

Volatile anesthetics decrease cardiac sodium current in a dose- and voltage-dependent manner, with halothane exerting twice the depressant effect of isoflurane or sevoflurane, which may contribute to anesthesia-induced dysrhythmias.

Cite This Study

Weigt et al. (1997) studied this question.

synapsesocial.com/papers/6a7271ebfebe604dd70a9bad https://doi.org/10.1213/00000539-199702000-00009

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Voltage-Dependent Effects of Volatile Anesthetics on Cardiac Sodium Current

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Voltage-Dependent Effects of Volatile Anesthetics on Cardiac Sodium Current

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

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