Altered potassium flux and myocardial dysfunction during sepsis

Area of Science:

• Cardiovascular Physiology
• Sepsis Pathophysiology
• Cellular Ion Transport

Background:

• Septic shock causes fluid shifts and electrolyte imbalances in skeletal muscle.
• The impact of sepsis on cardiac muscle ion concentrations and function is less understood.

Purpose of the Study:

• To investigate whether septic shock induces abnormal potassium (K+) efflux in cardiac muscle.
• To determine the correlation between septic plasma and myocardial contractility.

Main Methods:

• Utilized the Langer rabbit heart interventricular septal preparation.
• Perfusion with control and septic rabbit plasma, monitoring contractility, cation levels, and 42K efflux.

Main Results:

• Septic plasma perfusion significantly reduced septal contractility (developed tension and rate of tension change).
• Abnormal 42K efflux occurred during septic plasma perfusion, independent of plasma potassium levels.
• Cardiac function recovered upon return to control plasma perfusion.

Conclusions:

• Sepsis induces abnormal myocardial potassium efflux, similar to skeletal muscle.
• This abnormal K+ efflux is associated with and may cause the decline in cardiac contractility during sepsis.