Insulin accelerates recovery from QRS complex widening in a frog heart model of hyperkalemia.

Hyperkalemia is one of the most common electrolyte disorders. By injecting various concentrations of potassium chloride (KCl) solutions intravenously into bullfrogs, we demonstrated characteristic electrocardiogram (ECG) abnormalities of hyperkalemia in frog hearts. The widened QRS complexes induced by 100 mM KCl injection were accompanied by an increase in the resting membrane potential in cardiomyocytes and a decreased slope of phase 0 in the action potential.