The effect of intravenous potassium on myocardial contractility and cardiac dynamics

Influence of Extracellular Potassium Concentration on Myocardial Uptake and Inotropic Effect of Tritiated Digoxin

“…Leonard and Hadju (21) found no change in the inotropic effects of strophanthidin when [K] o varied between 2.5 to 5.0 mEq/liter in the frog heart or from 4.7 to 7.5 mEq/liter in guinea pig or rabbit hearts. Leight and coworkers (22) also reported that the digitalisinduced increase in right ventricular force in the open-chest dog was not affected by [K] o . In contrast, Lee et al (23) showed that in the cat papillary muscle a [K] o of 24 mEq/liter delayed the onset of the inotropic and toxic effects of ouabain, and diminished the peak inotropic response.…”

The effects of hyperpotassaemia on cardiac performance

“…In the in-situ dog heart, Leight et al (1963) reported that K does not alter cardiac dynamics or right ventricular contractility estimated by the strain gauge arch, and Goodyer et a1 (1964) found that hyperpotassaemia to the point of impaired ventricular conduction at 10 to 1 1.5 mmol/l caused no measurable changes in either the pressure function curve or max dp/dt. Wallace and Mignone (1 966), however, observed that at a serum K concentration of 7 to 8 mmol/l, left ventricular end-diastolic pressure was elevated, and substantial diminution of the force of contraction occurred with no diminution of conduction velocity.…”