Cardiac Effects of Isoproterenol, Norepinephrine and Epinephrine in Complete A-V Heart Block During Experimental Acidosis and Hyperkalemia

Key Points

• To evaluate the impact of acidosis and hyperkalemia on sympathomimetic amines' effectiveness in dogs with complete A-V heart block.
• Experimental design using dogs with induced complete A-V heart block
• Assessment of idioventricular rate changes with isoproterenol, norepinephrine, and epinephrine under varying acidosis levels
• Comparison of effects between states of acidosis and hyperkalemia
• Acidosis significantly reduced the effectiveness of isoproterenol, norepinephrine, and epinephrine in increasing idioventricular rate.
• The reduction in effectiveness correlated with the severity of acidosis.
• Hyperkalemia did not significantly impact the effectiveness of the sympathomimetic amines despite unchanged pH.

Abstract