HealthMap

Barium Toxicity and Cardiac Repolarization (QT Interval)

• Direct Effects on Potassium Channels: Barium is a potent blocker of inward rectifier potassium channels ($K_{ir}$) in cardiac cell membranes.
• Impaired Repolarization: By blocking these potassium channels, barium prevents potassium ions from flowing out of the cells properly during the repolarization phase of the cardiac action potential.
• Prolonged QT Interval: This disruption significantly delays cellular repolarization, which manifests clinically as a prolonged QT interval on an electrocardiogram (ECG).
• Arrhythmia Risk: The resulting QT prolongation increases the risk of dangerous ventricular arrhythmias, such as torsades de pointes, alongside other symptoms of barium toxicity like severe hypokalemia, muscle weakness, and hypertension.