A prolonged QT interval is usually the result of electrolyte imbalances. What is usually the treatment?

• A. Identify and correct electrolyte disturbances
• B. Start pacing and defibrillation
• C. Administer calcium channel blockers
• D. Begin magnesium sulfate infusion

Answer: (A)

Prolonged QT from electrolyte imbalances is best managed by correcting the underlying causes. The QT interval lengthens when electrolyte levels are off—low potassium, calcium, or magnesium disrupts cardiac repolarization. By identifying which electrolyte is disturbed and restoring it to normal, you reduce the risk of dangerous rhythms and shorten the QT toward normal. This means checking serum levels and replacing potassium, calcium, or magnesium as needed, and reviewing medications that can prolong QT.

Pacing or defibrillation is a rescue approach for unstable or ongoing life-threatening arrhythmias, not the standard first step for electrolyte-related QT prolongation. Calcium channel blockers don’t address the underlying electrolyte issue and can worsen conduction in some cases. Magnesium sulfate is specifically used if torsades de pointes is present or highly suspected, but the usual initial approach is correcting electrolyte disturbances.