Cardiac HealthStream Telemetry Practice Exam

Starting medications that prolong the QT interval requires vigilant monitoring of the QT interval and electrolytes because a longer QT can lead to dangerous arrhythmias like torsades de pointes. The best approach is to obtain a baseline ECG and electrolyte panel before therapy, then repeat the QTc and labs after starting or changing the dose, with close follow-up in the first 24–48 hours. Correct any electrolyte disturbances (potassium, magnesium, calcium) and avoid adding other QT-prolonging drugs. If the QTc lengthens beyond safe limits or rises substantially from baseline, reassess and adjust or discontinue the offending medication.