← Unrecognized Killers in Emergency Electrocardiography, Part II
Workout Quiz
5 questions. Answers are graded instantly with expert explanations.
1. A 55-year-old patient presents with severe dehydration, nausea, and vomiting. An ECG reveals significant QT prolongation primarily due to ST-segment prolongation with normal T-wave morphology. Which electrolyte abnormality most likely explains these findings?
Hypokalemia
Hypomagnesemia
Hypocalcemia
Hyperkalemia
2. Which of the following medications would NOT be recommended for the acute management of acquired QT prolongation associated with polymorphic ventricular tachycardia (Torsades de Pointes)?
Magnesium sulfate
Calcium gluconate
Isoproterenol
Procainamide
3. You evaluate a severely dehydrated patient whose ECG demonstrates significant QT prolongation. To promptly determine if cardiac monitoring is necessary before lab results return, what QTc interval cutoff should prompt immediate concern?
QTc >420 ms
QTc >460 ms
QTc >500 ms
QTc >550 ms
4. In a patient presenting with recurrent episodes of polymorphic ventricular tachycardia (Torsades de Pointes) who does NOT respond to multiple boluses of magnesium sulfate, you should strongly suspect:
Hyperkalemia
Hypomagnesemia
Hypocalcemia
Sodium channel blocker toxicity
5. A patient with QT prolongation secondary to hypomagnesemia and hypokalemia develops polymorphic ventricular tachycardia. Which initial management step would be most appropriate?
IV amiodarone infusion
IV calcium chloride infusion
IV magnesium sulfate bolus
IV magnesium sulfate bolus
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