NTA NTA Pharmacology and Medications 2

Question 1

Which drug classes are known to prolong the QT interval and increase the risk of Torsades de Pointes?

Accepted Answer

Certain antipsychotics and certain antibiotics

Answer

Drugs such as haloperidol (antipsychotic) and azithromycin (antibiotic) can prolong ventricular repolarization, widening the QT interval and predisposing the patient to Torsades de Pointes.

Question 2

Hypokalemia resulting from diuretic use typically produces which ECG changes?

Accepted Answer

Flattened T waves and prominent U waves

Answer

Low serum potassium flattens or inverts T waves and unmasks the U wave (a positive deflection after the T wave), and increases the risk of ventricular arrhythmias.

Question 3

Which electrolyte imbalance, commonly caused by medications like potassium-sparing diuretics, produces tall peaked T waves on ECG?

Accepted Answer

Hyperkalemia

Answer

Hyperkalemia causes tall, narrow, tent-shaped T waves on ECG and can progress to widened QRS, sine-wave pattern, and cardiac arrest if untreated.

Question 4

Calcium channel blocker overdose characteristically produces which ECG finding?

Accepted Answer

Bradycardia with prolonged PR interval and possible heart block

Answer

Calcium channel blockers slow AV node conduction; in overdose this manifests as bradycardia, prolonged PR interval, and potentially complete heart block.

Question 5

Hypocalcemia — which can be caused by certain medications — produces which ECG change?

Accepted Answer

Prolonged QT interval

Answer

Hypocalcemia delays ventricular repolarization, lengthening the QT interval on ECG and increasing the risk of ventricular arrhythmias.

NTA - National Telemetry Association Practice Test

NTA - National Telemetry Association Practice Test

NTA NTA Pharmacology and Medications 2