CET Cardiac Pharmacology Effects on ECG 2

Question 1

Amiodarone is known to prolong which ECG interval, increasing the risk of Torsades de Pointes?

Accepted Answer

QT interval

Answer

Amiodarone prolongs the QT interval by blocking potassium channels, which can precipitate Torsades de Pointes in susceptible patients.

Question 2

A patient receiving IV adenosine for SVT shows a brief pause on the ECG strip. What does this pause represent?

Accepted Answer

Transient AV block

Answer

Adenosine transiently blocks AV conduction, producing a brief AV block that terminates re-entrant SVT and appears as a pause on the ECG.

Question 3

Which beta-blocker ECG effect helps differentiate it from calcium channel blocker toxicity on the ECG?

Accepted Answer

Bradycardia with narrow QRS vs. bradycardia with wide QRS

Answer

Beta-blocker toxicity typically causes bradycardia with a narrow QRS, while calcium channel blocker toxicity may cause bradycardia with a wide QRS and conduction abnormalities.

Question 4

Sotalol combines beta-blocking and Class III antiarrhythmic properties. Which ECG change is most expected?

Accepted Answer

Prolonged QT interval

Answer

Sotalol's Class III action blocks potassium channels, prolonging repolarization and the QT interval.

Question 5

A patient on procainamide develops a wide-complex tachycardia on ECG. What drug toxicity phenomenon is most likely?

Accepted Answer

Proarrhythmia with widened QRS

Answer

Procainamide toxicity causes QRS widening due to sodium channel blockade, which can lead to proarrhythmic ventricular tachycardia.

(CET) Certified Electrocardiogram Technician Practice Test

(CET) Certified Electrocardiogram Technician Practice Test

CET Cardiac Pharmacology Effects on ECG 2