CET Electrolyte Imbalances & ECG Changes 2

Question 1

What is the FIRST ECG change seen as serum potassium rises in progressive hyperkalemia?

Accepted Answer

Peaked T waves

Answer

Absent P waves

Answer

Widened QRS complex

Answer

Sine wave pattern

Question 2

A patient with end-stage renal disease presents with absent P waves and a widened QRS. The most likely cause is:

Accepted Answer

Severe hyperkalemia

Answer

Atrial fibrillation from hypomagnesemia

Answer

Hypocalcemia

Answer

Digoxin toxicity

Question 3

The QTc interval is most reliably prolonged in which electrolyte condition?

Accepted Answer

Hypocalcemia

Answer

Hyperkalemia

Answer

Hypercalcemia

Answer

Hypermagnesemia

Question 4

Which electrolyte imbalance is the first-line treatment target when a patient develops torsades de pointes?

Accepted Answer

Hypomagnesemia correction

Answer

Hyperkalemia correction

Answer

Hypercalcemia correction

Answer

Hypernatremia correction

Question 5

How does hyperkalemia progressively affect the PR interval on ECG?

Accepted Answer

Prolongs it beyond 200 ms

Answer

Shortens it below 120 ms

Answer

Has no effect on the PR interval

Answer

Creates a delta wave at the start of QRS

Question 6

A patient on furosemide develops ST depression, T wave flattening, and prominent U waves. The most likely electrolyte cause is:

Accepted Answer

Hypokalemia

Answer

Hyponatremia

Answer

Hypercalcemia

Answer

Hypermagnesemia

Question 7

Which emergency medication stabilizes the cardiac membrane in hyperkalemia WITHOUT lowering the serum potassium level?

Accepted Answer

Calcium gluconate

Answer

Sodium bicarbonate

Answer

Regular insulin with dextrose

Answer

Sodium polystyrene sulfonate