Question

Prolonged P-R interval indicates

• A. Bradycardia
• B. Tachycardia
• C. Hypokalemia
• D. Hypercalcemia

Hint:

{ECG Basics:} - P wave: Atrial depolarization. - QRS complex: Ventricular depolarization. - T wave: Ventricular repolarization. - Prolonged P-R = AV Node delay (Heart Block).

Answer 1

The Correct Option is A

Step 1: Understanding ECG Intervals:
The P-R interval represents the time taken for the electrical impulse to travel from the SA node through the atria, AV node, and His-Purkinje system to the ventricles. The normal duration is 0.12 to 0.20 seconds.
Step 2: Analyzing "Prolonged" P-R Interval:
A P-R interval greater than 0.20 seconds indicates a delay in conduction, primarily at the AV node. This condition is called First-degree AV block. This delay typically results in a slower heart rate or is associated with conditions causing a slow heart rate, known as Bradycardia.
Step 3: Analyzing Other Options:
(B) Tachycardia: Fast heart rate (usually shortens intervals).
(C) Hypokalemia: Causes flattening of T waves and appearance of U waves.
(D) Hypercalcemia: Causes shortening of the QT interval.
Step 4: Final Answer:
Prolonged P-R interval is most closely associated with Bradycardia (slowing of the heart) in the context of conduction blocks.