Question

Which one of the following options correctly matches the ECG signals in Panel-1 with the cardiac conditions in Panel-2?

• A. X-(i); Y-(iii); Z-(ii)
• B. X-(i); Y-(ii); Z-(iii)
• C. X-(ii); Y-(i); Z-(iii)
• D. X-(ii); Y-(iii); Z-(i)

Hint:

Normal = clean regular P-QRS; AV block = delayed/dropped conduction; atrial flutter = fast sawtooth waves.

Answer 1

The Correct Option is A

Step 1: Understanding the Question.
The figure shows three ECG traces, X, Y and Z, and asks us to match each one to a cardiac condition: normal condition, atrial flutter, or atrioventricular (AV) block.

Step 2: Key Concept.
Each condition leaves a distinct fingerprint on the ECG. A normal ECG shows one clean P wave before every QRS complex, at a steady rate. In AV block, the electrical signal from the atria is delayed or fails to reach the ventricles on some beats, so the trace shows disturbed timing between atrial and ventricular activity, such as a stretched interval or a dropped QRS, while the overall rhythm still looks broadly regular otherwise. In atrial flutter, the atria fire abnormally fast, near 250 to 350 times a minute, producing a rapid, repetitive sawtooth pattern of flutter waves riding under the QRS complexes.

Step 3: Detailed Explanation.
Trace X shows evenly spaced beats with a normal-looking P-QRS-T pattern and no extra waves or missed beats, so X is the normal condition, item (i).
Trace Y shows disturbed timing between the atrial and ventricular activity, consistent with delayed or blocked conduction from atria to ventricles, the signature of atrioventricular block, item (iii).
Trace Z shows the fast, jagged, repeating sawtooth-like oscillations typical of the rapid atrial firing seen in atrial flutter, item (ii).

Step 4: Final Answer.
X matches (i) normal condition, Y matches (iii) atrioventricular block, and Z matches (ii) atrial flutter. This is option (A).
\[ \boxed{\text{X-(i); Y-(iii); Z-(ii)}} \]