Wolff-Parkinson's White syndrome

Hello! This post is regarding WPW syndrome. It is an Autosomal recessive disorder.
In Normal heart, conduction is from SA node to cardiac myocytes via AV node and Purkinje fibers. In WPW syndrome, SA node transfers electric activity directly to cardiac myocytes. This transfer is done by 'Bundle of Kent'.  Since AV node is responsible for delay of the conduction in normal heart, skipping of the AV node causes excitation prior to the expected time. Hence low Cardiac output is sign in WPW syndrome.

Investigation: ECG done

Findings in ECG.

1) Since AV node is skipped in conduction, short P-R interval is seen.

2) q wave is responsible for conduction in septal region, here also it is skipped in ECG (Remember conduction directly from SA node to cardiac myocyte!). At the same time we see Delta waves.

What are Delta waves?
-Change in the upswinging of the 'R' wave.

3) PJ interval is normal

What is PJ interval?
-J point is the point where S wave ends.
Starting point of P wave to J point is called as PJ interval.

(Remember: Segments does not include waves, interval loves waves! Example: ST segment is from end of S to start of T wave)

Now, as we can figure it out PJ interval is PR + qRS
PR becomes shorter and qRS becomes  broader in WPW syndrome. qRS is broader because conduction of cardiac myocytes is slower than Purkinje fibers. (Hope you remember clue sentence here - conduction from SA node directly to cardiac myocytes!) Hence PJ interval is normal.

Treatment:

Flecainide given orally is DOC.
Treatment of choice is Radio-frequency ablation.