Wolff-Parkinson-White syndrome

Now, I also have a heart condition.

It's called Wolfe-Parkinson-White, or WPW, okay? It's, uh, basically an extra electrical pathway, and, uh, it, it kinda simulates what, uh, atrial fibrillation or AFib, uh, in, in, in the fact that, like, it gets your heart going on a loop.

And, uh, you know, my heart can go from anywhere from A normal, uh, rhythm to all of a sudden just [mimicking drums] going crazy like I ran a marathon and just out of nowhere.

And then all of a sudden it's like kaboom, and, uh, it goes back to normal.

Digoxin specific antibody fragments, right? And remember, digoxin can also slow conduction down the AV node, right? It's an AV nodal blocking agent, so it can actually cause, uh, brady, bradycardia.

Just something you want to keep at the back of your mind for, for exams, right? So if, for example, a person has like AFib and they have WPW or they have like heart block, uh, giving them digoxin may not be the smartest idea in the world, right? Because in those circumstances, giving AV nodal blocking agents just gonna worsen your, your condition.

All right.

Now, what if they give you a question about, um, a person, right? You're, you're told that this person is, um, um, you know, has missed like the last two...

I mean, number one, you get the living history.

One of the chapters is about the history of arrhythmia surgery, WPW, AV node reentry, VTAC.

And then most of the book is about atrial fib.

There's 600 illustrations.

Oh, I know where you're going with this.

What if that AV node gatekeeper is completely compromised? What if the patient has Wolff-Parkinson-White syndrome?

BWPW.

Because WPW means a patient is born with an extra physical electrical highway, called the bundle of Kent.

It connects the atria and the ventricles, completely bypassing the AV node's natural speed limit.

It's a physical shortcut.

Right.

And on a normal day, their ECG shows a short PR interval and a slurred upstroke on the QRS, that's the delta wave, because the signal is taking that shortcut and pre-exciting the ventricles.

And this is a really big one not to miss, as continuing with a standard treatment, thinking this is AF with RVR, could prove fatal.

Hopefully, most of the people listening to this know what Wolff-Parkinson-White is.

If not, a quick recap.

Wolff-Parkinson-White is an accessory conduction pathway between the atria and the ventricles called the bundle of Kent.

This allows impulses to be conducted through something other than the AV node on their way down to the ventricles.

This means that when we have AF with the atria fibrillating, as Simon said, around their intrinsic rate of 300 beats per minute, impulses can be conducted through the ventricles, bypassing this decremental conduction of the AV node that I talked about earlier.

So if we have ventricular rates over 200, we need to start looking for that characteristic delta wave on the ECG, which is showing us that the second conduction pathway is there.

Now, why is this important? Well, treatment with AV nodal blocking drugs such as adenosine, calcium channel blockers, and beta blockers may increase the conduction via the accessory pathway with a resultant increase in ventricular rate and a possible degeneration into VT or VF.