What 2:1 AV Block Looks Like on Your Watch ECG

2:1 AV Block ECG
Qaly Heart
Qaly is built by Stanford engineers and cardiologists, including Dr. Marco Perez, a Stanford Associate Professor of Medicine, Stanford Cardiac Electrophysiologist, and Co-PI of the Apple Heart Study.

Key Takeaways

  • 2:1 AV Block is a type of heart block where every other electrical impulse fails to pass through your atrioventricular (AV) node to reach your heart's lower chambers, or ventricles.
  • To recognize 2:1 AV Block on your watch ECG, look for the tell-tale sign of two P Waves for every one QRS Complex.
  • 2:1 AV Block can cause symptoms like fainting, dizziness, chest pain, fatigue, shortness of breath, heart palpitations, rapid breathing, and nausea. If you suspect you have 2:1 AV Block, contact your healthcare provider immediately.

Got other questions on Heart Block? See the Qaly guides on Heart Block:

Introduction

Hello, heart hero. In your quest to identify that irregular heart rhythm you just felt, you may have come across the terms 2:1 Atrioventricular Block or 2:1 AV Block. With your trusty watch ECG now in hand, you may be wondering, "What does 2:1 AV Block look like on my watch ECG?" In this guide, we'll help you see 2:1 AV Block on your watch ECG. Let's dive in.

What's 2:1 AV Block?

Before trying to identify 2:1 AV Block on your ECG, it's helpful to remind yourself what 2:1 AV Block actually is. (If you're confident in your 2:1 AV Block knowledge, though, skip on ahead to the next section for some visual examples of a 2:1 AV Block ECG).

To start, remember how your heart beats? It produces an electrical signal, which squeezes and unsqueezes your heart, which in turn pumps your blood to your lungs for oxygen and then out to the rest of your body.

Your heart produces that electrical signal from your "sinus node" to generate a normal heartbeat. Then, that electrical signal travels from your heart's upper chambers, or atria, to your heart's lower chambers, or ventricles. To do this, your heart's electrical signal moves through a "gatekeeper" called your atrioventricular node, or AV node. In 2:1 AV Block, every other electrical impulse doesn't go through your AV node to get to your ventricles. As a result, every other P Wave on your ECG is not followed by a QRS Complex. 2:1 AV Block is a subtype of either Second-Degree AV Block Type 1 (Wenckebach) or Second-Degree AV Block Type 2.

So What Does 2:1 AV Block Look Like on My Watch ECG?

To identify 2:1 AV Block on your ECG, look for this tell-tale sign:

For visual examples, take a look at 2:1 AV Block seen on Qaly members' watch ECGs.

Here's 2:1 AV Block caught on a Qaly member's Apple Watch ECG. Notice the two P Waves for every one QRS complex. See them between the 1s mark and the 2s mark, as well as to the left and right of the 4s mark?
Here's 2:1 AV Block caught on a Qaly member's Apple Watch ECG. Notice the two P Waves for every one QRS complex. See them between the 1s mark and the 2s mark, as well as to the left and right of the 4s mark?

Here's another 2:1 AV Block caught on a Qaly member's Apple Watch ECG. While harder to see here, see if you can spot two P Waves for every one QRS Complex. Those larger waves after the narrow QRS Complexes are T Waves.
Here's another 2:1 AV Block caught on a Qaly member's Apple Watch ECG. While harder to see here, see if you can spot two P Waves for every one QRS Complex. Those larger waves after the narrow QRS Complexes are T Waves.

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Here's a third 2:1 AV Block caught on a Qaly member's Apple Watch ECG. The 2:1 ratio of P Waves to QRS Complexes are easier to see here. Psst, look right above at the 6s mark and onwards 🙂
Here's a third 2:1 AV Block caught on a Qaly member's Apple Watch ECG. The 2:1 ratio of P Waves to QRS Complexes are easier to see here. Psst, look right above at the 6s mark and onwards 🙂

Is 2:1 AV Block a Cause for Concern?

While some cases of heart block may be present at birth, most heart blocks develop during one's life. If you see signs of 2:1 AV Block, it's possible for your heart's electrical impulses not to reach your heart's lower chambers. This can cause your heart to skip beats and cause symptoms like:

  • Fainting, feeling dizzy.
  • Chest pain.
  • Feeling tired.
  • Shortness of breath.
  • Heart palpitations.
  • Rapid breathing.
  • Nausea.

As always, if you show signs of a potential 2:1 AV Block, contact your healthcare provider as soon as possible to rule out the presence of harmful underlying conditions.

If you're curious to learn about other heart blocks, here's what First-Degree AV Block looks like on your watch ECG, here's what Second-Degree AV Block Type 1 looks like on your watch ECG, here's what Second-Degree AV Block Type 2 looks like on your watch ECG, and here's what Complete Heart Block looks like on your watch ECG.

Conclusion

Well, that just about wraps up our guide on what 2:1 AV Block looks like on your watch ECG. We hope this could be of some help to you.

If you still need help interpreting your ECGs, don't worry, we understand how scary and confusing it can be to experience irregular heartbeats. That's why we created the Qaly app for you and for the hundreds of millions of people around the world who live with heart palpitations and abnormal heart rhythms. On the Qaly app, human experts will interpret your ECGs within minutes for clarity and peace of mind.

To get started with the Qaly app for free, grab the Qaly app from the App Store or Play Store today. If you have any more questions, or if you need our help in any other way, don't hesitate to reach out to us at support@qaly.co.

As always from the team at Qaly, stay heart healthy ❤️

Wondering if it's 2:1 AV Block? On the Qaly app, human experts will interpret your ECGs for 2:1 AV Block within minutes. Get started for free today.

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Wondering if it's 2:1 AV Block? On the Qaly app, human experts will interpret your ECGs for 2:1 AV Block within minutes. Get started for free today.

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