Premature Atrial Contraction (Single) Vs. Atrial Fibrillation on Your Watch ECG

PAC Afib 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

Got other questions on PAC or Afib? See the Qaly guides on PAC and Afib:

Introduction

Thanks to the power of sensor technology, keeping an eye on your heart health has never been easier. With the electrocardiogram (ECG) feature of your smartwatch, you can monitor heart rhythms like premature atrial contractions (PACs) and atrial fibrillation (Afib). Understanding the difference between these two rhythms — PAC vs Afib — can provide critical insights into your heart health. Let’s dive in.

What’s a Premature Atrial Contraction (PAC)?

Premature atrial contractions are early beats that originate from the atria — the upper chambers of the heart. On an ECG, PACs are identified by an early and often different-looking P wave, followed by a QRS complex and a compensatory pause. Here’s more on what a PAC looks like on your watch ECG.

PAC read on a Samsung Watch ECG through the Qaly app.
PAC read on a Samsung Watch ECG through the Qaly app.

PAC read on a Fitbit ECG through the Qaly app.
PAC read on a Fitbit ECG through the Qaly app.


Get your ECG checked by certified experts within minutes on the Qaly app.

Try Qaly for Free
App Store - Download Qaly | ECG Reader
Try Qaly for Free
Google Play - Download Qaly | ECG Reader
Try Qaly for Free
3 days free, cancel any time
QALY app - ecg reviews, ecg reader, ecg interpretations, review your ecg

What’s Atrial Fibrillation (Afib)?

Atrial fibrillation, often referred to as Afib, is a form of irregular heart rhythm, often characterized by a rapid, irregular beating of the atria. On an ECG, atrial fibrillation is represented by a lack of distinct P waves and an irregularly irregular RR interval. Here’s more on what Afib looks like on your watch ECG.

Afib read on a Fitbit ECG through the Qaly app.
Afib read on a Fitbit ECG through the Qaly app.

Afib read on a Kardia ECG through the Qaly app.
Afib read on a Kardia ECG through the Qaly app.

What’s the Difference Between PAC and Afib?

When comparing PAC vs Afib on ECG, the most noticeable difference is the regularity of the rhythm. While a single PAC is generally followed by a normal heart rhythm, Afib presents as a sustained, irregular rhythm.

Another significant difference lies in their implications for heart health. While a single PAC is typically not a cause for concern, persistent Afib can lead to increased risk of stroke, heart failure, and other heart-related complications. Therefore, it's crucial to get regular check-ups and consult your healthcare provider if you notice any persistent irregularities in your ECG.

Your smartwatch can be a valuable tool in monitoring your heart health, but it should not replace regular check-ups with your healthcare provider. Remember, being proactive about your heart health is the best way to ensure a healthy and happy heart!

Still Not Sure if It’s PAC (Single) or Afib on Your ECG?

Differentiating between PAC vs Afib on your ECG can be tricky. If you’re still looking for help interpreting your ECG, check out the Qaly app on App Store or Play Store. On Qaly, human experts will interpret your ECGs within minutes, day or night. Try out the Qaly app for free today!

Wondering if it's PAC or Afib? On the Qaly app, human experts will interpret your ECGs for PAC and Afib within minutes. Get started for free today.

Try free, cancel any time
Try Qaly for Free
App Store - Download Qaly | ECG Reader
Try Qaly for Free
Google Play - Download Qaly | ECG Reader
Try Qaly for Free
3 days free, cancel any time
QALY app - ecg reviews, ecg reader, ecg interpretations, review your ecg

Get 3 days of unlimited ECG reviews for free -->

Get 3 days of unlimited ECG reviews for free -->

Wondering if it's PAC or Afib? On the Qaly app, human experts will interpret your ECGs for PAC and Afib within minutes. Get started for free today.

Try Qaly for Free