Sinus Tachycardia Vs. Atrial Fibrillation on Your Watch ECG

Sinus Tach 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 Sinus Tachycardia or Afib? See the Qaly guides on Sinus Tachycardia and Afib:

Introduction

Today, the power of health sensors is literally at our fingertips — or rather, on our wrists. Electrocardiograms (ECGs) from smartwatches offer critical insights into our heart health. This article explores two important rhythms: sinus tachycardia and atrial fibrillation (Afib). Deciphering tachycardia vs Afib can be a key part of understanding our cardiovascular well-being. Let’s dive in.

What’s Sinus Tachycardia?

Sinus tachycardia is a condition where the heart beats faster than normal, at more than 100 beats per minute in adults. It’s often a normal response to stress, fever, dehydration, or strenuous physical activity.

Sinus Tachycardia read on a Kardia ECG through the Qaly app.
Sinus Tachycardia read on a Kardia ECG through the Qaly app.

Sinus Tachycardia read on a Samsung Watch ECG through the Qaly app.
Sinus Tachycardia read on a Samsung Watch ECG through the Qaly app.

On an ECG, sinus tachycardia is marked by a regular rhythm with a rate exceeding 100 beats per minute, where every QRS complex is preceded by a normal P wave. Here’s more on what sinus tachycardia looks like on your watch 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 Kardia ECG through the Qaly app.
Afib read on a Kardia ECG through the Qaly app.


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

What’s the Difference Between Sinus Tachycardia and Afib?

The comparison of Afib vs Sinus Tachycardia primarily revolves around their rhythm regularity and the nature of their onset. While sinus tachycardia is typically regular and often a response to external factors, Afib is irregular and may occur unpredictably, often due to structural or electrical issues within the heart.

In terms of health impact, while sinus tachycardia is usually not a cause for concern and resolves when the triggering factor is addressed, Afib can lead to complications like stroke or heart failure if left untreated. Thus, distinguishing between these rhythms — AFib vs Tachycardia — is crucial in managing heart health.

While smartwatches provide valuable information, remember they're not replacements for medical advice. Always consult with a healthcare professional about any heart rhythm abnormalities you notice. Stay tuned to your heart and stay heart healthy!

Still Not Sure if It’s Sinus Tachycardia or Afib on Your ECG?

Differentiating between sinus tachycardia 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 Sinus Tachycardia or Afib? On the Qaly app, human experts will interpret your ECGs for Sinus Tachycardia 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 -->

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

Try Qaly for Free