Premature Ventricular Contraction (PVC) Vs. Premature Atrial Contraction (PAC) on Your Watch ECG

PVC PAC 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 PVC or PAC? See the Qaly guides on PVC and PAC:

Introduction

Your wrist-worn smartwatch has become more than just a timepiece or fitness tracker — it's a mini, on-the-go electrocardiogram. It provides valuable insights into your heart's rhythms, and can help you monitor irregularities like premature ventricular contractions (PVCs) and premature atrial contractions (PACs). Understanding the difference between the often-confused PAC vs PVC heartbeats is crucial for maintaining your heart health. Let’s dive in.

What’s a Premature Ventricular Contraction (PVC)?

Premature ventricular contractions occur when the ventricles — the lower chambers of the heart — beat prematurely. In an ECG, this looks like an early, wide, and bizarre-looking QRS complex that is not preceded by a P wave, and often followed by a compensatory pause. Here’s more on what a PVC looks like on your watch ECG.

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

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

What’s a Premature Atrial Contraction (PAC)?

On the other hand, 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 Fitbit ECG through the Qaly app.
PAC read on a Fitbit ECG through the Qaly app.

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

What’s the Difference Between PVC and PAC?

When comparing PVC vs PAC on ECG, the key difference lies in their points of origin. PVCs originate from the ventricles, while PACs originate from the atria. This difference in origin is reflected in their ECG depictions, as explained above.

PVCs and PACs can both be benign or indicative of an underlying condition, depending on their frequency, pattern, and the individual's overall health. While single, isolated occurrences may not signify a serious issue, frequent PVCs or PACs could indicate underlying heart disease and should be evaluated by a healthcare professional.

PAC and PVC read on a Kardia ECG through the Qaly app.
PAC and PVC read on a Kardia ECG through the Qaly app.

Remember, although your watch ECG can provide valuable insights, it isn’t a substitute for professional medical advice. If you observe any persistent, abnormal rhythms on your ECG, reach out to a healthcare provider promptly. Stay informed, stay proactive, and stay heart healthy!

Still Not Sure if It’s PVC or PACs on Your ECG?

Differentiating between PVC vs PAC 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 today!

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

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

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