What Low Voltage Looks Like on Your Watch ECG

Low Voltage 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

  • Low voltage on an electrocardiogram (ECG) refers to smaller or flatter waves in the ECG recording, indicating that the amplitude of the waves representing the heart's electrical activity is lower than usual. It may appear as consistently small or flat waves across the entire tracing on a smartwatch ECG.
  • Having a low voltage ECG itself isn't necessarily harmful, but it can be an indicator of underlying health conditions that may require attention. Conditions like obesity, lung disease, or fluid accumulation around the heart can cause low voltage on the ECG. However, low voltage may also be a normal finding in older individuals or those with a naturally small stature.
  • If you observe low voltage on your smartwatch ECG and experience symptoms like shortness of breath, chest pain, or fatigue, it is essential to consult with a healthcare provider. They can evaluate the ECG findings in the context of your medical history and symptoms to determine if further investigations or interventions are necessary for your heart health.

Got other questions on Low Voltage? See the Qaly guides on Low Voltage:

Introduction

One of the remarkable advancements in wearable technology is the ability to use smartwatches to monitor heart activity via an electrocardiogram (ECG). As we use this technology to track our heart health, it's essential to understand the various features that can appear on an ECG, including something called “low voltage.” So what exactly does low voltage on an ECG mean, and how does it impact your heart health? Let’s dive in.

What’s Low Voltage on an ECG?

In an ECG recording, voltage corresponds to the height and depth of the waves that represent the electrical activity of the heart. Each wave reflects a specific part of your heart’s cycle, and the size of the waves, or “amplitude,” can provide crucial information about your heart health.

Low voltage on an ECG means that the amplitude of the waves on your ECG is lower than what is typically expected. On your ECG, low voltage may appear as consistently small or flat waves across the entire tracing, including a low voltage QRS. While it might be challenging to evaluate specific numeric values due to the often smaller and less detailed display on a smartwatch ECG, low voltage often looks like the overall ECG tracing is “smaller.”

Here's low voltage recorded on a Qaly member's Samsung Watch ECG. The Samsung ECG app labeled this as an Afib ECG. Notice the low voltage QRS, too, which isn't as tall as the QRS Intervals that you typically see on your ECG.
Here's low voltage recorded on a Qaly member's Samsung Watch ECG. The Samsung ECG app labeled this as an Afib ECG. Notice the low voltage QRS, too, which isn't as tall as the QRS Intervals that you typically see on your ECG.


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Low voltage seen on a Qaly member's Kardia ECG.
Low voltage seen on a Qaly member's Kardia ECG.

Is Low Voltage ECG Dangerous?

Having a low voltage ECG isn't necessarily dangerous on its own, but it can be a sign of underlying conditions that require prompt medical attention like large pericardial effusion or cardiac tamponade. It's often seen in conditions that reduce the electrical conductivity between the heart and the ECG electrodes. This can be due to various factors, such as obesity, lung disease, or conditions that lead to an accumulation of fluid around the heart, such as pericardial effusion.

However, it's essential to understand that low voltage might also be a normal finding, particularly in older individuals or those with a naturally small stature. Therefore, a low voltage ECG, in itself, should not be a cause for panic.

The key lies in correlating the ECG findings with symptoms and medical history. If you notice low voltage on your watch ECG and have symptoms like shortness of breath, chest pain, or fatigue, it would be wise to consult with a healthcare provider. They can help interpret the findings in the context of your overall health and determine if further investigations or interventions are necessary. Always remember to reach out to a healthcare professional for a comprehensive evaluation if you have concerns about your ECG readings.

Conclusion

Well, that just about wraps up our guide on what low voltage 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 low voltage? On the Qaly app, human experts will interpret your ECGs for low voltage 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

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

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