Low Voltage Vs. Sinus Rhythm on Your Watch ECG

Low Voltage Sinus Rhythm 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 Low Voltage or Sinus Rhythm? See the Qaly guides on Low Voltage and Sinus Rhythm:

Introduction

With the rise of wearable technology, electrocardiograms (ECGs) have become a crucial part of routine heart health monitoring. They allow us to record the electrical activity of the heart and detect various heart conditions. In this article, we will explore two ECG patterns: low voltage and sinus rhythm. Understanding the difference between low voltage vs sinus rhythm can help us comprehend our heart health better. 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. Specifically, it's defined as a peak-to-peak QRS amplitude of less than 5mm in all limb leads or less than 10mm in all precordial leads. Your Apple Watch, Fitbit, Samsung, or other smartwatch ECG is a limb lead.

Low Voltage read on a Samsung Watch ECG through the Qaly app.
Low Voltage read on a Samsung Watch ECG through the Qaly app.

On your ECG, low voltage may appear as consistently small or flat waves across the entire tracing. 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.”

Low Voltage read on a Kardia ECG through the Qaly app.
Low Voltage read on a Kardia ECG through the Qaly app.

What’s Sinus Rhythm?

Sinus rhythm, or normal sinus rhythm, is considered the standard rhythm of a healthy heart. In this pattern, electrical signals originate from the sinoatrial (SA) node located in the right atrium, initiating each heartbeat and ensuring they occur at a steady, regular rate.

Sinus Rhythm read on a Samsung Watch ECG through the Qaly app.
Sinus Rhythm read on a Samsung Watch 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
Download Qaly
Google Play - Download Qaly | ECG Reader
Download Qaly
Start today, cancel any time
QALY app - ecg reviews, ecg reader, ecg interpretations, review your ecg

On an ECG, sinus rhythm is characterized by a distinct P wave (indicating atrial contraction) followed by the QRS complex (signifying ventricular contraction), then the T wave (representing ventricular relaxation). This cycle repeats at a rate of 60-100 times per minute in adults at rest. Here’s more on what sinus rhythm looks like on your watch ECG.

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

What’s the Difference Between Low Voltage and Sinus Rhythm?

When we compare low voltage vs sinus rhythm, we are essentially comparing a pattern (low voltage) with a rhythm (sinus rhythm). Low voltage refers to the amplitude of the heart's electrical signals, while sinus rhythm describes the regular pattern of heartbeats set by the SA node.

Low voltage can occur in any rhythm, including sinus rhythm. In other words, a sinus rhythm ECG can have low voltage if the heart's electrical signals are weak. It's important to note that a low voltage finding, while usually benign, could indicate underlying conditions affecting the heart's electrical signal strength.

On the other hand, sinus rhythm is the normal, healthy rhythm of the heart. Deviations from sinus rhythm could signify potential cardiac disorders like arrhythmias.

In conclusion, recognizing and understanding the differences and potential implications of ECG patterns and rhythms, such as low voltage and sinus rhythm, can greatly assist in proactive heart health management. Nevertheless, it's crucial to consult with healthcare professionals for comprehensive heart health assessments, as personal ECG devices should supplement, not replace, professional medical advice. Stay informed, stay proactive, and stay heart healthy!

Still Not Sure if It’s Low Voltage or Sinus Rhythm on Your ECG?

Differentiating between low voltage vs sinus rhythm on your ECG can be tricky. If you’re still looking for help interpreting your ECG further, 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 Low Voltage or Sinus Rhythm? On the Qaly app, human experts will interpret your ECGs for Low Voltage and Sinus Rhythm within minutes. Get started today.

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

Get unlimited ECG reviews today, cancel anytime -->

Get unlimited ECG reviews today, cancel anytime -->

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

Download Qaly