Junctional Rhythm Vs. Supraventricular Tachycardia (Non-Sustained) on Your Watch ECG

Got other questions on Junctional Rhythm or SVT? See the Qaly guides on Junctional Rhythm and SVT:

• What Junctional Rhythm Looks Like on Your ECG
• What SVT Looks Like on Your ECG
• ‍How to Read an ECG: Stanford Cardiologist Explains
• ‍The Ultimate Cardiologist's Guide to the Smartwatch ECG

‍

Introduction

Today's smartwatches offer a wide array of health monitoring features, one of the most important being the ability to monitor heart rhythms. The electrocardiogram (ECG) feature allows users to identify potential heart irregularities. Among the varied rhythms that can be recorded, this article will focus on junctional rhythm and non-sustained supraventricular tachycardia (SVT), or junctional rhythm vs SVT. Let’s dive in.

‍

What’s Junctional Rhythm?

Junctional rhythm, also known as nodal rhythm, is when the heart's rhythm is regulated not by the SA node but by the atrioventricular (AV) node or junction. In this case, the AV node fires before the SA node can, resulting in a rhythm that, while regular, has a slower rate. On an ECG, a junctional rhythm might show absent or inverted P waves, owing to the different origin of the rhythm. Here’s more on what junctional rhythm looks like on your watch ECG.

‍

‍

‍

What’s Supraventricular Tachycardia (SVT)?

SVT is an abnormal fast heart rhythm starting in the upper chambers (atria) of the heart, leading to a heart rate often between 150 to 250 beats per minute.

On an ECG, SVT is identified by a rapid, regular rhythm with typically narrow QRS complexes. Often, P waves are difficult to see. 

‍

‍

“Non-sustained” SVT lasts less than 30 seconds, whereas “sustained” SVT lasts longer, sometimes even up to several hours. Here’s more on what SVT looks like on your watch ECG.

‍

‍

What’s the Difference Between Junctional Rhythm and Non-Sustained SVT?

Comparing junctional rhythm vs SVT, the most noticeable differences are the heart rate and the origin of the rhythms. While junctional rhythm is generally slower (40-60 bpm) and originates from the AV node, non-sustained SVT is faster (over 100 bpm) and comes from the atria or the part of the AV node above the bundle of His.

Furthermore, while both rhythms can occur in healthy individuals and cause minimal symptoms, the potential health implications differ. Junctional rhythm can be indicative of an SA node dysfunction or the side effect of certain medications, while non-sustained SVT can cause uncomfortable symptoms and potentially hint at more serious cardiac conditions if the episodes increase in frequency or duration.

In summary, understanding your ECG and differentiating between various heart rhythms like junctional rhythm and SVT is an essential step in proactive health management. However, these watch ECG readings should complement, not replace, regular check-ups with a healthcare professional for accurate diagnoses and treatment plans. Stay informed, stay proactive, and stay heart healthy!

‍

Still Not Sure if It’s Junctional Rhythm or Supraventricular Tachycardia (Non-Sustained) on Your ECG?

Differentiating between junctional rhythm vs SVT 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!