Stylized heart with a music box inside, representing heart rhythm and health.

Heart Hiccups: Understanding Atrial Arrhythmias and How to Keep Your Heart in Rhythm

Theo Raines in Health & Wellness August 2025 • 4 min read.

"Decoding AV Hysteresis: Learn how advanced heart devices can sometimes trigger atrial arrhythmias and what you can do to stay heart-healthy."

Imagine your heart as a finely tuned orchestra. When it plays in perfect rhythm, everything feels harmonious. But sometimes, a section might fall out of sync, causing what we call an arrhythmia. Atrial arrhythmias, specifically, are like a hiccup in the upper chambers of your heart. They can be unsettling, but understanding them is the first step to managing your heart health.

One of the fascinating areas of cardiology is understanding how implantable devices, designed to help the heart, can sometimes inadvertently trigger these arrhythmias. A recent study explored this phenomenon, focusing on a condition called AV hysteresis, where specific settings in devices like implantable cardioverter-defibrillators (ICDs) can lead to recurrent atrial arrhythmias. This article simplifies the key findings of that study, providing you with actionable insights to help keep your heart in rhythm.

Whether you're someone with a heart device, a caregiver, or simply interested in understanding more about heart health, this article is for you. We'll break down the technical jargon, explain the potential risks, and offer practical steps to discuss with your healthcare provider. Let’s explore how to keep your heart beating smoothly.

Decoding AV Hysteresis: When Heart Devices Cause Rhythm Problems

Stylized heart with a music box inside, representing heart rhythm and health.

AV hysteresis is a feature in some implantable heart devices designed to optimize heart function. These devices, such as ICDs, are programmed to support the heart's natural rhythm. However, certain settings, particularly those related to AV Search+ algorithms, can sometimes lead to problems. The AV Search+ feature adjusts the timing between the atria (upper chambers) and ventricles (lower chambers) to promote natural heart rhythms. In some cases, this adjustment can cause the atria to beat too quickly or out of sync, triggering atrial arrhythmias.

A recent case highlighted this issue in a 73-year-old man with an ICD. Doctors discovered that the AV Search+ setting, combined with sensor rate pacing, was causing short, coupled atrial paced intervals. These intervals acted as a trigger for recurrent episodes of automatic mode switch (AMS), a condition where the heart device changes its pacing mode due to detected arrhythmias. More than half of these AMS episodes followed a similar pattern, indicating that the device settings were contributing to the problem.

Here are key points about how AV hysteresis can lead to arrhythmias:

AV Search+ Feature: Designed to optimize heart rhythm but can cause issues.
Short Coupled Intervals: Rapid atrial pacing can trigger arrhythmias.
Sensor Rate Pacing: Combination with AV Search+ may increase risk.

After recognizing the issue, doctors reprogrammed the patient's ICD, turning off the AV Search+ feature. The result was significant: the patient experienced far fewer AMS episodes, and the overall burden of arrhythmias decreased dramatically. This case underscores the importance of carefully programming and monitoring heart devices to avoid unintended consequences.

Practical Steps for Managing Heart Rhythm with Devices

If you have an implantable heart device, understanding these potential issues is crucial. Regular check-ups with your cardiologist are essential to monitor your device settings and heart rhythm. Discuss any symptoms you're experiencing, such as palpitations, dizziness, or shortness of breath, as these could indicate an arrhythmia. It's also important to ensure your device is programmed in a way that minimizes the risk of triggering arrhythmias while still providing the necessary support for your heart. Stay informed, stay proactive, and work closely with your healthcare team to keep your heart beating in harmony.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1111/pace.13513, Alternate LINK

Title: Av Hysteresis Causing Initiation Of Recurrent Atrial Arrhythmias

Subject: Cardiology and Cardiovascular Medicine

Journal: Pacing and Clinical Electrophysiology

Publisher: Wiley

Authors: Christopher Monkhouse, Terry Dillon, Anthony W. C. Chow, Jonathan M. Behar

Published: 2018-10-17

Everything You Need To Know

What exactly are atrial arrhythmias, and why is it important to understand them?

Atrial arrhythmias are like a 'hiccup' in the upper chambers of the heart, disrupting its normal rhythm. While they can be unsettling, understanding them is crucial for managing heart health, especially for individuals with implantable heart devices like ICDs. It's essential to differentiate atrial arrhythmias from ventricular arrhythmias, which originate in the lower chambers and can be more life-threatening. Recognizing the specific type of arrhythmia is the first step toward appropriate management.

How does AV hysteresis in heart devices lead to rhythm problems?

AV hysteresis is a feature in some implantable heart devices, such as ICDs, designed to optimize heart function by adjusting the timing between the atria and ventricles. The AV Search+ feature, a part of AV hysteresis, aims to promote natural heart rhythms. However, certain settings can inadvertently cause the atria to beat too quickly or out of sync, potentially triggering atrial arrhythmias. Therefore, while AV hysteresis is intended to support the heart, it requires careful programming and monitoring to prevent unintended rhythm disturbances.

What are short coupled intervals, and how do they contribute to atrial arrhythmias in patients with heart devices?

Short coupled intervals refer to rapid atrial pacing that can trigger atrial arrhythmias. In the context of implantable heart devices, these intervals can occur when the AV Search+ feature is active, causing the device to pace the atria too quickly. When combined with sensor rate pacing, the risk of triggering arrhythmias may increase. Understanding the relationship between short coupled intervals and device settings is crucial for healthcare providers to optimize device programming and minimize the risk of arrhythmias.

How does sensor rate pacing interact with AV Search+ to potentially cause heart rhythm issues?

Sensor rate pacing is a feature in implantable heart devices that adjusts the pacing rate based on the patient's physical activity level. While it aims to mimic the heart's natural response to exercise, combining sensor rate pacing with AV Search+ settings may increase the risk of triggering atrial arrhythmias. This is because the increased pacing rate, coupled with the AV Search+ algorithm, can lead to short coupled intervals and rapid atrial pacing. Careful monitoring and adjustments are necessary to ensure that sensor rate pacing does not inadvertently contribute to rhythm problems.

What is Automatic Mode Switch (AMS), and how can it be related to heart device settings like AV Search+?

Automatic Mode Switch (AMS) is a condition where an implantable heart device changes its pacing mode due to detected arrhythmias. In the case discussed, recurrent episodes of AMS were triggered by AV Search+ settings combined with sensor rate pacing. More than half of these AMS episodes followed a similar pattern, indicating that the device settings were contributing to the problem. By reprogramming the ICD and turning off the AV Search+ feature, the patient experienced far fewer AMS episodes, highlighting the importance of personalized device programming to avoid unintended consequences.