Smartphone displaying a glowing heart with ECG waveform.

Smartwatch Heart Check: Is Your Smartphone Accurately Spotting AFib?

Jordan Keane in Health & Wellness November 2025 • 4 min read.

"Discover how smartphone tech is changing heart health, offering early AFib detection and peace of mind."

Atrial fibrillation (AFib), an irregular heart rhythm, is a significant health concern affecting millions. Early detection is key to preventing serious complications like stroke. Traditionally, diagnosing AFib required visits to a doctor and the use of specialized equipment. Now, technology is bringing heart health monitoring directly to your fingertips.

The rise of smartphones and wearable devices has opened new avenues for personal health monitoring. These devices, equipped with sophisticated sensors and algorithms, claim to detect AFib with increasing accuracy. One such device is the Kardia Mobile Cardiac Monitor (KMCM), a smartphone-compatible tool designed to detect AFib through a simple handheld sensor. But how reliable are these technologies, and can we truly depend on them for accurate heart rhythm assessments?

Recent research, including the "iREAD Study," has delved into the accuracy of these smartphone-based AFib detection methods. By comparing KMCM readings with traditional 12-lead electrocardiograms (ECGs), researchers are working to validate the effectiveness of these technologies and understand their potential role in modern healthcare.

How Accurate is Smartphone AFib Detection?

Smartphone displaying a glowing heart with ECG waveform.

The iREAD Study, conducted at the Cleveland Clinic, aimed to evaluate the accuracy of the Kardia Mobile system in detecting AFib. Researchers enrolled 52 patients with known AFib and compared KMCM readings with simultaneously obtained 12-lead ECGs, the gold standard for heart rhythm diagnosis. The results revealed some impressive findings. When the KMCM's automated algorithm provided a result, it demonstrated high sensitivity (96.6%) and specificity (94.1%) in detecting AFib compared to physician-interpreted ECGs.

This means the device was very good at correctly identifying AFib when it was present and accurately ruling it out when it wasn't. The study also found that when physicians directly reviewed the KMCM recordings, the accuracy improved even further, especially in cases where the device's automated algorithm couldn't provide a clear interpretation. This highlights the importance of combining technology with human expertise for the most reliable results.

High Sensitivity: The KMCM system accurately identified AFib in most cases when the automated interpretation was available.
Enhanced Accuracy with Physician Review: Direct review of KMCM recordings by a doctor significantly improved diagnostic yield, especially for unclassified recordings.
User-Friendly Technology: The majority of patients found the KMCM easy to use, reducing anxiety related to AFib diagnosis.
Potential for Continuous Monitoring: The KMCM offers a non-invasive way to monitor heart rhythm over an extended period, filling gaps in traditional monitoring methods.

However, the study also revealed limitations. In about 27.6% of the recordings, the KMCM algorithm couldn't provide a classification, labeling the rhythm as "unclassified." This often occurred due to factors like heart rates outside the algorithm's parameters, short recording durations, or excessive noise. In these instances, physician review of the KMCM recordings became crucial for accurate diagnosis. These instances suggest that while technology offers a convenient screening tool, it shouldn't replace comprehensive medical evaluation.

Empowering Patients, Enhancing Healthcare

Smartphone-based AFib detection is a promising advancement in healthcare. Devices like the Kardia Mobile offer a convenient and accessible way to monitor heart rhythm, empowering individuals to take a more active role in their health. While these technologies are not a replacement for traditional medical evaluations, they can provide valuable insights and support informed decision-making. As research continues and technology evolves, we can expect even more accurate and user-friendly tools to help manage and prevent AFib.

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: 10.1016/j.hrthm.2018.06.037, Alternate LINK

Title: Assessing The Accuracy Of An Automated Atrial Fibrillation Detection Algorithm Using Smartphone Technology: The Iread Study

Subject: Physiology (medical)

Journal: Heart Rhythm

Publisher: Elsevier BV

Authors: Amila D. William, Majd Kanbour, Thomas Callahan, Mandeep Bhargava, Niraj Varma, John Rickard, Walid Saliba, Kathy Wolski, Ayman Hussein, Bruce D. Lindsay, Oussama M. Wazni, Khaldoun G. Tarakji

Published: 2018-10-01

Everything You Need To Know

How accurate is the Kardia Mobile Cardiac Monitor (KMCM) in detecting Atrial Fibrillation (AFib), according to the research?

The Kardia Mobile Cardiac Monitor (KMCM) demonstrated high sensitivity (96.6%) and specificity (94.1%) in detecting AFib when its automated algorithm provided a result, compared to physician-interpreted ECGs. This means it was good at correctly identifying AFib when present and accurately ruling it out when it wasn't. However, in about 27.6% of recordings, the KMCM algorithm couldn't provide a classification, highlighting the need for physician review in some cases.

What was the purpose of the iREAD Study, and how did it assess the effectiveness of smartphone-based Atrial Fibrillation (AFib) detection?

The iREAD Study, conducted at the Cleveland Clinic, evaluated the accuracy of the Kardia Mobile system in detecting AFib by comparing KMCM readings with simultaneously obtained 12-lead ECGs. It showed the KMCM system's high accuracy when the algorithm provided a result, and even greater accuracy when physicians reviewed the recordings. This study helped validate the potential role of smartphone-based technology in modern healthcare for AFib detection.

How does using the Kardia Mobile Cardiac Monitor (KMCM) empower individuals in managing their heart health, and what are the benefits of this technology?

The Kardia Mobile Cardiac Monitor (KMCM) offers convenience and accessibility, allowing individuals to monitor their heart rhythm and take a more active role in their health. It provides continuous monitoring, filling gaps in traditional methods. The iREAD Study indicated that KMCM is user-friendly, reducing anxiety related to AFib diagnosis. However, the KMCM isn't a replacement for traditional medical evaluations but can offer insights to support informed decision-making.

What are the limitations of using devices like Kardia Mobile Cardiac Monitor (KMCM) for Atrial Fibrillation (AFib) detection, and why is professional medical evaluation still important?

While the Kardia Mobile Cardiac Monitor (KMCM) shows promise in detecting Atrial Fibrillation (AFib), it's important to recognize its limitations. In the iREAD Study, the KMCM algorithm couldn't classify about 27.6% of the recordings, often due to factors like heart rates outside the algorithm's parameters or short recording durations. Physician review of the KMCM recordings became crucial in these instances, highlighting the need for professional medical evaluation.

How do traditional methods like the 12-lead electrocardiogram (ECG) compare to smartphone-based devices like the Kardia Mobile Cardiac Monitor (KMCM) in detecting Atrial Fibrillation (AFib)?

While technologies like Kardia Mobile Cardiac Monitor (KMCM) are effective for Atrial Fibrillation (AFib) detection, understanding traditional diagnostic tools is essential. The 12-lead electrocardiogram (ECG) is the gold standard for heart rhythm diagnosis. The iREAD Study used 12-lead ECGs to validate the accuracy of the KMCM. The 12-lead ECG provides a comprehensive view of the heart's electrical activity, enabling healthcare professionals to accurately diagnose various heart conditions, ensuring thorough and reliable assessments.