Two late-breaking studies presented at AHA 2026 highlight AI's potential to extend cardiovascular screening and improve diagnostic workflow, while underscoring the continued importance of clinician oversight.

WATCH-LV

In the WATCH-LV study, researchers evaluated an AI model designed to identify left ventricular systolic dysfunction (LVSD, LVEF ≤40%) from 30-second, single-lead smartwatch ECGs. Among 2,211 adults undergoing echocardiography in South Korea, the model distinguished patients with and without LVSD similarly using Apple Watch and Samsung Galaxy Watch recordings, although 9% received discordant classifications between devices.

In a separate home-monitoring cohort, requiring positive AI results on at least two of three consecutive days cut false positives by 50%, but missed two additional LVSD cases compared with relying on a single positive day.

"A single smartwatch ECG is a snapshot, and repeated recordings can give different results," said Hak Seung Lee, MD. "Requiring repeated positive results reduced false positives in our study, yet it also missed some additional cases that should have been positive."

Based on the findings, Lee said that smartwatch ECGs analyzed with AI may help identify people who need additional heart screening such as an echocardiogram, but more research is needed before smartwatch ECG readings can replace traditional screening exams.

AI ECHO INSIGHT

A second randomized study out of California, AI ECHO INSIGHT, examined AI-generated preliminary interpretations of 1,200 echocardiograms. AI-assisted reports were comparable in accuracy to preliminary reports prepared by sonographers and cardiologists: substantial changes were made to 50.6% of AI-generated vs. 49.7% of human-generated preliminary interpretations. Importantly, AI assistance reduced cardiologist interpretation time from 8.5 to 4.6 minutes per exam, a 46% savings.

"We designed this study to capture even small differences between the preliminary reports and the cardiologists' final interpretations, allowing us to take a careful look at how well AI performed in a rigorous scientific manner," said Keane K. Lee, MD, MS. "Based on our prior work, we expected AI to demonstrate excellent accuracy, which was confirmed in this randomized trial. However, what surprised us was the extent to which using AI-generated reports reduced the time cardiologists needed to interpret echocardiograms."

Looking ahead, Lee and colleagues said that more research is needed to assess how AI-assisted interpretation may perform in real-world clinical settings with larger scale and volume of exams.

Clinical Topics: Heart Failure and Cardiomyopathies, Noninvasive Imaging, Echocardiography/Ultrasound

Keywords: AHA Annual Scientific Sessions, AHA26, Ventricular Dysfunction, Left, Artificial Intelligence, Electrocardiography, Echocardiography