# Severe silent ischaemia detected with an Apple Watch in the home setting: a case report

## TL;DR

An Apple Watch detected severe heart issues in a symptom-free man during home exercise, leading to successful treatment.

## Contribution

Demonstrates the Apple Watch's potential to detect asymptomatic myocardial ischaemia using lead 1 ECG.

## Key findings

- The Apple Watch recorded a negative T-wave in lead 1, indicating myocardial ischaemia.
- Further tests confirmed severe three-vessel coronary artery disease in an asymptomatic patient.
- Successful coronary artery bypass surgery followed the Apple Watch's initial detection.

## Abstract

The Apple Watch has the capability to record a lead 1 electrocardiogram (ECG) and can identify and report atrial fibrillation. The use for detecting myocardial ischaemia is not endorsed by Apple but is documented in this case.

A 76-year-old man made a lead 1 ECG with his Apple Watch immediately after exercising on a cross trainer. He was fully asymptomatic. The ECG showed an unusual negative T-wave in this lead 1 that deepened in a few minutes and returned to normal after 22 min. He consulted a cardiologist and a standard exercise ECG confirmed the negative T-wave in lead 1 after maximal exercise and in addition showed widespread ST-depression indicating myocardial ischaemia, again without any clinical symptoms. Further studies revealed severe obstructive three-vessel coronary artery disease that was considered not suitable for percutaneous intervention. A coronary artery bypass operation on all involved vessels was performed successfully. Recovery was uneventful and an exercise ECG repeated 11 weeks later was normal.

We demonstrated that the lead 1 ECG made with the Apple Watch can reliably record T-wave changes indicating myocardial ischaemia. The use of the Apple Watch to document ischaemic changes should be studied systematically for its potential to identify myocardial ischaemia, mainly triggered by symptoms but maybe for asymptomatic persons as well.