Question: A patient called in saying their smartwatch performed an ECG and found irregular heart rhythms. Isn’t an EKG used to evaluate heart rhythm, and doesn’t it involve several wires? I got the patient right in to see a physician since they were calling about their heart, but is an ECG and EKG the same thing? Michigan Subscriber Answer: As wearable medical technology has advanced and become more widely available, people who purchase and use technology like smartwatches may realize that they’re exhibiting signs or symptoms of concern and want to be seen by a clinician. ECGs and EKGs are two abbreviations for the same procedure — an electrocardiogram. An electrocardiogram is the recording of electrical activities of the heart and their interpretation by a physician. Physicians may be looking out for irregular or abnormal rhythms, like atrial fibrillation, which in some instances can cause an emergency condition like a stroke. In the heart, the sinoatrial (SA) node, located in the right atrium, sends electrical impulses to the heart’s muscles, which contract, resulting in systole. For example, if a clinician performs a 12-lead ECG, they use 12 electrodes placed on the skin over different regions of the patient’s body (the limbs and chest). These electrodes then record the heart’s electrical activities, and the recordings are put into a graphic format. 12-lead ECG: A 12-lead ECG provides a complete three-dimensional look at the heart’s electrical activity. With a 12-lead ECG, a cardiologist can identify conditions like myocardial ischemia and myocardial infarction and also get a picture of any arrhythmia that might be happening. 1-3 lead ECG: The cardiologist can also perform a 1-3 lead ECG, which is also known as a rhythm ECG. Rhythm ECGs focus on the patient’s heart rhythm and are useful for identifying heart block and tachyarrhythmias. Rhythm ECGs have no more than three leads. A smartwatch with ECG technology uses lights and sensors to monitor the wearer’s heart rhythm, and, unlike traditional ECGs, can track a patient’s heart rhythm (or heart rate or blood oxygen, for example) beyond the office, and potentially provide more data for a physician to evaluate. “Wearables are considered particularly efficient to fulfill [monitoring] because they can track a number of various biomedical processes depending on the types of sensors available and can be used for continuous and remote monitoring — as wearables can be worn constantly, they are ideally placed to collect data continuously,” say Stefano Canali, Viola Schiaffonati, and Andrea Aliverti in their paper, “Challenges and recommendations for wearable devices in digital health: Data quality, interoperability, health equity, fairness,” published October 2022 in PLOS Digital Health. In this situation, because atrial fibrillation and other irregular heart rhythms can be serious conditions, knowing what data patients might be able to collect and access on their own may help you figure out your appointment scheduling priorities.