It is an indisputable fact that patients with atrial fibrillation (AF) have a significantly higher chance of stroke, which can be disabling and fatal and seriously affect our health. Anticoagulation therapy has a positive significance in reducing the incidence of stroke in patients with atrial fibrillation. However, it is true that many patients do not realize that they have atrial fibrillation until they visit the clinic for a stroke, but by then the sequelae are already unavoidable. Therefore, atrial fibrillation is often called the “silent killer”. We have described some of the “clues” that may indicate atrial fibrillation in the past, and we hope that they will help us to recognize this arrhythmia as early as possible. However, there are still some patients whose AF episodes are completely asymptomatic, a real “silent killer”, which we call “asymptomatic AF”. We will briefly explain what “asymptomatic AF” is, how common it is in patients with AF, and whether there is any way to detect it. What is “asymptomatic” atrial fibrillation? As mentioned in the previous article, palpitations, dyspnea, fatigue, dizziness, etc. are common symptoms of atrial fibrillation, and even polyuria, blackouts and fainting may occur in a few patients. However, there are some patients who do not have any of these symptoms and do not feel atrial fibrillation at all, which is called “asymptomatic atrial fibrillation”. Research suggests that patients with persistent AF and the elderly may be more likely to be “asymptomatic”, but this is controversial and not absolute. Is asymptomatic atrial fibrillation common? Asymptomatic atrial fibrillation may seem like a “rare” condition, but it’s not. It’s special, and it’s not uncommon. As we know, atrial fibrillation can only be diagnosed by receiving an electrocardiogram at a medical institution, and this group of patients who do not “feel” atrial fibrillation will not take the initiative to consult a doctor, so the discovery of atrial fibrillation is often “accidental”, such as during a physical examination, or because of other illnesses, or even the development of complications, as mentioned above. Or even after complications, as mentioned above. This makes the exact prevalence of asymptomatic atrial fibrillation difficult to ascertain. Regular electrocardiograms do detect some, but they are still underestimated, and a long-range Holter or implantable device with ECG monitoring may help to detect more of these patients, which is true, but it is not realistic to generalize it to the general population. It is currently hypothesized, based on the results of various relevant studies, that asymptomatic AF accounts for approximately all patients with AF, which is seen to be not a small number. Studies involving implanted devices such as pacemakers have reported even higher percentages. In addition, studies have found that even patients with symptomatic AF have many asymptomatic episodes, and even more episodes than symptomatic episodes. Many patients with symptomatic atrial fibrillation say that they do not “feel” atrial fibrillation when they have an electrocardiogram that shows atrial fibrillation rhythms. Some patients with persistent atrial fibrillation describe their symptoms as paroxysmal, which we initially mistake for paroxysmal atrial fibrillation. How to detect asymptomatic AF Atrial fibrillation significantly increases the risk of stroke, and asymptomatic AF is no exception. However, wouldn’t it be terrible if we didn’t know anything about it when it happened? Is there actually anything we can do to improve our chances of detecting this type of atrial fibrillation? Happily, with advances in technology, the recent craze for “wearable devices” may offer a solution. 2013 study in Sweden gave older adults with at least one cardiovascular risk factor who did not have atrial fibrillation detected by routine electrocardiograms a portable, hand-held electrocardiogram-recording device to remotely transmit an electrocardiogram daily for 2 weeks. transmission of ECG for 2 weeks, and as a result, a number of asymptomatic patients with AF were identified and anticoagulation was started in a timely manner. Today, the advent of smart bracelets, watches, and other devices that can be worn for extended periods of time may be even more conducive to the detection of asymptomatic but dangerous conditions like asymptomatic AF. That day, we shall see. Of course, some patients have said, those devices will gradually become more popular, but after all, they are still expensive, is there an easier way? In the previous article we also taught you some ways to detect atrial fibrillation at home by yourself, such as feeling your pulse or through the available electronic blood pressure monitors, so feel free to refer to them.