In recent years, the incidence of various arrhythmias has been increasing year by year. Many patients have different manifestations when arrhythmias occur. For example, panic, shortness of breath, breath-holding, etc. Sometimes dizziness and sudden fainting (syncope) may occur due to insufficient blood supply to the heart and brain caused by the arrhythmia. However, there are also many patients who have no obvious symptoms or no symptoms at all when arrhythmias occur. In the latter case, it is very easy to delay the disease and miss treatment. Some people often say to me, “I keep checking my body every year, and even have an ECG several times a year, and no problem is found, so there shouldn’t be any problem, right?” In the process of treating patients clinically, I find that this statement is very different from the actual situation. In last week’s clinic, there were several patients who had this “very different” problem. One of them was a 52-year-old woman who had never been uncomfortable, but who was given multiple daily short-duration portable electrocardiograms (small, cellphone-sized ECG machines that can record ECGs at any time) and was found to have frequent ventricular asystole, which is a difficult ventricular parallel rhythm asystole. Then a 24-hour continuous ambulatory recording of her ECG (medically known as Holter) was performed and she actually had a total number of ventricular premature contractions of more than 10,000 in 24 hours. Her total heartbeat overview in 24 hours was more than 110,000, or 10% of the total number of heartbeats. She was followed up with some ECGs, but none of them “caught” these crazy arrhythmias.