Some patients who feel panic and weakness can take their own pulse, and if the pulse is irregular and lasts for a long time, it is highly suggestive of atrial fibrillation. To confirm the diagnosis of atrial fibrillation, an electrocardiogram is required at the time of the attack, and other basic tests include: echocardiogram, chest X-ray, blood routine, liver and kidney function, coagulation function, etc. Electrocardiogram is the most direct, safe and economical way to confirm the diagnosis of atrial fibrillation. Usually we refer to the resting 12-lead ECG examination, which can be done by lying down in the ECG room for about 1 minute and can be repeatedly traced. However, it is important to note that the diagnosis of atrial fibrillation can only be confirmed if the ECG is recorded at the time of the onset of atrial fibrillation. Before the ECG examination, patients should avoid strenuous exercise and relax to avoid rapid heart rate during the examination. Do not talk, cough, or move your body during the examination to avoid generating too many pseudo waves. If the patient’s panic attack is too short to do an ECG at the time of the attack, but the attack is more frequent, a 24-hour or even 48-hour ambulatory ECG (i.e. Holter monitoring) can be done to confirm the diagnosis of atrial fibrillation. An ambulatory ECG continuously records all of the patient’s ECG signals for 24 hours, which are analyzed by computer to detect events and arrive at a diagnosis. Patients are required to carry a small “box” on their back for this test and try to move as much as possible with their normal daily activities, but avoiding strenuous exercise that could dislodge the electrodes. Patients are asked to keep a log, including the type and time of activity, and the exact time of onset and termination of panic or cardiac distress, so that the physician can analyze whether there is a relationship between the ECG changes and the patient’s activity and cardiac distress. In addition, because some patients may have no conscious symptoms at all when they have atrial fibrillation, but as age increases and the risk factors for developing atrial fibrillation increase, it is recommended that an ECG be checked during routine physical examinations in order to detect atrial fibrillation in a timely manner. 2.Echocardiography Echocardiography, or cardiac ultrasound, is a routine cardiology examination that does not cause any damage to the patient. This examination can help to understand the structure and function of the heart and to detect possible causes of atrial fibrillation (e.g., rheumatic heart disease) and to evaluate the effect of atrial fibrillation on the heart structure. 3, chest X-ray Patients diagnosed with atrial fibrillation need to routinely do chest X-ray, chest X-ray not only can initially determine the size and shape of the heart, but also can understand whether the patient has lung disease. Chest X-ray can detect some lung diseases that may cause atrial fibrillation, and can also provide reference for the doctor to decide whether the patient can take amiodarone. Patients need to cooperate with the radiologist when checking the chest X-ray to adopt the appropriate position and remove metal accessories on the body to avoid interference with the image. After the diagnosis of atrial fibrillation is confirmed, some basic laboratory tests are needed: routine blood tests, liver and kidney function, coagulation function, etc. These tests will guide the doctor in the selection and dose adjustment of anticoagulation and antiarrhythmic drugs for patients with atrial fibrillation, so that the most reasonable and safe treatment plan can be formulated for the patient. In addition, screening for etiology, such as thyroid function, is also required. As mentioned earlier, hyperthyroidism is one of the causes of atrial fibrillation, and atrial fibrillation due to hyperthyroidism can be ruled out by taking blood to check thyroid function. 5. Transesophageal echocardiography Transesophageal echocardiography is a special test that may be required for patients with atrial fibrillation and is a special form of cardiac ultrasound. Because many patients with atrial fibrillation have atrial thrombus, a transesophageal cardiac echocardiogram is necessary to identify the presence of thrombus, as it is sometimes difficult to detect the thrombus with a normal cardiac echocardiogram from the body surface. Before this test, it is necessary to confirm the presence of infectious diseases such as hepatitis and AIDS, i.e., the patient needs to have blood drawn in advance for immunization. Patients are required to fast from food and water for 6 hours prior to the test. During the test, the sonographer will place an ultrasound probe through the mouth and into the esophagus to see if there is a blood clot in the heart. This test is similar to a gastroscopy, and the patient may experience slight discomfort such as nausea, but it is necessary to confirm the presence of blood clots in the heart.