When the pacing impulse from the high pacing point suddenly stops and the low potential pacing point just starts to deliver impulses at a frequency slower than its intrinsic frequency before gradually returning to its intrinsic frequency, this phenomenon is called the warm awakening phenomenon. This phenomenon is called warm awakening. It is commonly associated with arrhythmias or sinus reflex tachycardia. So what are the tests that need to be done for the warm awake phenomenon? 1, body electrocardiogram Electrocardiogram (ECG), commonly including ordinary 12-lead ECG and 24-hour ambulatory ECG (Holter). 12-lead ECG is the ordinary ECG, which is the most common non-invasive test for physical examination and clinical diagnosis of many diseases, and is also the preferred test for the diagnosis of arrhythmias. Some arrhythmias are paroxysmal, sudden and abrupt, and a 12-lead ECG can only observe the rhythm for a short period of time, often failing to detect abnormalities. This is when your physician will recommend further Holter refinement for early detection and treatment of abnormalities. However, it should be noted that the occurrence of arrhythmias is not always regular, sometimes more and sometimes less, or even once every few weeks or months. Therefore, a normal Holter result does not necessarily mean that you are fine. Sometimes you may be required to undergo multiple consecutive Holter tests when your physician has a high suspicion of a life-threatening arrhythmia in the past. 2. Clinical electrophysiological examinations For patients with more complex arrhythmias, physicians may recommend that patients undergo cardiac electrophysiological examinations in order to clarify the diagnosis and treatment and determine the prognosis. It can establish the diagnosis of arrhythmia and its type, understand the origin of the arrhythmia and the mechanism of its occurrence, and provide important strategic information for the subsequent interventional procedures. Some patients already have a clear type of arrhythmia through electrocardiogram, and when they are advised to improve their cardiac ultrasound, they will ask, “Why do we need to check when we already know what is wrong?” . Routine transthoracic ultrasound is the easiest and most effective way to examine the structure and function of the heart, helping the physician to gain a complete understanding of the disease and to give the patient the most reasonable treatment plan. Transesophageal ultrasound is another ultrasound tool, mainly used for patients with various heart or macrovascular diseases in which conventional transthoracic ultrasound imaging is difficult or the relevant structures are not satisfactorily displayed, making the diagnosis difficult to clarify, such as patients with atrial fibrillation who need to rank the left atrium and left ear for thrombus formation and cloudy echoes, which are crucial to the next step of treatment for patients with atrial fibrillation. 4. CT Some patients with atrial fibrillation may ask, “Why do I need a CT examination of the left atrium and pulmonary veins before doing radiofrequency ablation? . The target of RF ablation of atrial fibrillation is mainly located in the patient’s left atrium and pulmonary veins, and the anatomical structure of the left atrium and pulmonary veins varies from patient to patient, so understanding the anatomical characteristics of the patient through CT examination before surgery can help the physician to operate skillfully and select the individualized ablation procedure, thus shortening the operation time, reducing intraoperative and postoperative complications, and increasing the success rate of the surgery. In addition, CT examinations can also detect structural abnormalities of the heart and the presence of thrombus.