“Pre-excitation is the presence of one or more abnormal electrical conduction pathways (or bypasses) between the atria and the ventricles in addition to the normal conduction pathway (AV node), which can usually be clarified by a simple plain ECG. The presence or absence of “pre-excitation” can usually be determined by a simple plain ECG. Pre-excitation is present in about 0.1% to 0.3% of the general population. Some pre-excitation patients are asymptomatic and are detected only by physical examination, while the majority of pre-excitation patients are usually confirmed by ECG after the onset of tachycardia. Does pre-excitation require surgery or not? Many patients will have a lot of questions, the following I will combine clinical research and actual cases to explain in detail, I hope to be able to clear up the doubts, so as not to affect the ultimate health because of a small problem, because at present, pre-excitation can be completely cured. As mentioned before, most of the patients with “pre-excitation” are usually confirmed by electrocardiogram after the occurrence of tachycardia, that is to say, the most common manifestation of “pre-excitation” is detected because of the triggering of or participation in the tachycardia (the so-called symptomatic pre-excitation), which is the most common and the most common form of tachycardia. The most common and typical of these tachycardias is the paroxysmal supraventricular tachycardia (generally not fatal, but inevitably recurrent, with increasing frequency and duration of episodes with advancing age), for which the clinical consensus is to perform a catheter ablation procedure for its eradication. In a small percentage of patients with preexcitation, the tachycardia is not typical supraventricular tachycardia but atypical atrial fibrillation, atrial flutter, and other arrhythmias, which are ultimately confirmed by electrocardiography; catheter ablation is the preferred treatment for preexcitation in the majority of these patients, but comprehensive evaluation is needed, and some patients can be treated surgically with preexcitation only, while others will require further interventions for atrial flutter and atrial fibrillation. For patients with tachycardia who are “pre-excited,” the indications for surgical treatment are clear, and most patients are comfortable with it and generally have no questions about it. What about the “pre-excited” patient without tachycardia (which is the target population of this article: asymptomatic pre-excited patients)? There is a difference of opinion. Many physicians used to (and still do) believe that asymptomatic (tachycardia) preexcitation is benign, i.e., does not require further intervention. But this is a very wrong view. The first thing that needs to be clarified is that asymptomatic preexcitation is most likely only a phase of the state, because most patients with originally asymptomatic preexcitation may later develop tachycardia or other symptoms, such as cardiac enlargement, heart failure, etc., as they get older. In recent years, the medical community has been paying more attention to this issue, as there are many cases where very serious complications have developed before they are taken seriously, and many of them have been corrected or even reversed after the “asymptomatic” pre-excitation bypass pathway was removed. In a prospective follow-up study published in 2012 in Circulation, an authoritative international cardiovascular journal, it was found that in pre-excitation patients with one episode of tachycardia (without catheter ablation), the incidence of malignant arrhythmia was 7%, and the incidence of hemodynamic disorders and cardiac arrest was 1.4%. percent. A malignant arrhythmic event is defined as a potentially life-threatening arrhythmic episode in which a sustained episode of atrial fibrillation combined with a minimum pre-excited ventricular rate (heart rate) of more than 240 beats per minute is documented; or a very rapid episode of atrial fibrillation or ventricular fibrillation resulting in a sudden loss of effective flow, hemodynamic disturbances, and cardiac arrest that requires cardiopulmonary resuscitation and/or electrical defibrillation. Asymptomatic pre-excited patients, like those with symptomatic pre-excitation, are at risk for malignant arrhythmic events due to the short conduction omission period of the bypass tracts (which leads to tachycardia, or a very fast heartbeat), the metamorphosis of supraventricular tachycardia into atrial fibrillation, and the presence of multiple bypass tracts, among other characteristics.Another study published in 2014 in the same journal found that asymptomatic pre-excited patients had a high risk of developing ventricular fibrillation (a lethal arrhythmia) during follow-up observations, which required correction within several minutes. that need to be corrected within minutes or result in death) was much more common in patients with asymptomatic pre-excitation than in those with symptomatic pre-excitation, while there was no significant difference in the incidence of malignant arrhythmias. In other words, in patients with preexcitation, those with asymptomatic preexcitation were more likely to develop ventricular fibrillation than those with symptomatic preexcitation if no intervention was performed. The factors associated with the development of ventricular fibrillation are the short short response time of the preexcited bypass tract (which tends to lead to rapid ventricular rate and hemodynamic disturbances that ultimately lead to ventricular fibrillation) and the metamorphosis of supraventricular tachycardia into atrial fibrillation. Thus, although the presence or absence of symptoms has a significant impact on the treatment of patients with preexcitation, it is not the presence or absence of symptoms that affects the prognosis of patients, but rather the electrophysiologic characteristics of the preexcited bypass tract itself. In our clinical practice, we have encountered a number of patients who were confirmed to be asymptomatic pre-excitation patients after effective resuscitation due to sudden malignant arrhythmic events. These patients were usually asymptomatic and did not undergo further examination, but in a certain stressful situation (such as after drinking alcohol, exercise, emotional excitement) sudden atrial fibrillation with pre-excitation pre-transmission, hypotensive shock, blackout, fainting and other phenomena occurred, but fortunately in the end the rescue was timely, and through emergency electrical cardioversion out of the danger; after that, we gave them radiofrequency ablation, eradicated pre-excitation bypass tracts, so that the patients were rehabilitated. (For specific cases, please refer to my related article: “The most dominant preexcitation bypass in history”.) There were also some young patients who came to the clinic because of cardiac enlargement, cardiac insufficiency, and inability to walk, and then were found to be preexcited, but there was no obvious history of tachycardia episodes. Later, the pre-excitation bypass channel was eliminated by radiofrequency ablation, and after years of follow-up, the “aging” heart regained its youthfulness, heart size, cardiac function improved, and the quality of life improved, returning to a normal life. Since I have been practicing for many years, one of my most memorable cases is: 8 years ago (at the end of 2007), 20 year old Hu consulted the doctor because of an enlarged heart. At that time, the left ventricle was already significantly enlarged to 80mm (normally not more than 55mm in normal people with normal body size), accompanied by a significant decline in cardiac function. After a thorough examination, it was found that there was pre-excitation, and then the bypass channel was removed by radiofrequency ablation. After years of continuous adjustment of medication, the left ventricle of Little Hu has recovered to 56mm this year, and his heart function has improved significantly compared to the previous one. This is because some pre-excited bypass tracts grow in a special location (especially the right free wall bypass tract), for some susceptible people, it is easy to lead to the incoordination of the contraction activities of the left and right ventricles of the heart (the two ventricles do not work together, pulling each other’s legs, increasing the burden on the heart), and in the long run, it will be just like a rubber band that is stretched excessively and finally loses its elasticity, which will ultimately lead to the enlargement of the heart, cardiac function decline, and even affect the life. From the above, even if pre-excitation patients do not have any tachycardia symptoms, but there are still more risks of malignant arrhythmia, especially the risk of ventricular fibrillation is much higher than that of the symptomatic pre-excitation patients, and some asymptomatic pre-excitation patients will also have cardiac enlargement, cardiac hypoplasia and other complications. So how do we prevent this from happening and how do we give treatment recommendations? It is recommended that patients with asymptomatic pre-excitation should first undergo a complete cardiac ultrasound examination for any structural abnormalities, and if there is no intervention for pre-excitation, then regular follow-up cardiac ultrasound is needed to avoid serious enlargement of the heart that may cause delays in treatment. Secondly, ECG should be followed up regularly. If there is “intermittent preexcitation” (i.e. not all ECGs show preexcitation), most of the cases are “low risk”, and the relevant ECGs should be preserved (photocopying is recommended, as ECG paper tends to be faded and does not show up well) and the patient should be watched for tachycardia. The patient should be monitored for tachycardia (asymptomatic at the beginning, but many people will develop tachycardia later), and should be followed up regularly by a cardiologist. If the ECG is consistently “pre-excited”, an exercise stress ECG is recommended. If the pre-excitation disappears during exercise (indicating that the preexcitation has a long, but low rate of refractory period), this suggests that the patient may be a “low-risk” patient, and can be followed up regularly. If exercise preexcitation persists, further consideration of transesophageal pacing electrophysiology or intracardiac electrophysiology is recommended. Of these, intracardiac electrophysiology is the most precise and is a minimally invasive, minimally risky, inpatient procedure that allows for effective evaluation of preexcited collateral conduction, measurement of relevant electrophysiologic parameters, and determination of the presence or absence of multiple collaterals. The electrophysiologic characteristics of the preexcited collateral channels themselves can be known after the electrophysiologic examination, based on which the advantages and disadvantages of ablation can be determined by taking into account the characteristics of the patient’s condition and other factors, and deciding on the next therapeutic strategy. Generally speaking, if the electrophysiologic examination has already been performed, it is generally recommended to go directly to radiofrequency ablation to remove the excess pre-excited bypass tracts through radiofrequency ablation, so as to avoid the occurrence of tachycardia in the future and the need for electrophysiologic examination or radiofrequency ablation treatment again. In addition, there are issues that are unrelated to whether or not there is a risk of preexcitation paracentesis, and that is that the presence of preexcitation paracentesis can affect school physicals, work employment physicals, and reproductive arrangements, and this is more pronounced in younger people. Given that catheter ablation is now very powerful in curing pre-excitation (basically there is no pre-excitation that cannot be ablated), and the risks associated with the procedure are actually very small, many young people choose to undergo catheter ablation after physical examination to remove the extra pre-excitation collateral tracts and not to leave any restrictions on schooling, employment, and other aspects of their lives. In summary, some patients with preexcitation do not necessarily develop supraventricular tachycardia, so-called “asymptomatic preexcitation” (but most likely only temporarily asymptomatic), but the presence of preexcitation has certain effects: 1) an increased risk of ventricular fibrillation (fatal arrhythmia), and 2) a higher risk of developing later atrial fibrillation with preexcited precession. The risk of malignant arrhythmia increases, 3. affects the medical examination for admission to school and employment, and 4. affects the arrangement for childbirth. Although the old saying goes “the body hair skin, received by the parents, do not dare to destroy”, but this pre-excitation bypass is not a good thing, but is or cause trouble trouble, with the current level of medical care, this excess will be removed, the heart will be healthier, the quality of life will also improve. All in all, it is recommended to deal with pre-excitation with aggressive intervention and unnecessarily leave yourself open to so many risks.