OVERVIEW
由为房室旁道引起的心室预激并伴有快速型室上性心动过速
不发作时无症状
多是心脏先天发育不良引起
主要有药物治疗、电复律治疗及射频消融治疗等
Definition.
Normally, there is only one pathway that connects the atria and ventricles of the heart, but in some populations there are other pathways called atrioventricular paraventricular pathways, which when activated lead to premature activation of some or all of the muscles within the ventricles, triggering an arrhythmia that is referred to as the classic preexcitation syndrome.
The syndrome was first reported in 1930 by Wolff, Parkinson and White, hence typical preexcitation syndrome is also known as WPW (Wolf-Parkinson-White) syndrome [1].
Staging
The location of the atrioventricular paraventricular tract varies and the ECG waveforms behave differently.
Typing according to ECG characteristics
Type A is when the preexcitation wave is positive in all thoracic leads V1 to V5, and the QRS wave is also dominated by the R wave.
Type B is that the preexcitation wave is negative in lead V1, the QRS wave is dominated by the S wave, and both the preexcitation wave and the QRS wave are positive in leads V4 to V6.
Type C is rarer, with upward predominance of δ and QRS waves in leads with RS or R patterns, and QR or QS patterns in leads V5 and V6 [2].
Pathogenesis
There are no accurate genetic pathology data for typical preexcitation syndrome, and the prevalence of atrial paraventricular tracts in the population is 0.1% to 0.3%, with more males than females.
The incidence of atrial paraventricular tracts in patients with Ebstein’s malformation is as high as 10% to 29%.
Causes
Causes
The majority of typical preexcitation syndromes occur in patients without organic heart disease, mainly due to the developmental remnants of scattered interatrial connections of the myocardium, with a few occurring in patients with congenital or acquired heart disease.
Congenital heart disease
The most common congenital heart disease is Ebstein’s malformation.
Other congenital heart diseases may include ventricular septal defects, tetralogy of Fallot, atrial septal defects, mitral valve prolapse, and mitral valve multilobe malformation.
Acquired heart disease
These include heart valve disease, hypertrophic cardiomyopathy, dilated cardiomyopathy, hypertensive heart disease, coronary artery disease, and cardiac trauma.
Pathogenesis
Typical preexcitation syndrome occurs because of atrial excitation conducted by the atrioventricular bypass tract, which leads to premature excitation of some or all of the myocardium of the ventricles.
The normal atrioventricular conduction bundle from the atria to the ventricles is the AV node-Hipple system, and the ventricles receive commands from the sinus node through this pathway.
In typical preexcitation syndromes partial excitation of the atria is conducted by an abnormal pathway, the atrioventricular bypass tract.
The atrioventricular collateral tract is a myocardial bundle of some abnormal cardiac muscle fibers connecting the atria to the ventricles and is also known as Kent’s bundle [3-4].
Symptoms.
Typical preexcitation syndrome has no specific symptoms when tachycardia is not complicating the syndrome.
Paroxysmal palpitations and other symptoms may occur when tachycardia is complicating the syndrome.
Main symptoms
Paroxysmal palpitations, which are characterized by palpitations with dizziness, chest tightness, pallor and sweating.
Syncope, which is a sudden, transient and complete loss of consciousness that lasts for a few seconds to several minutes, and usually recovers quickly.
Cardiac insufficiency, mainly manifested as dyspnea, limitation of physical activity and drop in blood pressure.
Complications
If typical preexcitation syndrome is associated with atrial fibrillation or atrial flutter, and when the ventricular rate is greater than 200 beats per minute, there may be a risk of complications such as ventricular fibrillation and sudden cardiac death.
Ventricular Fibrillation
Clinical symptoms include loss of consciousness, convulsions, respiratory arrest or even death, loss of heart sounds on auscultation, inability to palpate the pulse, and inability to measure blood pressure.
Sudden cardiac death
Sudden death is preceded by manifestations such as chest tightness, chest pain, dizziness, palpitations, transient loss of consciousness and profuse sweating.
Consultation
Department of Medicine
Cardiovascular Medicine
Routine physical examination reveals abnormal electrocardiogram results, or symptoms such as chest tightness, palpitations, dizziness, etc. It is recommended to consult the Department of Cardiovascular Medicine promptly.
Emergency Medicine
Sudden and severe palpitations and dyspnea, etc., it is recommended to go to the Emergency Department immediately.
In case of loss of consciousness, respiratory and cardiac arrest, immediately call 120 emergency and perform CPR on the patient at the same time.
Preparation
Preparing for your visit: registration, information preparation, common problems
Tips for seeking medical treatment
Typical Pre-Excitation Syndrome is paroxysmal and ECG abnormalities can be detected during examination. You can always record the triggering factors before the onset of the symptoms to facilitate the doctor’s diagnosis.
Preparation Checklist
症状清单
Pay particular attention to the time of onset of symptoms, special manifestations, etc.
Is there any chest tightness or palpitation?
What are the triggering and relieving factors of the symptoms?
How many times do these symptoms occur? How long have they lasted?
病史清单
Is there a family history of the condition?
Are there any drug or food allergies?
Are there any other medical conditions?
检查清单
Test results from the last 6 months to bring to your doctor’s appointment
Blood tests
Electrocardiogram (including routine electrocardiogram, 24-hour ambulatory electrocardiogram, electrocardiogram exercise test, etc.)
Echocardiogram
Transesophageal cardiac electrophysiology
Cardiac magnetic resonance examination
用药清单
Medication use in the last 3 months, bring medication box or package to doctor if available
Sodium channel blockers/Propafenone, quinidine, lidocaine
Beta blockers: propranolol, atenolol
Potassium channel blockers: amiodarone, dronedarone
Calcium channel blockers: verapamil, diltiazem
Diagnosis
Disease diagnosis
Medical History.
May have a history of congenital heart disease
May have a history of myocardial infarction and coronary artery disease.
Clinical manifestations
Paroxysmal palpitations, sudden onset and offset
Chest tightness, shortness of breath.
Dizziness, even syncope.
Dyspnea.
Limitation of physical activity.
Electrocardiography
An electrocardiogram (ECG) should be performed whenever the presence of a classic preexcitation syndrome is suspected, regardless of the accompanying symptoms.
A 24-hour ambulatory electrocardiographic monitoring (Holter) may also be necessary if the routine ECG does not show abnormal manifestations.
The electrocardiogram is one of the primary tests used to confirm the diagnosis of typical preexcitation syndrome.
ECG features of typical preexcitation syndrome include.
PR间期缩短，小于0.12s。
QRS波群增宽，时限大于0.10s。
QRS波群起始部有粗钝的δ波（预激波）。
继发性ST-T改变。
Transesophageal cardiac electrophysiology
Cardiac electrophysiological examination involves recording the potentials of various parts of the heart during its own rhythm or when various electrical stimuli are given, analyzing their manifestations and characteristics, and making relevant diagnoses.
Transesophageal cardiac electrophysiology examination also clearly identifies atrial and ventricular electrical activity, determines the relationship between atrial and ventricular electrical activity, and performs differential diagnosis [5-6].
Differential diagnosis
Atrial flutter
Similarities: both may present with palpitations with dizziness, chest tightness, pallor, sweating, dizziness, or even syncope and dyspnea.
Differences: Differential diagnosis by ECG. Atrial flutter ECG has characteristic sawtooth wave.
Atrial pre-systole
Similarities: Both are relatively common arrhythmias, and both may present with symptoms such as rapid heartbeat, chest tightness, and fatigue.
Differences: Differential diagnosis can be made by electrocardiogram (ECG). Atrial pre-systole can be triggered by smoking, coffee consumption, etc. Typical pre-excitation syndrome is less likely to be affected by these factors than atrial pre-systole.
Myocardial infarction
Similarities: Chest tightness, dizziness, and pallor may occur.
Differences: Typical pre-excitation syndrome is a phenomenon of abnormal conduction from the atria to the ventricles, whereas myocardial infarction is caused by myocardial ischemia. Differential diagnosis can be made by ECG.
Bundle branch block
Similarities: Both can present with symptoms such as chest tightness, dizziness, or even fainting.
Difference: Bundle branch block is often without tachycardia, while typical preexcitation syndrome often has tachycardia. Differential diagnosis is made by electrocardiogram.
Right ventricular hypertrophy
Similarities: Paroxysmal palpitations, dyspnea, fatigue, and decreased work endurance may be present.
Differences: Differential diagnosis by ECG.
Treatment
Aims and principles of treatment
Therapeutic purpose: To achieve the therapeutic purpose of relieving symptoms and minimizing complications through medication, radiofrequency ablation and electrical cardioversion.
Principles of treatment: Typical preexcitation syndrome with only ventricular preexcitation ECG manifestations without ever having an arrhythmia and without a family history of sudden death usually does not need special treatment. If there are symptoms, combined with atrioventricular tachycardia episodes, or atrial flutter and atrial fibrillation, special treatment is needed [7].
Treatment
Pharmacologic treatment
Pharmacologic treatment of typical preexcitation syndrome mainly consists of medications to control the ventricular rate and rhythm control therapy.
Rhythm control is required during tachycardia episodes. Propofol or amiodarone can be used intravenously as prescribed.
For people with atrial flutter or atrial fibrillation, if hemodynamically stable, intravenous propafenone or amiodarone can be used after the physician’s assessment of the condition. Avoid the use of drugs such as Betalucil, digitalis, or verapamil, which are contraindicated due to their ability to speed up the conduction of the collateral channels, thereby accelerating the ventricular rate of the patient.
Electrical cardioversion
Patients with hemodynamic instability.
It is safe, has a high success rate, and hemodynamics can be significantly improved after electrical cardioversion.
Radiofrequency ablation therapy
Radiofrequency ablation is a technique that uses radiofrequency current to generate heat to block conduction to diseased tissues in the atrioventricular bypass to provide curative treatment.
Radiofrequency ablation bypass therapy is recommended as the first choice for patients with symptoms, tachycardia episodes, combined with other arrhythmic diseases, or combined with organic heart disease.
Radiofrequency ablation is also recommended for patients without a history of tachycardia episodes but with a short paracordal refractory period (<270ms), because these patients have a higher risk of ventricular fibrillation caused by rapid transmission of excitation through the paracordal channels in the event of atrial flutter or atrial fibrillation, or even sudden death.
Radiofrequency ablation therapy is one of the most effective methods for the eradication of typical preexcitation syndrome, with a high success rate and low recurrence rate, and has become the first-line treatment for typical preexcitation syndrome [8].
Prognosis
Cure
Typical preexcitation syndrome can be clinically cured by radiofrequency ablation.
Hazards
The most significant hazard of typical pre-excitation syndrome is the occurrence of tachyarrhythmias. The most common arrhythmias are paroxysmal supraventricular tachycardia and atrial fibrillation, which are associated with panic attacks and other discomforts that interfere with normal life.
Typical preexcitation syndrome has the potential to cause malignant arrhythmias such as ventricular fibrillation, which can lead to sudden death.
Daily
Daily Management
Dietary management
The principle of diet is low salt and low fat diet.
You can eat more green vegetables, fresh fruits, high calcium and potassium-containing foods, and try to choose fruits with low sugar and low calories.
At the same time, consume sufficient amount of high quality protein and less cholesterol-containing food.
Each meal should not be too full.
If combined with diabetes, you also need to control the intake of staple foods.
Lifestyle management
Ensure a reasonable amount of sleep.
Avoid excessive stress and relaxation.
Obese people should engage in appropriate and regular exercise to reduce weight scientifically. Normal weight people also need to exercise regularly to control their weight.
Avoid colds.
Exercise appropriately to enhance physical fitness.
Quit smoking and drinking.
Mood Management
Positively adjust bad moods and maintain a good mindset.
Special management
Monitor blood pressure and heart rate, and seek prompt medical attention for more obvious fluctuations.
Follow-up
Regular follow-up is crucial to the effectiveness of treatment.
Follow the doctor’s instructions for regular follow-up; if symptoms such as palpitations and loss of consciousness occur on a daily basis, it is recommended to consult a doctor immediately.
Patients with typical preexcitation syndrome may require an electrocardiogram (ECG) during follow-up.
Prevention
There is no effective prevention method for Typical Pre-Excitation Syndrome. Promoting good dietary habits and a positive attitude towards health can help prevent the disease.
You can eat more green vegetables, fresh fruits, high calcium and potassium-containing foods, and try to choose fruits that are low in sugar and calories.
At the same time, consume a sufficient amount of high-quality protein, and eat less food containing high cholesterol.
Ensure a reasonable amount of sleep.
Quit smoking and drinking.
Exercise and strengthen your body properly.
If a family member has similar symptoms, or has been diagnosed with classic preexcitation syndrome, you should pay attention to regular medical checkups, especially electrophysiological examination of the heart.
If paroxysmal palpitations occur frequently, it is recommended to seek medical treatment as soon as possible [9-10].
参考文献
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Priori SG, Wilde AA, Horie M, et al. HRS/EHRA/APHRS expert consensus statement on the diagnosis and management of patients with inherited primary arrhythmia syndromes: document endorsed by HRS, EHRA, and APHRS in May 2013 and by ACCF, AHA, PACES, and AEPC in June 2013. Heart Rhythm, 2013, 10 (12): 1932-1963.
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陈新.临床心律失常学—电生理和治疗[M].1版.北京：人民卫生出版社，2000.
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