Wolff-Parkinson-White Syndrome (WPW) is a pathological condition characterized by the existence of a secondary pathway along which the impulse passes. In the absence of any deviations, with the normal functioning of the heart, alternating contractions of the atria and ventricles begin to occur. The heart contracts due to the passage of impulses from the sinus node, which is also called the pacemaker. It is the main pulse generator, and its role in the conductive cardiac system is dominant.
The impulse that is produced by them reaches the atria, leading to their contraction, and then goes to the atrioventricular node, which is located between the atria and ventricles. This path is the only one along which the impulse can reach the ventricles. In the course of small fractions of a second, a pulse delay is observed in this node, which is provoked by the need to give the right time for the complete movement of the blood flow from the atria to the ventricles. Further, the impulse passes to the legs of the bundle of His, and the ventricles contract.
In the case of Wolf-Parkinson-White Syndrome (WPW), the impulse passes through other paths to reach the ventricles, bypassing the atrioventricular node. For this reason, a workaround contributes to the speedy conduct of the pulse compared to the next on conventional channels. Such a phenomenon may in no way affect the well-being of a person and be almost imperceptible. It is often possible to identify Wolf-Parkinson-White syndrome on an ECG solely in terms of heart functionality.
It should be noted that in addition to WPW syndrome, there is also a CLC phenomenon that is almost identical to it, but characteristic ECG abnormalities are not observed.
WPW syndrome as a phenomenon in the development of additional pathways for impulses has the nature of a congenital anomaly of the heart, and its prevalence is much greater than the number of recorded cases. At a young age, his presence is usually not accompanied by any symptoms. However, over time, certain factors may occur that provoke the development of this syndrome. This happens most often in cases of impairment of the conductivity of the pulse in the usual path of its passage.
Causes of WPW Syndrome
The causes of Wolff-Parkinson-White Syndrome (WPW), according to the majority of medical scientists, are based on innate factors and the fact that in the process of heart formation, adnexal atrioventricular connections are preserved. This phenomenon is also accompanied by the fact that during the period when fibrous rings form in the tricuspid and mitral valves, muscle fibers do not fully regress.
The correct course of development is the gradual thinning and subsequent complete disappearance of additional pathways that exist in the early stages of the embryo. Anomalies in which atrioventricular rings can form contribute to the fact that muscle fibers are preserved, which becomes the main anatomical prerequisite for the occurrence of Wolf-Parkinson-White syndrome - WPW.
Family forms of this pathology are much more often due to the presence of a large number of secondary atrioventricular connections.
In approximately the third part of all cases, this syndrome is associated with congenital heart defects in the form of mitral valve prolapse or Ebstein's anomaly. The main causes are also a deformed atrial or interventricular septum, connective tissue dysplasia or Fallot tetrad. An important role is also played by the factor of heredity, for example, hypertrophic hereditary cardiomyopathy.
The reasons for the detection of Wolf-Parkinson-White syndrome on the ECG, therefore, are violations of the formation of the heart in the process of embryo development. Nevertheless, despite the fact that this pathology is caused by congenital anatomy, its first signs can be detected both at an early and an older age.
Wolf-Parkinson-White syndrome in children
All age categories are susceptible to this pathology, but most often the detection of the disease occurs in the childhood or youth of the patient (from 10 to 20 years).
WPW syndrome in newborns has the following symptoms:
- tachypnea (rapid breathing);
- pallor;
- anxiety;
- refusal of feeding;
- sometimes fever may join.
VPU syndrome in older children usually has the following symptoms:
- palpitations
- chest pain
- labored breathing.
Symptoms of WPW Syndrome
Manifestations of such a painful condition may not occur until the presence of this pathology is determined in the results of the ECG. The main signs that indicate the presence of Wolf-Parkinson-White syndrome are a violation of the rhythm of heart contractions.
In the majority of cases, reciprocal ventricular tachycardia develops against this background, and atrial fibrillation is noted in about 20% of patients, atrial flutter in 9%, when the number of strokes reaches 300-320 per minute.
In addition, there is a high probability of developing a non-specific type of arrhythmia - ventricular extrasystole and tachycardia.
Arrhythmic seizures often result in conditions that are triggered by an overstrain of a person in the emotional sphere or by significant physical exertion.
One of the reasons for the development of a pathological condition can also be the abuse of alcohol, and sometimes the change in heart rhythms is spontaneous, and it is usually not possible to reliably establish their cause.
When an attack of arrhythmia occurs, it is most often accompanied by a feeling of fading of the heart and cardialgia. It may seem to the patient that he is suffocating. In a state of atrial fibrillation and flutter, fainting, shortness of breath, arterial hypotension, and dizziness very often occur. If there is a transition to ventricular fibrillation, then the probability of sudden death is not excluded.
Similar manifestations of WPW syndrome can last a few seconds, minutes, and even hours. The long duration of these paroxysms indicates the need to refer the patient to a hospital and involve a cardiologist in monitoring his condition.
What is latent Wolf-Parkinson-White syndrome?
Hidden Type of WPW Syndrome
The course of WPW syndrome in some cases can be completely hidden implicit. It is possible to assume its presence in the patient only on the basis of established tachyarrhythmia, where the main diagnostic method is to examine the heart electrophysiologically, when the ventricles are artificially stimulated by electric current. The need for this is due to the fact that additional paths can conduct an impulse retrograde, that is, they do not have the ability to travel in the antegrade direction.
The latent WPW syndrome is also ascertained on the basis that the rhythm is not accompanied by signs that indicate untimely early excitation of the ventricles, that is, on the ECG, the PQ interval does not deviate from the norm. In addition, a delta wave is not observed, however, there is a reciprocal atrioventricular tachycardia, which is characterized by retrograde conduction along secondary ventricular-atrial connections.
So, the hidden type of WPW syndrome can be detected either by the results of fixing the time period of the retrograde passage of the impulse, or when the ventricles are stimulated during the endocardial examination.
What other types of Wolf-Parkinson-White syndrome are there?
Manifesting WPW Syndrome
The main feature that distinguishes this variety of WPW syndrome is that when it occurs, the direction of the excitation can be both antegrade and retrograde, only retrograde passage of the pulse by auxiliary paths exceeds in frequency the cases of the development of antegrade conductivity.
The ability of an impulse to travel in the antegrade direction causes specific symptoms that distinguish this pathology in the results of an ECG. With signs that ventricular overstimulation is observed, a delta wave appears in the normal leads, the PQ interval is shortened, and an expanded QRS complex is noted.
The manifesting WPW syndrome is characterized by similar properties outside the reciprocal paroxysmal attack of a rapid heartbeat. The degree of danger in this pathology is mainly associated not with the presence of a similar heart syndrome, but with such attacks, as well as with atrial fibrillation and tachycardia.
The causes of the Wolf-Parkinson-White syndrome should be identified by the doctor.
WPW Type B Syndrome
Type B WPW syndrome is similar to type A of the same cardiac pathology. When it occurs due to the passage of an impulse through the right bundle of Paladino-Kent, a part of the right ventricle begins to be excited, which is ahead of the usual activation of both of them. This comes from an impulse passing through the atrioventricular junction.
The similarity with type A syndrome in this case is the early excitation of a certain area of the right ventricle. A similar phenomenon is displayed in a decrease in the PQ interval. In addition, WPW syndrome is characterized by activation of muscle tissue in the right ventricle, which occurs from one layer to the next. So the delta wave is formed. And finally, the processes of excitation of the ventricles cease to coincide in time. In this case, the right one is first excited, then the impulse is transmitted to the interventricular septum, and as a result, the left ventricle begins to act. This sequence is similar to the blockade of the left bundle branch block. On the ECG, signs of Wolf-Parkinson-White syndrome can only be detected by a qualified specialist.
Often there are cases that do not fall into type B WPW syndrome, but are not completely similar to type A of this syndrome. Certain of them are classified as transitional forms AB.
Transient Type of WPW Syndrome
This kind of pathology is a process when a transient character is observed in the pre-excitation of the ventricles. With this form of the syndrome, deviations from the norms of the cardiac complexes on the ECG at rest are observed sporadically, and a fairly long time period can be observed between them.
To determine this type of WPW syndrome is possible only as a result of targeted exposure, when carried out through esophageal atrial stimulation, the introduction of finoptin or ATP intravenously. Often, the detection of ventricular pre-excitation is possible with the artificial induction of a temporary blockade of conduction through the atrioventricular node.
A transient form of WPW syndrome is characteristic of the development of attacks of tachycardia. If this condition is not associated with the appearance of a violation of heart rhythms, then in this case we can talk about the WPW phenomenon. The transition of the pathology from syndrome to the phenomenon is a factor that indicates a favorable prognosis. Symptoms of Wolff-Parkinson-White syndrome depend on its type.
Intermittent Type of WPW Syndrome
A similar type of WPW syndrome is also called "intermittent." This name is displayed by the very essence of the process that occurs when it occurs. The ways of conducting an impulse are to alternately pass it through the atrioventricular node and the antegrade direction along the Kent beam. If as a result of this, a standard cardiogram outside of paroxysmal attacks of palpitations shows the presence of symptoms of premature formation of an impulse passing through the ventricles, then no manifestations of this pathology are detected at all. ECG indicators are characterized by the presence of signs of ventricular pre-excitation against the background of verified reciprocal atrioventricular tachycardia and sinus rhythm. The difficulty in diagnosing this kind of WPW syndrome is sometimes caused by the fact that it is not always possible to determine the phenomenon based on an electrocardiogram at rest.
With the intermittent form of WPW syndrome, a transient appearance of a delta wave on the ECG is observed, and it is thus characterized by a regularly changing direction of the pulse from the retrograde through the atrioventricular node to the antegrade through the Kent beam. As a result, this type of syndrome is often not diagnosed. What is the diagnosis of Wolff-Parkinson-White syndrome?
Pathology diagnostics
Diagnostic methods of this syndrome include conducting an ECG on a Holter and an ECG in 12 leads, as well as the use of pacing through the esophagus and examination of the heart.
Pacing through the esophagus can provide accurate confirmation that there are secondary impulse pathways that are characteristic of WPW syndrome.
Conducting an electrophysiological endocardial study as a diagnosis of Wolff-Parkinson-White syndrome can help establish the exact area of localization and the number of additional transmission pathways for impulses. The application of this method is also a way of verifying the form of WPW syndrome and helps in the selection of drugs for therapy. In addition, it allows you to evaluate the effectiveness of their use.
The determination of possible cardiac abnormalities and cardiomyopathies associated with EGK-signs of Wolf-Parkinson-White syndrome occurs by ultrasound of the heart. The main ECG criteria for WPW syndrome are the shortening of the PQ interval, as well as the presence of distortion of the drain QRS complex and the presence of a delta wave. To establish transient phenomena from the heart rhythm, daily ECG monitoring is used. Differential diagnosis of this cardiac pathology may require blockade of the legs of the bundle of His.
Diagnosis of this pathology is carried out using an integrated approach using various clinical and instrumental methods. However, the initial detection of such a disease occurs in the process of decoding the patient's electrocardiogram.
Wolf-Parkinson-White Syndrome Treatment
Therapy of this pathological phenomenon is carried out depending on the clinical picture of the disease and the data obtained during instrumental diagnostic studies, which implies the choice of the most appropriate of all existing methods.
Therapeutic measures are reduced to the use of the following measures. First of all, this is the implementation of antiarrhythmic therapy using a variety of medications. There is an important point here, which is that one should take into account the impossibility of using Ca-blockers and digitalis preparations.
A high degree of effectiveness is shown by the use of electrophysiological methods in the treatment of Wolf-Parkinson-White syndrome, which include cardioversion / defibrillation, which implies external defibrillation, carried out simultaneously with electrocardiography.
In addition, catheter ablation of secondary pathways is used in the treatment of WPW syndrome. Such a technique is a non-surgical manipulation that is aimed at the destruction of these impulse transmission pathways leading to the occurrence of WPW syndrome. Special catheters are inserted into the heart through the vascular system, which does not require the need for full surgical intervention. Therefore, this method is a fairly effective therapeutic measure, characterized by minimally invasiveness.
How else is Wolf-Parkinson-White syndrome treated in adults?
Surgical treatment of WPW syndrome
The operation in the development of this pathology represents modern methods of radical therapy, implying the implementation of catheter ablation, that is, destruction of the pathological secondary pathway.
The procedure for manipulation during such an operation involves the introduction of a catheter into the heart cavity through the subclavian vein, which houses special sensors that collect data using software. , . . .
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