WPW (Wolff-Parkinson-White) syndrome

WPW syndrome (Wolff-Parkinson-White) is a condition characterized by the existence of an additional pathway through which the impulse is carried out.

In the absence of any deviations, when the heart functions normally, alternate ventricular and atrial contractions occur. The heart is contracted because of the impulses from the sinus node. Sinus node, also called the rhythm driver, is the main pulse generator, so that in the conducting system of the heart its role is dominant. The pulse produced in the sinus node reaching the atrium leads to their contraction, after which it is directed to the atrioventricular node (AB) located between the ventricles and atria. Such a path is the only possible way in which the impulse is able to reach the ventricles. For some fractions of a second there is a delay in the pulse in this AV node, which is caused by the need to give some time necessary for the complete movement of blood to the ventricles from the atria. Then the pulse follows in the direction of the legs of the bundle of the Hisnus, and the ventricles contract.

In the case of the existence of WPW syndrome, to achieve a pulse of the ventricles without passing through the atrioventricular node, there are other ways, bypassing the latter. For this reason, this workaround contributes, to some extent, to a speedy impulse over it, as compared to that which follows the proper normal channels. Such a phenomenon can in no way affect the state of a person with a given cardiac syndrome, and be virtually imperceptible. It is often possible to identify it only in the indicators of cardiac activity displayed in the electrocardiogram.

It should be separately said that, in addition to WPW syndrome, there is also the CLC phenomenon, which is almost identical to it, except that characteristic changes are not observed on the ECG.

To summarize, we note that the WPW syndrome as a phenomenon of the emergence of additional ways of carrying out an impulse has mainly the nature of a congenital cardiac abnormality and its actual prevalence is greater than the number of recorded cases identified. At a young age, his existence is not accompanied by any significant symptomatology. But over time, there are certain factors that trigger the development of such a syndrome. This happens mainly if the impulse conductivity in the main path of its passage deteriorates.

Causes of WPW Syndrome

The causes of WPW syndrome, according to the majority of scientists in the field of medical science, are based mainly on innate factors. Namely - by the fact that in the process of unfinished heart formation, additional atrioventricular connections remain. This is accompanied by the fact that in the period when fibrotic rings are formed in the mitral and tricuspid valve, the muscle fibers do not regress fully.

The normal course of development is a gradual thinning and subsequently (with the achievement of a period of 20 weeks) complete disappearance of all additional muscle pathways existing in the early stages in all embryos. Anomalies with which fibrous atrioventricular rings can form, contribute to the preservation of muscle fibers, which becomes the main anatomical prerequisite for WPW syndrome.

The family form of WPW syndrome is more often characterized by the presence of a large number of additional atrioventricular compounds.

Approximately in the third part of all clinical cases, the syndrome is associated with the occurrence of congenital heart defects - mitral valve prolapse, Ebstein abnormality. The cause is also the deformed interventricular, interatrial septum of the Fallot tetrad, connective tissue dysplasia - dysembryogenetic stigma. In addition, the factor of heredity plays an important role, in particular hereditary hypertrophic cardiomyopathy.

The causes of WPW syndrome, as we see, mainly consist in the violation of the formation of such an important organ as the human heart in the process of embryonic development. Nevertheless, although this syndrome largely causes unfavorable congenital anatomical features, its first manifestations can be detected both in childhood and in adulthood.

[1], [2], [3], [4]

Wolff-Parkinson-White Syndrome

Statistics show that the Wolff-Parkinson-White syndrome is observed in 0.1 to 0.3% of the total population. The greatest number of cases it is characterized in connection with the fact that there is such a cardiac anomaly as an additional bundle of Kent, located between one of the ventricles and the left atrium. The existence of a bundle of Kent is one of the underlying pathogenic factors in the onset of such a syndrome. Among men who have the presence of Wolff-Parkinson-White syndrome, men predominantly predominate over women.

The clinic of this syndrome in some patients can be completely implicit. The main, easily identifiable consequence of a faster passage of the pulse along an additional conducting path, first of all, is that the rhythms of cardiac contractions are violated, and arrhythmia develops. More than half of the clinical cases occur supraventricular and reciprocal paroxysmal tachyarrhythmias, the phenomenon of flutter or atrial fibrillation. Often, the Wolff-Parkinson-White syndrome results in hypertrophic cardiac abnormality of Ebstein, mitral valve prolapse, cardiomyopathy.

Wolff-Parkinson-White syndrome is a phenomenon in which premature ventricular arousal occurs. The development of the syndrome, as a rule, is not accompanied by the appearance of any symptoms expressed in sufficient measure to detect it. Often, the presence of the Wolff-Parkinson-White syndrome is made possible exclusively by electrocardiogram data.

Symptoms of WPW Syndrome

Symptoms of WPW syndrome can not be manifested in any way, even as the presence of the electrocardiogram as the main method of confirmation is definitely established. It can happen at any time regardless of the person's age, and before that course of this cardiac symptom is mostly not accompanied by the appearance of any expressed inherent symptomatology

The main characteristic signs indicating that there is a syndrome WPW, are violations of the rhythm of the heartbeats. In 80% of cases against its background there is a reciprocal supraventricular tachycardia, with a frequency of 15 to 30%, atrial fibrillation occurs, 5% of patients have atrial flutter, when the number of beats per minute reaches 280-320.

In addition, there is the possibility of arrhythmias of a non-specific type - ventricular tachycardia and plesistolia: ventricular and atrial.

To arrhythmic attacks often lead to conditions caused by overstrain of the emotional sphere or the consequences of considerable physical exertion. As one of the reasons can also be the abuse of alcohol, and sometimes violations of the heart rhythms are of a spontaneous nature, and it is not possible to pinpoint exactly why they appear.

When there is an attack of arrhythmia, it is accompanied by sensations of heartbeat and heartbeat, cardialgia, the patient can feel that he suffocates. In a state of flutter and atrial fibrillation, fainting often occurs, shortness of breath, dizziness, arterial hypotension. If there is a transition to ventricular fibrillation, the possibility of sudden cardiac death is not excluded.

Such symptoms of WPW syndrome as arrhythmic paroxysms can have a duration of several seconds, as well as several hours. Their relief may occur either as a result of the fact that reflex receptions were performed or independently. The long duration of paroxysms calls for the need for referral to a hospital and for the involvement of a cardiologist to monitor these patient conditions.

Concealed WPW Syndrome

The course of WPW syndrome in some cases can have a completely implicit, hidden character. To make an assumption about its presence in the patient is possible on the basis of the revealed tachyarrhythmia, and the main diagnostic measure is heart examination by electrophysiological method, in which the ventricles get artificial stimulation by electric current. The necessity of this is due to the fact that additional conducting paths can carry out impulses exclusively retrograde and those do not have the ability to follow in the antegrade direction.

The hidden WPW syndrome is also stated on the basis of the fact that the sinus rhythm is not accompanied by manifestations indicative of premature ventricular excitation, that is, in the electrocardiogram PQ interval does not inherent deviation from the values that are the norm. In addition, there is also no delta wave, but there is an atrioventricular reciprocal tachycardia, which is inherent in retrograde conduction on additional atrial-ventricular connections. In this case, the spread of the depolarization region occurs in a sequence - from the sinus node to the atria, and further, passing through the atrioventricular node with the bundle of His, reaches the ventricular myocardium.

To summarize, it should be noted that the hidden WPW syndrome becomes possible to detect either by the results of fixing the time of retrograde conduction of the pulse, or when the ventricles are stimulated by endocardial examination.

[5], [6], [7], [8], [9], [10], [11], [12]

Manifesto syndrome WPW

The key feature of the WPW manifestation syndrome is that with it the direction of excitation can be not only antegrade, but also retrograde. Extremely retrograde impulse conduction by additional ways of ventricular excitation exceeds the anterograde conduction in frequency of the cases encountered.

The fact that the syndrome has an antegrade-manifesting type is said, because it "manifests", declares its existence in the form of emerging characteristic changes in the patient's electrocardiogram. The ability to follow the impulse in the antegrade direction actually determines the specific manifestations of how this syndrome differs in the results of electrocardiography. In particular, with signs of pre-excitation of the ventricles, the appearance of a delta wave in standard leads is noted, the PQ interval becomes shorter, the broadened QRS complex is observed. With respect to the delta wave, it must be separately noted that it has a greater value than that for a large region of the ventricular myocardium, excitation from the Kent beam is given.

Manifesting syndrome WPW is characterized by the above properties outside the paroxysmal reciprocal attack of tachycardia. The degree of danger, if it implies a danger to the life of the patient, is associated mainly not with the presence of this cardiac syndrome, but primarily with such attacks, with tachycardia and atrial fibrillation.

WPW syndrome type B

The syndrome of WPW type in many respects has the similarity to type A of the same heart syndrome. With him, as a result of the passage of a sinus pulse through the right bundle of Paladino-Kent, a part of the right ventricle is excited, outstripping the usual activation of both ventricles, which occurs from a pulse from the atrioventricular junction.

Similarity with a similar type A syndrome is the premature excitation of the ventricles, or more precisely, parts of the right ventricle. Such a phenomenon finds a mapping in the shortening of the interval PQ. Further, WPW syndrome is characterized by the activation of muscle tissue in the right ventricle, proceeding from one layer to the next successively. This causes the formation of a delta wave. And finally - the processes of excitation of the right and left ventricles do not coincide in time. The right is activated first, after which the excitation is transmitted to the interventricular septum, and finally the left ventricle is activated.

This sequence of ventricular excitation also has the similarity of blocking the left branch of the bundle of His.

Quite often there are cases that do not fall under the definition - WPW syndrome type-b, and in this case not all correspond to type A of such a syndrome. Some of them are classified as a transitional form AB. The emergence of WPW syndrome is not always necessarily due to the fact that there are additional ways of Paladino-Kent. It is also able to be called, in addition to the simultaneous activation of James's bundle and the bundle of Maheima. If the activation occurs only with a beam of James, LGL syndrome is formed.

Transient WPW Syndrome

Transient WPW syndrome occurs in a certain number of patients. In such cases, the pre-excitation of the ventricles is of a transient nature. With this form of such syndrome, specific deviations from normal cardiac complexes on an electrocardiogram at rest occur sporadically, and a sufficiently large amount of time between their appearances can occur, in which the ECG parameters of cardiac activity are not changed.

Define the syndrome WPW transient type is mainly possible only as a result of a certain targeted effect: when the transesophageal atrial stimulation is carried out, the introduction of ATP or phinoptin intravenously. Often, the identification of signs that there is ventricular pre-excitation is also possible only if the temporary blockade of conductivity through the atrioventricular node is artificially induced. In this case, the syndrome is called the latent syndrome WPW.

The transient syndrome of WPW is characterized by the appearance of tachycardia attacks.

If transient WPW syndrome is not associated with the occurrence of cardiac arrhythmias, talk about the phenomenon of WPW. The possible transition of the disease during its course from the syndrome to the phenomenon is a factor indicative of a favorable trend.

Intermittent WPW Syndrome

Intermittent WPW syndrome is also known as intermittent. This name is an accurate representation of the very essence of the processes that have a place to be with it. And the next thing happens: by alternating ways, then passing through the atrioventricular node, then the antegrade direction of the pulse through the Kent beam. Due to this circumstance, a standard electrocardiogram outside the paroxysmal attack of the tachycardia shows that there are signs of premature ventricular arousal, then no manifestations of this are detected. ECG indicators are characterized by a presence of sinus rhythm and verified atrioventricular reciprocal tachycardia signs of ventricular pre-excitation. The difficulties in diagnosing intermittent WPW syndrome can be caused by the fact that it is not possible in all cases to determine on the basis of a single electrocardiogram of the state of rest.

With the intermittent type of WPW syndrome, a transient appearance of a characteristic delta wave on the electrocardiogram is noted.

Intermittent WPW syndrome, thus, is characterized by a constantly changing direction of the sinus pulse from the retrograde through the atrioventricular node to the antegrade one - in the bundle of Kent. Because of this, this type of syndrome can often be difficult to diagnose.

WPW syndrome in adolescents

Adolescence is a time when there is a high probability of occurrence of all anomalies of the heart and the development of its pathologies. One of them is WPW syndrome in adolescents.

This cardiac syndrome occurs with the greatest number of cases, mainly in the age range from 10 to 15 years. After 10 years of age, teenage boys are more likely to be affected by this disease. The age of a teenager or as it is called - a transitional age, on an equal basis with the first year of a child's life, is one of two main periods when tachycardia and all sorts of other heart rhythm disturbances can occur.

When this occurs because of the adolescent's WPW syndrome, no characteristic physical signs are detected except for only its manifestations in the form of symptoms of tachyarrhythmias. And in adolescence, the severity of these symptoms is often extremely weak. However, if an attack occurs, it is accompanied by intense sweating, limbs become colder, hypotension and stagnation in the lungs may occur. The risk of such negative phenomena increases if there are heart defects, acquired or having an innate character.

In 70% of adolescents, WPW syndrome leads to paroxysmal tachycardia with a pulse rate reaching 200 beats per minute and a blood pressure drop to 60-70 mmHg. Art. And further down to critically minimal values.

WPW syndrome in adolescents, and above all the arrhythmia provoked by it, is in close connection with the possibility of sudden cardiac death. From 3 to 13 years of age, the incidence of such cases is 0.6%, and among young people under the age of 21, it is 2.3%, respectively.

Atypical WPW syndrome

To say what happens atypical WPW syndrome becomes possible on the basis of the fact that according to electrocardiography, with all other characteristics remaining, there is an incomplete presence of a set of characteristic ECG-signs.

In particular, the conclusion about atypical WPW syndrome is made if the interval P-Q has an unchanged value. The rationale for this fact is that after an atrioventricular delay of the pulse, an anomalous conduction in the Maheima fibers is observed, which branch off from the main trunk of the bundle of His.

In addition, the P-0 interval may not be shortened due to the phenomenon of atrial blockade. Diagnosis of this form of the syndrome is carried out on the basis of the form that the ventricular cardiac complexes with the delta wave adopt.

Also taken into account are the changes occurring in QRS complexes displaying characteristic rhythm disturbances.

In its typical form, the WPW syndrome has a short, less than 120 ms, PR interval and a wide QRS complex - over 120 ms, and also has a slow initial part and signs of altered repolarization.

As for the additional conducting paths of the left-hand arrangement, it should be noted that they are pre-excited to a lesser degree than the shunting tracts of the free wall on the right.

Atypical WPW syndrome is considered when the presence of pre-excitation is clearly traced (by a competent ECG specialist), although the PR interval is greater than or equal to 120 ms, and the QRS-complex, respectively, does not reach 120 ms. The pre-excitation is not expressed or unobvious, either because of the shortened PR interval, or when there is evidence of ventricular pre-excitation. Here, however, should be divided atypical WPW syndrome with the existence of hidden additional ways of carrying out.

[13], [14], [15], [16], [17]

Diagnosis of WPW syndrome

Diagnosis of WPW syndrome involves an electrocardiogram according to Holter and ECG of 12 leads, application of electrocardiostimulation through the esophagus, and cardiac examination by electrophysiological method.

Transesophageal electrocardiostimulation provides a reliable confirmation that there are additional ways of carrying out the pulse inherent in WPW syndrome, and also induces arrhythmic paroxysms.

Carrying out an endocardial electrophysiological study provides an opportunity to establish the exact area of localization and the amount in which there are additional pathways. The application of this method is also a method of verification of the clinical form of WPW syndrome and facilitates the selection of medications for therapy, and besides it allows evaluating the effectiveness of their use or radiofrequency ablation.

The determination of all possible heart defects and karyomyopathy associated with the existence of WPW syndrome occurs by performing an ultrasound examination of the heart.

The main criteria for electrocardiography in WPW syndrome consists in shortening the PQ interval to less than 0.12 s in the presence of deformation of the QRS-drainage complex, and in the presence of delta waves. And in order to establish transient rhythm disturbances resort to daily ECG monitoring.

For the differential diagnosis of this cardiac syndrome, blockages with the bundle of the bundle are required.

Diagnosis of WPW syndrome is carried out on the basis of an integrated approach using various clinical and instrumental diagnostic methods. However, the first detection of this disease occurs mainly during the process of deciphering the patient's electrocardiogram by the cardiologist.

[18], [19], [20], [21], [22], [23],

WPW syndrome on ECG

The syndrome of WPW per eq is as follows.

The occurrence of a sinus pulse in the left Paladino-Kent beam leads to the activation of a portion of the left ventricle earlier than the other parts of the ventricles are excited under the action of a pulse following the normal way through the atrioventricular junction. As a result of this, the ventricles, namely - part of the left ventricle is excited with the lead of normal time. Such a phenomenon finds a mapping on the cardiogram in the form of a shortening of the P-Q interval. In this case, it does not reach 0.10 s.

The next thing that is inherent in WPW syndrome on ECG is a sequential transition of excitation from one muscle layer in the left ventricle to the other. As a result, a delta wave is reflected on the electrocardiogram. The delta wave is a pathologically altered initial part in the ascending knee of the R wave, which has a jagged and broadened appearance.

And one more characteristic feature of ECG results in WPW syndrome is not the simultaneous excitation of both ventricles as a norm, but in the sequential transmission of excitation from one to the other. The process begins with an abnormally early activation of the left ventricle, then the impulse moves to the interventricular septum, and only then it appears in the right ventricle.

Thus, the excitation process has a similarity to that which occurs in the case of blockade of the right leg of the bundle.

So, among the main signs of WPW syndrome on ECG can be called, firstly, shortening to less than 0.10 of the P-Q (P-R) interval; in the second - the existence of a positive delta wave in the leads of the anterior wall of the left ventricle and negative, respectively, in the posterior. It has the similarity to the abnormal Q wave. And one more characteristic phenomenon is a broadening of more than 0.12 s and deformation of the QRS complex similar to the blockade of the right leg of the bundle.

The above features refer to the ECG indices of WPW syndrome A.

Type B of this syndrome has almost identical characteristics. It is typical for the shortening of the P-Q interval to less than 0.10 s, the presence of a delta wave negative in the right thoracic leads and positive in the left, QRS-complex in the broadened more than 0.12 s state and deformed in this way as it is inherent in the blockade left leg of the bundle.

In addition, there are many forms of WPW syndrome that are transitional from type A to type B, and the combination of these types into the so-called AB type of the syndrome. This is the reason for the diversity of the picture of the syndrome of WPW on eq.

Treatment of WPW syndrome

Treatment of WPW syndrome depending on what the clinical picture of the disease is and based on the data obtained with instrumental diagnostic studies, involves the selection of one of the most appropriate existing methods.

Medical measures are reduced to the application of a number of the following treatment measures.

First of all, this is an antiarrhythmic therapy with the appointment of a course of treatment with medications. Here, however, there is one important point, namely - it should be taken into account that the use of drugs acting as Ca-blockers is unacceptable, and also the drugs of digitalis are unacceptable.

To show a high level of efficiency is capable of showing the use of electrophysiological methods. These include cardioversion / defibrillation, which means that external defibrillation is synchronized with electrocardiography.

In addition, in the treatment of WPW syndrome resort to the use of a catheter ablation of additional ways of carrying out. This method is a non-surgical procedure aimed at destroying these pathologies of impulse transmission, causing heart rhythm disturbances and causing WPW syndrome. At the same time, special catheters are introduced into the heart through the circulatory system, which does not necessitate opening the patient's chest. For this reason, this method, representing a rather radical and effective therapeutic measure, at the same time is characterized by minimally invasive.

The treatment of WPW syndrome can be entrusted only to the appropriate medical specialist, since self-medication and self-administration of all medication and the use of various methods can pose a threat to the life of the patient. Since a person incompetent in the field of medicine is not in a position to independently establish objective causes, the nature and mechanism of disturbances of the heart rhythm. Especially, when the treatment of this syndrome requires an operative intervention. Here, without an experienced surgeon can not do.

Operation with WPW syndrome

The operation with WPW syndrome is a modern method of radical treatment, which refers to the conduct of catheter ablation, that is, the destruction of the existing pathological additional route.

The procedure during this operation assumes first to insert a special catheter into the cavity of the heart through the subclavian vein. It hosts a variety of sensors, data collected by them are analyzed using complex software. Due to this, it becomes possible to determine with the greatest degree of accuracy the region in which an additional pathway is localized.

Based on the diagnostic information obtained at this stage, called electrophysiological examination of the heart, an exact application of the additional pathway is effected using a high-frequency current. The consequence of this is the destruction of such a path.

The result of this operation with WPW syndrome with 97% probability is the complete disposal of the patient from such a heart syndrome. In the remaining 3% of cases, there may be a need for another such type of surgery. After a second operation, the success rate of this treatment method reaches 100%.

Patients who are undergoing surgery for WPW syndrome are hospitalized in a specialized department. Carrying out "cauterization", as is often called catheter ablation, takes place without blood and takes no more than one hour. The patient's discharge is often possible after the expiry of the day in the shortest possible time.

Prevention of WPW syndrome

To date, it can not be argued with any justification that there is, anyway, a special prevention of WPW syndrome, and there are a number of some measures that with a 100% guarantee can prevent the disease.

The development of this cardiac syndrome in many cases can be due largely to congenital factors. This means that if a person in this connection has prerequisites for the appearance of cardiac disturbances (including WPW syndrome), the latter will sooner or later manifest themselves under a certain unfavorable confluence of circumstances.

Even if there are no obvious symptoms of cardiac rhythm disturbance, and yet an electrocardiogram indicates a disease, this should be a sufficient reason for consulting a cardiologist.

If a person is diagnosed with WPW syndrome, his relatives should also undergo a comprehensive examination with electrocardiography, daily ECG monitoring, echocardiography. Perhaps, there will also be a need for an electrophysiological study. It is recommended to do this in order to minimize the possibility of their disease.

The prevention of WPW syndrome is essentially, in the first place, reduced to the timely detection of anxiety symptoms, to establish what exactly it is caused, and to puzzle what should be done to prevent further progress of negative events.

Forecast of WPW syndrome

The prognosis of WPW syndrome in cases when its presence in humans is not accompanied by the appearance of a full complex of characteristic symptoms is favorable.

The implementation of medical measures and taking on cardiological records is advisable only for those patients who have a family history, weighed down by sudden cardiac death of any of the relatives of such patients. Such a need also requires certain professional indications, for example, as for pilots, persons professionally involved in sports, etc.

If the patient has complaints or arrhythmias that can be life threatening, complete complex diagnosis is required to select the necessary treatment measures. After carrying out the radiofrequency catheter ablation, these patients should be observed by a cardiosurgeon and cardiologist-arrhythmologist.

About 80% of people with WPW syndrome undergo paroxysms of reciprocal tachycardia, with 15-30% probability of atrial fibrillation, and 5% of cases of atrial fluttering occur. There is also a slight risk of sudden cardiac death. It occurs in 0.1% of patients

In the case when a person is not disturbed by any negative manifestations associated with his WPW syndrome, this seems to be a positive prognostic factor.

The prognosis of WPW syndrome largely improves due to the fact that radiofrequency catheter ablation of pathological additional routes has been performed.

[24], [25], [26]