CLC syndrome, known as Laun-Ganong-Levine syndrome, occurs in approximately 0.5% of the population and causes tachycardia in 30% of cases, which is why it is worthwhile to learn how to diagnose the syndrome and how to deal with it.
Description
Clerk-Levy-Cristesco syndrome is a special case of the syndrome of premature excitation of the ventricles of the heart, which is characterized by conducting excitation to the ventricles through additional pathways. The human heart is designed so that the ventricles contract later than the atria, this is necessary for sufficient filling with their blood. The functioning of this mechanism is ensured by the atrioventricular node, which is located between the ventricles and the atria, in it the impulse goes much more slowly, which ensures a delay in the contraction of the ventricles. However, some people have congenital abnormal paths that conduct impulse to bypass the atrioventricular node, such conductive paths include James bundles, Kent bundles and Maheima fibers. Thanks to these paths, the pulse propagation time is reduced and the CLC phenomenon arises. This mechanism can be seen when conducting an ECG analysis. The phenomenon itself does not affect the functioning of the heart and manifests itself only on the cardiogram. But sometimes there are cases when a circular course of excitation occurs. This happens when, having passed along the abnormal path, the impulse returns through the atrioventricular node, or vice versa - after passing along the main path, it returns along the abnormal. All this causes a change in the rhythm of the heartbeat, this process is called CLC syndrome.
Phenomenon and CLC syndrome are congenital, the exact cause of these anomalies is unknown. There are suggestions that this is due to impaired fetal development at the stage of heart formation. Also, do not exclude that the reason may be in genetic disorders.
Cardiogram analysis
ECG analysis helps identify this syndrome. It is characterized by a reduction in the PR interval (PQ). This interval shows the time during which the excitation reaches the ventricular myocardium in the atria and atrioventricular junction. For people over 17 years of age, the 0.2 s interval is normal, but shortening this interval, which can cause tachyarrhythmia, can also be a prerequisite for diagnosing CLC syndrome. Since the symptom of Clerk-Levi-Cristesco syndrome is the phenomenon of the same name, characterized by the passage of an impulse through the anomalous channel - the James bundle connecting the atrium to the distal part of the atrioventricular connection, which causes a reduction in the PR (PQ) interval.
In addition to reducing the mentioned interval, in the presence of CLC syndrome on the ECG, there are no other changes. The ventricular complex (QRS complex - the most significant deviation on the cardiogram, showing the time of passage of excitation inside the ventricles) does not look abnormal. CLC syndrome is most often found in people whose heart does not have abnormalities.
Symptoms
The Clerk-Levy-Cristesco phenomenon does not have any manifestations, most people who have James's paths do not even know about them and live without discomfort.
Signs of CLC as a syndrome are a change in heart rate. The patient has sudden attacks of accelerated heartbeat, which may be accompanied by bloating, fainting, dizziness, and a noise in the head. Sometimes you can observe increased sweating and excessive urination before or after an attack. An accelerated irregular heartbeat may also be observed.
Treatment
In most cases, CLC syndrome does not require specialized intervention. During heart attacks, the patient can independently stop them with the help of a special massage, cooling his face with water or straining to inhale, that is, performing Valsalva tests. If these methods do not help, you must call an ambulance.
Also, in the fight against tachycardia attacks caused by CLC syndrome, you can resort to the services of a cardiologist, who must prescribe special medications, for example, Verapamil or Amiodarone.
In the case when tachycardia attacks strongly affect the patient's life, an operation is performed to destroy James beams, which prevents the occurrence of a circular passage of excitation. Such operations are not dangerous, and after the patient quickly goes on the mend.