CLC syndrome, known as Lown-Ganong-Levine syndrome, occurs in approximately 0.5% of the population and causes tachycardia in 30% of cases, which is why it is worth learning how to diagnose the presence of the syndrome and how to deal with it.
Description
Clerk-Levy-Christesco syndrome is a special case of premature ventricular excitation syndrome, which is characterized by conduction of 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 of them with blood. The functioning of this mechanism is provided by the atrioventricular node, which is located between the ventricles and the atria, in which the impulse goes much more slowly, which ensures a delay in the contraction of the ventricles. However, some people have congenital abnormal pathways that bypass the atrioventricular node, such pathways include James's bundles, Kent's bundles, and Maheim's fibers. Due to these paths, the pulse transit time is shortened and the CLC phenomenon occurs. This mechanism can be seenby analyzing the ECG. The phenomenon itself does not affect the functioning of the heart in any way and appears 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 one. All this causes a change in the rhythm of the heartbeat, this process is called the CLC syndrome.
The CLC phenomenon and syndrome are congenital, the true cause of these anomalies is unknown. There are suggestions that this is due to disorders in the development of the fetus at the stage of heart formation. Also, do not exclude that the reason may be in genetic disorders.
ECG analysis
An ECG analysis helps to identify this syndrome. It is characterized by a shortening of the P-R (P-Q) interval. This interval shows the time during which excitation reaches the ventricular myocardium through the atria and the atrioventricular junction. In people older than 17 years, an interval of 0.2 s is normal, however, a shortening of this interval, which can cause tachyarrhythmia, can also be a prerequisite for diagnosing CLC syndrome. Since the sign of the Clerk-Levy-Christesco syndrome is the phenomenon of the same name, characterized by the passage of an impulse through an abnormal channel - the James bundle, connecting the atrium with the distal part of the atrioventricular junction, which causes a reduction in the P-R (P-Q) interval.
Except for the abbreviation mentionedinterval, in the presence of CLC syndrome, there are no other changes on the ECG. The ventricular complex (the QRS complex is the most significant abnormality on the ECG, showing the transit time of excitation within the ventricles) does not look abnormal. CLC syndrome is most common in people whose heart has no abnormalities.
Symptoms
The Clerk-Levi-Christesco phenomenon has no manifestations, most people who have James paths do not even know about them and live without discomfort.
The symptoms of CLC as a syndrome are changes in heart rate. The patient has sudden attacks of rapid heartbeat, which may be accompanied by bloating, fainting, dizziness and noise in the head. Sometimes you can observe increased sweating and copious urination before or after an attack. There may also be an accelerated irregular heartbeat.
Treatment
In most cases, CLC syndrome does not require specialized intervention. During attacks of palpitations, the patient can independently stop them with the help of a special massage, cooling the face with water or straining while inhaling, that is, performing Valsalva maneuvers. If these methods do not help, you need to call an ambulance.
Also, in the fight against attacks of tachycardia caused by the CLC syndrome, you can resort to the services of a cardiologist who should prescribe special medications, such as Verapamil or Amiodarone.
Whenattacks of tachycardia greatly affect the life of the patient, an operation is performed to destroy the James bundles, which prevents the occurrence of a circular course of excitation. Such operations are not dangerous, and after the patient recovers quickly.
