Morgagni-Adams-Stokes syndrome, or MAS syndrome, is a group of symptoms accompanying a temporary cardiac arrest, which results from impaired pulse generation and conduction in the heart. Find out who is at risk of MAS seizures, how they can be treated, and the prognosis of such people.

Morgagni-Adams-Stokes syndrome( MAS ) are short-term, usually self-resolving, episodes of presyncope and syncope due to cerebral ischemia. The causes of these disorders are abnormalities in the heart's work - a temporary stoppage of its action, significant slowing down, and extremely dangerous ventricular arrhythmias (so-called torsades de pointes).

A prolonged loss of consciousness absolutely requires immediate action - calling for help and starting CPR. In the long term, a pacemaker is used for treatment because MAS poses a risk of asystole and sudden cardiac arrest.

Conductive system and MAS complex

The conductive system is a complex structure built into the heart that produces and conducts impulses. It is he who is responsible for the so-called automatism of the heart, which consists in the autonomous (own) stimulation of the heart to work.

How does a conductive system work?

Once created in the sinus node, the stimulus spreads through the atria, stimulating them to contract. The impulse then passes through the atrioventricular node, bundle branches, and Purkinje fibers to the ventricles, which are also activated when it arrives.

Such an operation of the conductive system ensures adequate stimulation of the heart, both in terms of frequency - e.g. acceleration of action during exercise, and proper spreading of stimuli.

Disturbances in the generation of impulses and their conduction can cause disease. Depending on the location of the damage, these are:

  • sinus node dysfunction
  • atrioventricular blocks
  • intraventricular blocks

It is these lesions that lead to the Morgagni, Adams and Stokes syndrome.

Causes of bradycardia and MAS syndrome

Bradycardia is a symptom, and the underlying diseases may bemany and not always cardiological diseases. The reasons for too slow heartbeat or temporary complete stopping of its heartbeat can be, among others:

  • thyroid disease
  • electrolyte disturbance
  • neurological diseases
  • drugs

Among cardiac diseases these are:

  • ischemic heart disease
  • myocarditis
  • congenital heart disease
  • atrioventricular blocks
  • the so-called sick sinus syndrome, i.e. a disease of the sinus node

Bradycardia

Bradycardia is a condition in which the heart beats too slowly, usually below 60 beats per minute. Sometimes it happens that bradycardia does not cause any symptoms, it depends on many factors: age, various diseases, especially cardiological ones. The most common ailments in people with bradycardia are:

  • easy fatigue
  • dizziness
  • fainting
  • palpitations
  • less fainting

There are rarely less specific symptoms:

  • difficulty concentrating
  • imbalance
  • blurred vision
  • shortness of breath

Morgagni-Adams-Stokes syndrome: symptoms of MAS seizure

Impaired stimulus production may, in addition to bradycardia, lead to a complete stoppage of the heartbeat, and inadequate conduction of impulses, in turn, lead to too slow ventricular action.

Both of these situations cause a reduction in the amount of blood pumped into the vessels or even a complete lack of blood flow, which results in very serious symptoms of ischemia and hypoxia of the central nervous system.

The group of ailments caused by an interruption in heart rate is the Morgagni, Adams and Stokes syndrome. What these symptoms will appear allows you to assume how long the cerebral ischemia lasted, they are, respectively:

  • spots in front of the eyes and dizziness in the case of 3-5 seconds ischemia
  • unconscious if it lasted 10-15 seconds
  • loss of consciousness and convulsions in the case of longer - 20-30 seconds
  • respiratory hold - more than 30 seconds pause in heartbeat
  • damage to the central nervous system or death in the event of prolonged cardiac arrest - more than 3 minutes, if assistance in the form of cardiopulmonary resuscitation is not provided

During the attack, the pulse is imperceptible, blood pressure drops, skin pale and sometimes cyanosis occurs. It is obvious that the longer the pauses occur, the more they aredangerous for the patient's life.

Morgagni-Adams-Stokes syndrome: diagnosis

In diagnostics, a carefully collected history is very important: about the situations in which the loss of consciousness takes place, how long it lasts, what symptoms accompany it, other diseases and the medications used are also of great importance.

If you experience MAS seizures, make sure that the unconsciousness is related to the abnormal heart beat. For this purpose, ECG monitoring using the Holter method is performed, i.e. extended recording, usually up to 24 hours, less often longer, even up to a week.

Event recorders are exceptionally used, i.e. devices recording the electrical activity of the heart in times of worse well-being and implantable recorders. In special cases, it may be necessary to perform an invasive electrophysiological test.

Morgagni-Adams-Stokes syndrome: treatment

In the event of unconsciousness, respiratory and circulatory arrest, it is necessary to immediately call an ambulance, provide help, and perform CPR. Such advanced MAS attacks are extremely rare, usually a short-term pause in the heart rate resolves itself, and if CPR is required, the underlying causes are usually different.

Unfortunately, pharmacological treatment of bradycardia, pauses and MAS syndrome is basically impossible, because there are no drugs that stimulate the heartbeat that can be administered orally for a long time. First of all, it is necessary to exclude reversible causes - electrolyte disturbances, thyroid diseases or the influence of medications used.

Sometimes you can stop taking some medications that can slow down the heart rate, used in high blood pressure, ischemic heart disease or heart failure.

If, nevertheless, MAS attacks occur and the cardiological cause of the symptoms is confirmed, a pacemaker is required. It is a permanent and effective treatment for Morgagni-Adams-Stokes syndrome, bradycardia, and advanced AV blocks.

About the authorBow. Maciej GrymuzaA graduate of the Faculty of Medicine at the Medical University of K. Marcinkowski in Poznań. He graduated from university with an over good result. Currently, he is a doctor in the field of cardiology and a doctoral student. He is particularly interested in invasive cardiology and implantable devices (stimulators).

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