With ” vasovagal syncope ” or “vaso-vagal” we mean a lack of blood flow in the brain area by rapid reduction of theblood pressure which leads to a reduction in the flow of blood to the brain and consequently to a temporary and short-lived sudden loss of consciousness (syncope), after which the subject becomes fully conscious and generally without any permanent damage. Vasovagal syncope is the most common form of syncope in healthy people and is part of the group of neuromediated syncopes. The onset of vasovagal syncope, according to some researchers, would represent a defense mechanism of the organism , a sort of “short break” from the intense work of the heart, reducing oxygen consumption, improving diastolic filling and coronary perfusion in the moment when the heart is trying too hard.
Causes and risk factors
Vasovagal syncope can be caused or favored by various conditions, including:
- very intense pains;
- prolonged psychophysical stress;
- high efforts;
- sudden emotions (fear, excitement …);
- crowded environments;
- high temperatures;
- perception of particularly annoying sensations;
- sight of blood;
- prolonged orthostatism (standing in an upright position for excessively long times);
- stress of various kinds;
- abundant meals (post lunch);
- psychosomatic pains;
- rapid alternation between sitting and standing position;
- coughing and sneezing;
- arterial hypotension;
- orthostatic hypotension;
- old age.
These stimuli are also called “triggers” precisely because they trigger a neurogenic mechanism mediated by the vagus nerve that leads to bradycardia (heart rate reduction), arterial hypotension (“low blood pressure”) and cerebral hypoperfusion (little blood arrives to the brain) with consequent loss of the senses.
In some cases syncope can also be favored by malignant brain pathologies, such as tumors or aneurysms: in this case we speak of malignant vasovagal syncope .
When a vasovagal syncope is about to arrive, the following symptoms generally appear, which obviously precede the actual fainting:
- a sense of weakness and tiredness that starts from the lower or upper limbs and then expands to the whole body;
- worsening tiredness;
- tinnitus (whistling in the ears);
- cold sweating;
- blurred vision;
- general malaise;
- tunnel vision;
- pain in the sternal region;
- gastrointestinal complaints;
- impaired perception of heat and / or cold;
The vasovagal syndrome can therefore be divided (from a clinical point of view) into two moments: the prodromal period (characterized by the symptoms listed above) and the actual fainting that follows from it. During fainting, the patient becomes unconscious, looks pale, the skin is cold and sweaty, the heart rate slows down to severe bradycardia. Sometimes there may also be loss of sphincter control with urine and / or stool release. The prodromal phase is followed by fainting: if this were not the case, we do not speak of syncope, but of lipotimia . If the loss of consciousness lasts more than 15-20 seconds the typical syncopal phenomena could be associated with a convulsive symptomatology (convulsive syncope) with hypertonicity and rare and short clones especially in the limbs.
Risks and complications
The warning symptoms can allow the patient to get into a safe position, such as sitting in the case of standing, or pulling the car over if he is driving, however this is not always possible and the risk – in such a situation – it is that loss of consciousness gives rise to falls or road or work accidents , with obvious risks for the patient (especially for the elderly) who could suffer from head injuries or serious fractures.
An often underestimated complication of a relapsing vasovagal syncope is that the patient, due to the fear that it occurs at important moments in his life, may trigger anxious and / or depressive syndromes that are difficult to treat .
Fainting is transient and transient, with a duration that can range from a few seconds to a few tens of seconds. Then the patient becomes conscious with total, rapid and spontaneous recovery. In the majority of cases there is no permanent damage, except for those cases in which the reduced cerebral perfusion has persisted for a long time: in that case the ischemic damage to the brain could cause also permanent sensorimotor damages.
The diagnosis is often made by excluding all the other more frequent causes of fainting and can make use of other tests and tests, in addition to anamnesis and general physical examination, including:
- cardiac physical examination ;
- electroencephalogram ;
- blood pressure measurement ;
- electrocardiogram (ECG) ;
- chest radiography ;
- cardiac enzymes ;
- coronary angiography (coronary angiography) , with possible angioplasty ;
- cardiac ultrasound (echocolordoppler) ;
- transesophageal echocardiogram ;
- stress echocardiogram (ecostress) ;
- 24-hour blood pressure monitor;
- 24-hour Holter ECG .
Laboratory tests and investigations with ultrasound, CT or magnetic resonance imaging, especially to identify brain pathologies such as epilepsies, malignant or benign tumor masses and intracranial aneurysms, are also very useful.
The Tilt test can also be used in the diagnosis: the patient is positioned on a special tilting bed and the bed is tilted from a horizontal starting position up to 60 degrees for 45 minutes, in order to trigger a possible crisis. During the test the patient is monitored by checking:
- breath frequency;
- heart rate;
- electrocardiographic tracing;
- blood pressure;
- oxygen saturation.
Vasovagal syncope has no effect on the brain system, but still needs to be treated because of the high risk of falling. The drug that is commonly used is Midodrina, which will have to be taken for a lifetime. Another drug commonly used is ethylephrine.
Tips and prevention
There are specific tips that allow you to decrease the risk of syncope occurring, including:
- recognize the warning symptoms;
- learn to recognize, and therefore avoid, the factors (triggers) capable of triggering syncope;
- avoid large meals, cigarette smoking, alcohol, obesity and unbalanced diets.
- the doctor may recommend an increase in the sodium and / or glucose levels in the diet, in order to restore the correct blood pressure and blood sugar parameters.
There are also some preventive measures that can be put into practice when you realize that you are in the phase that precedes a vasovagal syncope: isometric compression exercises:
- hand grip: contract a rubber ball in the dominant hand;
- arm tensing: hook one hand to the other keeping your hands in front of you and pulling outwards;
- leg crossing: cross the legs by contracting their muscles and abdominal muscles.
In some particular forms of vasovagal syncope, a pacemaker can be surgically inserted to stimulate the heartbeat, avoiding bradycardias of any kind.
Vasovagal syncope: what to do?
If the subject believes he is about to experience a syncope, he must immediately place himself in a safe position (sit with his head between his knees or pull over the car if he is driving or still leave dangerous work tools) to avoid trauma, fractures and bruises. If a person is struck by fainting, he must immediately be placed in a safe position, for example lying down with his legs raised by cushions or any type of support, so as to make the blood flow more to the brain.
Go to the doctor or not?
Vasovagal syncope is a generally benign event and occurs in healthy people, however, if it were repeated often, it could be the indicator of a pathology so it should not be underestimated if it recurs. A single event does not have to worry, but if the syncope recurs it is necessary to consult a doctor.