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The most common cause is vasovagal syncope, which is a drop in pressure with a sudden slowing of the heart. This type of syncope is often triggered by pain or emotional shock, particularly if the individual is dehydrated or has been standing for a long period. Over 20% of people in the general population experience vasovagal syncope at least once in their lifetimes. Syncope is a harmless event that does not lead to lasting effects in the majority of cases.
The other causes of syncope include heart valve disease, cardiomyopathy and pericarditis, high blood pressure medication and cardiac arrhythmia.
Vasovagal syncope is more common in young people and women. The other causes are more frequent in older people and especially in people with heart disease.
Cardiovascular syncope is a brief loss of consciousness (from a few seconds to a few minutes), that is characterized by rapid onset and spontaneous recovery. It is caused by decreased blood flow to the brain.
This type of syncope is different from other causes of fainting that occur without a decrease in cerebral blood circulation. These causes include hypoglycemia, epilepsy and stroke.
In general, your family doctor is the best person to make an initial exam, eliminate any non-heart-related causes of the fainting, and determine whether you need a more comprehensive cardiac assessment.
A cardiologist will then fill out a comprehensive questionnaire, perform a physical exam, and prescribe certain tests to confirm the diagnosis, establish the severity of the problem and determine the best treatment if he or she suspects a cardiovascular cause of the syncope.
- Holter monitor
- Cardiac magnetic resonance imaging
- Tilt table test
- Electrophysiology study
- Implantable heart monitor
When to Consult
Protection and prevention
In the case of vasovagal syncope, the doctor will recommend that you avoid becoming dehydrated. Unless otherwise contraindicated, an increase in salt intake may be recommended for some patients to promote fluid retention and an increase in blood pressure, which in this case is beneficial. Patients who experience a vasovagal reaction must try to avoid situations that have triggered syncope in the past and avoid medications that can cause a drop in blood pressure. In rare cases of severe vasovagal syncope, medication or even a pacemaker may be recommended.
The treatment of other causes of syncope depends on the specific cause. The possible treatments include an adjustment in medication, surgery to treat a valve disease, catheter ablation for fast arrhythmias, a pacemaker for a slow heart beat, or an implantable cardioverter defibrillator for patients at risk of sudden death.
People at Risk
Éditée par : Institut de cardiologie de Montréal.
Dernière mise à jour le : 2017.03.17