We all have that one moment of feeling like ‘fainting’ when we are outdoors and the sun shines so bright that the temperature gets more than 30 C. Worst, probably a friend of ours did faint out of sudden in the same heat. Certainly, we all will get shocked and panicked knowing someone just fainted in front of us. The person who just faint probably experiences a medical condition called a syncope episode, specifically vasovagal syncope.
Vasovagal syncope is defined as a sudden loss of consciousness due to a temporary decrease of the blood flow to the brain. It is the main cause of fainting and never was a sign relating to heart or the brain problems. Vasovagal syncope episodes usually occur after some triggers get stimulated, although, precisely it is not known how these triggers lead to this syncope episode. One thing for sure, these triggers cause a vasovagal reaction which causes sudden drop in blood pressure through slower heart rate and dilating blood vessels which in turn reduce the oxygen supply to the brain. This resulted in the brain to become cerebral hypoperfusion, meaning the brain did not get adequate supply of blood flow. The person will lose consciousness as a result of the oxygen deprived brain.
In short, vasovagal reaction is an exaggeration of an adaptive response that is meant to aid in times of trauma. Adaptive response such as in situations involving bleeding causes the body to reduce heart rate and blood pressure, this will help reduce the bleeding amount. However, with vasovagal reactions, even harmless triggers elicit such body responses. The most common triggers making a person at risk for this condition are:
- Excessive heat in the air
- Being in crowded area
- Intense emotions such as fear or sadness
- Intense pain
- Standing for long periods
- Strenuous exercises
- Dehydration
- Fasting
- Stressful events such as seeing blood or needles
Since fainting is itself a symptom of vasovagal syncope, most people would probably think there is not any other sign to know if they themselves will experience it. Actually, most patients with vasovagal syncope do have history of a syncopal prodrome. Syncopal prodrome are symptoms that happen a few seconds before the person completely loses their consciousness and faint. These symptoms include light-headedness, nausea, sudden warmth or cold feeling, blurry vision or tunnel vision, sweating and sometimes hearing changes such as ringing in the ear.
To diagnose a person having vasovagal syncope, a doctor will actually ask questions regarding the patients’ family history and personal health history that may be related to cardiovascular diseases, gastrointestinal problems or possible medications. For females, doctors will check for pregnancy if there is a possibility. Such questions are asked to eliminate other causes of the syncope episode. ECG test is done to help eliminate the possibility of arrhythmia. Healthy patients presenting with classic history of vasovagal syncope, normal examination and ECG, do not need further testing and usually no need for specific treatments.
A person may actually prevent a full-blown vasovagal syncope episode by identifying these prodrome symptoms and immediately lie down when they feel a syncope episode is coming. It is helpful for patients to avoid potential triggers and drinking lots of plain water to help maintain enough blood volume in the body. Some patients may actually experience orthostatic hypotension, a sudden drop in blood pressure associated with an abrupt transition from lying down or sitting to standing up. Hence, learning the exact way of this transition by standing up slowly from lying or sitting position can give enough time for the blood that is initially pooling in the leg’s veins to return to the heart.
