Autonomic Mediated (Neurocardiogenic) Syncope

Transcription

1 Autonomic Mediated (Neurocardiogenic) Syncope

2 Introduction Syncope is brief loss of consciousness causing collapse with spontaneous recovery. Other terms used to describe syncope include blackout, faint, or drop attack. Syncope may be caused by several things including a drop in blood pressure, change in heart rhythm, low blood sugar and hyperventilation. Simple fainting (Benign Vasovagal Syncope) This is the commonest cause of syncope in all age groups. It occurs most frequently in young adults. It is rarely seen for the first time in older people. Fainting may be brought on by the sight of blood, a sudden noise, severe pain etc, and is associated with warning symptoms such as nausea, sweating and loss of colour. Injury is unusual. Autonomic Mediated Syncope Autonomic Mediated Syncope, also known as Neurocardiogenic Syncope and Vasovagal Syncope, may happen for the first time at any age. It often occurs when upright, though can occur when sitting. It rarely occurs when lying down. Attacks are more likely in certain situations, for example when eating a large meal in a warm room, during long haul flights or after prolonged standing.

3 The onset may be sudden or associated with warning (prodromal) symptoms include tiredness, weakness, nausea, sweating, loss of colour, visual disturbance, abdominal discomfort, headache, pins-and-needles, light-headedness or vertigo. This phase may last for seconds or minutes. It may be absent in older people. If syncope happens, the individual usually lies still while unconscious, though occasionally may have a small fit caused by reduced oxygen supply to the brain. This may be mistaken for epilepsy. On recovery of consciousness common symptoms include nausea, clamminess, light-headedness, headache and tiredness. The person may be unable to stand up for several minutes. Full recovery may take considerably longer. Treatment of Autonomic Mediated Syncope Various simple non-drug measures often help prevent, or abort attacks of Autonomic Mediated Syncope. However, treatment with low dose medication may be necessary. Recommended non-drug measures 1. Avoid situations likely to induce syncope. For example: standing in a queue, taking a long hot bath, eating a large carbohydrate-rich meal in a warm room, or failing to drink sufficient fluid in a hot environment. 2. Take immediate action at the first warning of possible collapse. If you think a collapse is about to happen lie down flat propping your legs up on a chair or against a wall, or squat down on your haunches. Squatting can be very effective and is less likely to attack

4 attention! Less effectively, sit down with your head between your knees. All these actions improve blood pressure, swiftly restoring blood flow to the brain. When you feel better get up carefully. If your symptoms return or worsen squat down again, or lie down again. 3. Manoeuvres - If your symptoms are mild stand with your legs crossed, rhythmically squeezing one into the other, or rock backwards and forwards on your heels. These manoeuvres activate the muscle pump in your legs and move blood from the limbs into the chest. Pulling vigorously on clasped hands may also help prevent collapses. 4. Drink 200mls (1 glass) of water. This promptly increases blood pressure and may be helpful in preventing syncope. Ensuring adequate daily intake of fluids, confirmed by the clear appearance of urine, may also help prevent collapses. 5. Increase your dietary intake of salt if your salt intake is low. This can be easily checked by measuring how much sodium you excrete in 24 hours. Your salt intake can be increased by adding salt at the table, taking salt tablets (Slow Sodium) or drinking sport drinks. A recent study suggested that between 3 and 7g sodium intake per day may be optimal. A 5g teaspoonful of salt contains 2.3g sodium. Avoid junk foods which contain high levels of cholesterol as well as salt. The benefits of increasing salt intake are noticed within two or three days. You should not increase your salt intake if you have high blood pressure.

5 6. Sleep with the head of your bed raised by about 10 degrees. This reduces urinary salt loss overnight 7. Endurance training can be helpful if you are not fit. Using a rowing machine is an excellent form of exercise and may reduce your tendency to collapse. Pharmacological treatment A range of medications is used to treat Autonomic Mediated Syncope. Commonly used medications include Fludrocortisone, Midodrine, Bisoprolol and Prosac. The fact that so many different medications are used for treatment indicates that none is entirely effective. If one drug is not helping, it is always worthwhile trying one of the others from a different class. Sometimes, a combination of drugs is required. Pacemaker Occasionally permanent pacemaker implantation is necessary. Further information can be found at

6 GHPI0319_07_12 Author: Dr Deering Review due: XXXXXXXXX 20XX