Blackouts, Dizziness and Syncope
After early childhood, it is not common for people to faint, although it can happen to some people under stressful, hot circumstances. However, in an adult, the sudden loss of consciousness is termed syncope. It should always be investigated. There are many causes for this, ranging from swings of the blood pressure, so that the blood pressure is not adequate to support blood flow to the brain when an individual stands up, to more sinister causes, such as narrowings of the heart valves and significant heart rhythm disturbances. The cause may not be related to the heart and a further assessment by a neurologist may be needed- epilepsy will need to be excluded in some cases.
Danger signs that suggest you need more investigation are if there is a family history of epilepsy or sudden death under age 40, you have had a blackout or the cardiologist finds an abnormality on one of the heart tests.
Chart of causes of blackouts
I have had an episode of blackout.
It is imperative that you have this investigated as a matter of urgency. The cardiologist will take a history and examine you in detail, looking for signs of irregularity of the heartbeat, evidence of swings in blood pressure, or moreover, the sound of narrowing or leakiness of one of the heart valves. He will then perform an Electrocardiogram (ECG) Echocardiogram and may well order a 24hour tape analysis. A Reveal device may be needed if symptoms persist. A Reveal device is a self contained cardiac recorder, similar in size to a small pacemaker. It is implanted with a minor surgical procedure under local anaesthetic, just below the collarbone. It can remain in that position for anything up to three years. If you have one of your episodes of collapse, or palpitations, then it will be recorded by the loop device. The next morning you can report to the cardiologist office where the device can be analysed via a radio link to the computer and the exact pattern of the heart rhythm, immediately before and during your episode of collapse can be analysed. This allows the cardiac technician and cardiologist to make a precise diagnosis and plan your treatment appropriately.
ECG rhythm strip showing one possible cause of collapse- a very slow heart beat-Complete heart block.
What can I do to help myself?
Until a cause for the blackout is found, it may be best not to drive or go swimming. Increasing fluid intake and reducing both caffeine and alcohol intake may help. More specific treatment depends on the cause. If you get warning symptoms, it is best to lie down with your legs up in the air-this may prevent the blackout if it is cardiac in origin.