Dizziness and blackouts are symptoms that can occasionally be related to the heart. Dizziness may be described as lightheadedness or feeling faint, while a blackout (syncope) refers to a temporary loss of consciousness.

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In many cases these symptoms are caused by benign conditions such as vasovagal fainting, dehydration, or blood pressure changes. However, they can sometimes be related to heart rhythm disturbances or other cardiovascular problems.

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A cardiology assessment can help determine whether symptoms are related to the heart and whether further investigation is required.

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Possible causes of dizziness and blackouts

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Dizziness or blackouts may be caused by several conditions including:

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• Vasovagal syncope (a common faint)
• Blood pressure changes or low blood pressure
• Abnormal heart rhythms (arrhythmias)
• Dehydration
• Medication side effects
• Anxiety or stress

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Most people with these symptoms do not have significant heart disease, but identifying the underlying cause is important to guide management.

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When to seek medical advice

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You should consider cardiology assessment if you experience:

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• recurrent dizziness or near-fainting episodes
• unexplained blackout or fainting episodes
• dizziness or fainting associated with palpitations
• symptoms occurring during exercise
• symptoms with a family history of heart rhythm disorders or sudden cardiac death

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Urgent medical attention should be sought if a blackout occurs without warning, during exertion, or is associated with chest pain.

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How dizziness and blackouts are investigated

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Assessment may include:

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• ECG
• Ambulatory heart rhythm monitoring
• Echocardiogram
• Blood pressure assessment
• Exercise testing or further specialised testing where appropriate

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These investigations help determine whether symptoms may be related to heart rhythm abnormalities or structural heart disease.

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What happens during your consultation

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During your appointment, a detailed history of the symptoms will be taken and your cardiovascular risk assessed.

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Where appropriate, investigations can be arranged promptly to clarify the cause of dizziness or blackout episodes and guide further management.