Dizziness is a common symptom and is often not due to an important problem. Occasionally, particularly if it becomes blackouts (syncope) or near-blackouts (presyncope), it requires further investigation and possible treatment. The investigation may be as simple as wearing a heart rhythm recorder for 24 hours (‘Holter monitor’) whilst the patient gets on with their daily activities. The treatment can range from simply ensuring that the patient drinks enough water each day, to needing a pacemaker to ensure the heart beats often enough and doesn’t slow down at times when it shouldn’t. Dizziness and blackouts can also be due to the heart beating too quickly- called a tachycardia. Often this is not a serious problem and may simply need monitoring. Sometimes the patient may benefit from taking tablets to prevent the tachycardia, though some types of tachycardia can be cured using a special operation called an ablation. In a small number of patients, tachycardias can be dangerous and these patients may be recommended to have a special type of pacemaker called an Implantable Defibrillator (also referred to as an ‘ICD’).