Dizziness

Dizziness is a broad term describing an unpleasant sensation that includes lightheadedness, a feeling of faintness or unsteadiness, and a spinning sensation (vertigo). In the context of cardiac arrest and heart conditions, dizziness is often significant because it can indicate a problem with the heart's ability to maintain adequate blood pressure and flow to the brain.For survivors of sudden cardiac arrest, dizziness may arise from several causes. Orthostatic hypotension, a drop in blood pressure on standing, is common in the weeks following a cardiac arrest and can cause near-blackout episodes, particularly first thing in the morning or after prolonged sitting. Medications including beta-blockers, antiarrhythmics and diuretics all have dizziness as a potential side effect. Autonomic nervous system dysfunction, which can follow hypoxic-ischaemic brain injury, affects the body's ability to regulate blood pressure and heart rate in response to position changes.Dizziness that feels like a brief blackout, palpitations or a sudden awareness of the heart racing or slowing should always be reported to the cardiac team promptly. These patterns may indicate an arrhythmia and require investigation with a Holter monitor or implantable loop recorder. Dizziness that occurs regularly with position changes can be assessed with a tilt table test to distinguish cardiac from neurological or vestibular causes.Postural orthostatic tachycardia syndrome (POTS) is a recognised complication following cardiac arrest and prolonged critical illness, causing dizziness and rapid heart rate on standing. Management includes increased fluid and salt intake, compression garments, graded exercise rehabilitation and, in some cases, medication. Any new or worsening dizziness should be discussed with the GP or cardiac team rather than assumed to be benign.