Syncope
What is It?
Syncope is the medical term for fainting – a temporary, sudden loss of consciousness and muscle strength followed by quick, spontaneous recovery. It is caused by a temporary drop in blood flow and oxygen to the brain. Syncope is very common, affecting up to one-third of people at some point in their lifetime. The most common type is neurally mediated (vasovagal) syncope, though cardiac causes must also be excluded as they can be serious.
What are the symptoms?
Before fainting, individuals often experience warning symptoms (pre-syncope) including lightheadedness, dizziness, nausea, sweating, pale or clammy skin, tunnel vision, or buzzing in the ears. The loss of consciousness is usually brief (less than a minute) and recovery is typically rapid. Some patients may experience brief jerking movements during the episode. Syncope occurring without warning, during exertion, or while lying down may suggest a cardiac cause and warrants urgent assessment.
What are the causes?
At One Heart Centre our cardiologists screen for all causes of syncope. Causes include:
- Vasovagal (reflex) syncope: The most common cause, triggered by stress, pain, dehydration, prolonged standing, or emotional stimuli.
- Orthostatic hypotension: A sudden drop in blood pressure when standing, often related to medications or dehydration.
- Cardiac syncope: Serious causes including arrhythmias (both slow and fast), heart valve disease such as aortic stenosis, and heart failure.
- Neurological and situational causes: Seizures, transient ischemic attacks, or syncope triggered by coughing or urinating.
How is it investigated?
Assessment begins with a detailed history and physical examination, including lying and standing blood pressure measurements. A 12-lead ECG is essential to screen for arrhythmias or conduction abnormalities. Further tests may include an echocardiogram, Holter monitor or implantable loop recorder for prolonged rhythm monitoring, exercise stress test, and tilt-table testing to provoke vasovagal syncope. Blood tests are performed to exclude anaemia or electrolyte disturbances.
What are the treatments?
At One Heart Centre our cardiologists have post-fellowship training in managing syncope and will provide a personalised treatment plan for your syncope. Treatment options include:
- Lifestyle and non-pharmacological measures: Maintaining excellent hydration, increasing salt intake where appropriate, avoiding triggers, and learning counter-pressure manoeuvres such as leg crossing or squatting.
- Medications: Fludrocortisone or midodrine may be used in selected cases of recurrent vasovagal syncope.
- Pacemaker: For patients with bradycardia or severe cardioinhibitory vasovagal syncope.
- Implantable cardioverter defibrillator (ICD): For patients at risk of life-threatening arrhythmias.