Why recurrent fainting in an older adult matters
Most fainting in young people is vasovagal. In an older person, unexplained syncope is treated as cardiac until proven otherwise, because some causes are fatal and most are treatable once found. The history, and an ECG, do most of the work.
What to ask in the history
- What he was doing just before: standing, exerting, lying down, turning his head
- Warning symptoms beforehand (light-headedness, sweating, nausea) or none at all
- A witness account: colour, jerking, how long he was out, how fast he recovered
- Palpitations, chest pain or breathlessness around the episodes
- Injuries from falls, tongue biting, incontinence, confusion afterwards
- Medicines: beta-blockers, calcium channel blockers (verapamil, diltiazem), digoxin, antiarrhythmics, antihypertensives
- Previous heart disease, heart attack or heart surgery
- Family history of sudden death
Red flags
- Fainting during exertion, or while lying down
- No warning before the episode
- A significant injury from the fall
- Chest pain or breathlessness with the episodes
- A very slow pulse while awake, or long pauses
- Low blood pressure or signs of heart failure
- A known structural heart problem, or a family history of sudden cardiac death
What to examine
- Pulse: rate and rhythm, checked for a full minute
- Blood pressure lying and standing
- JVP
- Heart sounds and murmurs, especially an ejection systolic murmur
- Signs of heart failure: crackles, oedema
- Neurological examination, and a look for injuries
First investigations
- 12-lead ECG, the first and most useful test
- Electrolytes, especially potassium, and renal function
- Blood glucose and full blood count
- Thyroid function
- Troponin if ischaemia is possible; drug levels such as digoxin if relevant
- Echocardiogram
- Continuous monitoring or ambulatory ECG if the cause is not caught on the first ECG
Differential diagnosis of recurrent fainting in an older adult
Grouped, not ranked. Which one fits this patient is for you to work out in the case.
Reflex and postural
- Vasovagal syncope
- Orthostatic hypotension (including from medicines)
- Carotid sinus hypersensitivity
- Situational syncope (cough, micturition)
Cardiac: rhythm
- Sinus node disease
- Atrioventricular (heart) block
- Drug-induced bradycardia
- Ventricular tachycardia
Cardiac: structural
- Aortic stenosis
- Hypertrophic cardiomyopathy
- Ischaemia or myocardial infarction
Not syncope
- Seizure
- Hypoglycaemia
- Transient ischaemic attack (rarely causes loss of consciousness)
Common mistakes
- Accepting 'he just fainted' in an older man without an ECG.
- Missing a medicine (or a high potassium) that is slowing the heart.
- Calling the jerking seen in many faints a seizure. Brief jerks are common in syncope; a long post-ictal confusion is not.