In plain English
An Electrocardiogram is a routine part of UK dementia assessment, particularly before starting Cholinesterase Inhibitor medication. The test is quick, painless and provides important safety information.
What an Electrocardiogram is
An Electrocardiogram (ECG) records the electrical activity of the heart over a few seconds. Ten small adhesive electrodes are placed on the chest, arms and legs. The test takes 5 minutes from start to finish. There is no preparation and no aftercare.
Why an ECG is part of dementia assessment
Before Cholinesterase Inhibitor prescribing
Cholinesterase Inhibitors (Donepezil, Galantamine, Rivastigmine) can slow the heart rate slightly. A baseline ECG identifies pre-existing slow heart rate (bradycardia), heart block, or other conduction problems that would make these medicines unsuitable or require cardiology input. The ECG is performed before starting and informs the prescribing decision.
Identifying Atrial Fibrillation
Atrial Fibrillation is common in older adults and is an important risk factor for stroke and Vascular Dementia. The ECG identifies it. Treatment with anticoagulation reduces stroke risk substantially.
Detecting QT prolongation
Some medicines prolong the QT interval, increasing arrhythmia risk. Several medicines used in older adults can affect QT, and an ECG identifies a prolonged baseline that would influence prescribing.
Other findings
Past silent heart attack, left ventricular hypertrophy (suggesting longstanding Hypertension), and various rhythm abnormalities can all show on the ECG.
What the report means
A typical ECG report describes:
- Rhythm: sinus rhythm (normal), Atrial Fibrillation, or other rhythm;
- Rate: heart rate in beats per minute (60 to 100 is the normal range);
- Axis: the direction of electrical activity (left, normal, right axis);
- Intervals: PR, QRS, QT, particularly the corrected QT (QTc);
- ST segments and T waves: changes can suggest ischaemia or previous heart attack;
- Voltages: high voltages can suggest left ventricular hypertrophy.
Most reports finish with a clinical impression: "normal sinus rhythm" or specific abnormalities highlighted.
When the ECG is abnormal
- Bradycardia (heart rate below 60): Cholinesterase Inhibitors may be unsuitable or require cardiology review. Other contributors to slow heart rate (beta-blockers, hypothyroidism) are checked.
- Atrial Fibrillation: stroke risk assessment with CHA2DS2-VASc score; anticoagulation usually recommended unless contraindicated.
- Heart block: cardiology review; pacing may be needed.
- Prolonged QTc: medication review for QT-prolonging drugs.
- Signs of past heart attack or hypertensive heart disease: cardiology review; vascular risk reduction.
If you cannot have an ECG
Most people can have an ECG. Where it is genuinely not possible (severe agitation, dressings, pacemaker considerations), a clinical risk assessment may proceed without an ECG, with closer monitoring of pulse and any cardiac symptoms after starting medication.
Holter monitoring
Where intermittent rhythm problems are suspected, a 24-hour, 48-hour or 7-day ambulatory ECG (Holter monitor) may be requested. This is a small wearable device that records continuously and is reviewed by a cardiologist.
Where to have an ECG
NHS ECGs are done at GP practices and in hospital outpatient settings. Private ECGs are widely available through community phlebotomy services and private memory clinics including The Dementia Service.
Frequently asked questions
Does the ECG hurt?
No. The adhesive electrodes feel like sticky pads. The recording itself is passive and takes a few seconds.
Why do I need an ECG before Donepezil?
Donepezil and other Cholinesterase Inhibitors can slow the heart rate slightly. The ECG ensures the baseline heart rate and conduction are safe for the medicine.
What if I have Atrial Fibrillation?
Treatment focuses on stroke prevention (usually with an anticoagulant such as Apixaban) and rate or rhythm control. Atrial Fibrillation is treatable; identifying it on the ECG is a benefit of the test.
Will I need a 24-hour Holter?
Only if intermittent rhythm problems are suspected. Most people have a standard 12-lead ECG and nothing further.
Can I have an ECG privately?
Yes. Private clinics including The Dementia Service can arrange ECGs as part of an assessment package.
References
- NICE TA217: Donepezil, Galantamine, Rivastigmine and Memantine for Alzheimer's Disease.
- British National Formulary. Cholinesterase inhibitors cardiac monitoring.
- NICE NG196: Atrial Fibrillation: diagnosis and management.
- British Society for Heart Failure. ECG interpretation.