Diagnostics
Heart Rhythm Diagnostics
Different rhythm problems may need different tests. The choice depends on how often symptoms occur and on the question that needs to be answered. This page explains how the main tests fit together.
On this page
Choosing the right test
Why Different Tests Are Used
A heart rhythm is a moving target. Some problems are present all the time, and others appear only now and then. Some questions can be answered by a short recording, while others need longer monitoring or a look at the electrical activity inside the heart.
How assessment may proceed
Diagnostic Pathway
A typical route starts with your history and moves on to tests that record the rhythm more closely. Not every patient follows every step, and many people need only the first ones.
Symptoms and history
Your symptoms, medical history and family history are discussed.
Resting ECG
A short recording of the heart rhythm.
Ambulatory monitoring
Longer recording, when symptoms come and go.
Electrophysiology
assessment
Specialist assessment inside the heart, where appropriate.
Mapping
A 3D electrical map, where appropriate.
Existing guides
Diagnostic Methods
Each method has its own page with more detail about what it records, how it is done and what it can and cannot show.
A short recording of the heart’s electrical activity at rest.
Continuous recording of the rhythm over a longer period.
A device used for symptoms that occur less often, which records when triggered or when it detects a rhythm change.
Monitored exercise with a continuous ECG, used to assess rhythm and heart-rate response during exertion.
A monitored test used to bring out a Brugada pattern when the diagnosis is suspected.
An invasive test that records the electrical activity from inside the heart.
A computer-built map of the heart’s electrical activity and anatomy.
A guide, not a prescription
Which Test May Answer Which Question?
The table below describes what each type of test is generally able to show. The right choice for you is made by your doctor after assessment.
Snapshot
A short rhythm snapshot
An ECG records the rhythm at the moment of the test.
Continuous
Continuous rhythm monitoring
Holter monitoring records every beat over a set period.
Intermittent
Longer-term, intermittent monitoring
An event recorder is used over a longer time for less frequent symptoms.
Inside the heart
Intracardiac electrical assessment
An electrophysiology study records the electrical signals directly from inside the heart.
Localisation
3D electrical and anatomical localisation
Mapping helps to show where in the heart an abnormal rhythm arises.
Together
Combined information
Results from several tests are usually considered together.
Why monitoring varies
Intermittent Symptoms
If symptoms come and go, a single test may not catch them. An ECG taken while the rhythm is normal may look normal, even when a rhythm problem exists at other times.
For this reason, monitoring may be extended, using a Holter monitor or an event recorder, depending on how often symptoms occur. A longer recording does not always capture an event, and your doctor may adjust the approach as results come in.
Questions
Frequently Asked Questions
Which test will I need?
This depends on your symptoms and history. Your doctor will choose tests that answer the question in your case.
Do I need every test?
No. Many people need only a few of them.
What if my ECG is normal?
A normal ECG does not exclude a rhythm problem that comes and goes, so further monitoring may be suggested.
What is the difference between a Holter monitor and an event recorder?
A Holter monitor records continuously for a set period. An event recorder is used over a longer time. Depending on the device, it records when you press a button, when it detects a rhythm change automatically, or both.
When is an electrophysiology study considered?
It may be considered in selected patients when more detailed information about the heart’s electrical activity is needed.
What is 3D mapping used for?
It helps to show where an abnormal rhythm arises, and it is used in selected procedures.
Do these tests hurt?
ECG, Holter monitoring and most external event recorders are non-invasive. An implantable loop recorder is placed under the skin in a short procedure, and an electrophysiology study is a catheter procedure. Your team will explain what to expect.
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