Medically reviewed by Hootan Mohsenian, MSc — Advanced Practitioner in Echocardiography (BSE-accredited) —
An echocardiogram is an ultrasound scan of the heart. It is the first-line test for valve disease, heart failure, cardiomyopathy and fluid around the heart, and it uses sound waves rather than radiation. This guide explains which heart conditions an echo identifies, which it cannot, and what usually happens next.
Call 999 for chest pain that is severe, lasts more than 15 minutes, or comes with sweating, sickness, or pain spreading to the arm, neck or jaw. The same applies to sudden severe breathlessness or fainting. An outpatient echocardiogram is a planned investigation, not an emergency test — a suspected heart attack needs an ECG and blood tests in hospital, which an echo cannot replace.
What does “diagnosed by echocardiogram” actually mean?
An echocardiogram diagnoses conditions of heart structure and function — how the chambers are built, how the valves open and close, how strongly the muscle pumps, and how blood flows through it. Few cardiac diagnoses rest on the scan alone; the echo supplies the decisive evidence that a clinician combines with your symptoms, examination and other tests.
Three jobs an echo does for your clinician
Confirm or exclude. A murmur, an abnormal ECG or unexplained breathlessness raises a question. The echo answers whether a structural cause is behind it.
Measure severity. Not just whether a valve leaks, but how much — mild, moderate or severe. That grading is what decides whether you are monitored or referred for treatment.
Set a baseline. The measurements recorded today become the comparison for every future scan. This matters most in valve disease and cardiomyopathy, where the rate of change guides the timing of treatment.
What the sonographer is looking at
Chambers — the size and wall thickness of all four.
Valves — leaflet movement, narrowing and leakage.
Pumping function — wall motion and ejection fraction.
Doppler flow — the speed and direction of blood, used to grade valve problems and estimate pressures.
The pericardium — the sac around the heart, and any fluid within it.
Which heart conditions can an echocardiogram diagnose?
These are the conditions a standard resting echocardiogram identifies most often, what the report typically describes for each, and how far the scan can take the diagnosis on its own.
Condition
What the echo shows
How conclusive
Valve disease
Narrowing (stenosis) and leakage (regurgitation), leaflet motion, and the Doppler measurements used to grade severity
Diagnostic — echo is the primary test
Heart failure
Ejection fraction, chamber size, wall motion and filling-pressure estimates; separates reduced from preserved types
Central to the diagnosis, alongside symptoms and blood tests
Cardiomyopathy
Muscle thickening, dilatation or restricted filling — the pattern points to the type
Strongly suggestive; confirmation may need cardiac MRI or genetic testing
Pericardial effusion
Fluid around the heart, its volume and distribution, and whether it is compressing the heart
Diagnostic — echo is the test of choice
Pulmonary hypertension
Right heart size and function, plus an estimated pulmonary artery pressure from Doppler
Screening — confirmation needs right heart catheterisation
Consequences of a heart attack
Regions of muscle moving poorly, scarring, and any reduction in pumping function
Shows the damage, not the acute event
Congenital & structural findings
Bicuspid aortic valve, septal defects, and aortic root dimensions
Often the first test to detect these in adults
Cardiac contributors to stroke risk
Left atrial size, valve disease and pumping function in atrial fibrillation
Informs risk — detecting a clot usually needs a TOE
Severity grading and pressure estimates depend on image quality and on conditions on the day. Reports are written with that in mind, which is why serial scans are compared rather than read in isolation.
1) Valve disease — murmurs, narrowing and leakage
Echocardiography is the primary test for heart valve disease. If a clinician has heard a murmur, an echo is almost always the next step, because it shows both what the valve is doing and how much it matters.
A murmur is simply the sound of turbulent blood flow. Many murmurs are innocent. The echo separates those from the ones caused by a valve that has narrowed (stenosis) or become leaky (regurgitation), and then grades the problem. Grading is the important part: mild aortic regurgitation may need nothing more than a repeat scan in a few years, while severe aortic stenosis is a reason for prompt specialist referral.
Valve findings an echo assesses
Aortic stenosis — the aortic valve stiffens and narrows, so the heart must work harder to push blood out. Classically causes breathlessness on exertion, chest tightness or blackouts.
Aortic regurgitation — the valve fails to close fully and blood leaks back into the left ventricle.
Mitral regurgitation — leakage back into the left atrium, one of the most common causes of a murmur in adults.
Mitral stenosis — a narrowed mitral valve, less common in the UK but important where it occurs.
Mitral valve prolapse — leaflets that billow backwards during contraction, often benign but sometimes associated with leakage.
Prosthetic valve function — for anyone with a replacement valve, the echo checks it is opening, closing and sealing as it should.
Where the valve appearance is unclear from the front of the chest, the definitive next test is usually a transoesophageal echocardiogram, which images the heart from the oesophagus. Sonoworld does not currently offer TOE — it is arranged through a hospital cardiology service, and we will say so plainly in your report if it is what you need.
2) Heart failure — reduced and preserved ejection fraction
An echocardiogram is central to diagnosing heart failure. It measures how well the left ventricle pumps, how large the chambers have become, and whether pressures inside the heart are raised — the three things that distinguish the two main types of heart failure from each other.
The term “heart failure” frightens people more than it should. It does not mean the heart is about to stop. It means the heart is not pumping or filling efficiently enough to meet the body’s demands, and it is a condition that is managed, often for many years.
Reduced ejection fraction (HFrEF)
The muscle is weakened and cannot contract forcefully enough, so a smaller proportion of blood leaves the ventricle with each beat. The echo shows a lowered ejection fraction, often with an enlarged left ventricle and reduced wall motion.
Preserved ejection fraction (HFpEF)
The muscle is stiff and cannot relax properly to fill between beats. Ejection fraction can look normal, which is exactly why this type is missed on basic testing — it is Doppler assessment of filling pressures that reveals it.
Ejection fraction is the number people fixate on — and the one most often misread.
Ejection fraction is the percentage of blood pumped out of the left ventricle with each beat. It is meaningful, but it is a single measurement with real inherent variability, and it is interpreted alongside everything else on the scan rather than read as a score. Our companion guide explains the normal range and what the numbers mean in practice: normal ejection fraction explained.
3) Cardiomyopathy — thickened, dilated or stiffened heart muscle
Cardiomyopathy means disease of the heart muscle itself. An echocardiogram is usually the test that first identifies it, because each type produces a recognisable pattern of muscle thickness, chamber size and pumping behaviour.
Patterns an echo can identify
Hypertrophic cardiomyopathy (HCM) — abnormal thickening of the heart muscle, often most marked in the septum between the ventricles. Echo also checks whether the thickened muscle obstructs blood leaving the heart.
Dilated cardiomyopathy (DCM) — the left ventricle enlarges and the muscle weakens, reducing ejection fraction.
Restrictive cardiomyopathy — the muscle becomes stiff and fills poorly, even when the pumping action looks preserved.
Infiltrative disease — conditions such as cardiac amyloidosis produce characteristic appearances that prompt further, more specific testing.
Cardiomyopathies frequently run in families, which is why a diagnosis in one relative often leads to screening in others. Our guides on cardiomyopathy types and family screening and heart screening with a family history explain who should be scanned and how often. Confirming the type, and distinguishing it from lookalike conditions, may require cardiac MRI or genetic testing that sits outside what ultrasound can provide.
4) Fluid around the heart (pericardial effusion)
The pericardium is the thin sac surrounding the heart. When fluid collects inside it, ultrasound is the test of choice: an echocardiogram shows the fluid immediately, measures how much there is, and shows whether it is affecting how the heart fills.
Small effusions are common and frequently harmless, sometimes found incidentally on a scan requested for another reason. What matters clinically is not only volume but speed of accumulation — fluid that gathers rapidly can compress the heart even in modest quantities, a situation called cardiac tamponade, which is a medical emergency. The echo report describes the size of the effusion, where it sits, and whether there are any signs of the heart being compressed.
What tends to be reported
The size of the effusion, usually described as trivial, small, moderate or large.
Whether the fluid surrounds the heart evenly or is collected in one area.
Whether there is any evidence of the chambers being compressed.
Any thickening of the pericardium itself, which raises the question of constriction.
5) Right heart strain and raised lung pressures
The right side of the heart pumps blood to the lungs. When lung pressures rise, the right ventricle has to work against increased resistance and begins to change shape — changes an echocardiogram can see, and which often provide the first clue to pulmonary hypertension.
Using Doppler, the scan produces an estimated pulmonary artery pressure. That estimate is a screening figure, not a diagnosis: confirming pulmonary hypertension requires right heart catheterisation, a hospital procedure that measures the pressure directly. What the echo does well is flag the possibility and quantify the strain, so the right referral can be made.
What an echo may highlight
Enlargement of the right ventricle or right atrium.
Reduced right ventricular function.
An estimated pulmonary artery systolic pressure derived from the tricuspid valve.
Flattening of the septum between the ventricles, a sign of pressure or volume overload.
Dilatation of the inferior vena cava, which reflects pressures in the right side of the heart.
6) Atrial fibrillation — what the echo adds to the rhythm
An echocardiogram does not diagnose atrial fibrillation — an ECG does that. What the echo establishes is why the rhythm has become irregular and what it has done to the heart, which is what shapes treatment.
Once AF is confirmed on an ECG, a scan is standard practice. It measures the size of the left atrium, which tends to enlarge in longstanding AF, checks the valves for an underlying cause such as mitral valve disease, and measures pumping function, since a persistently fast irregular rhythm can weaken the muscle over time. Those findings feed into decisions about rhythm control and anticoagulation.
One thing a standard echo cannot reliably do is see inside the left atrial appendage, the small pouch where clots form in AF. Excluding a clot before certain procedures requires a transoesophageal echo, which is not currently available at Sonoworld. Our guide to atrial fibrillation and why it needs an echocardiogram covers this in more detail.
7) Congenital and structural findings in adults
Some structural differences present from birth are only discovered in adulthood, often when someone has a scan for an unrelated symptom. An echocardiogram is usually the test that finds them.
Findings that commonly surface
Bicuspid aortic valve — a valve with two leaflets rather than three. Common, frequently symptom-free for decades, but it narrows or leaks earlier in life than a normal valve, so it warrants monitoring.
Atrial septal defect — an opening between the two upper chambers, which may only declare itself in adulthood through breathlessness or right heart enlargement.
Aortic root dilatation — widening of the first part of the aorta, relevant in bicuspid valve disease and in connective tissue conditions such as Marfan syndrome.
Patent foramen ovale — a small flap-like opening that remains after birth. Detecting it reliably usually needs contrast or a TOE rather than a standard scan.
A structural finding on an adult scan is not automatically a problem to be fixed. Many are monitored for years without intervention — the value of the scan is knowing it is there, and having a baseline measurement to compare against.
What an echocardiogram cannot diagnose on its own
Being clear about the limits matters as much as listing the strengths. A normal echocardiogram is genuinely reassuring about heart structure, but it does not exclude every cardiac problem.
Blocked coronary arteries. A resting echo does not image the coronary arteries. It may show the consequences of a previous blockage, but assessing the arteries themselves needs CT coronary angiography, a stress test or invasive angiography.
An acute heart attack. Diagnosis rests on ECG changes and blood tests. Echo shows resulting damage rather than the event.
Intermittent rhythm problems. A scan is a snapshot. Palpitations that come and go need ECG monitoring over hours or days to catch them.
Small clots and vegetations. Assessment of the left atrial appendage, or of suspected infection on a valve, generally requires a transoesophageal study.
Definitive tissue characterisation. Distinguishing scar from inflammation, or confirming infiltrative disease, is the province of cardiac MRI.
Image quality is the other honest limitation. Lung tissue, body habitus and chest shape all affect how clearly the heart can be seen, and where images are limited the report says so rather than overstating certainty. Our detailed guide to the limitations of echocardiography covers this properly, and echo compared with ECG, CT and MRI sets out which test answers which question.
What happens after your echocardiogram?
You receive your findings verbally on the day, explained on screen before you leave, and a written report within 24 hours that is formatted for a GP or cardiologist to act on directly.
The report describes chamber sizes, wall thickness and motion, ejection fraction, each valve in turn, Doppler measurements, and the pericardium — followed by a conclusion and a recommendation. Where a finding needs specialist input, the recommendation says which specialist and how urgently. Where the scan is normal, that is stated plainly, along with what would be worth investigating instead if symptoms persist.
If the scan is normal
Most are. A normal echo excludes the major structural causes of your symptoms, which narrows the search considerably. Rhythm monitoring, lung function testing, blood tests for anaemia or thyroid problems, or coronary assessment are the usual next avenues, depending on your symptom pattern.
If something is found
The finding is explained to you at the time, in plain language, along with what it means and what happens next. Mild findings are typically monitored with a repeat scan; significant valve disease, cardiomyopathy or unexplained pumping impairment leads to a cardiology referral with your report in hand.
Booking a private echocardiogram in London
A resting echocardiogram at Sonoworld costs £350, all-inclusive, at our CQC-registered clinic at 29 Weymouth Street in Marylebone. No GP referral is required, and appointments are usually available within a few days.
The price covers the full study — chambers, valves, Doppler flow assessment and pumping function — along with verbal findings on the day and the written report within 24 hours. If a broader cardiovascular assessment is what you are after, our cardiac and stroke screening package combines the echocardiogram with carotid and aortic imaging.
Related echocardiogram guides
Use these to move from “what might it be?” to “what should I book?” without bouncing between unrelated pages.
Start here
What is an echocardiogram?
The basics: what it shows, how it works, and what to expect during the appointment.
Not directly. A resting echocardiogram does not image the coronary arteries themselves. It can show how well the heart muscle moves and pumps, and may suggest damage from a previous blockage, but assessing the arteries requires a different pathway — usually CT coronary angiography, a stress test, or invasive angiography, depending on your symptoms.
Will an echo show valve disease if I have a murmur?
In most cases, yes. Echocardiography is the main test used to evaluate a murmur. It shows valve narrowing and leakage, how the leaflets move, and the Doppler flow patterns used to grade severity. It also identifies murmurs that are innocent, meaning no valve problem is present and no follow-up is needed.
Can an echocardiogram detect heart failure?
Yes, an echocardiogram is central to diagnosing heart failure. It measures pumping function including ejection fraction, chamber sizes, and Doppler markers of filling pressure, which is what separates heart failure with reduced ejection fraction from the preserved type. The final diagnosis combines the scan with your symptoms, examination and blood tests.
What if my echo is normal but I still have symptoms?
That is a common and useful result. A normal echocardiogram rules out the major structural causes, which narrows the search considerably. Symptoms can still arise from rhythm disturbances, lung conditions, anaemia, thyroid problems, deconditioning or coronary disease. The right next test depends on your symptom pattern and history.
Can an echocardiogram diagnose atrial fibrillation?
No. Atrial fibrillation is a rhythm diagnosis made on an ECG. An echocardiogram is performed afterwards to find out why the rhythm changed and what effect it has had, by measuring left atrial size, checking the valves, and assessing pumping function. Those findings guide decisions about treatment and anticoagulation.
Does an echocardiogram show a previous heart attack?
Often, yes. Muscle damaged by a previous heart attack tends to move abnormally, and the scan can show the affected region, any thinning or scarring, and the effect on overall pumping function. It cannot diagnose a heart attack as it happens — that requires an ECG and blood tests in hospital.
How long does an echocardiogram take, and do I need to prepare?
Allow 30 to 45 minutes. No preparation is needed: eat, drink and take your usual medication as normal. You undress to the waist and lie on your left side while gel and a small probe are used to image the heart from several positions. You can return to normal activities immediately afterwards.
Is an echocardiogram safe?
Yes. A standard transthoracic echocardiogram uses sound waves rather than ionising radiation, involves no injections and no dye, and is very well tolerated. There is no recovery time and no restriction on driving or activity afterwards.
Clinical sources
NICE NG106. Chronic heart failure in adults: diagnosis and management — transthoracic echocardiography in the diagnostic pathway. nice.org.uk/guidance/ng106
NICE NG196. Atrial fibrillation: diagnosis and management — role of echocardiography after an AF diagnosis. nice.org.uk/guidance/ng196
British Society of Echocardiography. Departmental standards and minimum datasets for transthoracic echocardiography. bsecho.org
