What Does an Echocardiogram Show?

What Is an Echocardiogram?

An echocardiogram — often called an "echo" — is an ultrasound-scan of the heart. It uses high-frequency sound waves to produce real-time moving images of the heart's chambers, valves, walls, and the major blood vessels attached to it. Unlike an X-ray or CT scan, there is no ionising radiation. The probe emits sound waves that bounce off cardiac structures and return as electrical signals, which are converted into the images you see on the monitor.

The technique was first developed in the 1950s and has since become the cornerstone of cardiac diagnosis. Transthoracic echocardiography (TTE) is now recognised by the European Association of Cardiovascular Imaging as the most common imaging modality in cardiovascular disease — central to diagnosis, follow-up, management planning, and intervention guidance.^[1]

When a patient asks me "what will the echo show?", my honest answer is: almost everything that matters about how your heart is built and how it is functioning right now.

The Four Types of Echocardiogram

Not all echocardiograms are the same. The type I recommend depends on the clinical question I am trying to answer.

At Victoria Medical, I perform transthoracic echocardiograms in-house. If a transoesophageal echo is clinically indicated, I will arrange this at an appropriate facility and remain your supervising cardiologist throughout.

What an Echocardiogram Shows: The Six Key Assessments

1. Left Ventricular Ejection Fraction (LVEF)

The ejection fraction is the percentage of blood the left ventricle pumps out with each beat. A normal LVEF is 55–70%. A reduced LVEF — below 40% — indicates heart failure with reduced ejection fraction (HFrEF), a condition that requires immediate medical management. The echocardiogram is the gold standard for measuring LVEF, and it is the single most important prognostic marker in patients with known or suspected heart failure.^[2]

Even when LVEF appears normal, I can assess myocardial strain using speckle-tracking echocardiography — a technique that detects subclinical dysfunction before the ejection fraction falls. This matters enormously in patients receiving cardiotoxic chemotherapy or those with early hypertensive heart disease.^[3]

2. Heart Valve Function

Valvular heart disease is the most frequent abnormality I detect on echocardiography. A 2025 study using AI-assisted focused cardiac ultrasound found that valvular disease accounted for 42% of all confirmed cardiac abnormalities detected in primary care patients — more than any other category.^[4]

The echocardiogram assesses all four heart valves — aortic, mitral, tricuspid, and pulmonary — for both stenosis (narrowing) and regurgitation (leaking). Doppler colour flow mapping allows me to quantify the severity of any valve abnormality with high accuracy. Point-of-care ultrasound studies have demonstrated sensitivity of 90.9% and specificity of 100% for detecting moderate-to-severe aortic regurgitation, with excellent agreement with formal echocardiography (κ = 0.94).^[5]

Aortic stenosis is the most common valvular disease in developed countries, characterised by progressive narrowing of the aortic valve orifice and elevated transvalvular resistance. Transthoracic echocardiography is the first-line imaging modality for grading its severity and determining the timing of intervention.^[6]

3. Pericardial Effusion

A pericardial effusion is an abnormal accumulation of fluid around the heart. In its most severe form — cardiac tamponade — the fluid compresses the heart chambers, impairs filling, and becomes life-threatening. Echocardiography is the primary diagnostic tool for detecting and grading pericardial effusion, and for assessing haemodynamic significance through chamber collapse, inferior vena cava plethora, and respiratory flow variation.^[7]

Population data from the STAAB cohort study (4,965 participants) found incidental pericardial effusion in approximately 2.7% of individuals. The vast majority were small (<10 mm) and resolved spontaneously. The absence of cardiac chamber collapse on echocardiography carries the highest negative predictive value for excluding cardiac tamponade.^[8]

4. Right Heart Function and Pulmonary Pressure

The right ventricle is geometrically complex and historically under-assessed. Modern echocardiographic techniques — including 3D volumetric imaging, speckle-tracking strain analysis, and tissue Doppler — now allow comprehensive assessment of right ventricular function and pulmonary artery pressure. This is particularly important in patients with pulmonary hypertension, chronic lung disease, or right heart failure.^[9]

5. Aortic Root and Ascending Aorta

The echocardiogram measures the diameter of the aortic root and ascending aorta. Dilatation above 4.5 cm in the aortic root requires close surveillance; above 5.5 cm, surgical intervention is typically recommended. In patients presenting with acute chest pain, a transthoracic echocardiogram can detect indirect signs of aortic dissection — including intimal flap, aortic regurgitation, and pericardial effusion — with high specificity (94% for direct signs).^[10]

6. Left Atrial Size and Diastolic Function

Left atrial volume indexed for body surface area (LAVI) is one of the most important echocardiographic predictors of post-operative atrial fibrillation and is a key marker of diastolic dysfunction. A meta-analysis of 23 studies confirmed that increased LAVI is a robust predictor of atrial fibrillation across heterogeneous populations.^[11] Diastolic dysfunction — impaired relaxation of the left ventricle — is a common finding in hypertensive patients and those with heart failure with preserved ejection fraction (HFpEF), and can only be reliably diagnosed with echocardiography.

Which Conditions Does an Echocardiogram Diagnose?

The conditions I most commonly diagnose or exclude using echocardiography at Victoria Medical include:

When Should You Book an Echocardiogram?

I recommend an echocardiogram when a patient presents with any of the following symptoms or clinical findings:

You do not need a GP referral to book directly with me at Victoria Medical. If you have been told you need an echo by another doctor, or if you are experiencing any of the symptoms above, I can typically see you within 48 hours.

What to Expect at Your Echocardiogram Appointment

Patients are often anxious before their first echocardiogram. Here is exactly what happens at Victoria Medical:

Echocardiogram vs ECG: What Is the Difference?

This is one of the most common questions I receive. The two tests are complementary, not interchangeable.

At Victoria Medical, I routinely perform both an ECG and an echocardiogram at the same cardiology appointment. Together, they provide a complete picture of cardiac electrical activity and structural function.