Comparison · Medical test vs Medical test

ECG vs echocardiogram

One records the heart's electricity, the other shows its structure and motion. They answer different questions and are usually both needed when heart disease is suspected.

AspectElectrocardiogramEchocardiogram
What it showsElectrical rhythm, rate, conduction and signs of ischaemia, injury or strain over 10 secondsChamber sizes, wall thickness and motion, pumping function (ejection fraction), valves and pressures in real time
How it is doneTen electrodes on the chest and limbs; painless, no radiation, under 5 minutesUltrasound probe with gel on the chest for 20-40 minutes; no radiation; a transoesophageal version for detailed views
Best atArrhythmias, acute coronary syndromes (ST elevation), conduction block, electrolyte effects, QT prolongationHeart failure, valve disease, cardiomyopathy, pericardial fluid, sources of embolism, congenital disease
Cannot showPumping function, valve disease or coronary anatomy; may be normal early in a heart attackThe rhythm over time or the coronary arteries themselves
Who reads itAutomated interpretation confirmed by a clinician, often at the bedsideA sonographer or cardiologist, with a structured report
Typical sequenceFirst-line, repeated serially with troponinOrdered when the ECG, symptoms or BNP raise a structural question

Where Electrocardiogram fits

Chest pain, palpitations, blackouts, suspected heart attack or rhythm problem; a first test in minutes

Where Echocardiogram fits

Breathlessness with a raised BNP, murmurs and valve disease, after a heart attack, heart failure staging

Educational content. A comparison explains what each test, marker or medicine is for and how they differ. It is educational and does not say which one a person should have; that decision belongs to the clinician who knows the person and the question.