Cardiac imaging

Echocardiography

The most common cardiac investigation your patients will have had — how to read the report, which numbers change exercise prescription, and why ejection fraction tells you less than it seems to.

For clinicians
Ventilation–Perfusion (V/Q) Scanning Outcome Measures & Clinical Skills · 11 of 37 Blood Tests in Cardiorespiratory Practice
Authorship & review
Dr Sean James Ledger, BSc Physio (Hons) MSc PhD FHEA
Director and Principal Physiotherapist
Ahpra registration PHY0002298174
Version
1.0
Last updated
12 August 2026
Next review
12 August 2027
Every guide on this site is reviewed at least once a year, and sooner when the evidence changes.
How these guides are written and reviewed →
In plain language

Almost every cardiac patient and a large share of breathless respiratory patients arrive with an echocardiogram already done. The report is dense, largely numerical, and rarely explained. This guide covers what each measurement means, the handful that genuinely change physiotherapy, and the single most important caveat — that ejection fraction correlates poorly with how breathless a patient is or how far they can walk.

The four studies

StudyWhat it adds
Transthoracic (TTE)The standard study — probe on the chest wall, 30–45 minutes, no preparation. Answers almost every question below.
Transoesophageal (TOE)Probe in the oesophagus under sedation, fasted. Far better views of the valves, the left atrial appendage and prosthetic material — used for endocarditis, before cardioversion, and intra-operatively.
Stress echoImaging during exercise or dobutamine. Detects inducible ischaemia, and unmasks valve or filling abnormalities that are normal at rest — the study that most often explains exertional symptoms with a normal resting echo.
Contrast / bubble studyAgitated saline or contrast agent to improve endocardial definition, or to detect a right-to-left shunt such as a patent foramen ovale.

Left ventricular function

Ejection fraction is the fraction of end-diastolic volume ejected per beat, and it is the number everyone quotes. It classifies heart failure phenotype — reduced (≤40%), mildly reduced (41–49%) and preserved (≥50%) — which in turn determines drug therapy.1,2

Ejection fraction is not a measure of exercise capacityThe correlation between resting LVEF and both symptom burden and six-minute walk distance is weak. A patient with an EF of 30% may be walking comfortably; a patient with an EF of 55% may be severely limited by HFpEF, chronotropic incompetence, deconditioning or lung disease. Prescribe from the functional assessment in front of you, not from the number in the report. Exercise training carries a class I recommendation across the phenotypes.1

Global longitudinal strain (GLS) appears on many modern reports and detects impaired contractility while EF is still normal — it is more sensitive than EF, and is used to catch cardiotoxicity during cancer therapy. A normal EF with an abnormal GLS is an early abnormality, not a normal study.

Regional wall motion abnormalities localise previous infarction. A named territory (“anteroseptal hypokinesis”) maps onto a coronary artery and usually to a documented event.

Diastolic function — where HFpEF lives

Reported as grade I–III diastolic dysfunction, derived from mitral inflow velocities (E and A), tissue Doppler (e′), the E/e′ ratio, left atrial volume index and tricuspid regurgitant velocity.3

A raised E/e′ with an enlarged left atrium indicates elevated filling pressures — the mechanism behind exertional breathlessness in heart failure with preserved ejection fraction. This matters because those patients look normal on the headline EF and are frequently told their heart is fine. They are also the group in whom exercise training produces the clearest gains in quality of life.

The right heart — the part respiratory physiotherapy should read first

Right ventricular function is systematically under-read, and it is the side that matters in chronic lung disease.4

MeasureThresholdMeaning
TAPSE<17 mm suggests RV systolic dysfunction4Simple, reproducible, on almost every report
RV S′<9.5 cm/s abnormal4Tissue Doppler measure of RV contraction
Peak TR velocity>2.8 m/s intermediate; >3.4 m/s high probability of pulmonary hypertension5The screening signal — echo estimates probability, right heart catheterisation confirms
RV size and septal motionDilated RV, flattened septumPressure or volume overload — look for the cause

An echo cannot diagnose pulmonary hypertension; it assigns a probability that triggers further assessment.5 A patient with COPD or interstitial disease whose exercise tolerance has fallen out of proportion to their spirometry, with a raised TR velocity and a dilated RV, is a different clinical problem from deconditioning — see pulmonary hypertension.

Valves

Each valve is reported for stenosis and regurgitation, graded mild to severe. The one with the clearest implications for exercise prescription is aortic stenosis: severe disease is defined by a peak velocity ≥4.0 m/s, mean gradient ≥40 mmHg or valve area ≤1.0 cm².6

Severe aortic stenosis changes what you prescribeCardiac output is fixed by the obstruction, so it cannot rise to meet demand. Symptomatic severe AS is a contraindication to high-intensity and heavy resistance exercise, and Valsalva-loaded lifting should be avoided. Moderate, supervised, symptom-limited activity is generally appropriate. Exertional syncope, angina or breathlessness in known AS is a reason to stop and refer, not to progress. See aortic stenosis and TAVI.

Regurgitant lesions are usually better tolerated and less restrictive, but severe mitral or aortic regurgitation with LV dilatation warrants checking what the cardiologist has advised before progressing load.

Pericardium and other findings

What limits an echo

Image quality depends on acoustic windows, and they are poor in exactly the patients respiratory services see most: hyperinflated lungs, obesity, chest wall deformity, and post-operative dressings and drains. A report qualified as “suboptimal windows” deserves less weight, and may be why a contrast study or cardiac MRI followed. Doppler measurements are also load-dependent — volume status, blood pressure and rhythm at the time of the study all affect them, so an echo performed during an acute admission may not represent the patient's stable state.

What to tell the patient

What this means for physiotherapy

Related: Heart failure, blood tests for the natriuretic peptides that usually prompt the echo, cardiopulmonary exercise testing for what the heart does under load, and ECG basics.

References & evidence base

  1. McDonagh TA, Metra M, Adamo M, et al. 2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure. Eur Heart J. 2021;42(36):3599–3726.
  2. Bozkurt B, Coats AJS, Tsutsui H, et al. Universal definition and classification of heart failure. Eur J Heart Fail. 2021;23(3):352–380.
  3. Nagueh SF, Smiseth OA, Appleton CP, et al. Recommendations for the evaluation of left ventricular diastolic function by echocardiography. J Am Soc Echocardiogr. 2016;29(4):277–314.
  4. Rudski LG, Lai WW, Afilalo J, et al. Guidelines for the echocardiographic assessment of the right heart in adults. J Am Soc Echocardiogr. 2010;23(7):685–713.
  5. Humbert M, Kovacs G, Hoeper MM, et al. 2022 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension. Eur Heart J. 2022;43(38):3618–3731.
  6. Otto CM, Nishimura RA, Bonow RO, et al. 2020 ACC/AHA guideline for the management of patients with valvular heart disease. Circulation. 2021;143(5):e72–e227.

Further reading

References are numbered in citation order (Vancouver/BMJ style) and were current at the time of writing. Guidelines are living documents — verify against the latest version before clinical use.

Important: This page is written for health professionals as a summary of published evidence and guidance. It is not medical advice, does not replace the source documents, and does not substitute for clinical judgement or local policy.

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