Dyspnoea (breathlessness)
Heart or lung? Echo defines the HF phenotype, filling pressure, valves, pulmonary pressure and pericardium.
Echo approach, step by step
In suspected heart failure, the ESC recommends natriuretic peptides and echocardiography [12]. Echo classifies the LVEF phenotype, estimates filling pressure, and finds valve, pericardial, pulmonary vascular and congenital causes. Lung ultrasound adds B-lines (pulmonary oedema) at the same examination [202].
- LVVolumes, LVEF, GLS → HFrEF / HFmrEF / HFpEF [1,12].
- Filling pressureE/A, E/e′, TR velocity, LAVI; LA strain if indeterminate [2,32].
- ValvesAS, MR, MS, AR, prosthetic dysfunction [4,5,167].
- RV and PAPH probability, TAPSE/PASP [8].
- PericardiumEffusion; constriction (septal bounce, e′) [57].
- ShuntASD, sinus venosus; saline if hypoxic [175].
- Specific cardiomyopathyAmyloid red flags, HCM [13,30].
- LungsB-line profile (bilateral = interstitial oedema), pleural effusion [199,202].
- If rest is normalDiastolic stress echo, exercise PASP, dynamic MR or LVOT gradient [28,105,106].
- LVEF and phenotype
- Filling pressure
- Valves
- PH probability
- Pericardium
- Shunt
- Specific cardiomyopathy clues
- Lung ultrasound
- Exercise echo if rest is normal
Causes & echo clues
| Cause | Echo clue | Confirm / next |
|---|---|---|
| HFrEF | LVEF ≤40%, dilated LV | GDMT; aetiology work-up [12] |
| HFpEF | LVEF ≥50%, raised filling pressure, LVH, LA dilatation | H₂FPEF / HFA-PEFF; stress echo [101,102] |
| Valve disease | Severe AS, MR, MS, AR | Valve pathway [6] |
| Pulmonary hypertension | High TR velocity, RV dilatation | Right-heart catheterisation [8] |
| Chronic PE / CTEPH | RV pressure overload after PE | V/Q scan [8,124] |
| Constriction / effusion | Septal bounce, e′ preserved; effusion | CT, CMR [57] |
| Shunt (ASD) | RV volume overload | TOE, Qp:Qs [175] |
| Amyloidosis | Thick walls, low e′ and s′, apical sparing | Light chains, scintigraphy [30] |
| High-output state | Hyperdynamic, high CO | Haemoglobin, TSH, liver, AV fistula [201,208] |
| Lung disease, anaemia, obesity, deconditioning | Normal echo | Spirometry, CT, CPET |
Clinical pathway to the diagnosis
- History and examinationOnset (acute or chronic), orthopnoea, oedema, JVP, murmurs, wheeze, clubbing.
- ECGA normal ECG makes HF unlikely [12].
- Natriuretic peptideIn the non-acute setting, NT-proBNP <125 pg/mL (BNP <35 pg/mL) makes HF unlikely. In the acute setting the thresholds are NT-proBNP <300 pg/mL and BNP <100 pg/mL [12].
- EchoIf the peptide is raised or suspicion is high [12].
- Chest X-ray, spirometry, haemoglobin, TSHin parallel.
- If still unexplainedCT chest, CPET, exercise echo, right-heart catheterisation [8,101].
Clinical pearls & pitfalls
PitfallNormal LVEF does not mean a normal heart. Half of heart failure is HFpEF. Apply the scores; do not stop at "EF 60%" [101,102].
- Obesity lowers natriuretic peptides, and AF raises them [101].
- MR and AS severity can be underestimated at rest. Exercise echo when the symptoms do not fit [28,189].
- Constriction masquerades as HFpEF or liver disease. Look for septal bounce and preserved e′ [57].
- Hypoxaemia disproportionate to the echo → shunt (saline) or lung disease [176].
Red flags
- Orthopnoea, paroxysmal nocturnal dyspnoea, raised JVP, oedema → heart failure [12]
- Dyspnoea at rest, hypoxaemia, tachypnoea → acute (see Respiratory distress)
- Syncope on exertion → PH, AS, HCM [8,196]
- Pleuritic pain and tachycardia → PE [124]