Aortic aneurysm, coarctation & atheroma
Measure the root and ascending aorta the same way every time, find coarctation by Doppler, and grade the atheroma that embolises.
Numbers to remember
- Root and ascending aorta ≥55 mm → surgery; lower thresholds for bicuspid valve, Marfan and other high-risk genotypes [9,10]
- Growth ≥5 mm/year → surgery [9]
- Coarctation: a diastolic tail in the descending-aorta CW signal and blunted abdominal flow [25]
Questions echo must answer
- Aortic sizeAnnulus, sinuses, sinotubular junction, ascending aorta, arch and descending aorta [9,18].
- Change over timeCompare like with like — the same level and the same convention [9].
- CauseBicuspid valve, connective tissue disease, hypertension, atherosclerosis [9,174].
- CoarctationIn young hypertensives, and with a bicuspid valve [25].
- AtheromaThickness, mobility, ulceration — a source of embolism [176].
Acquisition protocol
- PLAX and high left parasternalRoot and ascending aorta, leading-edge to leading-edge in end-diastole [1,18].
- Right parasternalAscending aorta when PLAX does not reach it.
- SuprasternalArch, branches, proximal descending aorta; CW for coarctation.
- SubcostalAbdominal aorta pulsatility and flow.
- TOEArch and descending atheroma [35].
Diagnosis & severity
| Finding | Criterion |
|---|---|
| Aneurysm | Diameter ≥1.5 × expected for age, sex and body size |
| Complex atheroma | ≥4 mm thick, ulcerated or mobile [176] |
| Coarctation | Narrowing at the isthmus with a high-velocity jet and a diastolic tail [25] |
Thresholds that change management
- Root or ascending ≥55 mm → surgery; ≥50 mm in Marfan, bicuspid valve with risk factors, or at an experienced centre; ≥45 mm when another cardiac operation is planned [9,10].
- Coarctation with a significant gradient and hypertension → intervention [25].
- Mobile aortic atheroma after stroke → antithrombotic strategy per stroke guidance [176,197].
Pitfalls & mimics
- Mixing conventions Inner-edge CT and leading-edge echo differ by a few millimetres.
- Oblique cuts overestimate the diameter.
- Reverberation in the ascending aorta can mimic a dissection flap [173].