End-systolic meridional wall stress

ESWS · Derived (Reichek): σ = 0.334 × P × LVIDs / [PWs × (1 + PWs/LVIDs)], ×10³ dyn/cm²

Normal range & thresholds

Healthy adults typically lie between ≈50 and 90 ×10³ dyn/cm². Use it relatively — serially, or plotted against EF (the stress–shortening relation) — rather than against a fixed cut-off ^[117].

Pathophysiology

Laplace: stress = pressure × radius ÷ (2 × thickness). Hypertrophy normalises stress in pressure overload; when it cannot, afterload mismatch lowers EF without loss of contractility, and relieving the load (AVR, BP control) restores EF. In volume overload, rising end-systolic stress with a large radius heralds decompensation ^[117].

Raised by

• Inadequate hypertrophy for the load; dilated thin-walled ventricles; severe hypertension

Lowered by

• Concentric hypertrophy, HCM, small cavities

Technique & pitfalls

• End-systolic LVIDs and PWs from 2D-guided linear measurements; LV systolic pressure ≈ SBP (+ AS gradient).

Pseudo-change & artefact

• Oblique linear measurements; regional wall motion abnormalities.

Treatment thresholds

No threshold; helps distinguish afterload mismatch (reversible) from intrinsic dysfunction before valve intervention.

Next step

• EF–stress relation, contractile reserve on low-dose dobutamine (AS) ^[5,28].

Drugs

Afterload reduction lowers it.

Reversibility

Falls with relief of the load.