Stroke work & rate–pressure product

LVSWI, SW, RPP · Derived: SW ≈ SV × (MAP − PCWP) × 0.0136 (g·m); LVSWI = SVi × (MAP − PCWP) × 0.0136; RPP = HR × SBP

Normal range & thresholds

LVSWI ≈50–62 g·m/m² normal; lower values signal limited contractile reserve. In cardiac-ICU patients, echo-derived LVSWI integrated shock severity and predicted mortality ^[193]. RPP approximates myocardial oxygen demand (resting ≈6000–12000).

Pathophysiology

Stroke work is the pressure–volume loop area — the external work of one beat. RPP tracks myocardial oxygen consumption, the demand side of the supply–demand balance.

Raised by

• Exercise, inotropes, hypertension (RPP)

Lowered by

• Low SV, low MAP (shock), high filling pressure

Technique & pitfalls

• PCWP from the echo estimate or a catheter — state which.

Pseudo-change & artefact

• Compounded errors from SV, MAP and LAP estimates.

Treatment thresholds

No guideline threshold; LVSWI supports shock severity assessment ^[154,193].

Next step

• CPO (card 44) and coupling (card 50).

Drugs

Inotropes raise SW; β-blockers lower RPP (anti-anginal effect).

Reversibility

Tracks the haemodynamic state.