Key Points
- This research aims to evaluate the external mechanical work done by relaxing ventricles compared to stored elastic energy.
- Examined canine left ventricles weighing approximately 70g.
- Measured specific P-V area during isovolumic relaxation at varying ventricular volume release speeds (50–100 ml/s and 200–300 ml/s).
- Analyzed the conversion of the specific P-V area into external mechanical work.
- Approximately 2/3 of the specific P-V area was converted into external mechanical work during slow ventricular volume decrease (50–100 ml/s).
- The external work performed during relaxation was about twice the work produced by faster volume release (200–300 ml/s) at end-systole.
- Indicated that substantial external mechanical work is achievable during relaxation beyond the stored elastic potential energy.
Structured PICO
PPopulationCanine left ventricles (about 70g)
IInterventionDecreasing ventricular volume at a relatively slow speed (50–100 ml/s) during relaxation
CComparatorQuick release of ventricular volume at 200–300 ml/s at end-systole
OOutcomeAmount of external mechanical work performedsurrogate
The relaxing canine left ventricle can perform external mechanical work beyond stored elastic potential energy when volume is decreased slowly.