Key Points
- To evaluate the accuracy of various mathematical geometric models in estimating left ventricular circumferential wall stress compared with direct transducer measurements.
- Monitored phasic left ventricular wall force, wall thickness, and cavity pressure directly using transducers in open-chest dogs.
- Computed circumferential wall stress across diverse hemodynamic states altered by infusions of nitroglycerin, phenylephrine, and isoproterenol.
- Assessed model sensitivity to measurement errors in wall thickness, circumferential length, and base-to-apex length.
- Baseline measured peak and end-ejection wall stresses were 207 ± 19 and 104 ± 13 g/cm², closely matched by a modified thin-wall ellipse using midwall radius at 198 ± 18 and 117 ± 11 g/cm², respectively.
- Both modified thin-wall and thick-wall elliptical models consistently predicted wall stress across varied hemodynamic interventions, whereas alternative models systematically underestimated stress.
- Thick-wall spherical models displayed the highest sensitivity to circumferential length and wall thickness errors, while thick-wall elliptical models were the least sensitive.
Structured PICO
PPopulationOpen-chest dogs
IInterventionEstimation of left ventricular circumferential wall stress using several geometric models (including modified thin-wall ellipse and thick-wall ellipse)
CComparatorDirect measurement of circumferential wall stress using transducers
OOutcomeAccuracy of estimated wall stress compared to directly measured wall stresssurrogate
Modified thin-wall and thick-wall ellipse models accurately estimate left ventricular circumferential wall stress compared to direct measurements in a canine model.