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Updated: Aug 3, 2026
Cardiac Catheterization in Mice to Measure the Pressure Volume Relationship: Investigating the Bowditch Effect
Published on: June 14, 2015
Pressure-volume-based single-beat estimations cannot predict left ventricular contractility in vivo
Knut E Kjørstad1, Christian Korvald, Truls Myrmel
1Department of Thoracic and Cardiovascular Surgery, University Hospital of Tromsø, N-9038 Tromsø, Norway. knutek@fagmed.uit.no
Insights
Assessing heart contractility using single pressure-volume loops is challenging. Current single-beat methods for estimating cardiac contractility (elastance) lack the accuracy needed for reliable clinical use.
Area of Science:
- Cardiology
- Physiology
- Biomedical Engineering
Background:
- The end-systolic pressure-volume relationship is a key index for evaluating heart contractile state.
- Clinical application is limited by the need for preload alterations.
- Developing single pressure-volume loop methods for contractility assessment is an ongoing research area.
Purpose of the Study:
- To evaluate the accuracy of four different methods for calculating cardiac contractility from a single pressure-volume loop.
- To compare single-beat contractility estimates with preload-varied multiple-beat elastance.
Main Methods:
- Utilized combined pressure and conductance catheters in 37 pigs to obtain pressure-volume data.
- Applied four single-beat contractility estimation methods to 88 steady-state pressure-volume files.
- Included data from dopamine infusions to assess contractility changes.
Main Results:
- All evaluated single-beat methods exhibited low average bias but unacceptably high limits of agreement.
- None of the single-beat methods accurately predicted the increase in contractility observed during dopamine infusion.
- Multiple-beat elastance showed a significant increase with dopamine, which was not reflected by single-beat methods.
Conclusions:
- Current single-beat methods for assessing cardiac contractility are unreliable due to high variability.
- The clinical utility of these single-beat methods for estimating heart contractility is questionable.
- Further research is needed to develop accurate single-beat methods for cardiac contractility assessment.
Abstract:
The end-systolic pressure-volume relationship is regarded as a useful index for assessing the contractile state of the heart. However, the need for preload alterations has been a serious limitation to its clinical applications, and there have been numerous attempts to develop a method for calculating contractility based on one single pressure-volume loop. We have evaluated four of these methods. Pressure-volume data were obtained by combined pressure and conductance catheters in 37 pigs. All four methods were applied to 88 steady-state pressure-volume files, including eight files sampled during dopamine infusions. Estimates of single-beat contractility (elastance) were compared with preload-varied multiple-beat elastance [E(es(MB))]. All methods had a low average bias (-0.3 to 0.5 mmHg/ml) but limits of agreement (+/-2 SD) were unacceptably high (+/-2.6 to +/-3.8 mmHg/ml). In the dopamine group, E(es(MB)) showed an increase of 1.7 +/- 0.8 mmHg/ml (mean +/- SD) compared with baseline (P < 0.001). None of the single-beat methods predicted this increase in contractility. It is therefore doubtful whether any of the methods allow for single-beat assessment of contractility.
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