Table 1.
Summary of ex vivo heart preparations with the associated electromechanical function and working conditions
| Preparation | Brief description | Action potentials |
Full calcium cycling |
Cross-bridge cycling |
Contracts against resistance |
Pressure– volume work |
|---|---|---|---|---|---|---|
| Biventricular ejecting | LV and RV circulate fluid; provides own coronary perfusion |
✓ | ✓ | ✓ | LV and RV | LV and RV |
| Left ventricular ejecting |
LV circulates fluid; provides own coronary perfusion |
✓ | ✓ | ✓ | LV | LV |
| Working Langendorff | Coronary perfusion provided; balloon in LV, isovolumic contractions |
✓ | ✓ | ✓ | LV | — |
| Unloaded Langendorff |
Coronary perfusion provided; mechanically contracting |
✓ | ✓ | ✓ | — | — |
| Blebbistatin or BDM (≤10 mM) |
Electromechanically uncoupled |
✓ | ✓ | — | — | — |
| BDM (≥10 mM) | Electromechanically uncoupled; blunted Ca2+ cycling |
✓ | — | — | — | — |
| KCl arrest | No cardiac action potentials | — | — | — | — | — |
Abbreviations: BDM, 2,3-butanedione monoxime; LV, left ventricle; and RV right ventricle.