Related Experiment Videos
Regional differences in left ventricular wall motion in the anesthetized dog
J Diedericks1, B J Leone, P Foëx
1Nuffield Department of Anaesthetics, Radcliffe Infirmary, Oxford, United Kingdom.
Anesthesiology
|January 1, 1989
Summary
The left ventricle's apex is more dynamic and sensitive to negative inotropic drugs than its base. Anesthesia and drugs like halothane and verapamil impact regional left ventricular function differently.
Area of Science:
- Cardiology
- Anesthesiology
- Cardiovascular Physiology
Background:
- Left ventricular (LV) function can vary regionally.
- Understanding regional differences is crucial for assessing cardiac performance during anesthesia.
Purpose of the Study:
- To investigate the impact of negative inotropic agents used in anesthesia on regional LV function.
- To compare the effects of nitrous oxide (N2O), halothane, and verapamil on apical versus basal LV segments.
Main Methods:
- Mongrel dogs were anesthetized and instrumented for global and regional LV function assessment.
- Subendocardial sonomicrometry measured regional function in the apical and basal LV short-axis segments.
- Three interventions were tested: 67% N2O, stepwise increasing halothane concentrations, and verapamil infusion.
Main Results:
- Statistically significant differences in systolic shortening between apical and basal segments were observed at baseline and with minimal myocardial depression.
- The apical region was significantly more affected by myocardial depression than the basal region.
- Substantial myocardial depression induced by halothane or verapamil abolished regional function differences.
Conclusions:
- The apical region of the left ventricle exhibits greater dynamism and sensitivity to negative inotropic interventions compared to the basal region.
- These regional differences in sensitivity should be considered when evaluating segmental myocardial function, particularly under anesthesia.