Impact of anesthesia on echocardiographic evaluation of systolic and diastolic function in rats.

Background: Echocardiography is used on rats but general anesthesia is usually necessary to be able to obtain a good quality echocardiogram. Each type of anesthetic agent has specific impacts on hemodynamics and, therefore, may affect differentially the echocardiographic measurements.

Objectives: We sought to compare the echocardiograms of normal rats and rats with chronic aortic regurgitation under anesthesia using ketamine-xylazine or isoflurane.

Methods: Animals underwent an echocardiogram with both drugs sequentially. Echocardiographic measurements were compared.

Results: Mitral diastolic Doppler measurements (early diastolic filling wave [E] and late atrial diastolic filling wave [A] velocities) were significantly affected by the type of anesthesia in the normal group but not left ventricular dimensions or ejection fraction. Left ventricular dimensions were affected by the type of anesthesia in the aortic regurgitation group and diastolic Doppler flow.

Conclusion: The anesthetic agent has significant specific impacts on many echocardiographic measurements. Investigators working with rat models should be aware of those potential effects.