Left ventricular pressure-volume measurements in mice: comparison of closed-chest versus open-chest approach

We investigated whether in vivo closed-chest left ventricular pressure-volume measurements would yield similar values for LV hemodynamics compared with open-chest PV measurements under several anesthetics.

The right common carotid of C57Bl/6 mice was cannulated with a combined pressure-conductance catheter and inserted retrogradely into the left ventricle in the closed-chest model. The open-chest model consisted of an abdominal approach involving the opening of the thoracic cavity by transverse opening of the diaphragm and ventricular catheterization by apical stab. Measurements were performed under urethane or pentobarbital intraperitoneal injection anesthesia.

Cardiac function in the open-chest model was characterized by larger ejection fraction and stroke volume with a leftward shift in ventricular volume compared to the closed-chest model. Further observed characteristics include low end-systolic pressure and arterial-ventricular coupling mismatch in the open-chest model. Arrhythmias were not detected in either model.

Murine cardiac function determination via open-chest or closed-chest protocols is sensitive, reproducible and comparable. The choice for open- or closed-chest pressure-volume measurements in mice depends on the aims of the study.