Evaluation of a new fiber-optic pressure recording system for cardiovascular measurements in mice

We have tested a new fiber-optic pressure recording system, Samba, with a thin fiber [outer diameter (OD) = 0.25 mm] and a pressure sensor (length and OD = 0.42 mm) attached to the end. The accuracy of the system tested in vitro was good, with a coefficient of variation of 2.54% at 100 mm.Hg. The drift was <0.45 mmHg/h, and the temperature sensitivity was -0.07 mmHg/1degreesC between 22 and 37degreesC. The frequency response characteristics were similar to a 1.4-Fr Millar catheter (0 - 200 Hz). Introduction of the Samba sensor from the right carotid artery into the left ventricle in six mice caused no drop in mean aortic pressure, whereas introduction of a 1.4-Fr Millar catheter (OD = 0.47 mm; n = 6) caused a pressure drop from 91.6 +/- 9.2 to 65.1 +/- 6.2 mmHg; P < 0.05. Thus the Samba sensor system may represent a new alternative to assess hemodynamic variables in the murine cardiovascular system.