Ventricular catheterization in the rat is a widely deployed procedure. Current options allow a one-time catheterization procedure, introducing an error due to the inter-individual variability. Six Fischer rats underwent left ventricular catheterization through the right carotid artery, repeated seven days later via the left carotid artery. We acquired volume and pressure data from each animal during both procedures. Volumes and pressures were plotted to construct pressure-volume loops at the two time-points. The neurological outcome and the gross anatomy of the heart were also evaluated. We did not observe any major behavioral or neurological alteration in any of the animals. We observed a Horner syndrome with palpebral ptosis and enophtalmus in one animal. At the macroscopic evaluation of the explanted hearts, we observed perforation of the left ventricle in one case. This is a safe, easy, and reproducible procedure; it can be performed twice in the same animal with no neurological consequences. It is particularly suitable for longitudinal studies, to minimize the statistical error due to inter-individual variability.