eComment: Left ventricular catheterization for pressure-volume loop measurements in small laboratory animals

procedure of choice to make statistical analysis more accurate and less influenced by inter-individual variability, and allowing a dramatic reduction in number of animals deployed. w2x Zimmer HG. Measurement of left ventricular hemodynamic parameters in closed-chest rats under control and various pathophysiologic conditions. Experimental rat model representing both acute and chronic heart failure related to auto-immune myocarditis. Increases in coronary collateral blood flow produced by sevoflurane are mediated by calcium-activated potassium (BKCa) channels in vivo. We read with great interest the manuscript by Migneco et al. in which the authors present their method for multiple left ventricular cannulation in small laboratory animals w1x. Their proposal is attractive for ethical and limited use of small laboratory animals. Although authors have not been faced with clinical neurological sequelae (data have not been supported by the histopathologic examination of cerebral tissues at the end of first and second stage investigations in the manuscript w1x), besides the issues of unilateral acute occlusion of one-sided common carotid artery, we believe the technique has certain points to be discussed more in details. The authors used a 19F pressure-volume (P-V) catheter in their experiments in male Fischer rats. At our institution, ventricular P-V loop measurements have been instituted in different sets of experiments with the use of 0.8 or 1.1F catheters (Millar Instruments, ultra-miniature P-V catheters) in adult Lewis rats weighing ;300 g in similar settings w2x. The catheterization of the left ventricle by insertion of a catheter through the right carotid artery mainly has two reasons: first of all the right common carotid artery is slightly larger than the left one which facilitates the catheterization. The second reason is due to the angle between the ascending aorta and brachiocephalic trunk which eases the direction of the catheter into the left ventricle. The angulation is more prominent for the left common carotid artery at its origin from the aortic arch which usually requires multiple manipulations of the catheter in order to be directed into the left ventricle. Such manipulations may lead to blood loss that can further complicate the measurements and the results of the experiments. Additionally the advancement of the catheter from the left carotid artery is even harder when larger sized and/or stiff catheters are used. In conclusion, once again, we would like to congratulate the authors for their successful measurements on left ventricular catheterization with consecutive cannulation of both carotid arteries. References w1x Migneco …