Doppler velocity measurements from large and small arteries of mice

Abstract

Hartley CJ, Reddy AK, Madala S, Entman ML, Michael LH, Taffet GE. Doppler velocity measurements from large and small arteries of mice. Am J Physiol Heart Circ Physiol 301: H269 -H278, 2011. First published May 13, 2011; doi:10.1152/ajpheart.00320.2011With the growth of genetic engineering, mice have become increasingly common as models of human diseases, and this has stimulated the development of techniques to assess the murine cardiovascular system. Our group has developed nonimaging and dedicated Doppler techniques for measuring blood velocity in the large and small peripheral arteries of anesthetized mice. We translated technology originally designed for human vessels for use in smaller mouse vessels at higher heart rates by using higher ultrasonic frequencies, smaller transducers, and higher-speed signal processing. With these methods one can measure cardiac filling and ejection velocities, velocity pulse arrival times for determining pulse wave velocity, peripheral blood velocity and vessel wall motion waveforms, jet velocities for the calculation of the pressure drop across stenoses, and left main coronary velocity for the estimation of coronary flow reserve. These noninvasive methods are convenient and easy to apply, but care must be taken in interpreting measurements due to Doppler sample volume size and angle of incidence. Doppler methods have been used to characterize and evaluate numerous cardiovascular phenotypes in mice and have been particularly useful in evaluating the cardiac and vascular remodeling that occur following transverse aortic constriction. Although duplex ultrasonic echo-Doppler instruments are being applied to mice, dedicated Doppler systems are more suitable for some applications. The magnitudes and waveforms of blood velocities from both cardiac and peripheral sites are similar in mice and humans, such that much of what is learned using Doppler technology in mice may be translated back to humans. peripheral vascular flow; pulse wave velocity; coronary flow reserve; transverse aortic constriction; pressure overload hypertrophy THIS REVIEW ARTICLE is part of a collection on Assessing Cardiovascular Function in Mice: New Developments and Methods. Other articles appearing in this collection, as well as a full archive of all Review collections, can be found online at http://ajpheart.physiology.org/.The ability to alter the genotype of the mouse has produced numerous models for studying cardiovascular physiology and pathophysiology and has generated a need to evaluate the changes that occur in mice during phenotypic development and maturation (8). The genetic manipulations can alter the structure, anatomy, pathology, and physiology of cells, organs, or systems in ways that can be subtle and unpredictable and that often change with time (6, 33). The major problems in adapting existing methods for use in mice relate to the small size and high heart rates that place extreme demands on both spatial and temporal resolution (10). We will focus here on noninvasive ultrasonic Doppler methods, w...

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An RYR1 mutation associated with malignant hyperthermia is also associated with bleeding abnormalities

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