Inductive plethysmography in rats: towards a new standard for longitudinal non-invasive cardiac output monitoring in preclinical studies

OBJECTIVE: Cardiovascular function assessment is most often a mandatory requirement in preclinical studies in all industrialized countries. The invasiveness and impact of the monitoring devices used on animals have to be reduced as far as possible for scientific as well as ethical reasons. In humans, inductive plethysmography (IP) is a commonly used wearable non-invasive technology based on volume recordings. The innovative target of the present work is to transfer the IP technology to cardiac output (CO) measurement in rodents. APPROACH: A new IP device specifically designed for rodents was developed and compared with the gold standard equipment for CO assessment in rodents. CO was monitored in anesthetized rats equipped with both the IP device and an ultrasonic flow probe during a hemodynamic challenge (volume overload). MAIN RESULTS: Cardiac blood flow measurements with the new IP device are significantly correlated with those obtained with the ultrasonic probe throughout the volume overload procedure (r = 0.97, p < 0.001). SIGNIFICANCE: Our results clearly show that the IP device has adequate technological characteristics to allow accurate CO measurement and can therefore be used for longitudinal non-invasive monitoring in rats.