Title : Echocardiography in rodents: practical tips
Animals are an important tool for studying human diseases. Our research team has used rodents as
models of metabolic and oncological diseases, like diabetes and prostate, mammary, colon, liver, and
urinary bladder cancers. In our experiments, we have monitored the cardiac function by ultrasonography.
With this work, we intend to provide the readers with practical tips for the monitoring of cardiac function
in rats by ultrasonography.
The animals are anesthetized by an intraperitoneal injection of ketamine (37,5 mg/kg) and xylazine (5
mg/kg) and the left region of the thoracic wall is shaved using a machine clipper. For ultrasonographic
examination, the animals are placed in left lateral recumbency and ultrasound transmission gel is applied
in the left thoracic wall. We used the Logiq P6 apparatus and a high frequency linear probe (10-12 MHz).
Parasternal long-axis (LAX), parasternal short-axis (PAS), 4-chamber view and suprasternal views are
obtained, using B-mode, M-mode, Power Doppler, and Pulsed Doppler. The images are recorded in the
ultrasound apparatus, and then exported and analysed using Horos software. In the LAX images are
evaluated the following parameters: diastolic interventricular septal thickness (IVS d), diastolic left
ventricular lumen (LV d), diastolic left ventricular posterior wall thickness (LVPW d), systolic
interventricular septal thickness (IVS s), left ventricular lumen in systole (LV s), left ventricular posterior
wall thickness in systole (LVPW s) and aorta artery diameter (Ao d). Heart rate (HR) and pulmonary artery
dimeter (Pa d) are evaluated in LAX images. In the 4-chamber images can be evaluated the following
parameters: left atrial area (LA), right atrial area (AD), tricuspid annulus plane systolic excursion (TAPSE),
and E/A wave ratio. Additionally, left ventricular ejection time (LVET) is evaluated in the suprasternal view.