Basic values of M-mode echocardiographic parameters of the left ventricle in outbreed Wistar rats

Abstract

This paper describes the partial results of an echocardiographic study in sixty outbreed Wistar rats. Animals of parity sex ratio were chosen for the experiment. The animals were grown up during the observation period (the minimum weight was 220 g; the maximum weight was 909 g) and were then sequentially anaesthetised (2-2.5% of isoflurane, 3 l/min O 2 ). The second, fourth and fifth examinations were performed under anaesthesia maintained by intramuscular injections with diazepam (2 mg/kg), xylazine (5 mg/kg) and ketamine (35 mg/kg). Transthoracal examination was done using the SonoSite Titan echo system (SonoSite Ltd.) with a microconvex transducer C11 (8-5 MHz). M-mode (according to the leading-edge method of American Society of Echocardiography) echocardiography data were acquired at the papillary muscle: systolic and diastolic interventricular septum (IVSs, d) and left vetricular posterior wall (LVPWs, d) thickness, systolic and diastolic left ventricular dimension (LVDs, d), aorta (Ao) and left atrium (LA) dimensions. According to standard formulas, the following parameters were obtained: ejection fraction (EF), cardiac output (CO), stroke volume (SV), left ventricle end systolic volume (LVESV), left ventricle end diastolic volume (LVEDV), interventricular septum fractional thickening (IVSFT), left ventricular dimension fraction shortening (LVDFS), and left ventricle posterior wall fraction thickening (LVPWFS). In our study we performed 300 examinations both in male and female Wistar rats of various body weights and calculated regression equations to predict expected normal echocardiographic parameters for rats with arbitrary weights. The rats were examined by an echo scan. The first and third examinations were performed during monoanaesthesia induced by inhalation of isoflurane. Correlations, with one exception (LVDs), were very close, which means that the results of the calculations based on regression equations are very reliable.

Comparison of diffusion tensor imaging by cardiovascular magnetic resonance and gadolinium enhanced 3D image intensity approaches to investigation of structural anisotropy in explanted rat hearts

“…In order to assess the cardiac contractile state of the fixed ex vivo hearts, dimensions were compared to cardiac dimensions predicted by indexing to body mass [ 37 ] in Table 3 . The interventricular septum wall thickness and left ventricle posterior wall thickness are approximately twice the predicted systolic wall thicknesses.…”

“… Data in this table allows comparison of the state of the fixed ex vivo hearts with in vivo contraction states (diastolic/systolic). The in vivo ventricular wall thicknesses are predicted from body-mass using the published equations (fitted to echocardiographic data) [ 37 ]. To assist comparison the predicted in vivo diastolic and systolic thicknesses are expressed as a percentage of the measured ex vivo FLASH thickness.…”

Effect of exercise training intensity on mitochondrial dynamics and mitophagy in post myocardial infarction rats

“…[15]. At the end of operation, to recover the rats they were placed on the heating pad until anesthesia, warm sterile saline (0. to calculate the LV ejection fraction (EF) and fractional shortening (FS) the following formulas were applied [18,19] [%EF = (LVEDD2 -LVESD2)/ (LVEDD2) ×100]…”

Echocardiographic Assessment of Cardiac Anatomy and Function in Adult Rats

“…The electrocardiographic monitorization integrated in the equipment is very prone to artifacts, which is a constraint. Also, it is very important to state that the functional or hemodynamic cardiac status of the rat can depend on variables such as temperature, blood pressure and heart rate 4,5,6,7,8,9,13,14,17 .…”

“…Characterization of left ventricular diastolic function by pulsed Doppler imaging at the mitral valve and tissue Doppler imaging at the mitral annulus should include the following parameters: E-wave velocity, A-wave velocity, E/A ratio, e' velocity, a' velocity, E/e' ratio and deceleration time of E-wave1,3,4,10,14 .…”