Echocardiography in Saanen-goats: Normal findings, reference intervals in awake goats, and the effect of general anesthesia

Abstract

Echocardiographic assessment of cardiac structures, dimensions, and mechanical function in goats is poorly documented. The goal of this study was to describe normal findings, establish normal values for two-dimensional (2DE) and M-mode (MME) echocardiography, and investigate the influence of general anaesthesia. Standardized 2DE and MME recordings were obtained on 22 healthy female Saanen goats (3.7 ± 1.1 years [mean ± SD], 60.2 ± 10.6 kg) awake (standing) and during isoflurane anesthesia (sternal recumbency). Cardiac dimensions and function were assessed and compared between treatments (awake vs. anaesthetized). Color Doppler imaging and saline contrast studies served to assess abnormal blood flow patterns. Post mortem examination was performed in a subset of 12 goats. Transthoracic echocardiography was feasible in all goats. Indices of LV systolic function proved to be significantly increased during general anesthesia. The membranous and occasionally echolucent appearance of the oval fossa suggested abnormal interatrial communication in 9 goats. Color Doppler imaging and saline contrast studies proved to be inaccurate to detect interatrial shunting of blood. Post mortem examination confirmed small persistent foramen ovale in only 3 out of 7 goats, in which it had been suspected on echocardiography.

The use of strain, strain rate, and displacement by 2D speckle tracking for assessment of systolic left ventricular function in goats: applicability and influence of general anesthesia

“…Longitudinal and circumferential strain measurements were generally higher in anesthetized compared to awake goats, consistent with an overall increase in systolic LV performance. These findings were in agreement with previously reported findings obtained from the same population of goats, indicating that M-mode-based and 2DE-based LV ejection phase indices and peak systolic LV wall thickness were significantly higher under general anesthesia [ 22 ].…”

“…However, overall LV systolic performance appeared to be increased (see above). This can be attributed to the sum of interacting effects of altered loading, contractility, and heart rate caused by anesthetic drugs, fluid therapy, and mechanical ventilation [ 22 ].…”

“…Transthoracic echocardiography was performed using a high-end digital echocardiograph (GE Vivid 7 Dimension, BTO6, GE Medical Systems, Glattbrugg, Switzerland) with a phased array transducer (M4S, GE Medical Systems, Glattbrugg, Switzerland) at a frequency of 1.9/4.0 MHz (octave harmonics) [ 22 ]. A single lead electrocardiogram (lead I) was recorded simultaneously.…”

Repeatability, variability and reference values of pulsed wave Doppler echocardiographic measurements in healthy Saanen goats

“…A colour-flow Doppler echocardiography performed each day before each PW-Doppler echocardioghraphic protocol did not reveal any abnormality. Particularly, any suspicion of interatrial communication or patent foramen ovale such as reported in 9 healthy Saanen goats [17] could be excluded.…”

“…Time-motion mode (M-mode), two-dimensional (2D) and colour-flow Doppler echocardiography has been demonstrated to be feasible in Philippine native goats [14] and in a pygmy goat [15]. More recently, M-mode and 2D-echocardiographic reference values have been established in awake healthy Saanen goats after repeatability and variability studies [16] and the effect of general anaesthesia in Saanen goats was studied using 2D- and colour Doppler echocardiography [17]. By contrast, no reference values of PW Doppler parameters were reported in goats.…”