Anesthetic inhibition in ischemic and nonischemic murine heart: comparison with conscious echocardiographic approach

Abstract

It is well known that the level of anesthesia obtained by intraperitoneal injection is variable and may alter cardiac function. In this study, we compared the effects of different anesthetics on cardiac function with the conscious state using high-resolution two-dimensional echocardiography in nonischemic and ischemic mice. Eighty-four mice were tested before and after surgery with ligation of the coronary artery. All 84 mice were studied in the conscious state and under high-dose intraperitoneal anesthesia. Twenty-two of 84 mice were studied under low-dose intraperitoneal anesthesia. Another 22 mice were also studied under gas anesthesia and spontaneous breathing. Experiments in the conscious state were performed by two investigators before the administration of anesthesia: one investigator held the animal and the transducer and the other operated the ultrasound equipment. Left ventricular systolic function was measured, and measurements obtained after surgery were compared with infarcted areas assessed by histological staining. Results showed that both high- and low-dose intraperitoneal anesthesia significantly reduced heart rates and left ventricular contractility in both pre- and postsurgical mice as opposed to conscious mice (P < 0.01). There were significantly higher correlation coefficients between mean fractional area change (FAC) and infarcted area in conscious state compared with high-dose intraperitoneal anesthesia (P < 0.05). The correlation coefficient between FAC and infarcted area during gas anesthesia was also significantly higher compared with high-dose intraperitoneal anesthesia (P < 0.05). In conclusion, conscious experiments or the use of gas anesthesia is preferred for echocardiographic assessment of cardiac function in mice because intraperitoneal injection significantly induces a significant reduction in heart rate and left ventricular systolic function.

Lymphocytes Are Not Required for the Rapid Onset of Coronary Heart Disease in Scavenger Receptor Class B Type I/Apolipoprotein E Double Knockout Mice

“…38 -40 However, some studies of mice undergoing conscious echocardiography demonstrate perturbations in heart rate, including bradycardia before training and tachycardia after training. 38,39 The mean heart rate for our control mice anesthetized with a low dose of pentobarbital (522Ϯ24 bpm) was similar to that measured for conscious mice during echocardiography as reported by Takuma et al 40 and unrestrained mice undergoing telemetry, 39 suggesting the low dose of anesthetic used did not depress heart rate in the control mice. However, electrocardiography of dKOs has shown these mice to be hypersensitive to certain anesthetic agents.…”

“…Numerous studies suggest that anesthesia administered before echocardiography can depress heart rate 38 -40 that can, in turn, influence echocardiographically determined parameters of cardiac function, including contractility and FS. 39,40 Moreover, these effects vary with type and dosage of anesthetic and mouse strain studied. 38 -40 However, some studies of mice undergoing conscious echocardiography demonstrate perturbations in heart rate, including bradycardia before training and tachycardia after training.…”

Quantitative 3-Dimensional Echocardiography for Accurate and Rapid Cardiac Phenotype Characterization in Mice

“…A very light anesthetic protocol was used (1.25% to 1.5% isoflurane), which as shown previously, has virtually no cardiodepressant effects in both normal and infarcted mice. 20 Although the MRI technique provided a higher spatial inplane resolution than echocardiography, slice positioning at 1-mm thickness had to be carefully adjusted to avoid cutoff at the cardiac apex. Using a smaller slice thickness would either decrease the signal-to-noise ratio or prolong the scan time substantially to obtain the same signal-to-noise ratio.…”

A New Method of Inhalation Anesthesia with Nasopharyngeal Insufflation in Rat Experiment.

“…However, it is difficult to achieve precise control of anesthetic depth. Error of targeted site [3], a significant reduction in heart rate and left ventricular systolic function [8] and a significant increase in albumin leakage in the abdominal region [7] have all been reported. Inhalation anesthesia with orotracheal intubation or a proper respirator mask has also been reported [1,2].…”

“…This daily intraperitoneal anesthesia with injection might induce various errors i.e., missing the targeted site [3], significant reduction in heart rate and left ventricular systolic function [8] and significant increase in albumin leakage in the abdominal region [7]. Furthermore, the accumulative damage of the daily anesthesia on the rats for 14 days could increase mortality.…”