Researchers have released the first-ever mouse-specific reference ranges for electrocardiography (ECG) in a monumental advancement for the scientific community. This pioneering work is set to significantly enhance diagnostic decision-making in clinical medicine and our understanding of normality in pre-clinical scientific research involving in vivo models.

This breakthrough is backed by a robust dataset derived from over 26,000 laboratory mice, making it one of the most comprehensive ECG studies involving mice. These data were collected from C57BL/6N wildtype control mice, with the findings stratified by sex and age, adding to the robustness of the developed ECG reference ranges.

What makes this study genuinely groundbreaking are the intriguing findings revealed. The researchers reported minimal sexual dimorphism in heart rate and critical elements from the ECG waveform. This means no significant differences between male and female mice were observed in these parameters.

Furthermore, as expected, anesthesia was shown to induce a decrease in heart rate. This was observed for inhalation (isoflurane) and injectable (tribromoethanol) anesthesia. Such insights will be crucial for experiments where anesthesia is required, allowing researchers to account for these effects in their analysis.

In another important finding, researchers did not observe significant age-related ECG changes in C57BL/6N-inbred mice. The differences in the reference ranges of 12-week-old mice compared to 62-week-old mice were negligible, suggesting that age has a minimal impact on these ECG parameters in this mouse strain.

To test the generalizability of these reference ranges, they were compared with ECG data from a wide range of non-International Mouse Phenotyping Consortium (IMPC) studies. The close overlap in data from a wide variety of mouse strains suggests that these reference ranges have broad applicability and can serve as a robust and comprehensive indicator of normality.

This unique ECG reference resource offers a significant advantage for any experimental study of cardiac function in mice. The ability to compare observed data with robust, mouse-specific ECG reference ranges will significantly enhance the quality and reliability of future cardiac studies. It is a groundbreaking leap in mouse cardiac research with immense potential for future discoveries.

Read the full paper here to dive deeper into these exciting findings.