Objective To explore the intrinsic steady-state electrophysiological properties of mouse heart under physiological conditions by high-resolution quantitative analysis.Methods Twenty-two young adult C57BL/6 mice with a 1:1 male-to-female ratio were used.The limbs of the mice were fixed without anesthesia,and electrocardiographic waveforms,including characteristic P-waves,R-waves,and ST-waves,were recorded using a sensitive 12-lead electrophysiological recorder(ECGsqa)under spontaneous breathing.LabScribe software was used to extract and quantify high-resolution time course and amplitude parameters within a single cardiac cycle from the V3 precordial lead.Pearson correlation test combined with simple linear regression was used to generate a scatter plot of ECG parameter fitting.The common and unique correlation parameters were separately identified by joint associations for profiling the quantitative association network.Results ECGsqa analysis identified and quantified 14 characteristic ECG parameters,28.6%of which showed statistical differences between the groups.Compared to male mice,female mice exhibited higher amplitudes and velocities of R and ST waves.Among the 51 association pairs identified in primary association analysis,47.1%were positively correlated,including shared(29.2%),male-specific(29.2%),and female-specific(41.7%)association groups.Second-order clustering of the association pairs revealed that the amplitude-rate association pairs of each waveform voltage in both male and female mouse hearts were strongly correlated.The male mice showed an atrioventricular interconnection pattern,while the female mice showed a unique atrial conduction system quality dependence.The distribution network characteristics of the association groups showed that sex-specific and common correlation sets formed a certain series pattern.Conclusion We discovered a novel intrinsic correlation network of cardiac electrophysiological traits in male and female mice,which reveals the key internal quantitative characteristics and gender difference of both atrial and ventricular conduction systems.

Objective To explore the intrinsic steady-state electrophysiological properties of mouse heart under physiological conditions by high-resolution quantitative analysis.Methods Twenty-two young adult C57BL/6 mice with a 1:1 male-to-female ratio were used.The limbs of the mice were fixed without anesthesia,and electrocardiographic waveforms,including characteristic P-waves,R-waves,and ST-waves,were recorded using a sensitive 12-lead electrophysiological recorder(ECGsqa)under spontaneous breathing.LabScribe software was used to extract and quantify high-resolution time course and amplitude parameters within a single cardiac cycle from the V3 precordial lead.Pearson correlation test combined with simple linear regression was used to generate a scatter plot of ECG parameter fitting.The common and unique correlation parameters were separately identified by joint associations for profiling the quantitative association network.Results ECGsqa analysis identified and quantified 14 characteristic ECG parameters,28.6%of which showed statistical differences between the groups.Compared to male mice,female mice exhibited higher amplitudes and velocities of R and ST waves.Among the 51 association pairs identified in primary association analysis,47.1%were positively correlated,including shared(29.2%),male-specific(29.2%),and female-specific(41.7%)association groups.Second-order clustering of the association pairs revealed that the amplitude-rate association pairs of each waveform voltage in both male and female mouse hearts were strongly correlated.The male mice showed an atrioventricular interconnection pattern,while the female mice showed a unique atrial conduction system quality dependence.The distribution network characteristics of the association groups showed that sex-specific and common correlation sets formed a certain series pattern.Conclusion We discovered a novel intrinsic correlation network of cardiac electrophysiological traits in male and female mice,which reveals the key internal quantitative characteristics and gender difference of both atrial and ventricular conduction systems.

Objective: To understand the characteristics of adulthood weight change through the analysis on data from China Kadoorie Biobank (CKB) Study of 0.5 million adults from ten areas in China. Methods: An electronic questionnaire was used to collect the information about the body weight at age 25 years, social-demographic characteristics and lifestyle of the study subjects and their body weight were measured. After excluding the adults with self-reported histories of coronary heart disease, stroke, cancer or diabetes and those who had no data of body weight at age 25 years and those aged outside of 35-70 years, a total of 360 903 adults were included in the analysis. Adulthood weight change were defined as difference value between current body weight and body weight at age 25 years. Results: The mean adulthood weight change of the participants was 4.9 kg. The adults living in urban area showed more body weight increase compared with those living in rural area, so did the adults in northern area compared with those in southern area. Among the ten areas in China, Qingdao reported the highest adulthood weight increase (9.3 kg), and Gansu reported the lowest adulthood weight increase (1.5 kg). Older adults had higher BMI at early adulthood (25 years old), but the adults aged 45-50 years had the highest adulthood body weight increase. Adults with higher educational level, higher household income level, but lower physical activity level had more body weight increase, while current smokers, farmers and workers had less body weight increase. BMI at age 25 years was negatively associated with adulthood body weight change, but current BMI was positively associated with adulthood body weight change (P<0.001). Conclusion Adulthood body weight change varied greatly among population with different demographic characteristics and lifestyle and in ten areas in China.