surface electrodes  (ADInstruments)

Journal: iScience

Article Title: Aged gut microbiota promotes arrhythmia susceptibility via oxidative stress

doi: 10.1016/j.isci.2024.110888

Figure Lengend Snippet: Transplantation of gut microbiota from aged mice increases susceptibility to arrhythmia (A) Sample ECG traces of four different types of arrhythmic events: ventricular premature beats (VPB), ventricular tachycardia (VT), atrial fibrillation (AF), and atrioventricular block (AVB). (B) Summary the inducibility of VPB, VT, AF, and AVB in young and aged mice. Numbers in parentheses indicate the number of mice that were induced into VPB, VT, AF, AVB following ISO treated ( n = 6/per group). Data analyzed by Fischer’s exact test. (C) Differences in heart rates, PR intervals, QRS intervals, R amplitude, P duration and P amplitude among young-young FMT, young-aged FMT, aged-aged FMT and aged-young FMT mice ( n = 6/per group). Data are presented as the mean ± SD. Data analyzed by one-way ANOVA with Tukey’s post-hoc test. ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001. (D) Representative western blot and quantification of Cx43, Cx40, Nav1.5, Cav1.2, Serca-2A, Kv4.2, IL-6, IL-10, IL-1β, TNF-α, TGF-β, α-SMA, GAPDH in ventricular and atrial tissue of young-young FMT, young-aged FMT, aged-aged FMT and aged-young FMT mice ( n = 6/per group). GAPDH was used for internal normalization. Data are presented as the mean ± SD. Data analyzed by one-way ANOVA with Tukey’s post-hoc test. ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001. (E) Representative micrographs of Cx43 signal in ventricular and Cx40 in stained atrial sections visualized ( n = 6/per group). Cx43 indicates Connexin 43; Cx40, Connexin 40; ISO, isoproterenol; IL-6, Interleukin-6; TNF-α, tumor necrosis factor-α; TGF-β, transforming growth factor β.

Article Snippet: Surface electrocardiogram (ECG) was monitored by P3 plus (Data Sciences International), 1.5% isoflurane-oxygen mixture was anesthetized, and subcutaneous platinum electrode was placed on lead II.

Techniques: Transplantation Assay, Blocking Assay, Western Blot, Staining

Journal: iScience

Article Title: Aged gut microbiota promotes arrhythmia susceptibility via oxidative stress

doi: 10.1016/j.isci.2024.110888

Figure Lengend Snippet: Vitexin improved aged related arrhythmia through OLA1-Nrf2 signaling pathway (A) Experimental design for testing the anti-aging effect of vitexin on aged mice induced by 150 mg kg D-gal. (B) Sample ECG traces of three different types of arrhythmic events: ventricular premature beats (VPB), atrial fibrillation (AF), and atrioventricular block (AVB). (C) Summary of inducibility of VPB, AF, and AVB in vehicle, and vitexin treated aged mice. Numbers in parentheses indicate the number of mice that were induced into VPB, AF, AVB following ISO treated ( n = 6/per group). Data analyzed by Fischer’s exact test. And differences in heart rates, P-R intervals, QRS intervals, and R amplitude among different group ( n = 6/per group). Data are presented as the mean ± SD. Data analyzed by one-way ANOVA with Tukey’s post-hoc test. ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001. (D) The examples of HE, Sirius red staining in the ventricle and atria from different group of mice ( n = 6/per group). Scale bar, 100 μm. Viteixn attenuated fibrosis in aged mice measured by Sirius red staining. Data are presented as the mean ± SD. Data analyzed by one-way ANOVA with Tukey’s post-hoc test. ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001. (E and I) Cardiac, serum, colon MDA, SOD and GSH-px levels were quantified using commercial assay kits. ( n = 6/per group). Data are presented as the mean ± SD. Data analyzed by one-way ANOVA with Tukey’s post-hoc test. ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001. (F) Representative western blot and quantification of Cx43, Nav1.5, Cav1.2, Serca-2A, Kv4.2, α-SMA, OLA1, Nrf2, GAPDH in ventricle and atria in the four groups ( n = 6/per group). GAPDH was used for internal normalization. Data are presented as the mean ± SD. Data analyzed by one-way ANOVA with Tukey’s post-hoc test. ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001. (G) Experimental design for testing the anti-aging effect of Nrf2 activator and inhibitor on aged mice induced by 150 mg kg D-gal. Summary of inducibility of VPB, AF, and AVB in vitexin, DMF, ML385 treated aged mice. Numbers in parentheses indicate the number of mice that were induced into VPB, AF, AVB following ISO treated ( n = 6/per group). Data analyzed by Fischer’s exact test. (H) The examples of HE, Sirius red staining in the ventricle from different group of mice ( n = 6/per group). Scale bar, 100 μm. Viteixn and DMF attenuated fibrosis in aged mice measured by Sirius red staining. Data analyzed by one-way ANOVA with Tukey’s post-hoc test. Serum levels were quantified using commercial assay kits. ( n = 6/per group). Data are presented as the mean ± SD. Data analyzed by one-way ANOVA with Tukey’s post-hoc test. ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001. (J) Representative western blot and quantification of Cx43, Nav1.5, Cav1.2, Serca-2A, Kv4.2, α-SMA, OLA1, Nrf2, and GAPDH in ventricle in the four groups ( n = 6/per group). GAPDH was used for internal normalization. Data are presented as the mean ± SD. Data analyzed by one-way ANOVA with Tukey’s post-hoc test. ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001.

Article Snippet: Surface electrocardiogram (ECG) was monitored by P3 plus (Data Sciences International), 1.5% isoflurane-oxygen mixture was anesthetized, and subcutaneous platinum electrode was placed on lead II.

Techniques: Blocking Assay, Staining, Western Blot

Journal: Scientific Reports

Article Title: Open-source software for respiratory rate estimation using single-lead electrocardiograms

doi: 10.1038/s41598-023-50470-0

Figure Lengend Snippet: Respiratory rate (RR) estimation in spontaneously breathing humans. ( A ) RR estimates, in breaths per minute (bpm), during 3 levels of exercise in one subject. Algorithm-estimated RRs (estimated, blue) are compared with RR measured from the subject using the respiratory inductive plethysmography based Hexoskin monitor (expected, red) while performing three consecutive tasks: (1) resting, standing upright on a treadmill (Int 1); (2) walking on the treadmill at a moderate speed (1.2 m/s) (int 2); and (3) walking on the treadmill with 15% track inclination at the moderate speed (Int 3). ( B ) Summary results of algorithm-estimated and reference RRs (blue and red, respectively) during each subject-task interval. The data are from seven subjects, each performing either or all the three levels of exercise described above (subject-tasks), and presented in order of increasing average expected RR values. ( C ) The absolute errors (black) and relative errors (gray) of the algorithmic RR estimations across the subject-task intervals described above. Equivalence testing revealed that the expected and estimated RRs were the same ( p < 0.0001) for all subject-task intervals. ( D ) A comparison of the ECG cycle-to-cycle estimated and expected RR for all subjects and tasks with the indicated R 2 value (0.9092) and low root mean square error (RMSE, 2.2bpm) support a close linear relationship between the values. ( E ) Absolute error (bpm) and ( F ) relative error (%) distributions across all subjects.

Article Snippet: Single-lead body surface ECG signals were obtained during the procedure and 90 min after coil placement using the AD Instruments PowerLab 4/35 system with Labchart 8 software.

Techniques: Comparison

Journal: Scientific Reports

Article Title: Open-source software for respiratory rate estimation using single-lead electrocardiograms

doi: 10.1038/s41598-023-50470-0

Figure Lengend Snippet: Block diagram of respiration rate estimation algorithm. Raw single-lead ECG data are filtered (panels a and b ), R-peaks are detected (red symbols, panel c ), R-peak intervals are determined, QRS complexes are extracted (panel d ) and their root mean square amplitude (RMS) values are calculated (panel e ), a power spectrum is generated for a moving window of 16 QRS RMS values incremented one value at a time (panel f ), and its peak frequency and the R-peak interval data within the window are used to calculate the respiratory rate (RR) using the equation shown.

Article Snippet: Single-lead body surface ECG signals were obtained during the procedure and 90 min after coil placement using the AD Instruments PowerLab 4/35 system with Labchart 8 software.

Techniques: Blocking Assay, Generated

Journal: Circulation

Article Title: Autoimmune Atrial Fibrillation

doi: 10.1161/CIRCULATIONAHA.122.062776

Figure Lengend Snippet: Electrophysiological phenotyping of mice with K ir 3.4 autoantibodies. A , Study design of the experimental autoimmune AF model with Balb/c mice. B , Representative surface ECG traces derived from limb leads I and II, recorded from a sham-immunized and K ir 3.4-immunized mouse. C , Bar graphs overlaid with dot plots present mean ECG interval values±SD recorded in sham- (n=14) and K ir 3.4-immunized mice (n=10). Statistical significance was determined using the Student t test (PR, QRS, QTc, and JTc) and Mann-Whitney U test (RR). D , Representative bipolar intracardiac electrogram recordings at the level of the right ventricle (RV) and right atrium (RA). STIM denotes right atrial stimulation. ECG in lead II configuration shows the corresponding surface ECG signals. E , Bar graphs overlaid with dot plots present mean intracardiac electrophysiological data±SD acquired in sham- (n=14) and K ir 3.4-immunized mice (n=10). Statistical significance was determined using the Student t test (SNRT, cSNRT, AERP, and AVERP) and Mann-Whitney U test (WCL). F , Bar graph shows the proportion of sham- (4 of 14) and K ir 3.4-immunized mice (8 of 10) with burst pacing–induced AF. Points indicate mean AF duration±SD ( P =0.214). Statistical significance was determined by Mann-Whitney U test (AF duration), and Fisher exact test was used to assess the induced AF rate. AERP indicates atrial effective refractory period; AF, atrial fibrillation; AVERP, atrioventricular effective refractory period; cSNRT, corrected sinus node recovery time; EGM, electrogram; EPS, electrophysiological study; SNRT, sinus node recovery time; and WCL, Wenckebach cycle length.

Article Snippet: The body temperature was kept at 37 °C with a heating pad, and all mice were continuously monitored with surface 3-lead ECG connected to the data acquisition system PowerLab (16/35, ADInstruments Ltd, United Kingdom).

Techniques: Derivative Assay, MANN-WHITNEY