cardiac telemetry device data (dsi) st. paul  (Data Sciences International)

Journal: bioRxiv

Article Title: Ryanodine receptor inhibition improves cardiac repolarization reserve and contractile function and prevents sudden arrhythmic death in failing hearts

doi: 10.1101/2023.01.29.526151

Figure Lengend Snippet: ( A ) Schematic of experimental design. ( B ) Representative ECG tracings from 24-hour telemetry recordings. Spontaneous incidences of PVCs, VT and VF were suppressed in HF animals with chronic dantrolene treatment. ( C ) Dantrolene therapy lowered PVC burden (p<0.001) in HF animals (blue). ( D ) Kaplan Meier survival plot shows that over 50% of the animals in the vehicle group (HF, N=68, red) group experienced SCD. Chronic dantrolene treatment (HF + DS, N=10, blue) prevented VT and VF in heart failure models and mitigated SCD in 80% of the heart failure animals (p<0.05). A p<0.05 was considered significant; two-tailed log-rank analysis was performed on each group for each measure .

Article Snippet: An ECG transmitter (Data Sciences International ETA-F10 Biopotential Telemetry device) with leads in lead II arrangement and an iPRECIO programmable pump (Primetech Corp., Tokyo, Japan) were implanted in the abdominal cavity.

Techniques: Two Tailed Test

Journal: bioRxiv

Article Title: Ryanodine receptor inhibition improves cardiac repolarization reserve and contractile function and prevents sudden arrhythmic death in failing hearts

doi: 10.1101/2023.01.29.526151

Figure Lengend Snippet: ( A ) Plot shows heart rate derived from 24-hour continuous ECG recordings. The animals were subjected to mild transient β-AR stress for 1 hour. Continuous ECG analysis was performed at the following time points: resting heart rate (pre-stress); transient stress and, post stress recovery (4 hours post stress) ( B ) The box plots summarize HR during the resting and recovery phases. The dantrolene treated group (HF+DS) demonstrate a lower heart rate (HR) both at rest and post-stress recovery. The Δ Heart Rate (bpm) indicates the net increase in HR from resting HR to peak HR in response to transient β-AR stress. Failing hearts displayed higher resting HR and blunted chronotropic response to stress (P<0.02, N≥7 for all models). ( C ) Histogram shows resting HR distribution for all groups. Resting heart rate in decreased in HF+DS animals. However, the peak heart rates (during stress) are higher in HF+DS compared to HF (N; Ctrl=8, HF=10; HF+DS=7). ( D ) Dantrolene increases heart rate variability (HRV) both at rest and during stress (p<0.05, N≥7 for all models). A p<0.05 was considered significant; two-tailed log-rank analysis was performed on each group for each measure .

Article Snippet: An ECG transmitter (Data Sciences International ETA-F10 Biopotential Telemetry device) with leads in lead II arrangement and an iPRECIO programmable pump (Primetech Corp., Tokyo, Japan) were implanted in the abdominal cavity.

Techniques: Derivative Assay, Two Tailed Test

Journal: bioRxiv

Article Title: Ryanodine receptor inhibition improves cardiac repolarization reserve and contractile function and prevents sudden arrhythmic death in failing hearts

doi: 10.1101/2023.01.29.526151

Figure Lengend Snippet: ( A ) Schematic illustrates a randomized 2×2 cross-over experimental design to examine the impact of dantrolene therapy. The protocols were as follows (i) only vehicle administered till the endpoint i.e., week 4 (HF), (ii) dantrolene administered from the onset of HF till until chronic contractile dysfunction is evident in the untreated control HF group (usually 3 weeks post banding; HF+/-DS), or (iii) dantrolene administered after HF had already developed in the HF group (3 weeks post banding; HF-/+DS group). Echocardiography and ECG recordings were taken at week 2/3/4/5. ( B ) Kaplan Meier survival curve showed that 50% of the HF animals experience SCD. Treatment with dantrolene after HF development (around week 3) prevented additional SCDs and improved survival after starting dantrolene therapy in the HFDS-/+ group (purple). Discontinuation of Dantrolene however did not increaser mortality in HF+/-DS group(yellow). ( C ) Serial echocardiography plot shows that Dantrolene reversed heart failure in HF-/+DS (purple) animals. The FS% in this group initially declined at a pace similar to HF (red) animals, but it quickly normalized as soon as Dantrolene therapy was started. However, in the HF+/-DS (yellow) group when the therapy was stopped, the FS% started showing gradual decline, most likely due to washout effect without additional SCD. ( D ) Dantrolene treatment pre or post HF development alters RyR2 oxidation of HF animals (p<0.05). Treatment with dantrolene reduced RyR2 oxidation even when therapy was initiated or discontinued after HF development. ( E ) Close examination of the HF-/+DS (purple) group, pre and post dantrolene therapy shows an increase in PVC load with progression of HF. (G) The box plots summarize QTc pre-HF (light purple), during chronic HF (medium purple) and after dantrolene therapy was initiated (dark purple). The HF-/+DS group displays all symptoms of HF including prolonged QTc after development of HF (around week 3, medium purple box). After start of therapy (dark purple box), QTc shortened at rest and recovery. A p<0.05 was considered significant; two-tailed log-rank analysis was performed on each group for each measure .

Article Snippet: An ECG transmitter (Data Sciences International ETA-F10 Biopotential Telemetry device) with leads in lead II arrangement and an iPRECIO programmable pump (Primetech Corp., Tokyo, Japan) were implanted in the abdominal cavity.

Techniques: Two Tailed Test

Journal: bioRxiv

Article Title: Molecular and cellular mechanisms by which cardiac sympathetic denervation prevents heart failure and sudden cardiac arrest

doi: 10.1101/2023.01.29.526082

Figure Lengend Snippet: The star indicates p<0.01 vs. HF+ShamCSD. (A) In vivo picture of guinea pig stellate ganglia (SG) and sympathetic chain running along the right chest wall and anatomical landmarks-rib 1 (R1), rib 2 (R2) and Superior Vena Cava (SVC). The guinea pig SG is located between the first rib and the spine. The SG was accessed from the ventral side via the second intercostal space and is visible as a white fiber running parallel to the spine. (B) Representative example of heart rate changes during right [SG(R)] followed by left [SG(L)] stellate ganglionectomy. The box plots summarize the corresponding change in steady-state heart rates. (C) Representative immunohistochemistry imaging of excised SG tissue for tyrosine hydroxylase and neurofilament ( red/green ) with DAPI stained nuclei, confirming the presence of sympathetic neurons (scale bar 10 μm ). (D) Representative images of gross hearts (top) and corresponding cross-sections (bottom) at 4 weeks. (E) Representative M-mode echocardiography. (F) Echocardiographic features at 4 weeks (N≥15 per group). Sytolic and diastolic LV internal dimension (LVID) were significantly lower for HF+CSD and HF+mROS-scavenging compared to HF+shamCSD, but the ventricular septal (IVS) and LV posterior wall thickness (LVPW) were not significantly different between groups. Although the relative wall thickness (RWT), end diastolic (EDV) and systolic (ESV) volumes, fractional shortening (FS) and ejection fraction (EF) were significantly lower in both HF+shamCSD and HF+CSD animals, these features were only slightly lower in HF+CSD hearts compared to normal+shamCSD animals, suggesting CSD and mROS scavenging improve these aspects. (G) Representative segments from ECG adjudication. Premature ventricular contractions (PVCs), VT and VF were frequently noted in HF+sham, leading to SCA in >70% of the animals (N=68) ( H ). CSD (N=25) and mROS scavenging (N=15) mitigated the incidence of PVCs, VT and SCA (p<0.01; two-tailed log-rank test).

Article Snippet: An ECG transmitter (Data Sciences International ETA-F20 Biopotential Telemetry device) was implanted in the animal’s abdominal cavity, and the leads were secured in a lead II arrangement.

Techniques: In Vivo, Immunohistochemistry, Imaging, Staining, Two Tailed Test

Journal: bioRxiv

Article Title: Molecular and cellular mechanisms by which cardiac sympathetic denervation prevents heart failure and sudden cardiac arrest

doi: 10.1101/2023.01.29.526082

Figure Lengend Snippet: The star indicates p<0.01 vs. HF+ShamCSD. Continuous ECG analysis was performed before (rest), during mild transient β-adrenergic stress with low dose isoproterenol infusion with an automated implanted pump, and 4 hours after stress (recovery). (A) Representative heart rate tracings show HF+shamCSD (red) animals had increased heart rate at rest and recovery but reduced heart rate during stress compared to normal+shamCSD (gray), HF+CSD (blue) and HF+mROS-scavenging (green) animals. (B-D) The corresponding histograms show that CSD and mROS scavenging lowered the resting heart rate and preserved chronotropic responses (N≥7 animals/group). The box plots summarize the corresponding results for heart rate during rest ( E ) and recovery ( F ), chronotropic response during stress ( G ), heart rate variability, as indexed by SDNN during rest ( H ) and ( I ) recovery, the ratio of the low (LF) and high (HF) frequency bands of the heart rate power spectral density corresponding primarily to sympathetic and parasympathetic tone, respectively, during rest ( J ) and recovery ( K ), and the total power for all frequency bands at rest ( L ) and recovery ( M ) (N>8 per group).

Article Snippet: An ECG transmitter (Data Sciences International ETA-F20 Biopotential Telemetry device) was implanted in the animal’s abdominal cavity, and the leads were secured in a lead II arrangement.

Techniques: