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Don’t Miss a Beat: Arrhythmia Detection for Preclinical ECG Research
Henry Holzgrefe
Safety Pharmacology Consultant,
Charles River Laboratories,
Preclinical Research, Nevada
Belal A. Mohamed, MD
Clinic of Cardiology and Pneumology,Georg-August-University, Goettingen, Germany
InsideScientific is an online educational environment designed for life science researchers. Our goal is to aid in the sharing and
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Arrhythmias Score Correlates with the Stage of Myocardial Remodeling: a murine study using Data Insights
Belal A. Mohamed, MD
Clinic of Cardiology and Pneumology,Georg-August-University,
Goettingen, Germany
Copyright 2016 Belal Awd, Data Sciences Int’l & InsideScientific. All Rights Reserved.
TransaorticConstriction-induced Cardiac Remodeling
Takimoto E. et al., Nat med, 2005
• A suture is placed around the transverse aorta
• In acute stage: compensatory hypertrophy (CH)
• In chronic stage: heart failure (HF)
Chamber Dilation and Deteriorated Pump Function
• Increased left ventricle end-diastolic dimension (LVEDD)
• Decreased ejection fraction (EF)
TAC
2 wk (CH)
Serial Echo every week
9 wk (HF)
MorphometricMeasurement
• Increased Heart weight/Tibia length
• Increased Lung weight/ Tibia length (lung congestion)
Histological and Molecular Analyses
• Increased CSA of cardiomyocytes
• Increased Nppb expression (remodeling marker)
• Kaplan Maier Curves
Enhanced Mortality post-TAC
Gorski PA and Przemek A, Cell Metabolism, 2015
Excitation-Contraction Coupling
• Systole, AP opens the LTCC
• Ca2+ entrance• CICR • Ca2+ binds to TN-C• Muscle contraction• Diastole, Ca2+ removal• Decrease cytosolic Ca2+
• Dissociation of Ca2+
from TN-C• Muscle relaxation
Leak-Induced Arrhythmias
• Ca2+ leak is pumped out via the NCX, which brings Na+ into the cell
• This creates a depolarizing inward current
• Generation of DADs, triggered activity and arrhythmia induction
Wagner S. et al. Circ Res. 2015
Increased SR Ca2+ Spark Post-TAC
• Confocal scanning microscopy
Increased SR Ca2+
Spark Post-TAC
• Increased spark frequency and overlallspark-mediated Ca2+ leak
• Total SR Ca2+ leak includes Ca2+ spark- and non spark- dependent mechanisms
• Measurement of total SR Ca2+ leak according to shannon TR. et al., CircRes 2002
Increased Total SR Ca2+ Leak post-TAC
Implanted Ambulatory Telemetry in Lead II Configuration
• Anesthetizing the mouse
• Positive lead in the left abdomen
• Negative lead in the right chest
McCauley MD & Wehrens XHT, J Vis Exp, 2010
Detected Forms of Arrhythmias
Representative ventricular tachyarrhythmiaspost-TAC …
Ambulatory Telemetry Data
Telemetry
implantationTAC
1 wk 2 wk 7 wk
Arrhythmias
detection
Arrhythmias
detection
Ambulatory Telemetry Data
Programmed Electrical Stimulation
• Langendorff-perfused hearts
• Increased ventricular arrhythmias inducibility after TAC
Summary
• The elevated SR Ca2+ leak in myocardial remodeling increases arrhythmias vulnerability
• SR Ca2+ leak-induced arrhythmias, beside pump failure, are responsible for increased mortality after TAC
• Arrhythmia severity correlates well with the severity of myocardial remodeling in mice…
Moderate remodeling (CH) mostly single PVCsSevere Remodeling (HF) mostly VTs
Translational Outlook
• Inhibition of the SR Ca2+ leak could improve survival in patient with HF by reducing lethal arrhythmias
Assessment of the Proarrhythmic Effects of Ouabain: experience with Data Insights™
Henry Holzgrefe
Safety Pharmacology Consultant,
Charles River Laboratories,
Preclinical Research, Nevada
Copyright 2016 H. Holzgrefe, Charles River Laboratories, Data Sciences Int’l & InsideScientific. All Rights Reserved.
DATA INSIGHTS – Prior Validation
Data From 41 Hand-Scored Snippets
• Parallel analysis
• Cardiologist over read
• Data Insights
• PACs (8 vs. 11) only discrepancy
• 3 species
• Dog
• Cynomolgus
• Minipig
Arrhythmia Cardiologist Data Insights
Ventricular Ectopics 83 83
Junctional Complexes 38 38
AV Block 2nd degree 12 12
Sinus Pause 11 11
Premature Atrial Contraction 11 8
Ventricular Bigeminy 8 8
Ventricular Couplets 6 6
Interpolated Beats 4 4
Ventricular Triplets 1 1
Predefined Searches
an_ (analysis)
ar_ (arrhythmia)
dv_ (data validation)
Current Arrhythmias
Predefined Searches
– AV Blocks
– Junctional Beats
– Premature Atrial Contractions
– Ventricular Escape Beats
– Ventricular Ectopics ie. Couplets, Triplets, Runs, Bigeminy, Trigeminy
Existing searches may be modified or
new searches created
Introduction
• Proarrhythmic liability is a major cardiovascular risk
• CiPA will concentrate on in vitro and in silico analysis
• Continuous proarrhythmic analysis of large in vivo datasets will require automated technology
• Data Insights is currently validated with small data snippets
• Characterize in large datasets with time and dose-dependent proarrhythmic effects using known reference agent
Introduction
Experimental Design
• 5 telemetered beagle dogs: 8-15 kg; 7-15 months
– Isoflurane anesthesia
• Ouabain administration
– 20 µg/kg iv bolus + 1 µg/kg/min continuous infusion– 1 subject received 2x nominal dose
– Terminate at arrhythmia onset• Ectopy (~ 100%) primarily due to DADs related to abnormal Ca2+ homeostasis
• Hamlin, R.L. Pharmacology and Therapeutics, 113 (2007) 276-295
• TK samples through 3 hours postdose
• Present the most complex subject as exemplar
– Subject 1504
Experimental Design
• Telemetered data digitized at 500 Hz
• Primary ECG and BP analysis with Ponemah ver. 5.2, SP7
• Arrhythmia analysis with Data Insights
• Verify fiduciary ECG marks with Ponemah Pattern Recognition
• Employ prespecified searches to capture atrial and ventricular effects– Categorize PAC, 2°AVB, Junctional, and Ectopic beats
• PK/PD correlations
Methods
STUDY RESULTS
Ouabain PK (n=5)
y = 0.4985x + 6.7265R² = 0.6191
0
10
20
30
40
50
60
70
80
0 20 40 60 80 100 120 140
ng
/ml
Infused µg/kg
Ouabain Pharmacokinetics (n=5)
• Samples at 0, 15, 30, 60, 90, 120,150 and 180 min
• Where feasible
• Time and dose-dependent exposure in all subjects
• Between subject variability
• Exposures only possible in anesthetized dog via iv administration
• Intractable emesis
Ouabain – Hemodynamic Effects
0
10
20
30
40
50
60
70
80
90
100
0
20
40
60
80
100
120
140
160
0 1 2 3 4 5
ng/m
l
mm
Hg
Hours
Systolic
Diastolic
Ouabain
Subject 1504
Ouabain – Hemodynamic Effects
• Cardiac glycoside
• Inhibits Na+/K+-ATPase
• Increases intracellular Na
• Increases intracellular Ca2+
via NCX
• Positive inotrope
• Dose-dependent increase in systemic pressures
0
10
20
30
40
50
60
70
80
90
100
0
20
40
60
80
100
120
140
160
0 1 2 3 4 5
ng/m
l
mm
Hg
Hours
Systolic
Diastolic
Ouabain
0
50
100
150
200
250
0
200
400
600
800
1000
1200
1400
0 1 2 3 4 5
PR (m
s)
RR (m
s)
Hours
RR-I
PR-I
RR and PR Intervals
0
50
100
150
200
250
0
200
400
600
800
1000
1200
1400
0 1 2 3 4 5
PR (m
s)
RR (m
s)
Hours
RR-I
PR-I
Subject 1504
RR and PR Intervals
• Exposure-dependent increase in RR
• Inotropic component
• Exposure-dependent increase in PR
• Exceeds RR effect
• ↑PACs, 2°AVB
0
50
100
150
200
250
300
350
20
30
40
50
60
70
80
90
100
0 1 2 3 4 5
QTc
V (m
s)
QR
S (m
s)
Hours
QRS
QTcV
QRS and QTcV Interval
QRS and QTcV Intervals
0
50
100
150
200
250
300
350
20
30
40
50
60
70
80
90
100
0 1 2 3 4 5
QTc
V (m
s)
QR
S (m
s)
Hours
QRS
QTcV
Subject 1504
• Time and dose-dependent increase in QRS interval
• ↑Ventricular ectopy
• QTcV shortening
• Consistent with in vitro APD shortening
Pre
mat
ure
Atr
ial C
on
trac
tio
n Subject 1504
2°
AV
Blo
ckSubject 1504
Ventricular Ectopic Beats
Ven
tric
ula
r Ec
top
ic B
eats
Subject 1504
Ventricular Triplets
Ven
tric
ula
r Tr
iple
tsSubject 1504
Ventricular Escape Beat
Ven
tric
ula
r Es
cap
e B
eat
Subject 1504
Ventricular Run
Ven
tric
ula
r R
un
Subject 1504
Summary and Conclusions
Robust time and dose-dependent arrhythmia detection
Ouabain effects on AV conduction limited investigation of complex variants
Enables PK/PD modeling of arrhythmia incidence
Consistent with pending CiPA objectives
Example of failure of specific ion channel assays to predict in vivo arrhythmias
Cost and time-effective method for rapid semi-automated arrhythmia analysis in early drug development
For additional information on Data Insights Software and implantable telemetry solutions for physiological monitoring please visit:
http://www.datasci.com
Thank You!
Henry [email protected]
Dr. Belal A. [email protected]
![Automatic Detection of Cardiac Arrhythmia through ECG ...€¦ · Cardiac Arrhythmia [3], also known as irregular heartbeat, is a group of conditions in which the heartbeat is irregular,](https://img.pdfslide.us/doc/110x75/607210056cc22557db7f5efb/automatic-detection-of-cardiac-arrhythmia-through-ecg-cardiac-arrhythmia-3.jpg)
