CVRTICVRTI
Electric Imaging of Myocardial Ischemia
Electric Imaging of Myocardial Ischemia
Rob MacLeod, Bonnie Punske,Shibaji Shome, Bulent Yilmaz, and
Bruno Taccardi
Cardiovascular Research and Training InstituteBioenginering Department
University of Utah
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OriginsOrigins
OcclusionPre-PTCA Peak-PTCA
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Biophysics of Acute IschemiaBiophysics of Acute Ischemia
0
-80
mV
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Imaging ApproachImaging Approach
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Cardiac Mapping of IschemiaCardiac Mapping of Ischemia
Source of Electrocardiographic ST Changes inSubendocardial Ischemia Li et al. Circ. Res. 82:957-970, 1998
Epicardium
Endocardium
LAD LCx
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Research QuestionsResearch Questions
• ST elevation or (transient) depression?• Acute occlusion versus graded flow?• How do ST changes image on the body
surface?
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Technical ApparatusTechnical Apparatus
• “Andy III”• 370 electrodes• R = 500 cm• Homogeneous• 1024 channel
acquisition
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Isolated Heart PreparationIsolated Heart Preparation
TorsoTank Electrodes
Epicardial Sock Electrodes
Support Dog
Flow Regulators
Heat ExchangeC J
ElectrolyticTorso Tank
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Flow ControlFlow ControlRoller PumpIsolated HeartLeft anterior descending artery
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Epicardial Electrode Sock Epicardial Electrode Sock
• Nylon stocking material
• 490 recording wires• 24 pacing wires• Reference markers
for geometry
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ProtocolsProtocols
• Acute, complete occlusion– 3-minute duration– measurements each 30 s
• Graded flow – 2-minute intervals at each flow rate– measurement at end of each interval
• Graded heart rate– constant flow rate– increase rate in 2-minute intervals– measurement at end of each interval
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Signal ProcessingSignal Processing
ToffQon Soff
3/8 5/8
SToff
80ms
ST80
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Tank/Heart GeometryTank/Heart Geometry
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Acute Occlusion
ST
Acute Occlusion
ST
300270240210180150120
906030
30
24
18
12
6
0ml/min s
Flow Time
4Jan01-ocl1
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Graded FlowST
Graded FlowST
30 ml/m
24 ml/m
18 ml/m
12 ml/m
6 ml/m
0 ml/m
10Jan01-ocl1
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Graded Pacing ST80
Graded Pacing ST80
34 ml/m
24 ml/m
18 ml/m
12 ml/m
6 ml/m
0 ml/m
215
190
165
150
130
Flow Heart Rate
10Jan01-ocl4
(reduced flow)
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Fixed Rate, Decreased FlowFixed Rate, Decreased Flow
• Start flow at 35• Reduce to 0• Increase back to 35• 3 minutes at each flow rate
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ReducedFlow:
ST-80
ReducedFlow:
ST-80
19Jan01-ocl1
35
28
21
14
7
0ml/min min
Flow Time
30272421181512
963
33
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ReducedFlow:
ST-80
ReducedFlow:
ST-80
19Jan01-ocl1
35
28
21
14
7
0ml/min min
Flow Time
30272421181512
963
33
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ReducedFlow:
ST-80
ReducedFlow:
ST-80
19Jan01-ocl1
35
28
21
14
7
0ml/min min
Flow Time
30272421181512
963
33
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ReducedFlow:
ST-80
ReducedFlow:
ST-80
19Jan01-ocl1
35
28
21
14
7
0ml/min min
Flow Time
30272421181512
963
33
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ReducedFlow:
ST-80
ReducedFlow:
ST-80
19Jan01-ocl1
35
28
21
14
7
0ml/min min
Flow Time
30272421181512
963
33
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ReducedFlow:
ST-80
ReducedFlow:
ST-80
19Jan01-ocl1
35
28
21
14
7
0ml/min min
Flow Time
30272421181512
963
33
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ReducedFlow:
ST-80
ReducedFlow:
ST-80
19Jan01-ocl1
35
28
21
14
7
0ml/min min
Flow Time
30272421181512
963
33
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ReducedFlow:
ST-80
ReducedFlow:
ST-80
19Jan01-ocl1
35
28
21
14
7
0ml/min min
Flow Time
30272421181512
963
33
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ReducedFlow:
ST-80
ReducedFlow:
ST-80
19Jan01-ocl1
35
28
21
14
7
0ml/min min
Flow Time
30272421181512
963
33
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ReducedFlow:
ST-80
ReducedFlow:
ST-80
19Jan01-ocl1
35
28
21
14
7
0ml/min min
Flow Time
30272421181512
963
33
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ReducedFlow:
ST-80
ReducedFlow:
ST-80
19Jan01-ocl1
35
28
21
14
7
0ml/min min
Flow Time
30272421181512
963
33
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ReducedFlow:
ST-80
ReducedFlow:
ST-80
19Jan01-ocl1
35
28
21
14
7
0ml/min min
Flow Time
30272421181512
963
33
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Fixed Flow, Increased RateFixed Flow, Increased Rate
• Start flow at 35• Reduce to 21• Increase rate
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Increased Rate:ST-80
Increased Rate:ST-80
19Jan01-ocl1
35
28
21
14
7
0ml/min min
Flow Time
200
188
176
167
158
214
231
BPM
Rate
18
15
12
9
6
3
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Increased Rate:ST-80
Increased Rate:ST-80
19Jan01-ocl1
35
28
21
14
7
0ml/min min
Flow Time
200
188
176
167
158
214
231
BPM
Rate
18
15
12
9
6
3
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Increased Rate:ST-80
Increased Rate:ST-80
19Jan01-ocl1
35
28
21
14
7
0ml/min min
Flow Time
200
188
176
167
158
214
231
BPM
Rate
18
15
12
9
6
3
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Increased Rate:ST-80
Increased Rate:ST-80
19Jan01-ocl1
35
28
21
14
7
0ml/min min
Flow Time
200
188
176
167
158
214
231
BPM
Rate
18
15
12
9
6
3
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Increased Rate:ST-80
Increased Rate:ST-80
19Jan01-ocl1
35
28
21
14
7
0ml/min min
Flow Time
200
188
176
167
158
214
231
BPM
Rate
18
15
12
9
6
3
CVRTICVRTI
Increased Rate:ST-80
Increased Rate:ST-80
19Jan01-ocl1
35
28
21
14
7
0ml/min min
Flow Time
200
188
176
167
158
214
231
BPM
Rate
18
15
12
9
6
3
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Increased Rate:ST-80
Increased Rate:ST-80
19Jan01-ocl1
35
28
21
14
7
0ml/min min
Flow Time
200
188
176
167
158
214
231
BPM
Rate
18
15
12
9
6
3