(A) In acute MI, simulated ECGs show T-wave inversion (border zone model 1 (BZ1)), Brugada phenocopy (BZ2), and normal phenotypes (BZ3), in accordance with phenotypes found in clinical databases. (B)…
(A) Activation time maps reveal conduction delay in acute border zone in T-wave inversion and normal ST-T phenotypes, and conduction block in Brugada phenocopy, as well as large repolarisation …
(A) Conduction delay in chronic border zone occurs in slight QT prolongation and large T-wave phenotypes, while large repolarisation dispersion exists only in large T-wave. Red in activation map …
Pressure-volume loops are shown in black (control) or red (post-MI) traces for the baseline model, and in gray (control) or pink (post-MI) traces for the population of models. (A) Reduced LVEF in …
(B) Simulated APD and calcium traces in midmyocardial population of models with remote zone 2 (RZ2) remodelling. (C) Large action potential and calcium transient alternans were caused by EADs in …
(A), due to electrotonically-triggered EADs across the border zone (B). In (B), membrane potential changes for the first 1010ms of fast pacing simulation, showing ectopic wave generation driven by …
(A) Simulations using a population of ventricular models (n=17) to produce ECGs (light blue traces) and pressure-volume (PV) loops (grey traces) superimposed with the baseline ventricular model (ECG …
The blue and red traces are the initial and the accepted population, respectively. The black trace is the baseline endocardial model.
Acute BZ1 caused T wave inversion in precordial leads of V3 and V4, where the QT prolongation was more significant. Acute BZ2 caused Brugada phenocopy in leads V3-V5, while Acute BZ3 produced …
Both produced normal ECG morphology, and T waves are wider and taller in the anterior leads (V2–V4) of Chronic RZ2.
Acute BZ1 caused T wave inversion in precordial leads of V3 and V4, where the QT prolongation was more significant. Acute BZ2 caused Brugada phenocopy in leads V3-V5, while Acute BZ3 produced …
A mid-ventricular anterior transmural slice is taken from the left ventricle that shows the cross-section of the anterior infarction and border zones. The transmural gradient is evaluated as the …
Left: switching IKCa activity back to normal (black traces) caused AP prolongation and bigger alternans. Weaker IKCa also led to stronger CaT (bottom right, black solid line) and larger calcium …
Enhanced IKCa tended to inhibit alternans generation (A), whereas augmented CaMKII promoted alternans (B).
In addition, alternans models tended to have smaller CaTmin in epicardial populations of Chronic RZ1 (P<0.001) and RZ2 (P<0.05), while the difference was not statistically significant for Chronic BZ.
Clinical Phenotypes | Tissue or Cell Level phenomena | Corresponding Post Infarction Ionic Current Remodelling |
---|---|---|
Acute MI T-wave inversion in ECG | Reversed transmural repolarisation gradient due to delayed activation and repolarisation in the epicardial border zone | Inhibition of potassium currents in the border zone as well as the slower transmural conduction velocity |
Acute MI Brugada phenocopy in ECG | Delayed repolarisation, as well as a small region of activation failure in the epicardial border zone | Strong inhibitions of sodium, calcium and potassium ionic currents in the border zone |
Chronic MI upright tall T-waves in ECG | Large repolarisation time gradient between remote and border zones caused by more severe delay of repolarisation in the remote zone | More severe potassium channel suppression in the remote zone |
Chronic MI T-wave alternans | Cellular repolarisation alternans or early afterdepolarisation | Suppressed SERCA and augmented CaMKII activity for alternans; Enhanced late sodium current and suppressed hERG current for early afterdepolarisation |
Acute MI reduction in LVEF | Reduced calcium amplitude and/or regional conduction block | Inhibitions of calcium and sodium currents |
Chronic MI reduction in LVEF | Reduced calcium amplitude | Decreased SERCA activity |
Biomakers at 1 Hz | minimum | maximum |
---|---|---|
Vmax (mV) | 7 | 55 |
RMP (mV) | –95 | –80 |
dvdtmax (mV/ms) | 100 | 1000 |
APD90 (ms) | 180 | 440 |
APD50 (ms) | 350 | |
APD40 (ms) | 85 | 320 |
APD90-APD40 (ms) | 50 | 150 |
CaTD90 (ms) | 220 | 750 |
CaTD90 (ms) | 120 | 420 |
CaTamp (mM) | 2e-4 | 6e-4 |
CaTmax(mM) | 2e-4 | 10e-4 |
CaTmin (mM) | 0 | 4e-4 |
Name | Parameter | Value | Unit |
---|---|---|---|
Healthy baseline electromechanical parameters | |||
diffusivity in fibre, sheet and sheet normal directions | df | 0.00335 | cm/mS |
ds | 0.000723 | cm/mS | |
dn | 0.000153 | cm/mS | |
active mechanics: scaling parameter for active tension | Tscale | 12 | |
bulk modulus | K | 12185000 | Ba |
passive mechanics: exponential term in isotropic matrix, fibre, sheet and normal direction | a | 20000 | Ba |
b | 9.242 | ||
af | 30000 | Ba | |
bf | 15.972 | ||
as | 20000 | Ba | |
bs | 10.446 | ||
afs | 10000 | Ba | |
bfs | 11.602 | ||
Scar and border zone diffusion parameters | |||
diffusivity in fibre, sheet and sheet normal directions | df | 0.0012 | cm/mS |
ds | 0.00023 | cm/mS | |
dn | 0.000003 | cm/mS | |
Scar mechanical parameters | |||
active mechanics: scaling parameter for active tension | Tscale | 0 | |
bulk modulus | K | 12185000 | Ba |
passive mechanics: exponential term in isotropic matrix, fibre, sheet and normal direction | a | 200000 | Ba |
b | 9.242 | ||
af | 300000 | Ba | |
bf | 15.972 | ||
as | 200000 | Ba | |
bs | 10.446 | ||
afs | 100000 | Ba | |
bfs | 11.602 |
Name | Parameter | LV | RV | Unit |
---|---|---|---|---|
Pericardial stiffness | Kepi | 10000 | Ba cm–1 | |
Time to initial pressure | t0 | 0.02 | 0.02 | s |
Initial pressure | P0 | 5000 | 5000 | Ba |
Duration of passive diastolic filling | tdiastole | 0.08 (0.03) | 0.08 (0.03) | s |
Pressure at end of diastole | Pendd | 15000 | 15000 | Ba |
Arterial compliance | C | 0.00055908 | 0.00055908 | cm3 Ba−1 |
Arterial resistance | R | 250 | 100 | Ba s cm−3 |
Aortic pressure | Part0 | 90000 | 20000 | Ba |
Pressure at end of isovolumetric relaxation | Ppost | 10000 | 10000 | Ba |
Penalty parameters for isovolumetric contraction | Cv | 1 | 1 | cm3 s–1 Ba–1 |
Penalty parameters for isovolumetric relaxation | Cv | 0.2 | 0.2 | cm3 s–1 Ba–1 |
Penalty parameters for passive filling | Cp, Cv | 0.1,0.3 | 0.1,0.3 | cm3 Ba–1, cm3 s–1 Ba–1 |
Biomarkers | Experimental values | Simulated values | |
---|---|---|---|
Acute Post-MI Stage | Canine epi NZ APD (ms) (mean ± SD) | 295±34 Lue and Boyden, 1992 210±15 Gardner et al., 1985 219±39 Spear et al., 1983 Overall: [180, 329] | 227 |
Canine epi BZ APD (ms) (mean ± SD) | 346±60 Lue and Boyden, 1992 170±15 Gardner et al., 1985 220±26 Spear et al., 1983 Overall: [194, 406] | BZ1: 284, BZ2: 256, BZ3: 208 | |
Canine epi BZ Systolic Cai EBZ/NZ (%) | 74% Licata et al., 1997 | NZ: 686, BZ1: 517 (75%), BZ2: 133 (20%), BZ3: 457 (67%), | |
Canine epi BZ Voltage Clamp Cai at 0 mV EBZ/NZ | 53% Pu et al., 2000 | ||
Canine Cell shortening EBZ/NZ % | 12% Licata et al., 1997 | NZ systolic Ta: 40, BZ1: 24 (60%), BZ2: 0.37 (1%), BZ3: 20 (50%) | |
Chronic Post-MI Stage | Human Mid Systolic Cai Failing/Non-Failing (%) | 49% Piacentino et al., 2003 | NZ (800 ms CL):1219, RZ1: 744 (60%), RZ2: 608 (50%) |
Human Mid Systolic Cai MI/normal (%) 1 Hz | 37.5% Høydal et al., 2018 | ||
Human Mid Diastolic Cai Failing/Non-Failing (%) | 96% Piacentino et al., 2003 | NZ (800 ms CL): 80, RZ1: 37 (46%), RZ2: 39 (49%) NZ (500 ms CL): 86, RZ1: 52 (61%), RZ2: 62 (72%) | |
Human Mid Diastolic Cai MI/normal (%) 1 Hz | 115% Høydal et al., 2018 | ||
Human Mid Cell shortening MI/normal (%) 1 Hz | 33% Høydal et al., 2018 | NZ systolic Ta (800 ms CL): 65, RZ1: 58 (89%), RZ2: 45 (70%) |
For the acute stage, the Acute BZ1 and BZ2 induced significant APD prolongation, while the BZ3 led to mild APD shortening. The Acute BZ1 and BZ3 had similar degree of reduction in systolic Ca and …
Type | APD90 (ms) | CaTD90 (ms) | Diastolic Ca (nM) | Systolic Ca (nM) | Diastolic Ta (kPa) | Systolic Ta (kPa) |
---|---|---|---|---|---|---|
Control (800ms) | epi: 227, mid: 336, endo: 263 | epi: 298, mid: 333, endo: 336 | epi: 62.32, mid: 79.74, endo: 70.70 | epi: 686.27, mid: 1218.83, endo: 477.71 | epi: 0.06, mid: 0.10, endo: 0.07 | epi: 40.00, mid: 65.47, endo: 23.87 |
Acute BZ1 | epi: 284, mid: 391, endo: 315 | epi: 289, mid: 339, endo: 325 | epi: 59.63, mid: 63.52, endo: 65.62 | epi: 517.13, mid: 691.30, endo: 342.98 | epi: 0.05, mid: 0.06, endo: 0.06 | epi: 24.33, mid: 44.78, endo: 10.46 |
Acute BZ2 | epi: 256, mid: 373, endo: 341 | epi: 266, mid: 342, endo: 334 | epi: 45.11, mid: 57.08, endo: 57.98 | epi: 133.09, mid: 326.57, endo: 184.93 | epi: 0.03, mid: 0.05, endo: 0.05 | epi: 0.37, mid: 8.97, endo: 1.48 |
Acute BZ3 | epi: 208, mid: 316, endo: 247 | epi: 256, mid: 295, endo: 288 | epi: 49.05, mid: 60.49, endo: 59.79 | epi: 457.49, mid: 834.58, endo: 352.71 | epi: 0.03, mid: 0.05, endo: 0.05 | epi: 19.66, mid: 52.08, endo: 11.18 |
Chronic BZ | epi: 235, mid: 362, endo: 293 | epi: 419, mid: 444, endo: 474 | epi: 41.90, mid: 40.80, endo: 50.59 | epi: 324.87, mid: 499.97, endo: 285.67 | epi: 0.03, mid: 0.03, endo: 0.04 | epi: 10.44, mid: 31.40, endo: 7.76 |
Chronic RZ1 | epi: 247, mid: 411, endo: 313 | epi: 426, mid: 462, endo: 478 | epi: 39.64, mid: 37.47, endo: 49.34 | epi: 459.72, mid: 744.07, endo: 387.91 | epi: 0.03, mid: 0.05, endo: 0.04 | epi: 25.67, mid: 57.56, endo: 18.40 |
Chronic RZ2 | epi: 392, mid: 591, endo: 467 | epi: 498, mid: 569, endo: 557 | epi: 39.77, mid: 38.61, endo: 49.51 | epi: 444.67, mid: 607.59, endo: 361.11 | epi: 0.03, mid: 0.09, endo: 0.05 | epi: 25.14, mid: 44.80, endo: 16.17 |
Acute and (chronic) scar | epi: 250, mid: 366, endo: 295 | epi: 261, mid: 304, endo: 296 | epi: 49.17, mid: 62.49, endo: 59.70 | epi: 502.85, mid: 883.02, endo: 375.70 | epi: 0.03 (0), mid: 0.06 (0), endo: 0.05 (0) | epi: 24.23 (0), mid: 53.21 (0), endo: 13.28 (0) |
Control (500ms) | epi: 210, mid: 306, endo: 240 | epi: 265, mid: 276, endo: 298 | epi: 58.61, mid: 85.60, endo: 67.91 | epi: 760.33, mid: 1740.38, endo: 531.49 | epi: 0.38, mid: 1.81, endo: 0.33 | epi: 42.77, mid: 68.04, endo: 27.54 |
RZ1 (500ms) | epi: 226, mid: 296, endo: 271 | epi: 370, mid: 384, endo: 396 | epi: 47.10, mid: 52.52, endo: 65.07 | epi: 470.50, mid: 712.75, endo: 385.73 | epi: 0.50, mid: 2.04, endo: 0.51 | epi: 25.84, mid: 51.69, endo: 17.28 |
RZ2 (500ms) | epi: 316, mid: 395, endo: 366 | epi: 389, mid: 401, endo: 410 | epi: 50.88, mid: 61.53, endo: 65.99 | epi: 425.66, mid: 605.85, endo: 337.64 | epi: 0.52, mid: 1.94, endo: 0.46 | epi: 21.20, mid: 41.79, endo: 12.23 |
QTc was calculated using Bazett’s formula from the simulated QT intervals. Post-MI RVEF values were from ST-segment elevation myocardial infarction patients whose culprit and chronic total occlusion …
Biomarkers | Control | Acute Stage Post-MI | Chronic Stage Post-MI | |||
---|---|---|---|---|---|---|
Electrophysiological Biomarkers | Literature | Simulation | Literature | Simulation | Literature | Simulation |
QRS duration (ms) | 96 ± 9 in men, 85 ± 6 in women Carlsson et al., 2006 | 79 ± 2 | 88 ± 35 Yerra et al., 2006 | 91±5, 95±9, 92±6 | Max 127 ± 16 without VT Min 81 ± 15 without VT Perkiömäki et al., 1995 Max 137 ± 25 with VT Min 89 ± 20 with VT Perkiömäki et al., 1995 | 94 ± 6, 93 ± 5 |
QTc interval (Bazett formula) (ms) | 350–440 Johnson and Ackerman, 2009 | 360 ± 1 | 423 ± 50 without VA Ahnve, 1985 460±40 with VA Ahnve, 1985 | 398 ± 27, 415 ± 4, 376 ± 5 | Max 448 ± 39 without VT Min 383 ± 20 without VT Perkiömäki et al., 1995 Max 493 ± 51 with VT Min 388 ± 30 with VT ve stiffness parameters were calibrated based on Perkiömäki et al., 1995 | 430 ± 4, 578 ± 3 |
Mechanical Biomarkers | Literature | Simulation | Literature | Simulation | Literature | Simulation |
LVEDV (mL) | 142 ± 21 (SSFP-CMR) Maceira et al., 2006a | 129 | 116 ± 15 Uslu et al., 2013 | 124–125 | 106 ± 12 Uslu et al., 2013 | 126 |
RVEDV (mL) | 144 ± 23 (SSFP-CMR) Maceira et al., 2006b | 131 | 129 ± 28 with SDB Buchner et al., 2015 132 ± 28 without SDB Buchner et al., 2015 | 131 | 143 ± 29 with SDB Buchner et al., 2015 132 ± 31 without SDB Buchner et al., 2015 | 133 |
LVESV (mL) | 47 ± 10 (SSFP-CMR) Maceira et al., 2006a | 60 | 61 ± 12 Uslu et al., 2013 | 65~72 | 52 ± 10 Uslu et al., 2013 | 65 |
RVESV (mL) | 50±14 (SSFP-CMR) Maceira et al., 2006b | 63 | 56 21 with SDB Buchner et al., 2015 53 ± 16 without SDB Buchner et al., 2015 | 64 | 58 ± 21 with SDB Buchner et al., 2015 51 ± 15 without SDB Buchner et al., 2015 | 64 |
LVEF (%) | 67 ± 4.6 (SSFP-CMR) Maceira et al., 2006a, 62±7 (RNV) Nemerovski et al., 1982 | 53 | 48 ± 8 Uslu et al., 2013 | 43~47 | 52 ± 7 Uslu et al., 2013 | 48 |
RVEF (%) | 48 ± 5 (RNV) Nemerovski et al., 1982 | 52 | 53.0 ± 7.1 van Veelen et al., 2022 | 51 | 55.9 ± 5.4 van Veelen et al., 2022 | 52 |
For the acute stage, Acute BZ1 and BZ2 caused significant QT prolongation, longer T peak to T end, whereas the Acute BZ3 induced milder effects. For the chronic stage, both Chronic RZ1 and RZ2 led …
ECG biomarkers | Control | Acute BZ1 | Acute BZ2 | Acute BZ3 | Chronic RZ1 | Chronic RZ2 | Control CL = 500ms | Chronic RZ1 CL = 500ms | Chronic RZ2 CL = 500ms |
---|---|---|---|---|---|---|---|---|---|
QRS duration (ms) | 79±2 | 91±5 | 95±9 | 92±6 | 94±6 | 93±5 | 86±7 | 86±7 | 86±7 |
T duration (ms) | 96±17 | 163±40 | - | 113±18 | 122±42 | 291±20 | 97±19 | 100±15 | 140±37 |
T peak to T end (ms) | 59±10 | 101±31 | 122±46 | 68±8 | 68±11 | 153±30 | 57±8 | 55±12 | 82±17 |
T start to T peak (ms) | 38±8 | 61±30 | - | 45±10 | 54±32 | 138±12 | 40±11 | 45±6 | 58±22 |
QT interval (ms) | 322±1 | 356±24 | 371±3 | 336±5 | 385±4 | 578±3 | 305±2 | 344±4 | 419±4 |
QT dispersion (precordial) (ms) | 3 | 55 | 9 | 7 | 7 | 7 | 4 | 6 | 5 |
For the acute stage, Acute BZ1 and Acute BZ3 generated the same degree of reduction in SVL and LVEF, whereas the Acute BZ2 induced the smallest SVL and LVEF. For the chronic stage, both Chronic RZ1 …
Pressure-volume Biomarkers | Control | Acute BZ1 | Acute BZ2 | Acute BZ3 | Chronic RZ1 | Chronic RZ2 | |
---|---|---|---|---|---|---|---|
800 ms CL | EDVL (mL) | 129, 129, 129 | 124,124,124 | 124,125,125 | 124,124,124 | 127, 126, 126 | 127, 126, 126 |
EDVR (mL) | 130,131,131 | 130,131,131 | 130,131,131 | 130,131,131 | 132,133,133 | 132,133,133 | |
SVL (mL) | 68, 69, 69 | 59,59,59 | 53,53,53 | 59,59,59 | 62, 61, 61 | 62, 61, 61 | |
SVR (mL) | 68,68,68 | 67,67,67 | 67,67,67 | 67,67,67 | 69,69,69 | 69,69,69 | |
LVEF (%) | 53,53,53 | 47,47,47 | 43,43,43 | 47,47,47 | 49, 48, 48 | 49, 48, 48 | |
RVEF (%) | 52,52,52 | 51,51,51 | 51,51,51 | 51,51,51 | 52,52,52 | 52,52,52 | |
Peak left systolic pressure (kPa) | 12,12,12 | 11,11,11 | 11,11,11 | 11,11,11 | 11, 11, 11 | 11, 11, 11 | |
Peak right systolic pressure (kPa) | 4,4,4 | 4,4,4 | 4,4,4 | 4,4,4 | 4,4,4 | 4,4,4 | |
500 ms CL | EDVL (mL) | 111,112,113, 113,113,113 | NA | 114,107,111, 108,110,108 | 116,108,111, 109,110,109 | ||
EDVR (mL) | 123,122,123, 123,123,123 | 125,117,122, 119,121,119 | 126,119,123, 120,121,120 | ||||
SVL (mL) | 53,53,54, 54,54,54 | 50,43,47, 44,45,44 | 51,43,46, 44,45,44 | ||||
SVR (mL) | 61,61,61, 61,61,61 | 64,56,62, 56,60,57 | 65,57,62, 59,60,59 | ||||
LVEF (%) | 47,47,47, 47,47,47 | 44,39,42, 40,41,40 | 44,39,41, 40,41,40 | ||||
RVEF (%) | 49,49,49, 49,49,49 | 51,47,50, 47,50,48 | 51,48,50, 49,49,49 | ||||
Peak left systolic pressure (kPa) | 11,11,11, 11,11,11 | 10,10,10, 10,10,10 | 10,10,10, 10,10,10 | ||||
Peak right systolic pressure (kPa) | 4,4,4, 4,4,4 | 4,4,4, 4,4,4 | 4,4,4, 4,4,4 |
Population of models (n=245) | No. of alternans at CL = 300ms | No. of alternans at CL = 400ms | No. of alternans at CL = 500ms | Key parameters for alternans |
---|---|---|---|---|
Chronic BZ | Mid (110)>Epi (47) | Mid only (84) | Mid only (10) | ↑GCaL, ↑GKr, ↑PJup |
Chronic RZ1 | Epi (195)>Mid (81)>Endo (60) | Mid (158)>Epi (110)>Endo (4) | Mid (67)>Epi (1) | ↑GCaL, ↑PJup |
Chronic RZ2 | Epi (88)>Mid (48)>Endo (2) | Mid (58)>Epi (42) | Mid (37)>Endo (8)>Epi (3) | ↑GCaL, ↑GKr, ↓GNCX, ↑PJup, ↑PJrel |
Population of models (n=245) | No. of EADs and RFs at CL = 1000ms | Key parameters for EADs and RFs |
---|---|---|
Chronic BZ | Mid only (11) | ↑GCaL, ↓GKr, ↑GNCX |
Chronic RZ1 | Mid only (52) | ↑GCaL, ↓GKr, ↑GNCX |
Chronic RZ2 | Mid (118)>Epi (9)>Endo (1) | ↑GCaL, ↓GKr, ↑GNCX, ↑PJup |