REAGENT or RESOURCE	SOURCE	IDENTIFIER
Antibodies
Mouse monoclonal anti-α-actinin	Sigma-Aldrich	Cat#A7811; RRID: AB_476766
Mouse monoclonal anti-troponin T2 (TnT2)	Santa Cruz Biotechnology	Cat#SC-20025; RRID: AB_628403
Rabbit polyclonal anti-connexin 43	Sigma-Aldrich	Cat#C6219; AB_476857
Mouse monoclonal anti-β-MHC	Santa Cruz Biotechnology	Cat#SC-53089; RRID: AB_2147281
Alexa Fluor 488 anti-mouse IgG	Jackson Immuno Research	Cat#715-546-150; RRID: AB_2340849
Alexa Fluor 594 anti-mouse IgG	Jackson Immuno Research	Cat#715-586-150; RRID: AB_2340857
DyLight-594 anti-mouse IgM	Jackson Immuno Research	Cat#715-516-020; RRID: AB_2340843
Alexa Fluor 647 anti-rabbit IgG	ThermoFisher	Cat#A21245; RRID: AB_2535813
Alexa Fluor 488 anti-rabbit IgG	ThermoFisher	Cat#A21206; RRID: AB_2535792
mouse monoclonal IgG (isotype)	Santa cruz	Cat#sc-2025; RRID: AB_737182
Chemicals, peptides, and recombinant proteins
4′,6-Diamidino-2-phenylindole, dihydrochloride (DAPI)	Wako Pure Chemical Industries, Ltd.	Cat#342-07431
Primate embryonic stem cell medium	ReproCELL	Cat#RCHEMD001
Human basic fibroblast growth factor (bFGF)	ReproCELL	Cat#RCHEOT002
Mitomycin C	Wako Pure Chemical Industries, Ltd.	Cat#139-18711
AccumaxTM	Nacalai Tesque	Cat#17087-54
StemPro-34 medium	Thermo Fisher Scientific	Cat#10640-019
Ascorbic acid	FUJIFILM Wako Pure Chemical Corporation	Cat#012-04802
1-thioglycerol	Sigma-Aldrich	Cat#M1753-100ML
Bone morphologic protein 4	R&D Systems	Cat#314-BP-010/CF
Activin A	R&D Systems	Cat#338-AC-010/CF
Vascular endothelial growth factor (VEGF)	FUJIFILM Wako Pure Chemical Corporation	Cat#229-01313
IWR-1	Sigma-Aldrich	Cat#I0161-5MG
IWP-2	Sigma-Aldrich	Cat#686770-61-6
Dulbecco’s modified Eagle’s medium (DMEM)	Nacalai Tesque	Cat#08458-45
Dulbecco’s Modified Eagle’s Medium (DMEM)-high glucose	Sigma-Aldrich	Cat#D5796
Iscove’s Modified Dulbecco’s Medium (IMDM)	Sigma-Aldrich	Cat#I3390
Fetal bovine serum (FBS)	Biosera	Cat#FB-1280/500
iMatrix-511Silk	MATRIXOME	Cat#387-10131
PDMS	Dow Corning	SYLGARD 184
D-PBS	TaKaRa	Cat#T900
Y-27632	Nacalai Tesque	Cat#034-24024
non-essential amino acid solution	Sigma-Aldrich	Cat#M7145
penicillin-streptomycin	Gibco	Cat#15140-122
L-glutamine	Gibco	Cat#ref. 25030-081
0.25% Trypsin-EDTA	Gibco	Cat#25200-072
Seahorse XF DMEM Medium, pH7.4	Agilent	Cat#103575-100
Seahorse XF 1.0M Glucose Solution	Agilent	Cat#103677-100
Triton X-100	Nacalai Tesque	Cat#9002-93-1
Tween 20	Nacalai Tesque	Cat#28353-14
iCell Cardiomyocytes Plating Medium	Fujifilm	Cat#M1001
iCell Cardiomyocytes Maintenance Medium	Fujifilm	Cat#M1003
Trizol Reagent	Invitrogen	Cat#108-95-2
E−4031	Sigma-Aldrich	Cat#M5060
Aspirin	Sigma-Aldrich	Cat#1044006
Ranolazine	Sigma-Aldrich	Cat#1598744
Mexiletin	Abcam	Cat#ab141823
Isoproterenol	Sigma-Aldrich	Cat#I5627
Metroprolol	Sigma-Aldrich	Cat#M5391
Verapamil	Sigma-Aldrich	Cat#V4629
Propranolol	Sigma-Aldrich	Cat#P0884
Dobutamine	Sigma-Aldrich	Cat#D0676
Milrinon	Wako	Cat#1504/10
Experimental models: Cell lines
iCell2	Cellular Dynamics International (CDI)	Lot105451
Human Ventricular Cardiac Fibroblasts	Lonza	Cat#CC-2904
253G1 iPSC	Riken	HPS0002
Mouse embryonic fibroblast cells	ReproCELL	RCHEFC003
Software and algorithms
FlowJo software	Treestar Inc.	N/A
Fiji: ImageJ	Fiji	https://fiji.sc/
MATLAB R2020	MathWorks	N/A
Origin2019	OriginLab	N/A
iDEP	Ge et al.69	http://bioinformatics.sdstate.edu/idep/
Metascape	Zhou et al.70	http://metascape.org/
EC50/IC50 value calculator	AAT Bioquest, Inc.	www.aatbio.com/tools/ic50-calculator
Deposited data
TW and Control group data	This paper	GSE251914
Fetal and adult heart data	Kohjitani et al.60	GSE137255
Critical commercial assays
Seahorse XF Cell Mito Stress Test Kit	Agilent Technologies	103015–100
Others
Confocal microscope	Nikon	NIKON A1
Cell Motion Imaging System	SONY	SI8000
FACS Canto II flow cytometer	BD Biosciences	N/A
Transmission electron microscope	Hitachi Co.	H-7650
Extracellular flux analyzer	Agilent Technologies	Seahorse XFe 96
MEA data system	Multi Channel Systems	USB-ME64-System