Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Protocol
  • Published:

Modeling heart rhythm using human engineered heart tissues

Nature Protocols volume 21, pages 827–850 (2026)Cite this article

Subjects

Abstract

Heart rate is both an indicator and modulator of cardiovascular health. Prolonged elevation in heart rate or irregular heart rhythm can trigger the onset of cardiac dysfunction, a condition termed ‘tachycardia-induced cardiomyopathy’. While large animals have historically served as the primary model for studying this condition owing to their similar resting heart rates to humans, their use is limited by cost and throughput constraints. We recently developed the first engineered model of tachycardia-induced cardiomyopathy to overcome this technical bottleneck. Our model uses matured human engineered myocardium coupled with programmable electrical stimulation to emulate the pathophysiological changes in human heart rhythm. This in vitro model, capable of acutely and chronically modulating both beating rate and rhythm, recapitulated the clinical hallmarks of tachycardia-induced cardiomyopathy, and its utility was further validated via molecular comparisons against data from a canine model and human patients. Moreover, this model has improved the throughput and relevance to human genetics, enabling deep mechanistic explorations that were previously impossible. Here we present a comprehensive workflow detailing the fabrication and maturation of human engineered heart tissue, assembly of the electrical pacing system, functional analysis using open-source software and preparation for proteomic and transcriptomic analyses. This 5-week Protocol could be implemented by an experienced bench scientist with strong expertise in cell culture, ideally involving stem cell-derived cardiomyocytes. Given the broad implications of heart rhythm alterations in various cardiac conditions, this workflow can be employed with other biophysical and chemical cues to generate more complex and physiologically relevant cardiac models.

Key points

  • The programmable stimulation of mature engineered heart tissue (EHT) emulates diverse patterns of heartbeats associated with physiological and pathological changes, providing a platform to dissect the intricate role of heart rhythm on cardiac physiology at functional and molecular levels.

  • This procedure covers EHT fabrication and maturation; the construction of a cost-effective, portable and programmable pacing system; ready-to-use example code; the functional analysis of EHTs and sample preparation for proteomic and transcriptomic analysis.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on SpringerLink
  • Instant access to the full article PDF.

USD 39.95

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Graphical illustration of modeling heart rhythm using human EHT.
Fig. 2: Customized stimulation chamber for EHTs.
Fig. 3: Overview of the setup.
Fig. 4: Steps of EHT fabrication.
Fig. 5: Representative stimulation patterns from the customized pacing device.
Fig. 6: Mature EHTs are highly responsive to electrical pacing.
Fig. 7: Simulation of arrhythmias in EHTs.
Fig. 8: Proteomic and transcriptomic changes induced by simulated tachycardia.

Similar content being viewed by others

Data availability

All source data and design files are provided within the paper. RNA-seq data are available at the National Center for Biotechnology Information Gene Expression Omnibus repository, under accession number GSE242727. Source data are provided with this paper.

Code availability

Custom code is provided within the paper.

References

  1. Fox, K. et al. Heart rate as a prognostic risk factor in patients with coronary artery disease and left-ventricular systolic dysfunction (BEAUTIFUL): a subgroup analysis of a randomised controlled trial. Lancet 372, 817–821 (2008).

    Article  PubMed  Google Scholar 

  2. Nanchen, D. et al. Resting heart rate and the risk of heart failure in healthy adults. Circ. Heart Fail. 6, 403–410 (2013).

    Article  CAS  PubMed  Google Scholar 

  3. Huizar, J. F., Ellenbogen, K. A., Tan, A. Y. & Kaszala, K. Arrhythmia-induced cardiomyopathy. J. Am. Coll. Cardiol. 73, 2328–2344 (2019).

    Article  PubMed  PubMed Central  Google Scholar 

  4. Böhm, M. et al. Heart rate as a risk factor in chronic heart failure (SHIFT): the association between heart rate and outcomes in a randomised placebo-controlled trial. Lancet 376, 886–894 (2010).

    Article  PubMed  Google Scholar 

  5. Ling, L. et al. Irregular rhythm adversely influences calcium handling in ventricular myocardium. Circ. Heart Fail. 5, 786–793 (2012).

    Article  CAS  PubMed  Google Scholar 

  6. Slawik, J. et al. Irregular pacing of ventricular cardiomyocytes induces pro-fibrotic signalling involving paracrine effects of transforming growth factor beta and connective tissue growth factor. Eur. J. Heart Fail. 21, 482–491 (2019).

    Article  CAS  PubMed  Google Scholar 

  7. White, D. W. & Raven, P. B. Autonomic neural control of heart rate during dynamic exercise: revisited. J. Physiol. 592, 2491–2500 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  8. Zouhal, H., Jacob, C., Delamarche, P. & Gratas-Delamarche, A. Catecholamines and the effects of exercise, training and gender. Sports Med. 38, 401–423 (2008).

    Article  PubMed  Google Scholar 

  9. Vega, R. B., Konhilas, J. P., Kelly, D. P. & Leinwand, L. A. Molecular mechanisms underlying cardiac adaptation to exercise. Cell Metab. 25, 1012–1026 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  10. Rosen, K. M., Lau, S. H. & Damato, A. N. Simulation of atrial flutter by rapid coronary sinus pacing. Am. Heart J. 78, 635–642 (1969).

    Article  CAS  PubMed  Google Scholar 

  11. Powers, J. C. & Recchia, F. in Experimental Models of Cardiovascular Diseases: Methods and Protocols (ed. Ishikawa, K.) 309–325 (Springer, 2018).

  12. Coleman, H. N. et al. Congestive heart failure following chronic tachycardia. Am. Heart J. 81, 790–798 (1971).

    Article  PubMed  Google Scholar 

  13. Hobai, I. A. & O’Rourke, B. Enhanced Ca2+-activated Na+–Ca2+ exchange activity in canine pacing-induced heart failure. Circ. Res. 87, 690–698 (2000).

    Article  CAS  PubMed  Google Scholar 

  14. Brixius, K., Wollmer, A., Bölck, B., Mehlhorn, U. & Schwinger, R. H. G. Ser16-, but not Thr17-phosphorylation of phospholamban influences frequency-dependent force generation in human myocardium. Pflug. Arch. 447, 150–157 (2003).

    Article  CAS  Google Scholar 

  15. Hirt, M. N., Hansen, A. & Eschenhagen, T. Cardiac tissue engineering. Circ. Res. 114, 354–367 (2014).

    Article  CAS  PubMed  Google Scholar 

  16. Tu, C., Chao, B. S. & Wu, J. C. Strategies for improving the maturity of human induced pluripotent stem cell-derived cardiomyocytes. Circ. Res. 123, 512–514 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  17. Strimaityte, D. et al. Contractility and calcium transient maturation in the human iPSC-derived cardiac microfibers. ACS Appl. Mater. Interfaces 14, 35376–35388 (2022).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  18. Mannhardt, I. et al. Human engineered heart tissue: analysis of contractile force. Stem Cell Rep. 7, 29–42 (2016).

    Article  CAS  Google Scholar 

  19. Kim, H., Kamm, R. D., Vunjak-Novakovic, G. & Wu, J. C. Progress in multicellular human cardiac organoids for clinical applications. Cell Stem Cell 29, 503–514 (2022).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  20. Lewis-Israeli, Y. R. et al. Self-assembling human heart organoids for the modeling of cardiac development and congenital heart disease. Nat. Commun. 12, 5142 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  21. Ng, W. H., Varghese, B., Jia, H. & Ren, X. Alliance of heart and endoderm: multilineage organoids to model co-development. Circ. Res. 132, 511–518 (2023).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  22. Jiang, S., Feng, W., Chang, C. & Li, G. Modeling human heart development and congenital defects using organoids: how close are we? J. Cardiovasc. Dev. Dis. 9, 125 (2022).

    CAS  PubMed  PubMed Central  Google Scholar 

  23. Campostrini, G., Windt, L. M., van Meer, B. J., Bellin, M. & Mummery, C. L. Cardiac tissues from stem cells. Circ. Res. 128, 775–801 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  24. Yang, H. et al. Transcriptome analysis of non human primate-induced pluripotent stem cell-derived cardiomyocytes in 2D monolayer culture vs. 3D engineered heart tissue. Cardiovasc. Res. 117, 2125–2136 (2021).

    Article  CAS  PubMed  Google Scholar 

  25. Querdel, E. et al. Human engineered heart tissue patches remuscularize the injured heart in a dose-dependent manner. Circulation 143, 1991–2006 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  26. Maihemuti, W., Murata, K., Abulaiti, M., Minatoya, K. & Masumoto, H. Simultaneous electro-dynamic stimulation accelerates maturation of engineered cardiac tissues generated by human iPS cells. Biochem. Biophys. Res. Commun. 733, 150605 (2024).

    Article  CAS  PubMed  Google Scholar 

  27. Shen, S. et al. Physiological calcium combined with electrical pacing accelerates maturation of human engineered heart tissue. Stem Cell Rep. 17, 2037–2049 (2022).

    Article  CAS  Google Scholar 

  28. Ronaldson-Bouchard, K. et al. Advanced maturation of human cardiac tissue grown from pluripotent stem cells. Nature 556, 239–243 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  29. Hirt, M. N. et al. Functional improvement and maturation of rat and human engineered heart tissue by chronic electrical stimulation. J. Mol. Cell. Cardiol. 74, 151–161 (2014).

    Article  CAS  PubMed  Google Scholar 

  30. Ruan, J.-L. et al. Mechanical stress conditioning and electrical stimulation promote contractility and force maturation of induced pluripotent stem cell-derived human cardiac tissue. Circulation 134, 1557–1567 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  31. Ronaldson-Bouchard, K. et al. Engineering of human cardiac muscle electromechanically matured to an adult-like phenotype. Nat. Protoc. 14, 2781–2817 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  32. Ma, Z. et al. Contractile deficits in engineered cardiac microtissues as a result of MYBPC3 deficiency and mechanical overload. Nat. Biomed. Eng. 2, 955–967 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  33. Wijnker, P. J. M. et al. Hypertrophic cardiomyopathy dysfunction mimicked in human engineered heart tissue and improved by sodium–glucose cotransporter 2 inhibitors. Cardiovasc. Res. 120, 301–317 (2024).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  34. Bliley, J. M. et al. Dynamic loading of human engineered heart tissue enhances contractile function and drives a desmosome-linked disease phenotype. Sci. Transl. Med. 13, eabd1817 (2021).

    Article  CAS  PubMed  Google Scholar 

  35. Tu, C. et al. Tachycardia-induced metabolic rewiring as a driver of contractile dysfunction. Nat. Biomed. Eng. 8, 479–494 (2024).

    Article  CAS  PubMed  Google Scholar 

  36. Breckwoldt, K. et al. Differentiation of cardiomyocytes and generation of human engineered heart tissue. Nat. Protoc. 12, 1177–1197 (2017).

    Article  CAS  PubMed  Google Scholar 

  37. Tiburcy, M. et al. Defined engineered human myocardium with advanced maturation for applications in heart failure modeling and repair. Circulation 135, 1832–1847 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  38. Yang, X. et al. Fatty acids enhance the maturation of cardiomyocytes derived from human pluripotent stem cells. Stem Cell Rep. 13, 657–668 (2019).

    Article  CAS  Google Scholar 

  39. Parikh, S. S. et al. Thyroid and glucocorticoid hormones promote functional t-tubule development in human-induced pluripotent stem cell–derived cardiomyocytes. Circ. Res. 121, 1323–1330 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  40. Wang, L. et al. Triiodothyronine and dexamethasone alter potassium channel expression and promote electrophysiological maturation of human-induced pluripotent stem cell-derived cardiomyocytes. J. Mol. Cell. Cardiol. 161, 130–138 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  41. Tandon, N. et al. Electrical stimulation systems for cardiac tissue engineering. Nat. Protoc. 4, 155–173 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  42. Qi, X. Y. et al. Cellular signaling underlying atrial tachycardia remodeling of L-type calcium current. Circ. Res. 103, 845–854 (2008).

    Article  CAS  PubMed  Google Scholar 

  43. Chen, Y.-J. et al. Effects of rapid atrial pacing on the arrhythmogenic activity of single cardiomyocytes from pulmonary veins. Circulation 104, 2849–2854 (2001).

    Article  CAS  PubMed  Google Scholar 

  44. Viero, C., Kraushaar, U., Ruppenthal, S., Kaestner, L. & Lipp, P. A primary culture system for sustained expression of a calcium sensor in preserved adult rat ventricular myocytes. Cell Calcium 43, 59–71 (2008).

    Article  CAS  PubMed  Google Scholar 

  45. Lim, C. C., Apstein, C. S., Colucci, W. S. & Liao, R. Impaired cell shortening and relengthening with increased pacing frequency are intrinsic to the senescent mouse cardiomyocyte. J. Mol. Cell. Cardiol. 32, 2075–2082 (2000).

    Article  CAS  PubMed  Google Scholar 

  46. Ritzer, A., Roeschl, T., Nay, S., Rudakova, E. & Volk, T. Rapid pacing decreases L-type Ca2+ current and alters Cacna1c isogene expression in primary cultured rat left ventricular myocytes. J. Membr. Biol. 256, 257–269 (2023).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  47. Louch, W. E., Sheehan, K. A. & Wolska, B. M. Methods in cardiomyocyte isolation, culture, and gene transfer. J. Mol. Cell. Cardiol. 51, 288–298 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  48. Wei, F., Pourrier, M., Strauss, D. G., Stockbridge, N. & Pang, L. Effects of electrical stimulation on hiPSC-CM responses to classic ion channel blockers. Toxicol. Sci. 174, 254–265 (2020).

    Article  CAS  PubMed  Google Scholar 

  49. Cui, C. et al. Structural and electrophysiological dysfunctions due to increased endoplasmic reticulum stress in a long-term pacing model using human induced pluripotent stem cell-derived ventricular cardiomyocytes. Stem Cell Res. Ther. 8, 109 (2017).

    Article  PubMed  PubMed Central  Google Scholar 

  50. Thorpe, J. et al. Development of a robust induced pluripotent stem cell atrial cardiomyocyte differentiation protocol to model atrial arrhythmia. Stem Cell Res. Ther. 14, 183 (2023).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  51. Sönmez, M. I. et al. Human induced pluripotent stem cell–derived atrial cardiomyocytes recapitulate contribution of the slowly activating delayed rectifier currents IKs to repolarization in the human atrium. EP Europace 26, euae140 (2024).

    Article  Google Scholar 

  52. Geng, L. et al. Rapid electrical stimulation increased cardiac apoptosis through disturbance of calcium homeostasis and mitochondrial dysfunction in human induced pluripotent stem cell-derived cardiomyocytes. Cell. Physiol. Biochem. 47, 1167–1180 (2018).

    Article  CAS  PubMed  Google Scholar 

  53. Branco, M. A. et al. Transcriptomic analysis of 3D cardiac differentiation of human induced pluripotent stem cells reveals faster cardiomyocyte maturation compared to 2D culture. Sci. Rep. 9, 9229 (2019).

    Article  PubMed  PubMed Central  Google Scholar 

  54. Shinbane, J. S. et al. Tachycardia-induced cardiomyopathy: a review of animal models and clinical studies. J. Am. Coll. Cardiol. 29, 709–715 (1997).

    Article  CAS  PubMed  Google Scholar 

  55. Patel, D., Stohlman, J., Dang, Q., Strauss, D. G. & Blinova, K. Assessment of proarrhythmic potential of drugs in optogenetically paced induced pluripotent stem cell-derived cardiomyocytes. Toxicol. Sci. 170, 167–179 (2019).

    Article  CAS  PubMed  Google Scholar 

  56. Quach, B., Krogh-Madsen, T., Entcheva, E. & Christini, D. J. Light-activated dynamic clamp using iPSC-derived cardiomyocytes. Biophys. J. 115, 2206–2217 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  57. Lemme, M. et al. Chronic intermittent tachypacing by an optogenetic approach induces arrhythmia vulnerability in human engineered heart tissue. Cardiovasc. Res. 116, 1487–1499 (2020).

    Article  CAS  PubMed  Google Scholar 

  58. Lemoine, M. D. et al. Intermittent optogenetic tachypacing of atrial engineered heart tissue induces only limited electrical remodelling. J. Cardiovasc. Pharmacol. 77, 291 (2021).

    Article  CAS  Google Scholar 

  59. Dwenger, M. et al. Chronic optical pacing conditioning of h-iPSC engineered cardiac tissues. J. Tissue Eng. 10, 2041731419841748 (2019).

    Article  PubMed  PubMed Central  Google Scholar 

  60. Schwarzová, B. et al. Modulating cardiac physiology in engineered heart tissue with the bidirectional optogenetic tool BiPOLES. Pflug. Arch. 475, 1463–1477 (2023).

    Article  Google Scholar 

  61. Monfredi, O., Dobrzynski, H., Mondal, T., Boyett, M. R. & Morris, G. M. The anatomy and physiology of the sinoatrial node—a contemporary review. Pacing Clin. Electrophysiol. 33, 1392–1406 (2010).

    Article  PubMed  Google Scholar 

  62. Min, S. et al. Versatile human cardiac tissues engineered with perfusable heart extracellular microenvironment for biomedical applications. Nat. Commun. 15, 2564 (2024).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  63. Noor, N. et al. 3D printing of personalized thick and perfusable cardiac patches and hearts. Adv. Sci. 6, 1900344 (2019).

    Article  Google Scholar 

  64. Sekine, H. et al. In vitro fabrication of functional three-dimensional tissues with perfusable blood vessels. Nat. Commun. 4, 1399 (2013).

    Article  PubMed  Google Scholar 

  65. Sharma, A. et al. Use of human induced pluripotent stem cell–derived cardiomyocytes to assess drug cardiotoxicity. Nat. Protoc. 13, 3018–3041 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  66. Lian, X. et al. Directed cardiomyocyte differentiation from human pluripotent stem cells by modulating Wnt/β-catenin signaling under fully defined conditions. Nat. Protoc. 8, 162–175 (2013).

    Article  CAS  PubMed  Google Scholar 

  67. Windt, L. M. et al. Miniaturized engineered heart tissues from hiPSC-derived triple cell type co-cultures to study human cardiac function. Biochem. Biophys. Res. Commun. 681, 200–211 (2023).

    Article  CAS  PubMed  Google Scholar 

  68. Lock, R. I. et al. Macrophages enhance contractile force in iPSC-derived human engineered cardiac tissue. Cell Rep. 43, 114302 (2024).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  69. Bhagwan, J. R. et al. Isogenic models of hypertrophic cardiomyopathy unveil differential phenotypes and mechanism-driven therapeutics. J. Mol. Cell. Cardiol. 145, 43–53 (2020).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  70. O’Mahony, C., Elliott, P. & McKenna, W. Sudden cardiac death in hypertrophic cardiomyopathy. Circ. Arrhythm. Electrophysiol. 6, 443–451 (2013).

    Article  PubMed  Google Scholar 

  71. Nes, B. M., Janszky, I., Wisløff, U., Støylen, A. & Karlsen, T. Age-predicted maximal heart rate in healthy subjects: the HUNT fitness study. Scand. J. Med. Sci. Sports 23, 697–704 (2013).

    Article  CAS  PubMed  Google Scholar 

Download references

Acknowledgements

C.T. discloses support for the research described in this study from the American Heart Association (AHA) (grant no. 20POST35080175) and the National Institutes of Health (NIH) (grant no. K99 HL164962). A.C. discloses support for the publication of this study from the NIH (grant no. F32HL173968) and AHA (grant no. 908136). S.M.N. discloses support for the publication of this study from the NIH (grant no. R01 HL162260). J.C.W. discloses support for the publication of this study from the NIH (grant nos. R01 HL176822, R01 HL163680, R01 HL141851, R01 HL141371, R01 HL113006, R01 HL130020, and U01 AI183953) and the National Aeronautics and Space Administration (grant no. 80ARC022CA003).

Author information

Authors and Affiliations

  1. Stanford Cardiovascular Institute, Stanford University, Stanford, CA, USA

    Chengyi Tu, Arianne Caudal, Yu Liu, Sanjiv M. Narayan & Joseph C. Wu

  2. Department of Medicine, Stanford University, Stanford, CA, USA

    Sanjiv M. Narayan & Joseph C. Wu

  3. Greenstone Biosciences, Palo Alto, CA, USA

    Joseph C. Wu

Authors
  1. Chengyi Tu
    View author publications

    Search author on:PubMed Google Scholar

  2. Arianne Caudal
    View author publications

    Search author on:PubMed Google Scholar

  3. Yu Liu
    View author publications

    Search author on:PubMed Google Scholar

  4. Sanjiv M. Narayan
    View author publications

    Search author on:PubMed Google Scholar

  5. Joseph C. Wu
    View author publications

    Search author on:PubMed Google Scholar

Contributions

C.T. and J.C.W. initiated and oversaw the entire study. C.T. designed and validated the pacing system and optimized the EHT fabrication method and stimulation protocol. C.T. collected all functional data. A.C. developed the method for EHT proteomic analysis and provided data. Y.L. performed transcriptomic analysis. C.T., A.C., Y.L., S.M.N. and J.C.W. wrote and edited the manuscript.

Corresponding authors

Correspondence to Chengyi Tu or Joseph C. Wu.

Ethics declarations

Competing interests

J.C.W. is a cofounder and advisory board member of Greenstone Biosciences.

Peer review

Peer review information

Nature Protocols thanks Jamie Vandenberg and Aaron Baker for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Key reference

Tu, C. et al. Nat. Biomed. Eng. 8, 479–494 (2024): https://doi.org/10.1038/s41551-023-01134-x

Extended data

Extended Data Fig. 1 Confocal images of EHT.

Cryo-sections of EHTs were immunostained for cardiomyocyte marker (TNNT2, shown in green), nonmyocyte marker (vimentin, shown in red) and nuclei (DAPI, shown in blue). Scale bar, 50 μm.

Extended Data Fig. 2 Assembly of the pacing device.

a, Custom-built H-bridge circuit on a breadboard with 830 points. b, The connection of the output wires to the H-bridge circuit. The alligator clips, shown in red and black, will be connected to the stimulation chamber. c, The power source (black adapter) connection to the H-bridge circuit. This power source determines the voltage of electrical stimulation. d, The connection of the Arduino microprocessor to the circuit. Pacing programs will be uploaded to and stored in the Arduino. Arduino requires an independent power source (power adapter in white). e, An overview of the completed pacing device. f, The Arduino and the breadboard are installed on a specialized holder (shown in blue).

Extended Data Fig. 3 Circuit diagram of the pacing system.

a, When both pins 9 and 12 are off, the circuit is open and there is no current flowing through the load (EHTs). b, When pin 9 is on, and pin 12 is off, the current passes the EHTs from left to right (shown in red). c, When pin 9 is off and pin 12 is on, current passes the EHTs from right to left (shown in blue).

Supplementary information

Reporting Summary (download PDF )

Supplementary Data 1

CAD design file of the stimulation chamber.

Supplementary Video 1

EHT beating without pacing.

Supplementary Video 2

EHT paced at 1.5 Hz.

Supplementary Video 3

EHT paced at 3 Hz.

Supplementary Video 4

EHT paced at 4 Hz.

Supplementary Video 5 (download MOV )

Demonstration of the pacing system using light-emitting diodes.

Supplementary Code 1 (download RTF )

Example Arduino code for different pacing programs.

Source data

Source Data Fig. 6 (download XLSX )

Contractility of EHTs being paced at different frequencies.

Source Data Fig. 8 (download XLSX )

Differentially expressed proteins in EHTs induced by sustained tachypacing.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Tu, C., Caudal, A., Liu, Y. et al. Modeling heart rhythm using human engineered heart tissues. Nat Protoc 21, 827–850 (2026). https://doi.org/10.1038/s41596-025-01217-w

Download citation

  • Received:

  • Accepted:

  • Published:

  • Version of record:

  • Issue date:

  • DOI: https://doi.org/10.1038/s41596-025-01217-w

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing