{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,7,30]],"date-time":"2025-07-30T09:46:19Z","timestamp":1753868779862,"version":"3.41.2"},"reference-count":19,"publisher":"Wiley","issue":"9","license":[{"start":{"date-parts":[[2023,9,25]],"date-time":"2023-09-25T00:00:00Z","timestamp":1695600000000},"content-version":"vor","delay-in-days":24,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Current Protocols"],"published-print":{"date-parts":[[2023,9]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>Human induced pluripotent stem cell (hiPSC)\u2010derived cardiomyocytes (hiPSC\u2010CMs) hold tremendous potential for cardiovascular disease modeling, drug screening, personalized medicine, and pathophysiology studies. The availability of a robust protocol and functional assay for studying phenotypic behavior of hiPSC\u2010CMs is essential for establishing an <jats:italic>in vitro<\/jats:italic> disease model. Many heart diseases manifest due to changes in the mechanical strain of cardiac tissue. Therefore, non\u2010invasive evaluation of the contractility properties of hiPSC\u2010CMs remains crucial to gain an insight into the pathogenesis of cardiac diseases. Speckle tracking\u2013based strain analysis is an efficient non\u2010invasive method that uses video microscopy and image analysis of beating hiPSC\u2010CMs for quantitative evaluation of mechanical contractility properties. This article presents step\u2010by\u2010step protocols for extracting quantitative contractility properties of an hiPSC\u2010CM system obtained from five members of a family, of whom three were affected by DiGeorge syndrome, using speckle tracking\u2013based strain analysis. The hiPSCs from the family members were differentiated and purified into hiPSC\u2010CMs using metabolic selection. Time\u2010lapse images of hiPSC\u2010CMs were acquired using high\u2010spatial\u2010resolution and high\u2010time\u2010resolution phase\u2010contrast video microscopy. Speckled images were characterized by evaluating the cross\u2010correlation coefficient, speckle size, speckle contrast, and speckle quality of the images. The optimum parameters of the speckle tracking algorithm were determined by performing sensitivity analysis concerning computation time, effective mapping area, average contraction velocity, and strain. Furthermore, the hiPSC\u2010CM response to adrenaline was evaluated to validate the sensitivity of the strain analysis algorithm. Then, we applied speckle tracking\u2013based strain analysis to characterize the dynamic behavior of patient\u2010specific hiPSC\u2010CMs from the family members affected\/unaffected by DiGeorge syndrome. Here, we report an efficient and manipulation\u2010free method to analyze the contraction displacement vector and velocity field, contraction\u2010relaxation strain rate, and contractile cycles. Implementation of this method allows for quantitative analysis of the contractile phenotype characteristics of hiPSC\u2010CMs to distinguish possible cardiac manifestation of DiGeorge syndrome. \u00a9 2023 Wiley Periodicals LLC.<\/jats:p><jats:p><jats:bold>Basic Protocol 1<\/jats:bold>: Differentiation of iPSCs into iPSC\u2010derived cardiomyocytes (iPSC\u2010CMs) and metabolic selection of differentiated iPSC\u2010CMs<\/jats:p><jats:p><jats:bold>Support Protocol 1<\/jats:bold>: Culture, maintenance, and expansion of human iPSCs<\/jats:p><jats:p><jats:bold>Support Protocol 2<\/jats:bold>: Immunohistochemistry of iPSC\u2010CMs<\/jats:p><jats:p><jats:bold>Basic Protocol 2<\/jats:bold>: Time\u2010lapse speckle imaging of iPSC\u2010CMs and speckle quality characterization<\/jats:p><jats:p><jats:bold>Support Protocol 3<\/jats:bold>: Enhancement of local contrast of videos by applying contrast limited adaptive histogram equalization (CLAHE) to all frames<\/jats:p><jats:p><jats:bold>Support Protocol 4<\/jats:bold>: Evaluation of average speckle size<\/jats:p><jats:p><jats:bold>Support Protocol 5<\/jats:bold>: Evaluation of average speckle contrast<\/jats:p><jats:p><jats:bold>Support Protocol 6<\/jats:bold>: Determination of relative peak height, Pc(x), of consecutive images acquired from video microscopy of iPSC\u2010CMs<\/jats:p><jats:p><jats:bold>Basic Protocol 3<\/jats:bold>: Speckle tracking\u2013based analysis of beating iPSC\u2010CMs<\/jats:p><jats:p><jats:bold>Support Protocol 7<\/jats:bold>: Validation of sensitivity of the speckle tracking analysis for mapping the contractility of iPSC\u2010CMs<\/jats:p><jats:p><jats:bold>Basic Protocol 4<\/jats:bold>: Data extraction, visualization, and mapping of contractile cycles of iPSC\u2010CMs<\/jats:p>","DOI":"10.1002\/cpz1.889","type":"journal-article","created":{"date-parts":[[2023,9,25]],"date-time":"2023-09-25T13:59:23Z","timestamp":1695650363000},"source":"Crossref","is-referenced-by-count":0,"title":["Speckle\u2010Tracking Strain Analysis for Mapping Spatiotemporal Contractility of Induced Pluripotent Stem Cell (iPSC)\u2010Derived Cardiomyocytes"],"prefix":"10.1002","volume":"3","author":[{"given":"Mohammad","family":"Izadifar","sequence":"first","affiliation":[{"name":"Lunenfeld\u2010Tanenbaum Research Institute Sinai Health System  Toronto Ontario Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tunde","family":"Berecz","sequence":"additional","affiliation":[{"name":"Institute of Enzymology Research Centre for Natural Sciences  Budapest Hungary"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Biao","family":"Li","sequence":"additional","affiliation":[{"name":"Lunenfeld\u2010Tanenbaum Research Institute Sinai Health System  Toronto Ontario Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jean Kitty Kit Yee","family":"Tang","sequence":"additional","affiliation":[{"name":"Lunenfeld\u2010Tanenbaum Research Institute Sinai Health System  Toronto Ontario Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gabor","family":"Foldes","sequence":"additional","affiliation":[{"name":"Heart and Vascular Center Semmelweis University  Budapest Hungary"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Agota","family":"Apati","sequence":"additional","affiliation":[{"name":"Institute of Enzymology Research Centre for Natural Sciences  Budapest Hungary"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andras","family":"Nagy","sequence":"additional","affiliation":[{"name":"Lunenfeld\u2010Tanenbaum Research Institute Sinai Health System  Toronto Ontario Canada"},{"name":"Australian Regenerative Medicine Institute Monash University  Melbourne Victoria Australia"},{"name":"Department of Obstetrics and Gynecology University of Toronto  Toronto Ontario Canada"},{"name":"Institute of Medical Science University of Toronto  Toronto Ontario Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2023,9,25]]},"reference":[{"key":"e_1_2_15_2_1","doi-asserted-by":"publisher","DOI":"10.5935\/abc.20160005"},{"key":"e_1_2_15_3_1","doi-asserted-by":"publisher","DOI":"10.1038\/nmeth.2999"},{"key":"e_1_2_15_4_1","doi-asserted-by":"publisher","DOI":"10.1038\/nrm3448"},{"key":"e_1_2_15_5_1","doi-asserted-by":"publisher","DOI":"10.1007\/7651_2019_222"},{"key":"e_1_2_15_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.celrep.2015.09.025"},{"key":"e_1_2_15_7_1","doi-asserted-by":"publisher","DOI":"10.1109\/83.988953"},{"key":"e_1_2_15_8_1","doi-asserted-by":"publisher","DOI":"10.1161\/CIRCRESAHA.119.315862"},{"key":"e_1_2_15_9_1","doi-asserted-by":"publisher","DOI":"10.1088\/2057\u20101976\/aa8e0d"},{"key":"e_1_2_15_10_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.medengphy.2006.01.001"},{"key":"e_1_2_15_11_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.stemcr.2018.10.008"},{"key":"e_1_2_15_12_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.yjmcc.2020.12.007"},{"key":"e_1_2_15_13_1","doi-asserted-by":"publisher","DOI":"10.1038\/srep19194"},{"key":"e_1_2_15_14_1","doi-asserted-by":"publisher","DOI":"10.1161\/CIRCRESAHA.117.312067"},{"key":"e_1_2_15_15_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.bpj.2017.11.1763"},{"key":"e_1_2_15_16_1","unstructured":"Sleppy 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