Rebecca Josowitz
Areas of expertise: Echocardiography, Fetal cardiology
Locations: Main Building
About Rebecca Josowitz
Bio: Rebecca Josowitz, MD, PhD, is an attending physician in the Division of Cardiology at Children's Hospital of Philadelphia. In addition to caring for general cardiology patients, Dr. Josowitz specializes in echocardiography and fetal cardiology.
Dr. Josowitz's research explores how the prenatal environment, including the health of the placenta, can influence the development of congenital heart disease and affect long-term outcomes. Using patient data and samples from CHOP's biorepository, she combines imaging, genetic, molecular, and outcomes research approaches to better understand the molecular signature of abnormal placental development in congenital heart disease and its role in adverse outcomes. Her work has been recognized with multiple awards, including the JACC William W. Parmley Young Author Achievement Award, and has been supported by funding from CHOP and the National Institutes of Health.
Titles
Attending Physician
Assistant Professor, Perelman School of Medicine at the University of Pennsylvania
Certifications
Pediatric Cardiology – American Board of Pediatrics
Pediatrics – American Board of Pediatrics
Awards and Honors
2025, Journal of the American College of Cardiology William W. Parmley Young Author Achievement Award
2025, Emerging Innovator in Collaborative Research Award, Children’s Hospital of Philadelphia
2024, Research Travel Award, Children’s Hospital of Philadelphia
2013, Young Investigator Award, Mindich Child Health and Development Institute annual retreat, Icahn SOM at Mount Sinai
2013, Young Investigator Award, Third International Meeting of the Genetic Syndromes of the Ras/MAPK Pathway
2013, 2014, Best Poster Award, Pediatric Research Day, Icahn SOM at Mount Sinai
2008, Phi Beta Kappa National Honor Society, Univ. of Richmond
2006, 2008, Outstanding Research Student Award, Univ. of Richmond
2006, Howard Hughes Research Scholar, Univ. of Richmond
2005, Howard Hughes Undergraduate Research Fellowship, Univ. of Richmond
2004-2008, Ethyl and Albermarle Science Research Full Scholarship, Univ. of Richmond
Leadership and Memberships
2024-present, Fetal Heart Society
2023-present, American Society of Echocardiography
2022-present, American Heart Association
Education & training
Undergraduate Degree
BS in Biochemistry and Molecular Biology - University of Richmond, Richmond, VA
Medical Degree
MD - Icahn School of Medicine at Mount Sinai, New York, NY;
Residency
Pediatrics - Children’s Hospital of Philadelphia, Philadelphia, PA
Fellowship
T32 Research - Children’s Hospital of Philadelphia, Philadelphia, PA
Pediatric Cardiology Advanced Imaging - Children’s Hospital of Philadelphia, Philadelphia, PA
Pediatric Cardiology - Children’s Hospital of Philadelphia, Philadelphia, PA
Publications
Publications
2025
Josowitz R, Woyciechowski S, Jadhav T, Jammihal T, Linn RL, Rychik J, Gaynor JW, Rajagopalan R*, Spinner NB*. Placental Malperfusion is Associated with Adverse Outcomes in Congenital Heart Disease and With Genetic Variants in Placental Developmental Pathways. J Am Coll Cardiol. Nov 11;86(19):1704-1720, 2025.
Josowitz R*, Ho DY*, Shankar S, Mondal A, Zavez A, Linn RL, Tian Z, Gaynor JW, Rychik J. Fetuses with congenital heart disease have decreased mid-gestational placental blood flow, increased placental malperfusion defects, and impaired growth. JACC Adv. Jan 16;4(2):101559, 2025.
2024
Josowitz R, Rogers LS. Double outlet right ventricle – the 50% rule has always been about the conus. Curr Opin Cardiol. 39(4):348-355, 2024.
Rodriguez N, Patel N, Dariolli R, Ng S, Aleman A, Gong J, Lin H, Rodriguez M, Josowitz R, Sol-Church K, Gripp K, Lin X, Song S, Fishman G, Sobie E, Gelb BD. HRAS-mutant cardiomyocyte model of multifocal atrial tachycardia. Circ Arrhythm Electrophysiol. 17(4):e012022, 2024.
2023
Josowitz R, Linn R, Rychik J. The Placenta in Congenital Heart Disease: Form, Function and Outcomes. NeoReviews 24(9):e569-e582, 2023.
2020
Ho D, Josowitz R, Katcoff H, Griffis, HM, Tian Z, Gaynor JW, Rychik J. Mid-gestational Fetal Placental Blood Flow is Diminished in the Fetus with Congenital Heart Disease. Prenat Diagn.
40(11):1432-1438, 2020.
2017
Belkaya S, Kontorovich AR, Byun M, Mulero-Navarro S, Bajolle F, Cobat A, Josowitz R, Itan Y, Quint R, Lorenzo L, Boucherit S, Stoven C, Di Filippo S, Abel L, Zhang SY, Bonnet D, Gelb BD, Casanova JL. Autosomal Recessive Cardiomyopathy Presenting as Acute Myocarditis. J Am Coll Cardiol. 69(13): 1653-1665, 2017.
2016
Cashman TJ, Josowitz R, Gelb BD, Li RA, Dubois NC, Costa KD. Construction of Defined Human Engineered Cardiac Tissues to Study Mechanisms of Cardiac Cell Therapy. J Vis Exp. (109):e53447, 2016.
Cashman TJ*, Josowitz R*, Johnson BV, Gelb BD, Costa, KD. Human Engineered Cardiac Tissues Created using Induced Pluripotent Stem Cells Reveal Functional Characteristics of BRAF-Mediated Hypertrophic Cardiomyopathy. PLoS One. 11(1):e0146697, 2016.
Josowitz R, Mulero-Navarro S, Falce C, Cohen N, Ullian EM, Weiss LA, Rauen KA, Sobie EA, Gelb BD. Autonomous and non-autonomous defects underlie hypertrophic cardiomyopathy in BRAF-mutant hiPSC-derived cardiomyocytes. Stem Cell Reports. 7(3):355-369, 2016.
2014
Josowitz R, Lu J, Falce C, D'Souza SL, Wu M, Cohen N, Dubois NC, Zhao Y, Sobie EA, Fishman GI, Gelb BD. Identification and purification of human induced pluripotent stem cell-derived atrial-like cardiomyocytes based on sarcolipin expression. PLoS One. 9(7):e101316, 2014.
2011
Josowitz R, Carvajal-Vergara X, Lemischka IR, and Gelb BD. Induced pluripotent stem cell-derived cardiomyocytes as models for genetic cardiovascular disorders. Curr Opin Cardiol, 26(3):223-9, 2011.
2008
Burkhardt R, Kenny EE, Lowe JK, Birkeland A, Josowitz R, Noel M, Salit L, Maller JB, Pe’er I, Daly MI, Altschuler D, Stoffel M, Friedman JM, Breslow JL. Common SNPs in HMGCR in Micronesians and whites associated with LDL-cholesterol levels affect alternative splicing of exon13. Arterioscler Thromb Vasc Biol, 28(11):2078-84, 2008.
Toda H, Mochizuki H, Flores R, Josowitz R, Krasieva T, LaMorte V, Suzuki E, Gindhart J.G, Furukubo-Tokunaga K, Tomoda T. UNC-51/ATG1 kinase regulates axonal transport by mediating motorcargo assembly. Genes Dev, 22(23):3292-307, 2008.
Abstracts (includes Posters and Scientific Presentations)
2026
Thomas AR, Bostwick A, Mathew Leny, Josowitz R, Ades A, Reynolds T, Foglia E. Transitional Physiology and Interventions During Delivery Room Resuscitation of Newborns with d-Transposition of the Great Arteries. Pediatric Academic Societies. Boston, MA, 2026.
2025
Josowitz R, Edwards J, Reddy S, Woyciechowski S, Gaynor JW, Mercer-Rosa L. A precision medicine study design: explaining phenotypic variability and outcomes in tetralogy of Fallot using multi-omics analysis. 10th International Cardiovascular Genomic Medicine & SickKids Cardiac Precision Medicine Conference. Toronto, CA, 2025.
2024
Josowitz R, Woyciechowski S, Linn RL, Rychik J, Gaynor JW, Rajagopalan R, Spinner NB. Fetuses with congenital heart disease and placental malperfusion have adverse outcomes and de novo variants in key placental developmental pathways. Moderated Oral Digital Poster, AHA Scientific Sessions. Chicago, IL, 2024.
Josowitz R, Ho DY, Shankar S, Mondal A, Zavez A, Linn RL, Tian Z, Gaynor JW, Rychik J. Fetuses with congenital heart disease have echocardiographic evidence of decreased mid-gestational placental blood flow, placental malperfusion defects at birth, and impaired fetal growth. American Society for Echocardiography. Portland, OR, 2024.
Lectures by Invitation
2026
Josowitz R. “Adverse outcomes in CHD: the role of the placenta". 3rd annual Delivery Room of the Future conference, Children’s Hospital of Philadelphia, Philadelphia, PA. October 14, 2026.
Josowitz R. “Quick Tips: Assessing for Biventricular Repair”. 17th Annual Imaging Symposium, Fetal 360, Icahn School of Medicine at Mount Sinai. New York, NY. May 16, 2026.
Josowitz R. “Characterizing the Placenta in CHD and Its Impact on Outcomes”. “The Placenta and Genetics “Together”: Key Factors Influencing Clinical Outcomes in CHD” 29th Annual Update on Pediatric and Congenital Cardiovascular Disease. Phoenix, AZ. February 25, 2026.
Josowitz R. “The Placenta in Congenital Heart Disease: Causes and Effects”. Fetal Heart Society webinar “The Placenta-Cardiac Axis” February 12, 2026.
2025
Josowitz R. “Prenatal diagnosis of Atrioventricular Canal Defects”. 5th Annual Cardiac Center Education Lecture Series. Children’s Hospital of Philadelphia, Philadelphia, PA. June 4, 2025.
Editorials, Reviews, Chapters
2026
Josowitz R, Savla J. Atrioventricular septal defect. Yagel S, Gembruch U, Silverman NH, Moon-Grady AJ, Cohen S (eds). Fetal Cardiology (4th Edition). CRC Press. In Preparation.
2024
Josowitz R, Rychik J. The placenta in congenital heart disease. Rychik J, Tian Z (eds). Fetal Cardiovascular Imaging: A Disease Based Approach (Edition 2). Elsevier. 2024. In Press.