Toronto Notes 2022 PDF Medical Review

TORONTO NOTES COMPREHENSIVE MEDICAL REFERENCE AND A REVIEW FOR MCCQE Editors-in-Chief Yuliya Lytvyn & Maleeha A. Qazi Associate Editors, Primary Ming Li & Jacqui van Warmerdam Associate Editors, Medicine Thomas Chang & Andreea Damian Associate Edit...

TORONTO NOTES COMPREHENSIVE MEDICAL REFERENCE AND A REVIEW FOR MCCQE Editors-in-Chief Yuliya Lytvyn & Maleeha A. Qazi Associate Editors, Primary Ming Li & Jacqui van Warmerdam Associate Editors, Medicine Thomas Chang & Andreea Damian Associate Editors, Surgery Winston W. Li & Ashmita Singh Production Managers Anders Erickson & Jennifer Parker TORONTO NOTES 2022 Comprehensive Medical Reference and a Review for the Medical Council of Canada Qualifying Exam (MCCQE) 38th Edition Editors-in-Chief: Yuliya Lytvyn & Maleeha A. Qazi Toronto Notes for Medical Students, Inc. Toronto, Ontario, Canada 2 Editorial Toronto Notes 2022 Thirty-eighth Edition Copyright © 2022 – Toronto Notes for Medical Students, Inc. Toronto, Ontario, Canada Typeset and production by Type & Graphics Inc. ISBN 978-1-927363-94-2 (38th ed.) All rights reserved. Printed in Toronto, Ontario, Canada. Toronto Notes 2022 is provided for the sole use of the purchaser. It is made available on the condition that the information contained herein will not be sold or photocopied. No part of this publication may be used or reproduced in any form or by any means without prior written permission from the publisher. Every effort has been made to obtain permission for all copyrighted material contained herein. Previous editions copyright © 1985 to 2022. Cover illustration: Ariadna Villalbi and Aimy Wang Illustrations: Biomedical Communications, University of Toronto Notice: THIS PUBLICATION HAS NOT BEEN AUTHORED, REVIEWED, OR OTHERWISE SUPPORTED BY THE MEDICAL COUNCIL OF CANADA NOR DOES IT RECEIVE ENDORSEMENT BY THE MEDICAL COUNCIL AS REVIEW MATERIAL FOR THE MCCQE PART I. THIS PUBLICATION HAS NOT BEEN AUTHORED, REVIEWED, OR OTHERWISE SUPPORTED BY THE NATIONAL BOARD OF MEDICAL EXAMINERS U.S.A. NOR DOES IT RECEIVE ENDORSEMENT BY THE NATIONAL BOARD AS REVIEW MATERIAL FOR THE USMLE. The editors of this edition have taken every effort to ensure that the information contained herein is accurate and conforms to the standards accepted at the time of publication. However, due to the constantly changing nature of the medical sciences and the possibility of human error, the reader is encouraged to exercise individual clinical judgement and consult with other sources of information that may become available with continuing research. The authors, editors, and publisher are not responsible for errors or omissions or for any consequences from application of the information in this textbook, atlas, or software and make no warranty, expressed or implied, with respect to the currency, completeness, or accuracy of the contents of the publication. In particular, the reader is advised to check the manufacturer’s insert of all pharmacologic products before administration. FEEDBACK AND ERRATA We are constantly trying to improve the Toronto Notes and welcome your feedback. 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The rod of Asclepius consists of a single serpent entwined around a staff. This icon symbolizes both rebirth, by way of a snake shedding its skin, and also authority, by way of the staff. In ancient Greek mythology, Asclepius was the son of Apollo and a skilled practitioner of medicine who learned the medical arts from the centaur Chiron. Asclepius’ healing abilities were so great that he was said to be able to bring back people from the dead. These powers displeased the gods, who punished Asclepius by placing him in the sky as the constellation Orphiuchus. The rod of Asclepius is at times confused with the caduceus, or wand, of Hermes, a staff entwined with two serpents and often depicted with wings. The caduceus is often used as a symbol of medicine or medical professionals, but there is little historical basis for this symbolism. As you may have guessed, our logo uses the rod of Asclepius that is modified to also resemble the CN Tower – our way of recognizing the university and community in which we have been privileged to learn the art and science of medicine. Thomas O’Brien, MD Class of 2009, M.D. Program, University of Toronto 4 Editorial Toronto Notes 2022 Preface – From the Editors Dear reader, The 2022 edition features substantial content revisions to the text, figures, and graphics of all 32 chapters, following a We are grateful to present Toronto Notes 2022 to you. This comprehensive review by our student and faculty editorial edition is the product of an exceptional effort from the team. Up-to-date, evidence-based medicine studies are also hundreds of editors and contributors who worked tirelessly summarized in highlighted boxes throughout the text. This year, with us as we navigated through the challenges posed by the one of our priorities was to include a table of often discussed on-going COVID-19 pandemic. Together, we have created Landmark Clinical Trials in every chapter. Alongside our the thirty-eighth edition of Toronto Notes, thus continuing textbook-wide revisions, the Cardiology and Cardiac Surgery, our organization’s rich tradition of providing an up-to-date, the Geriatric Medicine, and the Infectious Diseases chapters comprehensive, and concisely written medical resource to our have received substantial expansions to increase their utility readers. in practice. In addition to content updates, the Toronto Notes 2022 Clinical Handbook chapters now include a section on Do Thirty-eight years ago, Toronto Notes began as a humble Not Miss Diagnoses to guide your learning during clerkship initiative, with medical students from the University of Toronto rotations. Toronto Notes prioritizes cultural sensitivity, health collecting and circulating their notes. Nearly four decades later equity, and strives for accurate representation of our vibrant and – with annual editions and an ever-expanding vision – Toronto diverse communities. To enhance our team’s editorial lens on Notes has become one of the most trusted medical review texts; these concepts while editing the chapters, training was provided it is a resource that is cherished by trainees and physicians by the Anti-Racism and Cultural Diversity Office and Office of throughout Canada and around the world. Inclusion & Diversity at the University of Toronto. The Toronto Notes for Medical Students Inc. is a nonprofit We sincerely thank each of our 207 student editors and 101 faculty corporation whose mission is to provide a trusted medical editors, whose meticulous revisions and shared dedication to resource in order to give back to our community. This year, the bettering of this text has helped make Toronto Notes 2022 while our global community continued their fight for racial possible. We have learned so much from leading this team, and justice and battled the COVID-19 pandemic, locally we were are especially grateful to everyone for contributions to Toronto also devastated by the loss of our colleague, Mohammad Asadi- Notes with challenging time commitments and demands. We Lari, an MD-PhD student at the Temerty Faculty of Medicine, thank our incredible Associate Editors – Ming Li, Jacqui van who was a passenger on the Ukrainian Airlines Flight 752 that Warmerdam, Thomas Chang, Andreea Damian, Winston Li crashed on January 8th, 2021. As a country, we also reeled from and Ashmita Singh – for their tireless leadership, exceptional the discovery of unmarked graves across Residential Schools in organization, and wonderful teamwork. We, and the success of Canada, reminding us once again of the discrimination, injustice, this edition, lean on their shoulders. We also thank our Clinical and racism Indigenous Peoples have faced and continue to Handbook Editors – Benjamin Baker, Cathy Huilin Lu, and face. Keeping in line with our values and community needs, Chunyi Christie Tan—for their exceptional editorial leadership all proceeds from Toronto Notes sales are directly donated to and spearheading the work on this resource. We are grateful support both global and local initiatives. This year we have to our Production Managers – Jennifer Parker and Anders contributed to a new program by the Community of Support at Erickson – who make Toronto Notes’ operations a reality with the University of Toronto, the Indigenous Student Mentorship their daily work. We owe a great deal of gratitude to the Editors- Fund, to support Indigenous students in gaining mentorship in-Chief of the 2021 edition – Megan Drupals and Matthaeus for careers in medicine. Toronto Notes also supported the Black Ware – for their continued guidance over the past two years. Health Alliance with their African, Caribbean, Black (ACB) Lastly, we thank our longtime partners at Type & Graphics Inc COVID-19 Public Awareness Initiative – a collaboration with – especially our backbone, Enrica Aguilera and Maria Garcia — the Black Medical Students Association of Canada, and the for their years of support and excellent work producing Toronto Black Youth Helpline. Among other initiatives, we have also Notes 2022. Finally, we thank you for supporting our initiative supported U of T Medicine class activities, student scholarships by purchasing and reading our product. We hope that you will and bursaries (such as the Mohammad and Zeynab Asadi-Lari find Toronto Notes 2022 to be a useful companion on your award), our Daffy annual musical fundraiser for the Canadian medical journey, both now and for years to come. Cancer Society, and the entirety of our (over twenty-five) student-led outreach programs that seek to enrich lives in the community. Sincerely, This is why we, and all the members of our U of T team, gladly dedicated so many hours toward this immensely involved Yuliya Lytvyn, PhD, MD student project. As our valued reader, we thank you for your honest Maleeha A. Qazi, PhD, MD student and vital financial contribution through your purchase of our Editors-in-Chief, Toronto Notes 2022 textbook. Each book sold makes an important difference. 5 Editorial Toronto Notes 2022 Acknowledgements We would like to acknowledge the exceptional work of all previous Toronto Notes (formerly MCCQE Notes) Editors-in-Chief and their editorial teams. The 38th edition of this text was made possible with their contributions. 2021 (37th ed.): Megan Drupals and Matthaeus Ware 2020 (36th ed.): Sara Mirali and Ayesh Seneviratne 2019 (35th ed.): Taraneh (Tara) Tofighi and Mark Shafarenko 2018 (34th ed.): Tina Binesh Marvasti and Sydney McQueen 2017 (33rd ed.): Jieun Kim and Ilya Mukovozov 2016 (32nd ed.): Zamir Merali and Justin D. Woodfine 2015 (31th ed.): Justin Hall and Azra Premji 2014 (30th ed.): Miliana Vojvodic and Ann Young 2013 (29th ed.): Curtis Woodford and Christopher Yao 2012 (28th ed.): Jesse M. Klostranec and David L. Kolin 2011 (27th ed.): Yingming Amy Chen and Christopher Tran 2010 (26th ed.): Simon Baxter and Gordon McSheffrey 2009 (25th ed.): Sagar Dugani and Danica Lam 2008 (24th ed.): Rebecca Colman and Ron Somogyi 2007 (23rd ed.): Marilyn Heng and Joseph Ari Greenwald 2006 (22nd ed.): Carolyn Jane Shiau and Andrew Jonathan Toren 2005 (21st ed.): Blair John Normand Leonard and Jonathan Chi-Wai Yeung 2004 (20th ed.): Andrea Molckovsky and Kashif S. Pirzada 2003 (19th ed.): Prateek Lala and Andrea Waddell 2002 (18th ed.): Neety Panu and Sunny Wong 2001 (17th ed.): Jason Yue and Gagan Ahuja 2000 (16th ed.): Marcus Law and Brian Rotenberg 1999 (15th ed.): Sofia Ahmed and Matthew Cheung 1998 (14th ed.): Marilyn Abraham and M Appleby 1997 (13th ed.): William Harris and Paul Kurdyak 1996 (12th ed.): Michael B. Chang and Laura J. Macnow 1995 (11th ed.): Ann L. Mai and Brian J. Murray 1994 (10th ed.): Kenneth Pace and Peter Ferguson 1993 (9th ed.): Joan Cheng and Russell Goldman 1992 (8th ed.): Gideon Cohen-Nehemia and Shanthi Vasudevan All former Chief Editors from 1991 (7th ed.) to 1985 (1st ed.) 6 Editorial Toronto Notes 2022 Student Contributors Editors-in-Chief Production Managers Clinical Handbook Editors Yuliya Lytvyn Anders Erickson Benjamin Baker Maleeha A. Qazi Jennifer Parker Cathy Huilin Lu Chunyi Christie Tan Communications Managers Online Content Managers Copyright Managers Michelle Lim Alex Beomju Bak Wei Fang Dai Grace Xiaoxi Zhou Jeffrey Lam Shin Cheung Saba Manzoor Huaqi Li Eric Plitman Rayoun Ramendra BMC Production Editors Ariadna Pomada Villalbi Aimy Wang BMC ILLUSTRATORS Sherry An Jennifer Gu Cassie Hillock-Watling Min Jee Kim Willow Yang Jennifer Barolet Mimi Guo Alexandra Ho Abeeshan Selvabaskaran Amy Zhang PRIMARY Associate Editors EBM Editors Ming Li Sarah House Jacqui van Warmerdam Vrati Mehra CHAPTER EDITORS Ethical, Legal, and Clinical Pharmacology Family Medicine Paediatrics Psychiatry Organizational Medicine Mark Khoury Anson Cheung Melanie El Hafid Ava Abraham Happy Inibhunu Sahar Zarabi Cathy Huilin Lu Anna Jiang Jeanette Hui Andrew Lagrotteria Amanda Poxon Shakiba Khalkhali Ard- Fiona Moloney Joseph Kates Rose Dermatology Emily Tam estani Cindy Na-Young Kang Benjamin Martinez Public Health and Anesthesia Maria Leis Medical Genetics Preventive Medicine Carlos Khalil Sara Mirali Yaanu Jeyakumar Palliative Medicine Glen Katsnelson Isabelle Laksono Nicholas Light Brian Hyung Caleb Tackey Evan Tang Emergency Medicine Jack Su Yousuf Ahmed Medical Imaging Danny Ma Jeffrey Lam Shin Cheung Jackie Tsang Sabrina Fitzgerald Kenneth Williams COPY EDITORS Ethical, Legal, and Clinical Pharmacology Family Medicine Paediatrics Psychiatry Organizational Medicine Brian Hyung Leah Bennett Zachary Blatman Jude Sanon Sahibjot Grewal Robert Lao Tsz Ying So Noel Kim Brian Serapio Zuhal Mohmand Dermatology Medical Genetics Palliative Medicine Public Health and Anesthesia Emma Price Brian Hyung Khizar Abid Preventive Medicine Matthew McGarr Adrian Witol Robert Lao Kaylee Sohng Zuhal Mohmand Adanna Odunze Max Solish Emergency Medicine Medical Imaging Matthaeus Ware Maria Leis Raza Syed Mitchell Segal Brian Tsang 7 Editorial Toronto Notes 2022 Student Contributors MEDICINE Associate Editors EBM Editors Thomas Chang Peter Nakhla Andreea Damian Kyle Seigel CHAPTER EDITORS Cardiology and Cardiac Gastroenterology Hematology Nephrology Respirology Surgery Tedi Hoxha Vanessa Arciero Anshika Jain Kevin Jia Qi Chen Ahmed Abdelaal Rohit Jogendran Justin Brunet Tiange Li Jenny Sue Hyun Cho Nitish K. Dhingra Jocelyn Price Reid Gallant Jenny Liao Lina Elfaki Nathalie Loeb Neurology Abdullah Malik Geriatric Medicine Juweiriya Ahmed Rheumatology Dustin Tanaka Jim TC Chen Infectious Diseases Moriam Ahmed Sabrina Campbell Maggie Li Rawaan Elsawi Keshav Narang Dario Ferri Endocrinology Dorothy Qian Yici (Andrea) Liu Lindsey Hatcher Arjuna Maharaj Kyung Young (Peter) Kim Alicia Serrano COPY EDITORS Cardiology and Cardiac Gastroenterology Hematology Nephrology Respirology Surgery Miski Dahir Manu Sharma David Buchan Orli Silverberg Harsukh Benipal Rachel Goldfarb Cimon Song Anna Lee Rajiv Tanwani Erika Opingari Geriatric Medicine Infectious Diseases Neurology Rheumatology Endocrinology Sahibjot Grewal Daniel Teitelbaum Armin Farahvash Xinran Liu Roslyn Mainland Shamara Nadarajah Rachel Tran Yajur Iyengar Eden Meisels Christine Wu Golsa Shafa SURGERY Associate Editors EBM Editors Winston W. Li Isra Hussein Ashmita Singh Lisa Vi CHAPTER EDITORS General and Thoracic Neurosurgery Ophthalmology Otolaryngology Urology Surgery Dan Budiansky Yuri V. Chaban Emily YiQin Cheng Edem (Andy) Afenu Noor Bakir Zaid Salaheen Anubhav (Avi) Garg Christopher End Adree Khondker Justin Lu Raza Syed Bryan Wong Smruthi Ramesh Raumil Patel Plastic Surgery Audrey Shakespeare Obstetrics Orthopaedic Surgery Shaishav Datta Vascular Surgery Jessica Trac Ye Rin (Yenah) Seo Anser Daud Max Solish Monish Ahluwalia Katie Wilkins Robert Koucheki Mithila Somasundaram Lyon Qiao Gynaecology Wei (Sheila) Yu Geoffrey Schemitsch Zainab Doleeb Michelle Lee Matthew Tersigni Melissa Tigert COPY EDITORS General and Thoracic Neurosurgery Ophthalmology Otolaryngology Urology Surgery Alyssa Li Arjan Dhoot Isabella Janusonis Wei Fang Dai Alyssa Li Rachel Tran Glen Katsnelson Kathak Vachhani Tiffany Ni Saba Manzoor Matthaeus Ware Orthopaedic Surgery Plastic Surgery Vascular Surgery Gynaecology Obstetrics Marc Anthony Manzo Khizar Abid Catherine Meng Sonia Igboanugo Sallie Han Zarian Shahzad Irina Sverdlichenko Sandra Sabongui Claire Sethuram Julianah Oguntala 8 Editorial Toronto Notes 2022 Faculty Contributors, University of Toronto All of the following contributors have been appointed at the University of Toronto. PRIMARY ETHICAL, LEGAL, AND ORGANIZATIONAL MEDICINE Kaif Pardhan, BSc MD MMEd FRCPC Giuseppe (Joey) Latino, MD, FRCPC Andria Bianchi, PhD Emergency Physician Department of Paediatrics Bioethicist, University Health Network Sunnybrook Health Sciences Centre & McMaster Division of Genetics, Department of Medicine Assistant Professor, Dalla Lana School of Public Children’s Hospital North York General Hospital Health, University of Toronto Affiliate Scientist, KITE Research Institute, David Rosenstein, BSc Arch, MD, CCFP(EM) Laila Premji, MD, FRCPC Toronto Rehab Emergency Physician, Michael Garron Hospital, Division of Paediatric Medicine, Education Investigator 2, TIER (The Institute for Toronto East Health Network Department of Paediatrics Education Research) The Hospital for Sick Children FAMILY MEDICINE Chase Everett McMurren, BA, BEd, MD, CCFP Ruby Alvi, MD, CCFP, MHSc FCFP Shazeen Suleman, MSc, MD, MPH (FRCPC) Department of Family and Community Medicine Department of Family and Community Medicine Women and Children’s Health University of Toronto University of Toronto St. Michael’s Hospital, Unity Health Toronto ANESTHESIA Chung Kit (Jacky) Lai, MD, CCFP PALLIATIVE MEDICINE Ahtsham Niazi, MBBS, FCARCSI, FRCPC Department of Family and Community Medicine Risa Bordman, MD, CCFP(PC), FCFP Department of Anesthesia and Royal Victoria Regional Health Centre Associate Professor Pain Management, University Health Network University of Toronto Faculty Development Program Lead, Office of Education Scholarship Diana Tamir, MD, FRCPC Chase Everett McMurren, BA, BEd, MD, CCFP Department of Family & Community Medicine Staff Anesthesiologist Department of Family and Community Medicine Toronto General Hospital University of Toronto Adam Rapoport, MD, FRCPC, MHSc Clinical Director of the Acute Pain Service Departments of Paediatrics and Family & Postgrad Anesthesia Site Assistant Coordinator Rachel Walsh, MD, MSc, CCFP Community Medicine, University of Toronto Department of Anesthesia and Pain Management Department of Family and Community Medicine Paediatric Advanced Care Team, SickKids Toronto General Hospital Sunnybrook Health Sciences Centre Emily’s House Children’s Hospice University of Toronto CLINICAL PHARMACOLOGY Donna Spaner, MD, CCFP(PC), FCFP, MScCH David Juurlink, BPhm, MD, PhD, FRCPC MEDICAL GENETICS Division of Palliative Care, Department of Family Division of Clinical Pharmacology and Hanna Faghfoury, MDCM, FRCPC, FCCMG and Community Medicine Toxicology, Departments of Medicine and The Fred A Litwin Family Centre in Toronto Grace Health Centre Paediatrics, Sunnybrook Health Sciences Centre Genetic Medicine, Department of Medicine Mount Sinai Hospital and University Health PSYCHIATRY Cindy Woodland, PhD Network Saulo Castel, MD, PhD, FRCPC Associate Professor, Teaching Stream Director, Inpatient Services Director, Collaborative Specialization in Graeme AM Nimmo, MBBS, MSc, FRCPC, FCCMG Sunnybrook Health Sciences Centre Biomedical Toxicology The Fred A Litwin Family Centre in Genetic Assistant Professor, Department of Psychiatry Director, Applied Clinical Pharmacology Program Medicine, Department of Medicine Mount Sinai Hospital and University Health Tamara Milovic, MD, MBA, FRCPC DERMATOLOGY Network Psychiatrist, Centre for Addiction and Mental Health Patrick Fleming, Sc(Nutrition), MSc(Community Lecturer, Department of Psychiatry, Health), MD, FRCPC, FCDA MEDICAL IMAGING University of Toronto Assistant Professor of Medicine, Department of Angela Atinga, MB, BChir, BA, MA (Cantab), FRCR Medicine, University of Toronto Sunnybrook Health Sciences Centre, Department Jerome Perera, MD, FRCPC Dermatologist, York Dermatology & of Medical Imaging, Division of Musculoskeletal Psychiatrist, North York General Hospital Research Centre Imaging Clinician Teacher, Department of Psychiatry, Consultant Dermatologist, Assistant Professor, Department of Medical Imaging, University of Toronto University Health Network University of Toronto Ilana Shawn, MD FRCPC Marissa Joseph, MD, MScCH, FRCPC, FRCPC Nasir Jaffer, MD, FRCPC Department of Psychiatry, St. Michael’s Hospital Division of Dermatology, Department of Medicine Division of Abdominal Imaging, Assistant Professor, Department of Psychiatry Women’s College Hospital and The Hospital for Sick Department of Medical Imaging Children Mount Sinai Hospital and PUBLIC HEALTH AND University Health Network PREVENTIVE MEDICINE Jensen Yeung, MD, FRCPC Joint Department of Medical Imaging Onye Nnorom, MDCM, CCFP, MPH, FRCPC Division of Dermatology, Department of Medicine University of Toronto Dalla Lana School of Public Health, Women’s College Hospital University of Toronto Kieran Murphy, MB, FRCPC, FSIR Department of Family and Community Medicine, EMERGENCY MEDICINE Interventional Neuroradiology, University of Toronto Mark Freedman, BSc, MD, FRCPC Professor of Medical Imaging Department of Emergency Medicine Jason J Pennington, MD, MSc, FRCSC Sunnybrook Health Sciences Centre Ciara O’Brien, MB BCh BAO (MD), FFR RCSI Division of General Surgery, Department of Surgery, Staff Radiologist, Abdominal Division Scarborough Health Network Adam Kaufman, MD CCFP(EM) Joint Department of Medical Imaging Assistant Professor, Department of Surgery, Emergency Physician, Michael Garron Hospital, University Health Network, Mt. Sinai Hospital, University of Toronto Toronto East Health Network Women’s College Hospital Assistant Professor, Department of Family and Com- Assistant Professor, Department of Medical Imaging, Lisa Richardson, MD, MA, FRCPC munity Medicine, University of Toronto University of Toronto Division of General Internal Medicine Department of Medicine Jo Jo Leung, MD, CCFP(EM), MScCH(HPTE) PAEDIATRICS University Health Network Emergency Physician, University Health Network Julie Johnstone, MD (FRCPC), MScCH and Trillium Health Partners Division of Paediatric Medicine, Assistant Professor, Department of Family and Department of Paediatrics Community Medicine, University of Toronto The Hospital for Sick Children 9 Editorial Toronto Notes 2022 Faculty Contributors, University of Toronto MEDICINE CARDIOLOGY AND CARDIAC SURGERY GERIATRIC MEDICINE NEPHROLOGY Paul Dorian, MD, MSc, FRCPC Vicky Chau, MD, MScCH, FRCPC Damien Noone, MB BCh BAO, MSc Division of Cardiology Division of Geriatric Medicine, Division of Paediatric Nephrology, St. Michael’s Hospital Department of Medicine Department of Paediatrics Sinai Health System & University Health Network The Hospital for Sick Children Douglas J. Ing, MD, FRCPC, FACC Division of Cardiology Karen A. Ng, MD, FRCPC Gemini Tanna, MD, FRCPC Toronto General Hospital Division of Geriatric Medicine, Division of Nephrology, Department of Medicine Department of Medicine Sunnybrook Health Sciences Centre Rebecca Noad, MB BCh BAO PhD MRCP (UK) Sinai Health System DipMedED Alireza Zahirieh, MD, FRCPC Division of Cardiology Thiru Yogaparan, MD, FRCPC Division of Nephrology, Department of Medicine Toronto General Hospital Division of Geriatric Medicine, Sunnybrook Health Sciences Centre Department of Medicine, Jacob A. Udell, MD, MPH, FRCPC Associate Professor, University of Toronto NEUROLOGY Division of Cardiology, Department of Medicine Baycrest Health Sciences Charles D. Kassardjian, MD, MSc, FRCPC Women’s College Hospital and Division of Neurology, Department of Medicine Toronto General Hospital HEMATOLOGY St. Michael’s Hospital University of Toronto Matthew Cheung, MD, FRCPC Division of Medical Oncology and Hematology, Mary Jane Lim-Fat, MD, MSc, FRCPC ENDOCRINOLOGY Department of Medicine Division of Neurology, Department of Medicine Angela Assal, MD, MHSc, FRCPC Sunnybrook Health Sciences Centre Sunnybrook Health Sciences Centre Division of Endocrinology and Metabolism, Depart- ment of Medicine Lisa Chodirker, MD, FRCPC Alexandra Muccilli, MD, MEd, FRCPC Sunnybrook Health Sciences Centre Division of Medical Oncology and Hematology, Division of Neurology, Department of Medicine University of Toronto Department of Medicine St. Michael’s Hospital Sunnybrook Health Sciences Centre Jeremy Gilbert, MD, FRCPC RESPIROLOGY Division of Endocrinology and Metabolism Helena Dhamko, MD, FRCPC, MScCH Samir Gupta, MD, FRCPC Sunnybrook Health Sciences Centre Division of Hematology, Department of Medicine Division of Respirology, Department of Medicine University Health Network Unity Health Toronto Adrian Lau, MD, MScCH, FRCPC Division of Endocrinology and Metabolism Zachary Liederman, MD, FRCPC, MScCH Ambrose Lau, MD, MEd, FRCPC Department of Medicine Division of Hematology, Department of Medicine Division of Respirology, Department of Medicine Women’s College Hospital University Health Network University Health Network and University of Toronto Unity Health Toronto Martina Trinkaus, MD, FRCPC Assistant Professor, University of Toronto Maria Wolfs, MD MHSc FRCPC Division of Hematology, Department of Medicine Division of Endocrinology and Metabolism St. Michael’s Hospital Christopher Li, MD, FRCPC, DABSM St. Michael’s Hospital Division of Respirology, Department of Medicine INFECTIOUS DISEASES Unity Health Toronto - St. Michael’s GASTROENTEROLOGY Andrea K. Boggild, BSc, MSc, MD, DTMH, Maria Cino, BSc(Hon), Hon BSc, MSc, MD, FRCPC RHEUMATOLOGY FRCPC, CAGF Tropical Disease Unit, Toronto General Hospital Arthur Bookman, MD, FRCPC Division of Gastroenterology, Division of Infectious Diseases, Division of Rheumatology, Department of Medicine Department of Medicine University Health Network University Health Network University Health Network - Toronto Western Site Department of Medicine, University of Toronto Associate Professor, University of Toronto Institute of Medical Science, University of Toronto Shirley Lake, MD, FRCPC, MSc (QIPS) Division of Rheumatology, Department of Medicine Flavio Habal, MD,PhD,FRCP,FAGA Paul E. Bunce, BSc, MA, MD, FRCPC Sunnybrook Health Sciences Centre Division of Gastroenterology Division of Infectious Diseases, Department of University Health Network, Medicine Toronto Western Division University Health Network Associate Professor, University of Toronto Susan M. Poutanen, MD, MPH, FRCPC Piero Tartaro, MD, MScCH, FRCPC Department of Microbiology, Division of Gastroenterology, University Health Network & Sinai Health Department of Medicine Division of Infectious Diseases, Sunnybrook Health Sciences Centre Department of Medicine University Health Network & Mount Sinai Hospital 10 Editorial Toronto Notes 2022 Faculty Contributors, University of Toronto SURGERY GENERAL AND THORACIC SURGERY Eric M. Massicotte MD, MSc, MBA, FRCSC OTOLARYNGOLOGY Mary-Anne Aarts, MD, FRCSC Associate Professor University of Toronto Yvonne Chan, MD, MSc, FRCSC Department of Surgery, Michael Garron Hospital Staff Neurosurgeon, University Health Network Otolaryngologist-in-chief, Department of Surgery, University Health Network Medical Director, Back & Neck Program Altum St. Michael’s Hospital, Unity Health Department of Surgery, St. Joseph’s Hospital Health Associate Professor and Continuing Professional Development Director Abdollah Behzadi, MD, MBA, FRCSC, FACS OBSTETRICS Department of Otolaryngology - Division of Thoracic Surgery, Department of Surgery Richard Pittini, MD, MEd, FRCSC, FACOG Head & Neck Surgery Trillium Health Partners, University of Toronto Department of Obstetrics and Gynecology, University of Toronto Antoine Eskander, MD, ScM, FRCSC Laura Donahoe, MD, MSc, FRCSC Sunnybrook Health Sciences Centre Assistant Professor Division of Thoracic Surgery, Department of Surgery Department of Otolaryngology - Toronto General Hospital, University Health Mara Sobel, MD, MSc, FRCSC Head & Neck Surgery Network Department of Obstetrics and Gynecology, Sunnybrook Health Sciences Centre, University of Toronto Odette Cancer Centre Jesse Pasternak, MD, MPH, FRCSC Mount Sinai Hospital Michael Garron Hospital Section of Endocrine Surgery University Health Network, Division of General Surgery, Department of Surgery Toronto General Hospital Jonathan Irish, MD, MSc, FRCSC University Health Network Women’s College Hospital Department of Otolaryngology, Head and Neck Surgery GYNAECOLOGY Melissa Walker, MD, MSc, FRCSC University Health Network Karthika Devarajan, MD, FRCSC Staff Obstetrician Gynecologist, Department of Division of General Obstetrics and Gynaecology Obstetrics & Gynecology, Mount Sinai Hospital PLASTIC SURGERY Department of Obstetrics and Gynaecology Assistant Professor, Department of Obstetrics & Siba Haykal, MD, PhD, FRCSC, FACS North York General Hospital Gynecology, University of Toronto Division of Plastic and Reconstructive Surgery, Department of Surgery Colleen McDermott, MSc, MD, FRCSC OPHTHALMOLOGY University Health Network Division of Female Pelvic Medicine & Asim Ali, MD, FRCSC Reconstructive Surgery Professor of Ophthalmology, University of Toronto Melinda Musgrave, MD, PhD, FRCSC Department of Obstetrics & Gynaecology Ophthalmologist-in-Chief, The Hospital for Sick Division of Plastic and Reconstructive Surgery, Mount Sinai Hospital Children Department of Surgery St. Michael’s Hospital Evan Tannenbaum, MSc, MD, FRCSC Wai-Ching Lam, MD, FRCSC Division of General Obstetrics & Gynaecology Department of Ophthalmology and Vision Science UROLOGY Department of Obstetrics & Gynaecology University Health Network, Toronto Western Yonah Krakowsky, MD, FRCSC Mount Sinai Hospital Hospital Division of Urology The Hospital for Sick Children Women’s College & Mount Sinai Hospital Cici Zhu, MD, FRCSC Department of Obstetrics and Gynecology, North Jonathan Micieli, MD, FRCSC Jason Lee, MD, MHPE, FRCSC York General Hospital Department of Ophthalmology and Vision Sciences; Division of Urology, Department of Surgery Division of Neurology, Department of Medicine; University Health Network, Toronto General NEUROSURGERY Kensington Vision and Research Centre, Hospital Sunit Das, MD, PhD St. Michael’s Hospital, University of Toronto Division of Neurosurgery Michael Ordon, MD, MSc, FRCSC St. Michael’s Hospital ORTHOPAEDIC SURGERY Division of Urology, Department of Surgery Paul Kuzyk, MD, MASc, FRCSC St. Michael’s Hospital Michael G. Fehlings, MD, PhD, FRCSC, FACS Assistant Professor Professor of Neurosurgery, Department of Surgery, Lower Extremity Reconstruction Surgery VASCULAR SURGERY University of Toronto Division of Orthopaedic Surgery Elisa Greco, BSc, MEd, MD, RPVI, FRCSC Vice Chair Research, Department of Surgery, Vascular Surgeon, St Michael’s Hospital University of Toronto Jesse Wolfstadt, MD, MSc, FRCSC Senior Scientist, Krembil Brain Institute, Granovsky Gluskin Division of Orthopaedic Surgery, George Oreopoulos, MD, MSc, FRCSC University Health Network Department of Surgery Division of Vascular Surgery, Staff Neurosurgeon, University Health Network Sinai Health System Department of Surgery Co-Director, University of Toronto Spine Program University Health Network Nader Hejrati, MD, FMH Division of Genetics and Development Krembil Brain Institute, University Health Network Division of Neurosurgery and Spine Program, Department of Surgery University Health Network 11 Editorial Toronto Notes 2022 Table of Contents Index Abbreviations Common Acronyms and Abbreviations Used in Medicine Common Unit Conversions Commonly Measured Laboratory Values Ethical, Legal, and Organizational Medicine.......................................................... ELOM Anesthesia....................................................................................... A Cardiology and Cardiac Surgery.................................................................... C Clinical Pharmacology............................................................................. CP Dermatology..................................................................................... D Emergency Medicine.............................................................................. ER Endocrinology.................................................................................... E Family Medicine.................................................................................. FM Gastroenterology................................................................................. G General and Thoracic Surgery...................................................................... GS Geriatric Medicine................................................................................ GM Gynaecology..................................................................................... GY Hematology...................................................................................... H Infectious Diseases............................................................................... ID Medical Genetics................................................................................. MG Medical Imaging.................................................................................. MI Nephrology...................................................................................... NP Neurology....................................................................................... N Neurosurgery.................................................................................... NS Obstetrics....................................................................................... OB Ophthalmology................................................................................... OP Orthopaedic Surgery.............................................................................. OR Otolaryngology................................................................................... OT Paediatrics....................................................................................... P Palliative Medicine................................................................................ PM Plastic Surgery................................................................................... PL Psychiatry....................................................................................... PS Public Health and Preventive Medicine.............................................................. PH Respirology...................................................................................... R Rheumatology.................................................................................... RH Urology......................................................................................... U Vascular Surgery................................................................................. VS 12 Editorial Toronto Notes 2022 How To Use This Book This book has been designed to remain as one book or to be taken apart into smaller booklets. Identify the beginning and end of a particular section, then carefully bend the pages along the perforated line next to the spine of the book. Then tear the pages out along the perforation. The layout of Toronto Notes allows easy identification of important information. These items are indicated by icons interspersed throughout the text: Icon Icon Name Significance This icon is found next to headings in the text. It identifies key objectives and conditions as determined by the Medical Council of Canada or the National Board of Medical Examiners Key Objectives in the USA. If it appears beside a dark title bar, all subsequent subheadings should be considered key topics. This icon is found in sidebars of the text. It identifies concise, important information which Clinical Pearl will aid in the diagnosis or management of conditions discussed in the accompanying text. Memory Aid This icon is found in sidebars of the text. It identifies helpful mnemonic devices and other memory aids. This icon is found in sidebars of the text. It indicates information or findings that require Clinical Flag urgent management or specialist referral. This icon is found in sidebars of the text. It identifies key research studies for evidence- Evidence Based Medicine based clinical decision making related to topics discussed in the accompanying text. This icon is found next to headings in the text. It indicates topics that correspond with Colour Photo Atlas images found in the Colour Photo Atlas available online (www.torontonotes.ca). This icon is found next to headings in the text. It indicates topics that correspond to images Radiology Atlas found in the Radiology Atlas available online (www.torontonotes.ca). This icon is found next to headings in the text. It indicates topics that correspond with Online Resources electronic resources such as Functional Neuroanatomy or ECGs Made Simple, available online (www.torontonotes.ca). Chapter Divisions To aid in studying and finding relevant material quickly, many chapters incorporate the following general framework: Basic Anatomy/Physiology Review features the high-yield, salient background information students are often assumed to have remembered from their early medical school education Common Differential Diagnoses aims to outline a clinically useful framework to tackle the common presentations and problems faced in the area of expertise Diagnoses the bulk of the book etiology, epidemiology, pathophysiology, clinical features, investigations, management, complications, and prognosis Common Medications a quick reference section for review of medications commonly prescribed 13 Editorial Toronto Notes 2022 Common Acronyms and Abbreviations Used in Medicine The following are common medical acronyms/abbreviations that may be used without definition throughout the Toronto Notes text. These are typically not included in the acronym list at the beginning of each chapter. Please refer back to this list for definitions. [] concentration ECG electrocardiogram β-hCG beta human chorionic gonadotropin ED emergency department EEG electroencephalography ABx antibiotics EMG electromyography ACE angiotensin-converting enzyme ENT ears, nose, and throat ACTH Adrenocorticotropic hormone ESR erythrocyte sedimentation rate AIDS acquired immune deficiency syndrome EtOH ethanol/alcohol ALP alkaline phosphatase ALT alanine aminotransferase FMHx family medical history AR absolute risk FSH follicle stimulating hormone ASA acetylsalicylic acid AST aspartate transaminase G6PD glucose-6-phosphate dehydrogenase aSx asymptomatic GGT gamma-glutamyl transferase AXR abdominal x-ray GH growth hormone GHB gamma hydroxybutyrate BID twice a day (bis in die) GI gastrointestinal BMI body mass index GU genitourinary BP blood pressure BPM/bpm beats per minute Hb hemoglobin HIV human immunodeficiency disease C/I contraindication HR heart rate C&S culture and sensitivity HTN hypertension CAD coronary artery disease Hx history CBC complete blood count CC chief complaint I&D incision and drainage CHF congestive heart failure ICP intracranial pressure COPD chronic obstructive pulmonary disease ICU intensive care unit CPR cardiopulmonary resuscitation IM intramuscular Cr creatinine IV intravenous CRH corticotropin-releasing hormone CSF cerebrospinal fluid JVP jugular venous pressure CT computed tomography CXR chest x-ray LDH lactate dehydrogenase LFT liver function test D&C dilatation and curettage LH luteinizing hormone dBP diastolic blood pressure LR likelihood ratio DDx differential diagnosis DM diabetes mellitus DNR do not resuscitate Dx diagnosis 14 Editorial Toronto Notes 2022 MAO monoamine oxidase sBP systolic blood pressure MAOI monoamine oxidase inhibitor SC subcutaneous MDI metered-dose inhaler SL sublingual MI myocardial infarction SLE systemic lupus erythematosus MRI magnetic resonance imaging SOB shortness of breath MSK musculoskeletal STAT urgent or immediately (statum) STI sexually transmitted infection N/V nausea/vomiting Sx symptom(s) NG nasogastric NMDA N-Methyl-D-aspartate T1DM type 1 diabetes mellitus NPO nothing by mouth (nil per os) T2DM type 2 diabetes mellitus NSAID non-steroidal anti-inflammatory drug TB tuberculosis TID three times a day (ter in die) OR operating room TNM tumour, nodes, and metastases OTC over-the-counter TRH thyroid releasing hormone TSH thyroid stimulating hormone PCR polymerase chain reaction Tx treatment PE pulmonary embolism PMHx past medical history U/A urinalysis PO oral administration (per os) U/S ultrasound POCUS point-of-care ultrasound UTI urinary tract infection PPI proton pump inhibitor UTox urine toxicology screen PRN as needed (pro re nata) VDRL Venereal Disease Research Laboratory test QID four times a day (quater in die) WBC white blood cell RBC red blood cell wt weight RCT randomized controlled trial ROS review of symptoms Rx medical prescription 15 Editorial Toronto Notes 2022 Common Unit Conversions To convert from the conventional unit to the SI unit, multiply by conversion factor To convert from the SI unit to the conventional unit, divide by conversion factor Conventional Unit Conversion Factor SI Unit ACTH pg/mL 0.22 pmol/L Albumin g/dL 10 g/L Bilirubin mg/dL 17.1 µmol/L Calcium mg/dL 0.25 mmol/L Cholesterol mg/dL 0.0259 mmol/L Cortisol µg/dL 27.59 nmol/L Creatinine mg/dL 88.4 µmol/L Creatinine clearance mL/min 0.0167 mL/s Ethanol mg/dL 0.217 mmol/L Ferritin ng/mL 2.247 pmol/L Glucose mg/dL 0.0555 mmol/L HbA1c % 0.01 proportion of 1.0 Hemaglobin g/dL 10 g/L HDL cholesterol mg/dL 0.0259 mmol/L Iron, total µg/dL 0.179 µmol/L Lactate (lactic acid) mg/dL 0.111 mmol/L LDL cholesterol mg/dL 0.0259 mmol/L Leukocytes x 103 cells/mm3 1 x 109 cells/L Magnesium mg/dL 0.411 mmol/L MCV µm3 1 fL Platelets x 103 cells/mm3 1 x 109 cells/L Reticulocytes % of RBCs 0.01 proportion of 1.0 Salicylate mg/L 0.00724 mmol/L Testosterone ng/dL 0.0347 nmol/L Thyroxine (T4) ng/dL 12.87 pmol/L Total Iron Binding Capacity µg/dL 0.179 µmol/L Triiodothyronine (T3) pg/dL 0.0154 pmol/L Triglycerides mg/dL 0.0113 mmol/L Urea nitrogen mg/dL 0.357 mmol/L Uric acid mg/dL 59.48 µmol/L Celsius → Fahrenheit F = (C x 1.8) + 32 Fahrenheit → Celsius C = (F – 32) x 0.5555 Kilograms → Pounds 1 kg = 2.2 lbs Pounds → Ounces 1 lb = 16 oz Ounces → Grams 1 oz = 28.3 g Inches → Centimetres 1 in = 2.54 cm 16 Editorial Toronto Notes 2022 Commonly Measured Laboratory Values Test Conventional Units SI Units Arterial Blood Gases pH 7.35-7.45 7.35-7.45 PCO2 35-45 mmHg 4.7-6.0 kPa PO2 80-105 mmHg 10.6-14 kPa Serum Electrolytes Bicarbonate 22-28 mEq/L 22-28 mmol/L Calcium 8.4-10.2 mg/dL 2.1-2.5 mmol/L Chloride 95-106 mEq/L 95-106 mmol/L Magnesium 1.3-2.1 mEq/L 0.65-1.05 mmol/L Phosphate 2.7-4.5 mg/dL 0.87-1.45 mmol/L Potassium 3.5-5.0 mEq/L 3.5-5.0 mmol/L Sodium 136-145 mEq/L 136-145 mmol/L Serum Nonelectrolytes Albumin 3.5-5.0 g/dL 35-50 g/L ALP 35-100 U/L 35-100 U/L ALT 8-20 U/L 8-20 U/L Amylase 25-125 U/L 25-125 U/L AST 8-20 U/L 8-20 U/L Bilirubin (direct) 0-0.3 mg/dL 0-5 µmol/L Bilirubin (total) 0.1-1.0 mg/dL 2-17 µmol/L BUN 7-18 mg/dL 2.5-7.1 mmol/L Cholesterol 75 yr 1 volume overload (e.g. aortic insufficiency) leads to dilatation (i.e. eccentric remodeling) remodeling results in decreased forward CO resulting in activation of the SNS and RAAS Orthopnea present 2 SNS causes tachycardia Lack of cough 1 RAAS causes Na+ and water retention to increase preload and afterload Current loop 1 net result is increased cardiac demand leading to eventual decompensation diuretic use (before presentation) Heart Failure with Reduced Ejection Fraction (HFrEF: LVEF ≤40%) Rales on lung exam 1 impaired myocardial contractile function → decreased LVEF and SV → decreased CO Lack of fever 2 volume overload is the typical phenotype Elevated NT-proBNP 4 findings: apex beat displaced, S3, cardiothoracic ratio >0.5, decreased LVEF, LV dilatation (>450 pg/mL if 900 pg/mL if >50 yr) ischemic (e.g. extensive CAD, previous MI) Interstitial edema 2 non-ischemic on CXR ◆ HTN Total /14 ◆ DM Likelihood of HF ◆ EtOH (and other toxins) Low = 0-5 ◆ myocarditis Intermediate = 6-8 ◆ DCM (multiple causes see Dilated Cardiomyopathy, C47) High = 9-14 ◆ tachycardia-induced Heart Failure with Mid-Range Ejection Fraction (HF-mrEF: LVEF 41-49%) includes patients who are recovering from HFrEF, declining from HFpEF, and transitioning to HFpEF BNP is secreted by Vs due to LV stretch characterization of HFmEF ongoing; guideline management does not currently exist and wall tension. Cardiomyocytes secrete BNP precursor that is cleaved Heart Failure with Preserved Ejection Fraction (HFpEF: LVEF ≥50%) into proBNP. After secretion into Vs, previously known as “diastolic HF” proBNP is cleaved into the active C-terminal portion and the inactive concentric remodelling with a “stiff” LV is the typical phenotype NT-proBNP. The above scoring algorithm 50% of patients with HF have preserved EF; confers similar prognosis to HFrEF; more common in the developed by Baggish et al. is commonly elderly and females used. A score of 900 augmentation LVAD/RVAD >75 >1800 cardiac transplant Limitations: Age, body habitus, renal function, PE Long-Term Management overwhelming majority of evidence-based management applies to HFrEF currently no proven pharmacologic therapies shown to reduce mortality in HFpEF; control risk Features of HF on CXR factors for HFpEF (e.g. HTN) prevent fluid overload with appropriate diuretic strategies HERB-B Heart enlargement (cardiothoracic ratio >0.50) Conservative Measures Pleural Effusion symptomatic measures: oxygen in hospital, bedrest, elevate the head of bed Re-distribution (alveolar edema) lifestyle measures: diet, exercise, DM control, smoking cessation, decrease EtOH consumption, patient Kerley B lines education, sodium, and fluid restriction Bronchiolar-alveolar cuffing multidisciplinary HF clinics: for management of individuals at higher risk, or with recent hospitalization Non-Pharmacological Management Patients on β-blocker therapy who from CCS guidelines (2020 update) have acute decompensated HF should cardiac rehabilitation: participation in a structured exercise program for NYHA class I-III after continue β-blockers where possible (provided they are not in cardiogenic clinical status assessment to improve quality of life (HF-ACTION trial) shock or in severe pulmonary edema) C43 Cardiology and Cardiac Surgery Toronto Notes 2022 Pharmacological Therapy ACEI/ARB: RAAS blockade ACEI: slows progression of LV dysfunction and improves survival CCS/CHFS Heart Failure Guidelines Update: ◆ all symptomatic patients functional class II-IV Defining a New Pharmacologic Standard of Care ◆ all asymptomatic patients with LVEF 16 yr of age, 5-yr risk estimates provocative maneuver and/or exercise stress test is performed to assess for dynamic LVOTO can be considered to fully inform patients during shared decision-making discussions development ‡ It would seem most appropriate to place TEE for preoperative planning of septal reduction, assessment of MR etiology, SAM and LVOTO greater weight on frequent, longer, and faster cardiac MRI to clarify inconclusive echocardiogram results or determine method of septal reduction runs of NSVT CMR = cardiovascular magnetic resonance; ECG/holter monitor for initial workup, regular follow-up, and assessment of SCD risk EF = ejection fraction; HCM = hypertrophic LVH, high voltages across precordium, prominent Q waves (lead I, aVL, V5, V6), tall R wave in cardiomyopathy; ICD = implantable cardioverter-defibrillator; LGE = late gadolinium V1, P wave abnormalities enhancement; LVH = left ventricular cardiac catheterization (only when patient being considered for invasive therapy) hypertrophy; NSVT = nonsustained ventricular genetic studies to clarify uncertain diagnoses and facilitate screening of family members tachycardia; SCD = sudden cardiac death Figure 44. ICD implantation in HCM C49 Cardiology and Cardiac Surgery Toronto Notes 2022 Management avoid factors which increase obstruction (e.g. volume depletion) avoidance of high-intensity competitive sports unless exceptional circumstances mild-to-moderate-intensity exercise is safe treatment of HOCM medical agents: β-blockers, verapamil or diltiazem (started only in monitored settings), disopyramide, phenylephrine (in setting of cardiogenic shock) avoid digoxin and vasodilators (e.g. nitrates, dihydropyridine calcium channel blockers, and ACEi/ARB) as they are inotropic and afterload reducing, respectively patients with HOCM and drug-refractory symptoms require septal reduction therapy at experienced centres surgical myectomy alcohol septal ablation - percutaneous intervention that ablates the hypertrophic septum with 100% ethanol via the septal artery dual chamber pacing (rarely done) treatment of non-obstructive HCM symptomatic: β-blockers or non-dihydropyridine calcium channel blockers and diuretics if refractory symptoms comorbid atrial fibrillation: direct oral anticoagulant or warfarin regardless of CHA2DS2-VASc score consequent systolic dysfunction: consider candidacy for transplant treatment of patients at high-risk of sudden death: ICD (see Figure 44, ICD implantation in HCM) history of survived cardiac arrest/sustained VT FMHx of premature sudden death other factors associated with increased risk of SCD ◆ syncope (presumed to be arrhythmic in origin) ◆ LVEF 50mmHg, NYHA Restrictive Cardiomyopathy II-III) from 68 clinical centers in 13 countries were randomized to mavacamten or placebo for 30 wk. The primary endpoint was a >1.5mL/kg/min increase Definition in peak O2 consumption and at least one NYHA class impaired ventricular filling with preserved systolic function in a non-dilated, non-hypertrophied reduction, or >3.0mL/kg/min increase in peak O2 ventricle secondary to factors that decrease myocardial compliance (fibrosis and/or infiltration) consumption with no NYHA class reduction. biatrial enlargement is often present despite normal AV valve functioning Results: 45 (37%) of 123 patients on mavacamten vs. 22 (17%) of 128 on placebo met the primary endpoint. Patients on mavacamten had greater reductions in Etiology post-exercise LVOT gradient and greater increase most commonly: amyloidosis, sarcoidosis, and hemochromatosis in peak O2 consumption.34% more patients in the infiltrative: amyloidosis, sarcoidosis mavacamten group improved by at least 1 NYHA class. non-infiltrative: scleroderma, idiopathic myocardial fibrosis, diabetic cardiomyopathy Safety and tolerability were comparable to placebo. storage diseases: hemochromatosis, Fabry’s disease, Gaucher’s disease, glycogen storage diseases Conclusion: Mavacamten improved exercise capacity, LVOT obstruction, NYHA functional class, endomyocardial and health status in patients with HOCM. endomyocardial fibrosis (late presentation), Loeffler’s endocarditis, or eosinophilic endomyocardial disease radiation heart disease carcinoid syndrome (may have associated tricuspid valve or pulmonary valve dysfunction) RCM vs. Constrictive Pericarditis Clinical Manifestations Present similarly but constrictive pericarditis is treatable with surgery CHF (usually with preserved LV systolic function), arrhythmias elevated JVP with prominent x and y descents, Kussmaul’s sign RCM Constrictive Pericarditis S3, S4, MR, TR thromboembolic events family history prior surgical history no pulsus paradoxus in some cases systolic murmurs pulsus paradoxus Investigations LVH may be present ECG: low voltage, non-specific, diffuse ST-T wave changes ± non-ischemic Q waves normal pericardium pericardial rub CXR: mild cardiomegaly due to biatrial enlargement (intracardiac no LVH echo: LAE, RAE; specific Doppler findings with no significant respiratory variation pathology) pericardial myo- and calcification cardiac MRI: assessment of myocardial fibrosis, determination of etiology and exclusion of endocardial and pericardial constrictive pericarditis later gadolinium thickening cardiac catheterization: increased end-diastolic ventricular pressures enhancement (LGE) pericardial late endomyocardial biopsy: to determine etiology (especially for infiltrative RCM) elevated BNP gadolinium enhancement (LGE) reduced BNP C50 Cardiology and Cardiac Surgery Toronto Notes 2022 Management exclude constrictive pericarditis control HR, anticoagulate if AFib Key Investigations treat underlying disease: (e.g. cardiac amyloidosis, cardiac sarcoidosis, hemochromatosis) Echo: may show respiratory supportive care and treatment for CHF, arrhythmias, and prevention of SCD when indicated variation in blood flow in constrictive judicious use of diuretics (excess volume reduction reduces filling pressures versus pathologic pericarditis CT: may show very thickened requirements triggering hypoperfusion) pericardium and calcification in cardiac transplant: might be considered for CHF refractory to medical therapy constrictive pericarditis MRI: best modality to directly Prognosis visualize pericardium and myocardium depends on etiology Left Ventricular Noncompaction Cardiomyopathy Definition failure of LV compaction leading to endomyocardial trabeculations that increase in number and prominence characterized by abnormal trabeculations in the LV, most frequently at the apex Etiology genetics are incompletely understood can occur in healthy individuals (e.g. athletes and pregnancy) as well as concomitantly with congenital heart diseases and other cardiomyopathies (i.e. HCM, RCM, DCM, ARVC) can be reversible Clinical Manifestations if occurring in absence of concomitant cardiomyopathy and congenital heart disease, LV non- compaction can be benign symptoms range from SOBOE to rest symptoms many patients are asymptomatic ventricular arrhythmias or complete AV block (presents as syncope and sudden death) thromboembolic events more likely when systolic dysfunction and LV dilatation are present Investigations directed by primary pathology when LV non-compaction is comorbid with congenital disease or other cardiomyopathies TTE and cardiac MRI most common diagnostic method is the ratio of the thickness of the non-compacted layer to that of the compacted layer (greater than 2:1 at the end of diastole) role of routine genetic screening remains in question typically performed in the setting of LV non-compaction with comorbid cardiomyopathy Management at-risk first-degree relatives are recommended to undergo screening therapy is largely driven by concomitant myocardial dysfunction, arrhythmias, and congenital heart disease ICD is an option if patients have syncope or documented VT antiplatelets or systemic anticoagulation should be considered in adults, especially when the LV or atria are dilated Prognosis dependent on LV function and presence of comorbid conditions (e.g. congenital heart disease and cardiomyopathy) Cardiac Transplantation treatment for end-stage heart failure median survival is 11.6 years and median survival conditional on survival to 1-year is 13.9 years matching is according to blood type, body size and weight (should be within 25%), HLA tissue matching, and geographical considerations (to minimize ischemic time) Indications for Surgery severe cardiac disability despite maximal medical therapy (e.g. recurrent hospitalizations for CHF, NYHA III or IV, peak metabolic oxygen consumption 10 mmHg during quiet breathing) JVP “x” descent only, blunted “y” descent hepatic congestion/peripheral edema severity of signs/symptoms depend on rate of accumulation, volume of pericardial contents, pericardial distensibility, cardiac filling pressures, and chamber compliance Investigations ECG: electrical alternans (pathognomonic variation in R wave amplitude), low voltage CXR: enlarged cardiac silhouette; slow-accumulating effusions CT/CMR: less available; usually only necessary if Doppler echo is infeasible echo (diagnostic modality of choice): pericardial effusion (size, location, hemodynamic impact), swinging of the heart, compression of cardiac chambers (RA and RV) in diastole, etc. → echo also used for the purpose of guiding pericardiocentesis cardiac catheterization (rare) Treatment urgent drainage: needle pericardiocentesis recommended (with echo or fluoroscopic guidance); surgery (i.e. pericardiotomy) is an alternative drainage approach (e.g. with purulent pericarditis or in an urgent situation involving bleeding into the pericardium) avoid diuretics and vasodilators (these decrease venous return to already under-filled RV → decrease LV preload → decrease CO) as well as mechanical ventilation IV fluid may increase CO treat underlying cause C66 Cardiology and Cardiac Surgery Toronto Notes 2022 A. No pathology B. Cardiac tamponade (inspiration) Interventricular Ventricular wall septum collapse on inspiration Pericardium Pericardial effusion (pericardial sac with Pericardial fluid pericardial fluid) pressure on cardiac chambers C. Cardiac tamponade (expiration) D. Pericardiocentesis Improvement in Resolution of cardiac ventricular output on wall collapse expiration Pericardial effusion Pericardial fluid pressure Removal of excess on cardiac pericardial fluid chambers ©Jennifer Lee 2021 Figure 53. Cardiac tamponade pathophysiology Constrictive Pericarditis Definition loss of pericardial elasticity caused by granulation tissue formation; leads to restricted ventricular filling Etiology chronic pericarditis resulting in fibrosed, thickened, adherent, and/or calcified pericardium any cause of acute pericarditis may result in chronic pericarditis major causes are idiopathic, post-infectious (viral, bacterial pericarditis/purulent pericarditis, TB), radiation, post-cardiac surgery, uremia, MI, collagen vascular disease any pericardial disease process can cause constrictive pericarditis; risk of progression to constrictive pericarditis is based on the etiology of the pericardial disease DDx Pulsus Paradoxus Signs and Symptoms Most etiologies of RV failure except impaired ventricular filling during diastole is characteristic; classic presentation related to right HF restrictive cardiomyopathy (e.g. acute with preserved ventricular function and otherwise no myocardial disease RV MI) in advanced cases, there can be systolic dysfunction if myocardial fibrosis or atrophy present Constrictive pericarditis (rarely) dyspnea, fatigue, palpitations Severe obstructive pulmonary disease (e.g. asthma) abdominal pain Pneumothorax may mimic CHF (especially right-sided HF) PE venous congestion, ascites, hepatosplenomegaly, edema, pleural effusions Cardiogenic shock increased JVP, Kussmaul’s sign (paradoxical increase in JVP with inspiration), Friedreich’s sign Cardiac tamponade (prominent “y” descent) Effusive-Constrictive pericarditis C67 Cardiology and Cardiac Surgery Toronto Notes 2022 BP usually normal (and usually no pulsus paradoxus) precordial examination: ± pericardial knock (early diastolic sound) see Table 19 for differentiation from cardiac tamponade Investigations ECG: non-specific findings low voltage, flat T wave, ± AFib CXR: pericardial calcification, effusions echo/CT/CMR: pericardial thickening, calcification ± characteristic echo-Doppler findings (Note: CMR is discouraged if patient is hemodynamically impaired) cardiac catheterization: indicated if other, non-invasive imaging modalities are insufficient to make diagnosis; assess for equalization of end-diastolic chamber pressures diagnosis: right HF symptoms + diastolic filling impairment caused by constriction (documented on ≥1 imaging modality including echo, CT, CMR, and/or catheterization) note: in up to 20% of patients, constriction can occur even with normal thickness of the pericardium (pericardiectomy equally efficacious in these patients) Treatment surgery (pericardiectomy): mainstay treatment for chronic, permanent constrictive pericarditis medical therapy: can be used in 3 situations 1. for specific pathologies/etiologies (e.g. TB) 2. for transient constriction that is temporarily caused by pericarditis, or new constriction diagnosis with evidence of inflammation of the pericardium (use anti-inflammatories) 3. supportive when high/prohibitive surgical risk (goal is to relieve congestive symptoms diuretics, salt restriction) prognosis best with idiopathic or infectious cause and worst in post-radiation death may result from HF Table 19. Differentiation of Constrictive Pericarditis vs. Cardiac Tamponade Characteristic Constrictive Pericarditis Cardiac Tamponade JVP “y” > “x” “x” > “y” Kussmaul’s sign Present Absent Pulsus paradoxus Uncommon Always Pericardial knock Present Absent Hypotension Variable Severe C68 Cardiology and Cardiac Surgery Toronto Notes 2022 Extracorporeal Circulation Aortic cross-clamp Systemic flow line Pressure P T Temperature Cardioplegia delivery line Aortic root suction Cardioplegic Cardiotomy suction solution Left ventricular vent One-way valve Venous Cardiotomy clamp reservoir Filter Vent Suction Suction Blood cardioplegia Arterial filter pump and bubble Venous Level sensor reservoir trap Gas filter Flowmeter Oxygenator Systemic blood pump Cooler heater water source Air O2 Gas Anaesthetic Blender