Physician Chiefs
Charmaine van Schaik, MD
Chief of Staff
Charmaine van Schaik, MD trained in Paediatrics at McMaster University, after completing a Bachelor of Science in Biology and Psychology and Master’s of Science in Kinesiology. Since joining Southlake Health in 2004, Charmaine has acted as a Physician Leader at Southlake Health in multiple capacities, as well as the previous Chief of Paediatrics and Medical Director of the Pediatric Oncology Group of Ontario (POGO) Satellite Clinic when it launched at Southlake in 2009. More recently, Charmaine served on Southlake’s COVID-19 Clinical Advisory Panel (CCAP) and is the Co-Medical Lead for Southlake’s COVID-19 Vaccination Committee, where she was instrumental in promoting community awareness through regular appearances in local media.
Charmaine advises Ontario’s Ministry of Health on pediatric cancer care as the Vice Chair of the Board of Directors at POGO and is a Lecturer with the Department of Pediatrics at the University of Toronto.
Charmaine is also a very proud mother of five children.
Tonya de Waal, MD
Chief of Anesthesia
Dr. de Waal has practiced at Southlake Health since 2003 providing anesthetic services to general surgery, thoracic surgery, vascular surgery, obstetrics, orthopedics and otolaryngology. She completed her medical degree, general surgery residency and anesthesia residency at McMaster University.
Christopher Overgaard, MD
Chief of Cardiac Health
Leading cardiologist, Dr. Overgaard, joined Southlake Health in 2019 and held various leadership positions before being named as the organization’s first Chief of Cardiac Health in 2024. His practice focuses on complex coronary interventional cardiology, a medical speciality that uses small tubes known as catheters to provide life-saving care without open-heart surgery. As a leader in his field, Dr. Overgaard is known for being the first physician in Canada to perform several procedures, some of which were done at Southlake. In 2017, Dr. Overgaard became the first doctor in Canada to successfully transplant a TandemHeart cardiac-assist device in a high-risk heart failure patient.
Dr. Overgaard studied at Queens University before training in internal medicine and cardiology at the University of Toronto.
Steven Segal, MD
Chief of Critical Care
Dr. Segal started his practice at Southlake in 2003 as medical staff in the Department of Anesthesia. He completed his medical degree at the University of Ottawa, anesthesia residency at the University of Western Ontario and a critical care fellowship at the University of Western Ontario.
Dr. Segal brings years of leadership experience as the previous Medical Director of the ICU from 2005 to 2011 and most recently Division Head of Critical Care within the Department of Medicine and Critical Care Outreach Team (CCOT) Lead.
David Srour, MD
Chief of Complex Medical Rehabilitation
Philip Buckler, MD
Chief of Diagnostic Imaging
Dr. Philip Buckler joined Southlake Health in 2009 following his M.D. and residency in Diagnostic Radiology at the University of Toronto, and Fellowship in Body Imaging and MRI at the University of Pennsylvania.
He is a Fellow of the Royal College of Physicians of Canada and a Diplomate of the American Board of Radiology. Philip also holds staff appointments at Mackenzie Richmond Hill and Cortellucci Vaughan Hospitals and is a partner in X-ray Associates Clinics.
Gaurav Puri, MD
Chief of Emergency Medicine
Mina Moussa, MD
Chief of Family & Community Medicine
Syed Kazimi, MD
Chief of Laboratory Medicine
Dr. Kazimi studied medicine at the University of Karachi in Pakistan before completing his residency in pathology at Yale University. He then completed two fellowships – one in hematopathology at Wayne State University in Detroit and the other in cytopathology at Henry Ford Hospital. Dr. Kazimi joined Southlake Health in 2010 and was named Chief of Laboratory Medicine in 2019.
Dr. Kazimi is a member of the Canadian Medical Association (CMA), the Ontario Medical Association (OMA), the Ontario Association of Pathologist (OAP), and the College of American Pathologists (CAP). He is licensed by the College of Physicians and Surgeons of Ontario and holds various board certifications.
Shahzad Qureshi, MD
Chief of Medicine
Dr. Qureshi credits the patient population of Newmarket and Northern York Region as his reason for practicing Internal Medicine at Southlake Health since 2008. He began his education at Saint George’s School of Medicine in Grenada, before completing his Internal Medicine Residency and Nephrology Fellowship at Loyola University Medical Center in Chicago. Passionate about his specialty, he is always learning and being challenged by patients with complex medical cases and shares his knowledge with future physicians as an Adjunct Lecturer for the Department of Medicine at the University of Toronto.
As an avid sports enthusiast, Dr. Qureshi volunteers his time as a coach for his son’s rep basketball team.
Anne Fortier, MD
Chief of Obstetrics & Gynecology
Dr. Anne Fortier has practiced at Southlake Health since 2009, first joining us as Locum staff. She trained in medicine at the University of Western Ontario, graduating in 2003, and then completed her residency in obstetrics and gynecology at McMaster University in 2008. Dr. Fortier completed the Southlake Rotman Leadership Academy through the Rotman School of Management in 2024 and also holds a Master of Science from Queen’s University. Academic appointments include Assistant Clinical Professor (Adjunct) at McMaster University and a part-time Clinical appointment with the University of Toronto.
Michael Hill, MD, FRCPC
Interim Chief of Paediatrics
Dr. Michael Hill completed medical school at the University of Toronto and residency at the Hospital for Sick Children before beginning practice as a community paediatrician at Orillia Soldier’s Memorial Hospital. He later found a home at Southlake Health, where he provides in-hospital paediatric care and established a community consulting clinic. His clinical interests include newborn jaundice, asthma, and complex care. Dr. Hill is the Clinical Lead of Southlake’s Paediatric Complex Care Program and a recipient of the Canadian Paediatric Society (CPS) Certificate of Merit, recognizing his leadership in advancing care for medically complex children.
Beyond clinical work, Dr. Hill has a strong interest in computer programming and developing technological solutions to enhance patient care. He is the developer of hyperbili, a web-application that helps newborn care providers implement the recommendations from the CPS for management of jaundice in newborns. He is dedicated to leveraging technology and artificial intelligence to improve paediatric medicine.
Mahdi Memarpour, MD
Chief of Psychiatry
Dr. Memarpour studied medicine at Carol Davila University in Romania and then completed for his psychiatric residency at Western University in London Ontario. Fascinated by the complexities of the human mind, Dr. Memarpour is dedicated to treating patients holistically – addressing their mental, emotional, and physical well-being. He is passionate about reducing the stigma around mental health and advocating for its importance by collaborating with community programs such as the Canadian Mental Health Association’s Assertive Community Treatment.
Having joined Southlake Health in 2009, Dr. Memarpour credits the hospital’s dedication to comprehensive, patient-centered care, as well as its strong reputation in the community, for delivering essential mental health treatments that make a meaningful impact to patients. He currently serves as the Chief of Psychiatry.
John Randle, MD
Chief of Surgery
Physician Leader, Surgical and Perioperative Services
Dr. Randle, an innovator and pioneer in shoulder repair and reconstruction, joined Southlake Health in 2001. Since then, he has held various leadership roles at Southlake, including Division Head of Orthopaedics, Vice-President of Medical Staff, President of Medical Staff, and Physician Leader of Quality. Currently, he serves as the Physician Leader for Surgery.
Dr. Randle focuses on improving patient outcomes through surgical innovation and physician mentoring. As part of this mission, he has designed surgical arthroscopy tools and has taught his techniques to orthopaedic surgeons in more than 70 countries.
Physician Leaders
Alisha Kassam, MD, MPH, B.Eng
Physician Leader, Regional Cancer Program
Dr. Alisha Kassam brings extensive expertise in paediatric oncology and palliative care. She currently serves as Division Head of Palliative Care and Co-Medical Director of the Paediatric Oncology Program. Her research focuses on improving outcomes for children and young adults with advanced cancer, and she is the Founder and Medical Lead of the Adolescent and Young Adult (AYA) Program at Southlake Health’s Regional Cancer Centre.
In addition to her clinical leadership, Dr. Kassam is an Associate Professor in the Department of Paediatrics at the University of Toronto and the Palliative Care Undergraduate Education Lead in the Division of Family and Community Medicine. She has been widely recognized for her leadership, innovation, and commitment to advancing equitable, patient-centered cancer care, as well as for mentoring the next generation of healthcare professionals.
Dr. Kassam earned her MD from the University of Ottawa, followed by paediatric residency and oncology fellowship training at The Hospital for Sick Children in Toronto, a palliative medicine fellowship at the University Health Network, and a Master of Public Health at Harvard University. She began her academic journey with a Bachelor of Engineering in Electrical Engineering from McMaster University.
In 2023, she received Southlake Health’s President’s Award for her dedication, compassion, and excellence in patient care.
Ian Mak, MD
Physician Leader, Emergency Medicine Program
Dr. Ian Mak is a full time emergency physician and was previously the Deputy Chief of Emergency Medicine at Southlake. He has been part of the medical staff since June 2013. Dr. Mak earned his medical degree at the University of Western Ontario and completed his family medicine residency at the University of Toronto – Mount Sinai site. Dr. Mak held the title of Education Lead in the Emergency Department from 2019-2023. In this role he reshaped the postgraduate education program within the ER department, implementing simulation days, hands on point of care ultrasound teaching, and even career advice. He remains passionate about teaching, but is excited to embrace his new leadership role.
David Srour, MD
Physician Leader, Medicine Programs
Peter Watt, MD
Physician Leader, Maternal Child Program
Dr. Watt has been a constant at Southlake Health for over 30 years, having joined the organization in 1992 as an Obstetrician and Gynecologist, certified by the Royal College of Physicians and Surgeons of Canada.
Throughout his time at Southlake, Dr. Watt has been instrumental in building a successful and well-rounded Women’s Health Program. His interest in reproductive medicine stems from the ability to combine medical and surgical specialties that make a difference for families.
Dr. Watt originally studied pharmacy and was a Licensed Pharmacist from 1984 to 2015. He earned his MD at the University of Toronto and then trained as a Fellow of Society of Obstetricians and Gynecologists of Canada and a Fellow of American College of Obstetrics and Gynecology. He is Board Certified by the American Board of Obstetrics and Gynecology.
Beyond his work at Southlake, Dr. Watt is a lecturer at the University of Toronto and an Assistant Clinical Professor at McMaster University. He has been an active in the Ontario Medical Association and was honoured by his local MP as Community Volunteer of the Year in 2013.
John Randle, MD
Physician Leader, Surgical and Perioperative Services
Dr. Randle, an innovator and pioneer in shoulder repair and reconstruction, joined Southlake Health in 2001. Since then, he has held various leadership roles at Southlake, including Division Head of Orthopaedics, Vice-President of Medical Staff, President of Medical Staff, and Physician Leader of Quality. Currently, he serves as the Physician Leader for Surgery.
Dr. Randle focuses on improving patient outcomes through surgical innovation and physician mentoring. As part of this mission, he has designed surgical arthroscopy tools and has taught his techniques to orthopaedic surgeons in more than 70 countries.