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About Sickkids
About SickKids

Gil Gross, MD, FRCP(C)

The Hospital for Sick Children
Staff Cardiologist

University of Toronto
Associate Professor
Department of Paediatrics

Institute of Medical Sciences

Richard Lewar/Heart & Stroke Centre of Excellence

Phone: 416-813-7326
Fax: 416-813-5857
Email: gil.gross@sickkids.ca
Alternate Contact: Calvin Arsenault
Alternate Phone: 416-813-7654 x 203523
Alternate Email: calvin.arsenault@sickkids.ca

Brief Biography

Dr. Gil Gross is a clinical and basic electrophysiologist who joined the attending staff of the Cardiology Division at The Hospital for Sick Children (Sick Kids) in 1999.

Gross obtained his MD degree at Queen's University in Kingston, Ontario in 1984. After graduating from medical school, Gross completed a mixed internship at McMaster University in Hamilton, Ontario. He then moved to Ottawa, where he completed his paediatric residency at the Children's Hospital of Eastern Ontario (CHEO).

Gross is a clinical and basic electrophysiologist who joined the attending staff of the Division of Cardiology at The Hospital for Sick Children (SickKids) in 1999.

Gross obtained his MD at Queen's University in Kingston, Ontario, in 1984. After graduating from medical school, Gross completed a mixed internship at McMaster University in Hamilton, Ontario. He then moved to Ottawa, where he completed his paediatric residency at the Children's Hospital of Eastern Ontario (CHEO).

In 1990, Gross began a combined clinical and research fellowship in paediatric cardiology at Boston Children's Hospital and Harvard Medical School. After completing his core clinical training requirements, Gross spent a year in the ion channel laboratory of Dr. Diomedes Logothetis as the 1992-3 recipient of the Albert S. Hyman Fellowship in Cardiac Pacing and Electrophysiology awarded by the North American Society of Pacing and Electrophysiology (NASPE). Gross subsequently moved to Dr. Neil Castle's patch clamp electrophysiology and pharmacology laboratory in Anesthesia Research at Brigham & Women's Hospital, also in Boston. During his training there, Gross was supported by a fellowship from the Medical Research Council of Canada.

Upon completion of his training in 1996, Gross secured a junior faculty position at the University of Manitoba in Winnipeg. He established an independent, grant-funded basic electrophysiology laboratory at the St. Boniface General Hospital Research Centre while providing clinical coverage at the Variety Children's Heart Centre, including six months as Acting Head of Paediatric Cardiology just prior to his relocation to SickKids in 1999.

Gross is married to an ER physician, Dr. Debra Kiez, and with their five children they enjoy travel including camping, canoeing and hiking. Gross is also an avid cyclist and jazz music fan.

Gross is spending the 2008-9 academic year as a visiting sabbatical scholar in the renowned stem cell research laboratory of Dr. Lior Gepstein at the Technion's Rappaport Institute in Haifa, Israel.

Clinical Care Activities

Gross is an attending cardiologist with responsibilities that include a weekly outpatient clinic and staff coverage of the cardiology consult service. He is also responsible for a satellite outpatient clinic in Sudbury, Ontario. As a member of the Arrhythmia Service, he is involved in diagnostic and therapeutic procedures related to heart rhythm disturbances .

Research Interests

  • Heart rate dependent ventricular remodeling
  • Paediatric arrhythmias
  • Developmental aspects of cardiac myocyte repolarizing currents

Research Activities

My clinical expertise in paediatric cardiology, with a special interest in arrhythmias, gives me an excellent vantage point for investigation of the basic cellular and molecular mechanisms underlying normal and disturbed heart rhythm. Since my arrival at Sick Kids, my laboratory associates and I have developed a novel model of acquired heart block with compensated ventricular bradycardia. This model now provides the primary focus for our investigation of ventricular electrical remodeling in the setting of chronically abnormal heart rates.

We use techniques ranging from implantable real time wireless ECG telemetry to whole cell patch clamp study of repolarizing currents in isolated ventricular myocytes. My laboratory incorporates two complete, state-of-the-art patch clamp set-ups including temperature control, multi-drug perfusion, gas superfusion, and programmed electrical stimulation capabilities. Additional techniques used in the laboratory include Langendorff heart perfusion and cardiac myocyte isolation, real time PCR, and Western immunoblotting.

My co-investigators and I are particularly interested in defining the earliest manifestations and progression of electrical remodeling, and in relating the onset of electrocardiographically detectable changes to alterations in regulation and expression of cardiac myocyte potassium channels.

External Funding

Ventricular Repolarization in Bradycardic Electrical Remodeling.
Heart & Stroke Foundation of Ontario (2007 - 2010)

Contractile Adaptations to Constrained Heart Rate Conditions.
Canadian Institutes of Health Research (2008 - 2012)


  • Schwartz-Reisman Visiting SickKids Scholarship; The Hospital for Sick Children. 2008
  • Robert Salter Humanitarian Award; SickKids Foundation. 2006
  • Subspecialty Teaching Award; Department of Paediatrics, The Hospital for Sick Children. 2003


Suto F, Zhu W, Chan A, Gross GJ: IKr and IKs remodeling differentially affects QT interval prolongation and dynamic adaptation to heart rate acceleration in bradycardic rabbits. American Journal of Physiology/Heart & Circulatory Physiology 2007: 292: pp H1782-8.

Anand N, McCrindle BW, Chiu-Man C, Hamilton RM, Kirsh JA, Stephenson E, Gross GJ: Chronotropic incompetence in young patients with late postoperative atrial flutter: a case-control study. European Heart Journal 2006: 27: pp 2069-73.

Gross GJ, Chiu CC, Hamilton RM, Kirsh JA, Stephenson EA: Natural history of postoperative heart block in congenital heart disease: Implications for pacing intervention. Heart Rhythm 2006: 3: pp 601-4.

Gross GJ: Bradycardia-mediated ventricular electrical remodeling. Journal of Cardiovascular Electrophysiology 2006: 17: pp S178-82.

Costantini DL, Arruda EP, Agarwal P, Kim K-H, Zhu Y, Zhu W, Lebel M, Cheng CW, Park CY, Pierce SA, Guerchicoff A, Pollevick GD, Chan TY, Kabir MG, Cheng SH, Husain M, Antzelevitch C, Srivastava D, Gross GJ, Hui C-C, Backx PH, Bruneau BG: The homeodomain transcription factor Irx5 establishes the mouse cardiac ventricular repolarization gradient. Cell 2005: 123: pp 347-58.

Suto F, Zhu W, Cahill SA, Greenwald I, Navarro AC, Gross GJ: Ventricular rate determines early bradycardic electrical remodeling. Heart Rhythm 2005: 2: pp 293-300.

Cahill SA , Gross GJ: Propafenone and its metabolites preferentially inhibit IKr in rabbit ventricular myocytes. Journal of Pharmacology and Experimental Therapeutics 2004: 308: pp 59-65.