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35. Wykoff RF. Delusions of parasitosis: areview. Rev Infect Dis. 1987;9:433-7.36. Milia A, Mascia MG, Pilia G, ParibelloA, Murgia D, Cocco E, et al. Efficacyand safety of quetiapine treatment fordelusional parasitosis: experience in anelderly patient. Clin Neuropharmacol.2008;31:310-2.37. Narayan V, Ashfaq M, Haddad PM.Aripiprazole in the treatment of primarydelusional parasitosis. Br J Psychiatry.2008;193:258.REVIEWStem cells in cardiac repair: A review of the changinglandscape of cardiovascular medicineNicholas A. Avdimiretz, BScMedical Student (2013), Faculty of Medicine and Dentistry University of Alberta, Edmonton, CanadaCorrespondence to Nicholas Avdimiretz: Email: naa1@ualberta.caAbstractCardiac disease is the leading cause of deathfor both men and women in developedcountries. In Canada, the incidence ofdiabetes and hypertension has recentlyincreased by 90% in middle income groups,resulting in substantially more cardiacdisease. How can medical professionalskeep up with these statistics? Imagine ifphysicians could regenerate the woundedheart post-myocardial infarction, or evenbioengineer an entirely new organ. Thisis the future of cardiovascular medicine.Regenerating myocardium is hardly an easyundertaking; the heart contains about 20million cardiomyocytes per gram of tissue,meaning – in the left ventricle alone – thereare approximately 4 billion cardiomyocytesat risk during a heart attack. Many cells arerequired to replace damaged tissue, makingcomplete regeneration challenging. In lightof the rich therapeutic potential seen inboth adult and embryonic stem cells, it is nosurprise that biomedical research on thesecells has seen an intense amount of activityin the past decade. From fetal-derivedcardiomyocytes and skeletal myoblasts, tobone marrow stromal cells and peripheralblood CD34 + cells, a myriad of cell lineshave been tested to date. The last decadehas seen an explosion of novel approachesusing these cells to restore cardiac functionpost-infarction: from developing cell-basedpacemakers and cardiac grafts, to buildingbioartifical hearts. This review will paint apicture of the rapidly changing landscapeof cardiovascular medicine by elaboratingon these new technologies. Limitationsof these approaches will be discussed, aswell as future developments. In the field ofcell-based cardiac repair, the possibilitiesseem endless.PreambleCardiac disease is the leading causeof death for both men and women indeveloped countries. In fact, cardiovasculardisease – including coronary heart disease,hypertension, stroke, and congestive heartfailure – has ranked as the number onecause of death in the US every year since1900, except during the 1918 influenzaepidemic. 1 In 2007, heart disease accountedfor 26% of all deaths in the US, resultingin an age-adjusted death rate of 211 per100,000 people. 2 Also shocking is the costof medication, health care services, and lostproductivity due to heart disease in the US:a projected $508 billion in 2010. 3 This costis not expected to decrease any time soon.In Canada, the incidence of risk factors forcardiac disease has increased substantiallyover the past decade: both diabetes andhypertension have increased by 90% inmiddle income groups (roughly 50% ofthe population), 4 resulting in substantiallymore cardiovascular disease. What if thereexisted a therapeutic technique to treat thatwhich physicians have for so long deemedincurable? What if one could regenerate thewounded heart after a myocardial infarctionusing stem cells? Imagine if one couldbioengineer a new heart. This could be thefuture of cardiovascular medicine.Over the last decade, the utilization ofstem cells to repair the damaged heart hasseen an explosion of advancements. Noveltherapeutic techniques will be addressed indetail: the methods used and the resultingapplications of these innovations will bedescribed. Limitations of these techniquesand future developments will also bereviewed.Introduction to Cardiac RepairCell therapy has experienced muchgrowth over the last 25-30 years: fromits first applications for reconstitutingthe immune system after a bone marrowtransplant, to treating diabetes withpancreatic islet transplantation. 5 More recenttreatments include those for liver cirrhosis,Huntington’s disease, and Parkinson’sdisease. 6 As for heart disease, the majorityof therapies have been centered on thetreatment of heart damage post-myocardialinfarction (MI). How can myocardial repairoccur in an organ that is thought to beincapable of naturally self-repairing itself?The heart does not experience regenerationas the liver does; following MI, scar tissueforms over the infarcted area. Therefore,much of the research has been gearedtowards using cell-based approaches toregenerate myocardium directly fromdonor stem cells. Regenerating heartmuscle following an MI is hardly an easyundertaking; the myocardium containsabout 20 million cardiomyocytes per gram oftissue, so there are approximately 4 billioncardiomyocytes at risk in the left ventriclealone during a heart attack. Assumingthat any repair therapy restores at least1/2 to 2/3 of the damaged myocardium,true regeneration would require 500 to 800million cells. 7 In light of the therapeuticpotential seen in both adult and embryonicstem cells (coined ES cells by Martin in1981), 8 it is no surprise that biomedicalresearch on these cells has seen an intenseamount of activity in the past decade.Stem Cell SourcesStem cells not only have an unlimitedcapacity to self-renew, but they are alsopluripotent; this means that stem cellscan be induced to differentiate into cellsUniversity of Alberta Health Sciences Journal • April 2012 • Volume 7 • Issue 1 13