Table Of ContentEncyclopedia of Heart Diseases
Encyclopedia of Heart Diseases
M. Gabriel Khan, MD, FRCP [London], FRCP[C], FACC
Cardiologist, The Ottawa Hospital, Ottawa, Canada
Associate Professor of Medicine, University of Ottawa
With a Foreword by
Christopher P. Cannon, MD
TIMI Study Group, Brigham and Women’s Hospital
Harvard Medical School
Boston, MA
Editor-in-Chief, Cardiosource Science and Quality
With255Figuresand70Tables
MGabrielKhan
UniversityofOttawa
Cardiologist
TheOttawaHospital
Ottawa,ONK1H8L6
Canada
ISBN:978-1-60761-218-6
TheelectronicversionwillbeavailableunderISBN978-1-60761-219-3
TheprintandelectronicbundlewillbeavailableunderISBN978-1-60761-220-9
DOI10.1007/978-1-60761-219-3
SpringerNewYorkDordrechtHeidelbergLondon
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(cid:1)SpringerScience+BusinessMediaLLC2011
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Acknowledgments
Peoplewhoneedpeople
The vast amount of information provided to readers is indicative of the efforts and perseverance of the numerous
investigatorswhose publishedworksIhavehadthepleasureofquoting.Thesetalentedwomenandmenofmedicine
deservemyrespect,mythanks,andmycongratulations.Ifeelcertain,however,thatthenamesofmanyresearchershave
beenomittedbecauseofmyoversightandbecausereferencesprovideonlythreenames.
SandraFabiani: ExecutiveEditor, my Publisher atSpringer,hadtheforesightto acceptmy proposal;without her
remarkablevision,thissecondeditionwouldnothaveemerged.
ImustexpressmythankstoSusanneFriedrichsen,AssociateEditor,andherteamthatincludes:
● UlrikeEggert-Neben,EditorialAssistant
● Chandramohan Sivasubramanian, Project Manager whofacedthe taskofproduction ofthe book without disap-
pointingmewiththeirpatienceforacceptingmynumerousadditionalupdates.
The printing style is what I requested – a text that is noncompressed, user friendly, and with well-positioned
illustrations.Fewpublishersareabletofollowthewhimsofauthors.
Last,ImustthankDoctorsScottSolomonandBernardBulwerforallowingmetouseanimatedechocardiographic
imagesfetchedfromtheirbookEssentialEchocardiography.
Thereislittledoubt,however,thatwithouttheloveandcommitmentofmywifeBrigid,thisdauntingtaskofthe
productionofasingle-authored,96-chapterencyclopediawouldnothavebeenpossible.
Preface
Cardiovasculardiseasecurrentlyisresponsibleformorethan14milliondeathsworldwideannuallyandisestimatedthat
thiswillincreasetomorethan25milliondeathsintheyear2025inapopulationof7.9billionpeople.Thiswidespread
diseasecausesmoredeathsthanallformsofcancer,diabetes,infections,andlungdiseases.Thisepidemiccanonlybe
curbedbyrelevantandsoundresearch.Suchresearch,however,requiresacquisitionofaccuratecoreknowledge.The
buddingresearcherneedstoknowwhatistrulyprovenandwhatneedstobeproven.
Cliniciansrequireonlinemedicalupdatesbroughtrapidlytotheircomputerssoastorendermoreefficientcarefortheir
patients.
● Thisencyclopedicworkisdirectedatallphysicianswhorendercaretocardiovascularpatientsandtoallwhowishto
pursuearesearchcareerinmedicine,pharmacology,biomedicalengineering,andtechnologicinnovations.Hope-
fully,practicingclinicianswouldgleancrucialandup-to-dateinformationthatwouldprovideamelioratingbenefits
for their patients. At the end of a patient–doctor consultation, it is the prescription handed to the patient that
provides a cure or salutary effect. Thus, the text gives considerable amount of information on cardiovascular
therapeutics.
● Bothcareerresearchersandthosewhowishtodevoteonlyafewyearsinresearchwillfindtheinformationprovided
invaluable.Postgraduatesinscienceandtechnology,includingMDsandPhDs,whowishtopursueresearchinthe
medicalsciencesmusthaveareferencesourcethatprovidescoreknowledgeinmedicine,particularly,pathogenesis,
pathophysiology,clinicaldiagnosticfeatures,diagnostictechniques,andmanagementstrategies.Thetextprovides
thisinformation.
● Inaddition,ourseniorcollegeyouthworldwideareclamoringfornewknowledgethatisnotprovidedbytutorswho
preferstudentstoresearchtopics.Muchisprovidedbytheinternetbutinaccuracyabounds.Somematerialinthe
textisattimessimplifiedtoreachthecollegeaudience.
● Thetextoftendescribeshistoricaleventsthatleduptocertainhallmarkdiscoveries;thisisdonetoindicatetothose
interested in research that simple thoughts and perseverance bring fruits from research. It is my hope that this
historicalandrelevantcardiologicinformationwillprovidemotivationandawakeningofnewinterestsinthesolving
ofthepathogenesis,pathophysiology,diagnosis,andmanagementstrategiesofavarietyofheartdiseases.
● Often,majordiscoveriesaremadebythosewhopursueonlyafewyearsinresearch,andinnovationsmaybemadeby
simple thought processes. A prime example is the one revealed by Reverend Hales, the father of hemodynamic
medicine.DuringhisstudiesintheologyatCambridge,hewasfortunatetodomathematicsandscienceandhad
conversationswithamedicalstudent.In1733,aftermanyyearsinhisministry,atTeddingtonoutsideLondon,he
foundthetimeforthestudyofcirculation.Figure1intheentry▶BloodPressureshowsHalesobservingtheblood
pressureinahorse,andheiscreditedtobethefirsttodemonstratethemeasurementofbloodpressure.
● The vascular surgeon Korotokoff, in Russia in 1900, recognizing that a constricted artery makes no sound, used
astethoscopetoobservethesoundsmadebythebloodflowingthroughthearteryinthearmconstrictedbyanarm
band;heheardsoundsasthebandwasreleased.Thefirstsoundsweretakenasthesystolicbloodpressureandthe
sounds are called Korotkoff sounds; the technique is used to this day without change. Korotokoff’s innovative
discoveryrequiredonlyhisthoughtofsound;hewasnotaresearcher.Surgeonsdonotnormallyusestethoscopesbut
vascularsurgeonsdoso,becausetheylistenoverexpandedarteries,aneurysmsthatemitaloudbruit,asoundmade
asthebloodstrikestheexpandedwalloftheartery.
● Manyofthetechnologicadvancesinmedicinehavebeenprovidedforusbythecollaborationofengineers,physicists,
biologists,andmedicaldoctors.Einthovenwouldnothaveproducedtheelectrocardiogramin1901,ifAdlerhadnot
providedthewirelesstelegraph;also,thestringgalvanometer,anonmedicaldevice,wasthenavailabletoEinthoven.
● TheadventofultrasonographywasaninnovationpromptedbytheTitanicdisasterandtheunderwatersearchfor
submarinesin1939.Attheendofthewar,physicistsandmedicaldoctorscollaboratedtoprovidetheultrasoundfor
neurologicinvestigations.Echocardiographystemmedfromanengineerwhoworkedincollaborationwithamedical
studentandaphysician.In1964,Dr.HarveyFeigenbaumsawtheunsophisticatedmachineattheAmericancollegeof
x Preface
cardiologyscientificsession.Hewentbacktohislabandborrowedanultrasoundmachinefromtheneurosurgical
divisionandusedthistoshowthatpericardialeffusionsaroundtheheartcouldbeobservedbyultrasonictechnique
andpresentedhishallmarkpaper(Feigenbaum2008).
His research work was not overwhelming and did not require much scientific thought or expertise. He was not
amajorresearchscientist.Manyoftheadvancesinechocardiographyduring1965to1990canbeattributedtohiswork
andtothesophisticationbytheengineers.
● BernardLowniscreditedintheWesternworldwithinitiatingthemoderneraofcardioversion(Cakulevetal.2009).
Lownrecalledthefollowing:
" NeverhavingseenanACdefibrillator,Ihadn’ttheremotestideahowtouseone.Ahostofquestionsneededpromptanswers:
Was the shock painful? Was the anesthesia required? Was there an appropriate voltage setting to reverse ventricular
tachycardia?Iftheshockfailed,howmanyadditionalonescouldbedelivered?(Lown1996)
He“fortunately,andquiteaccidentally,metabrilliantyoungelectricalengineer,BaruchBerkowitz,”whohadbeen
developing a DC defibrillator while working for the American Optical Corporation. Berkowitz in 1961 had the
instrumenttestedinanimalsbyBernardLown(Lown1996).
Medicalsciencehasmadehugeprogressinthepastfewdecadesbutfarmoreremainsunresolved.Aprimeexampleis
theknowledgethatisavailableonthedevelopmentofatheromaandatherothrombosis,adiseaseprocessresponsiblefor
heartattacks,angina,suddendeaths,stroke,intermittentclaudication,andgangreneoftheleg.Thewordatheromais
derived from the Greek word “athere,” meaning porridge or gruel. Ancient Greekphysicians removedtheplaques of
atheromathatobstructedarteries,andcuttingtheplaqueofatheromarevealedagelatinousporridge-likematerial.At
least, we do know that the porridge-like material which exudes from a ruptured atheromatous plaque is highly
thrombogenicandpromotestheclottingofcirculatingblood,andthusthearterialocclusionwhichresultsinmyocardial
infarction(heartattack)orcerebralinfarctions(strokes).
Atheromaisthebasisforheartattacksandstrokeandismainlyresponsiblefortheepidemicdescribedabove.After
morethan60yearsofresearch,wedonotknowhowtoeffectivelypreventtheatheromaformationanditsprogressionto
vesselocclusion.OurnewdiagnosticarmamentariumincludesCTcalciumscoringandCTcoronaryangiograms,bothof
whichgeneratesunjustifiableradiationhazardsandgiveonlycluestothepresenceofvulnerableatheromatousplaques.
MRIisoflimitedvalue.Theinformationgleanedfromtheresultsofthesetestsmostoftendonotsignificantlyalterthe
therapyforthemillionsaffectedworldwidebytheepidemicofatheromatouscardiovasculardisease.
Developmentsoftechnologicinstrumentsthatmayprovidenoninvasivedetectionofatheromatousobstructionin
coronaryarteriesthatpresentlycanonlybeobservedwithcertaintybyaninvasivecoronaryangiographyareurgently
required.CTcoronaryangiographyprovidesconsiderableinformationbutisnotasubstituteforaninvasivecoronary
angiographywhichgivesthecrucialinformationrequiredforapercutaneouscoronaryinterventionorabypasssurgery.
Theinformationprovidedinthisreferenceworkismainlyfactualanddoesnotdiscusscontroversies.But,twoentries
ofthe96,ofnecessity,discusstworecentandimportantcontroversiesincardiovascularmedicine.
1.Worldwide,therearemorethanonebillionhypertensiveindividualswhorequiredrugtreatment.Sadly,aftermore
than 70 years of research, there are only four drugs available: diuretics, beta blockers, calcium antagonists, and ACE
inhibitors(angiotensinreceptorblockersaresimilaragents).Otheragents:methyldopaisusedmainlyforhypertension
inpregnancyandalphablockerscauseheartfailureandhenceitsuseisrestricted.Thissituationcanonlybecorrectedif
pharmaceuticalfirmsandexpertsinthefieldofhypertensionrecognizethatonlyfourdrugsareavailable.
Morethan60%ofhypertensivepatientsrequiretwoorthreedrugstoattainbloodpressurecontrol.
● Recently, peer-reviewed journals have provided editorials by notable physicians who state that the beta blockers
shouldnotbeprescribedforprimaryhypertensionbecauseoftheirineffectivenessandtheymaycausediabetes.An
entry entitled ▶Beta Blockers Hypertension Controversy addresses this topic that is important for clinicians
worldwide.
2. Increase in the incidence of diabetes is a concern: Many investigators have reported recently in peer-reviewed
journals that diuretics and beta blockers cause diabetes mellitus and their use should be restricted. This information
wouldgreatlydecreasetheprescribingoftwooftheonlyfourantihypertensiveagentsavailable.Thesetwoagentsare
