Robbins Essential Pathology Heart PDF

122 CHAPTER 8 Heart Adventitia and e duraon o e occuson, e meaboc demands...

122 CHAPTER 8 Heart Adventitia and e duraon o e occuson, e meaboc demands o e myo- Media cardum, and e exsence o coaera vesses. Mos narcs nvove Intima e et venrce, because e rg venrce s reavey proeced by ower bood pressure (and us ower meaboc demands) and per- NORMAL uson durng bo dasoe and sysoe (due o ower wa pressures). An narc usuay aceves s u exen wn 3 o 6 ours. Cnca ner venon wn s crca wndow o me can essen e sze o e narc wn e “error y a rsk. ” Atherosclerosis Dependng on e poson and degree o coronar y arer y obsruc- Adventitia on, wo paerns o narcon are seen: Media    Transmura nfarcts resu n e dea o myocyes across e u Intima FIXED CORONARY ckness o e myocardum, excep or a n ayer o subendocar- OBSTRUCTION da myocyes a receve er oxygen and nuren suppy drecy Lipids (Typical angina) rom bood n e venrces. hese narcs are generay caused by Atherosclerotic plaque compee obsrucon o an epcarda coronary vesse. Because suc narcs usuay produce eevaed ST segmens n eecrocardograms (ECGs), ey are aso caed ST-segmen eevaed MI (STEMI). Platelet    Endocarda nfarcts resu n e dea o myocyes n e nner aggregate poron o e myocardum. hs ype o narc may be caused by obsrucon o more dsa coronar y vesses or by severe, bu ncom- pee, obsrucons. he aer may preerenay k endocardum because  s n e dsa dsrbuon o e coronar y areres and Healing aso s exposed o g venrcuar pressures, wc mpede dev- er y o bood. On e bass o common ECG ndngs, ese narcs are caed non-ST-segmen eevaed MI (NSTEMI). PLAQUE DISRUPTION SEVERE FIXED CORONARY Myocarda scema aso dsurbs eecrca conducance n e OBSTRUCTION ear, ncreasng e rsk o arrymas. Indeed, aoug myocarda (Chronic ischemic heart disease) scema and narcon can resu n dea due o pump aure, n 80% o 90% o cases dea s caused by venrcuar braon, a parcuary Thrombus Thrombus ea arryma. Morphology. he gross and mcroscopc appearance o a myocar- da narcon depends on e age o e njur y. here s a gy caracersc sequence o morpoogc canges: (1) coaguave necross; (2) acue and en cronc nlammaon; and (3) bross. Myocarda narcs ess an 12 ours od usuay are no grossy MURAL THROMBUS OCCLUSIVE apparen, bu narcs more an 3 ours od can be vsuazed by WITH VARIABLE THROMBUS OBSTRUCTION/? EMBOLI (Acute transmural myocardial exposng myocardum o va sans (Fg. 8.7). Mcroscopcay, (Unstable angina, or acute infarction or sudden death) ypca eaures o coaguave necross become deecabe wn subendocardial myocardial 4 o 12 ours o narcon (Fg. 8.8). By 12 o 24 ours, an narc infarction or sudden death) usuay can be grossy dened by red-bue dscooraon caused by rapped bood. Necroc myocardum ecs acue nlammaon ACUTE CORONARY SYNDROMES (wc ypcay peaks 1 o 3 days ater narcon) oowed by an Fig. 8.5 Diagram of sequential progression of coronary artery lesions nlux o macropages, wc remove necroc myocyes and neuro- leading to various acute coronary syndromes. (Modified and redrawn p ragmens, and s mos pronounced 5 o 10 days ater narcon. from Schoen FJ: Interventional and surgical cardiovascular pathology: Durng s me, narcs become progressvey beer deneaed clinical correlations and basic principles, Philadelphia, Saunders, 1989, p. 63.) as sot, yeow-an areas a by 10 o 14 days become rmmed by gy vascuarzed granuaon ssue. Heang requres e mgra- on o nlammaor y ces and ngrow o new vesses rom e von Webrand acor, and ssue acor, eadng o paee adeson narc margns, and arge narcs ake onger o ea an sma and aggregaon and acvaon o coaguaon acors (see Fg. 8.5). ones. Evenuay, over a perod o weeks, brous scar repaces e Paees are cenra o rombus ormaon n e g sear sress narced ssue. envronmen n areres. hereore, anpaee agens (e.g., asprn) are useu n bo e prevenon and reamen o myocarda narcon. Wn seconds o vascuar obsr ucon, aerobc gycoyss ceases Clncal Features. e cassc myocarda narcon s eraded by n e myocardum, adenosne rpospae eves a, and noxous severe, crusng subserna ces pan or pressure a radaes o e meaboes (e.g., acc acd) accumuae. Loss o conracy occurs neck, jaw, epgasrum, or et arm. In conras o angna pecors, e wn a mnue or so o e onse o scema. Iscema asng 20 assocaed pan s perssen and s no reeved by nrogycern or res. o 40 mnues causes rreversbe damage and myoc ye dea n e In a mnory o paens, myocarda narcon may be asympom- orm o coaguave necross (see Caper 1). he ocaon, sze, and ac. Suc “sen” narcs are reavey common n oder paens and morpoogc eaures o a myocarda narc depend on e sze and dabecs (due o auonomc neuropaes a bun e percepon o dsrbuon o e nvoved vesse (Fg. 8.6), e rae o deveopmen pan).  CHAPTER 8 Heart 123 TRANSMURAL INFARCTS NON-TRANSMURAL INFARCTS Restoration of flow (reperfusion) Per manent Transient/par tial occlusion of obstruction left anterior regional descending subendocardial branch infarct Posterior Per manent Global occlusion of hypotension RV LV left circumflex circumferential branch subendocardial infarct Anterior Per manent occlusion of Small the posterior intramural descending vessel branch of the occlusions right coronar y microinfarcts ar ter y Fig. 8.6 Dependence of myocardial infarction on the location and nature of the diminished perfusion. Left, Patterns of transmural infarction resulting from major coronary artery occlusion. The right ventricle may be involved with occlusion of the right main coronary artery (not depicted). Right, Patterns of infarction resulting from partial or transient occlusion (top), global hypotension superimposed on fixed three-vessel disease (mid- dle), or occlusion of small intramyocardial vessels (bottom). and s ocaon n e ear. Serum eves o proens a eak rom njured myocarda ces are useu n dagnoss. Cardac roponns T and I ave g speccy and sensvy or myocarda damage (Fg. 8.9). More an 90% o paens wo make  o a ospa sur vve e acue even, bu neary ree ours experence one or more o e oowng compcaons (Fg. 8.10):    Contracte dysfuncton. Inarcs mpar et venrcuar pump unc- on n proporon o e voume o damaged myocardum. Severe “pump aure” (cardogenc sock) occurs n rougy 10% o paens w ransmura narcs, ypcay ose a damage 40% or more o e et venrce.    Papary musce dysfuncton. Aoug papar y musces rupure nrequeny ater narcon, ey oten are dysuncona, eadng o posnarc mra regurgaon.    Myocarda r upture. Rupure compcaes on y 1% o 5% o narc- ons bu s  requen y a a w en  o cc urs. I s more common n  os e w o receve  romb oy c  erapy. L et ven r c uar  ree wa r upure s mos common, usuay resu ng n rapd y a a  emo- Fig. 8.7 Acute myocardial infarct of the posterolateral left ventricle p er cardum and cardac  amp onade (s ee Fgs. 8.7 and 8.10A). demonstrated by a lack of triphenyltetrazolium chloride staining in areas Venr c uar s ep a r upure may cre ae a et-o-r g  sun (s ee of necrosis (arrow); the absence of staining is due to enzyme leakage Fg. 8.10B), and papar y mus ce r upure may e ad o s e vere after cell death. Note the anterior scar (arrowhead), indicative of remote mra regurg aon (Fg. 8.10C). Rupure usuay o cc urs w n infarction. The myocardial hemorrhage at the right edge of the infarct  e rs 5 days n 50% o cas es and w n  e rs wo weeks n (asterisk) is due to ventricular rupture, and was the acute cause of death 90% o cas es,  e me dur ng  e e ang pro cess w en muc o in this patient (specimen is oriented with the posterior wall at the top).  e narc  consss o s ot,  r abe granuaon ssue. he puse usuay s rapd and weak and paens are oten dapo-    Arrytma. Approxmaey 90% o paens deveop some orm o rec and nauseaed. Dyspnea s common, due o mpared myocarda rym dsurbance. he rsk or serous arryma (e.g., venrcu- conracy and dysuncon o e mra vave apparaus, w resu- ar braon) s greaes n e rs our and decnes ereater. I an acue pumonar y congeson and edema. W massve myocarda s responsbe or e majory o deas occurrng pror o ospa- narcon, cardogenc sock deveops due o pump aure. zaon. Caracersc eecrocardograpc abnormaes are usuay presen    Percardts. Transmura narcon can ec a panu brnoem- and can ep o deermne e ype o narcon (STEMI or NSTEMI) orragc percards due o underyng myocarda nlammaon 124 CHAPTER 8 Heart A B C D E Fig. 8.8 Microscopic features of myocardial infarction and its repair. (A) One-day-old infarct showing coag- ulative necrosis and wavy fibers, compared with adjacent normal fibers (right). Necrotic cells are separated by edema fluid. (B) Dense neutrophilic infiltrate in the area of a 2- to 3-day-old infarct. (C) Nearly complete removal of necrotic myocytes by phagocytic macrophages (7 to 10 days). (D) Granulation tissue character- ized by loose connective tissue and abundant capillaries. (E) Healed myocardial infarct consisting of a dense collagenous scar. A few residual cardiac muscle cells are present. (D) and (E) are Masson’s trichrome stain, which stains collagen blue. 40 (see Fg. 8.10D). Percards ypcay appears 2 o 3 days ater narcon and resoves over e nex ew days.    V entrcuar daton and aneurysm formaton. Because necroc mus- )timil ce s weak, ere may be dsproporonae srecng, nnng, and ecnerefer daon o e narced regon (especay w anerosepa narcs). 30 n oi tartnecn oc In some arge ransmura narcons, s eads o venrcuar aneu- Troponin I rysms (see Fg. 8.10F), wc are prone o mura romboss and are CK-MB assocaed w arryma and ear aure. Rupure s uncommon. reppu Myoglobin    Mura trombus. Sass due o dmnsed myocarda conracy 20 evitaleR and endocarda damage osers mura romboss (see Fg. 8.10E), fo w rsk or et-sded romboembosm selpitlum=(    Reper fuson njury. As dscussed n Caper 2, resoraon o bood low o scemc musce may paradoxcay cause e dea o va- 10 be “a-rsk” myocardum. he precse mecansm s unceran: ncreased producon o reacve oxygen speces rom ces w damaged mocondra, ncreased upake o cacum no ces w damaged membranes, and deeerous efecs o nlammaor y ces 0 ave a been proposed o conrbue 4 20 40 he ong-erm prognoss ater myocarda narcon depends on Hours after onset of chest pain many acors, e mos mporan o wc are et venrcuar unc- Fig. 8.9 Increases in myocardium-derived troponin I, myocardial cre- on and e severy o aerosceroc coronar y arer y dsease. he atine kinase (CK-MB), and myoglobin following myocardial infarction. overa moray rae wn e rs year s abou 30%, ncudng Troponins are particularly sensitive and specific markers of myocardial deas occurrng beore e paen reaces e ospa. ereater, injury.  CHAPTER 8 Heart 125 A B C D E F Fig. 8.10 Complications of myocardial infarction. (A to C) Cardiac rupture. (A) Anterior free wall myocardial rupture (arrow). (B) Ventricular septal rupture (arrow). (C) Papillary muscle rupture. (D) Fibrinous pericarditis, with a hemorrhagic, roughened epicardial surface overlying an acute infarct. (E) Recent expansion of an anteroapical infarct with wall stretching and thinning (arrow) and mural thrombus. (F) Large apical left ven- tricular aneurysm (arrow). (A to E, Reproduced by permission from Schoen FJ: Interventional and surgical cardiovascular pathology: clinical correlations and basic principles, Philadelphia, Saunders, 1989; F, Courtesy of William D. Edwards, MD, Mayo Clinic, Rochester, Minnesota.) e annua moray rae or paens wo ave sufered a myocarda Clncal Features. Cronc scemc ear dsease s assocaed w narcon s 3% o 4%. severe, progressve ear aure, occasonay puncuaed by new ep- sodes o angna or narcon. Arryma, ear aure, and nercur- Chronic Ischemic Heart Disease ren myocarda narcon accoun or mos o e assocaed morbdy and moray. Chronic ischemic heart disease, also called ischemic cardiomyopa- thy, is characterized by progressive heart failure due to cumulative myocardial damage. ARRHYTHMIA Aberrant heart rhythm (arrhythmia) frequently arises in the set- Pathogeness. Usuay, ere s a sor y o one or more myocarda ting of myocardial ischemia or scarring and is a major cause of narcons: Cronc scemc ear dsease occurs wen compensa- sudden death. or y mecansms o e resdua myocardum can no onger manan he eecrca sgnas a coordnae myocarda conracon are cardac uncon. In oer cases, severe coronar y arer y dsease and ransmed rom ce o ce roug gap juncons n a wave a cronc scema cause wdespread myocarda dysuncon wou propagaes rom e snoara node (e cardac pacemaker) roug over myocarda narcon. e arovenrcuar node o e base o e venrces. Aberran ryms may sar any were n e conducon sysem and are subd- Morphology. Cronc scemc ear dsease ypcay resus n et vded based on e se o orgn, eer e supravenrcuar (ara) venrcuar daon and yperropy, oten w dscree areas o or venrcuar myocardum. Arrymas may be susaned or spo- scarrng rom prevous eaed narcs. Invaraby, ere s moderae radc, and can manes as ryms a are oo sow (bradycarda), o severe aerosceross o e coronary areres. he endocardum oo as (tacycarda), rreguar, or a precude efecve cardac generay sows pacy, brous ckenng, and mura romb may pumpng (ventrcuar ibraon and asysoe). Ara braon be presen. Mcroscopc ndngs ncude myocye yperropy and occurs wen ara myoc yes become “rrabe” and depoarze nde- bross a ses o pror narcon. pendeny and sporadcay (as occurs w ara daon); e sgnas 126 CHAPTER 8 Heart are varaby ransmed roug e arovenrcuar node, eadng o n sze (boxcar nuce). W aure, degenerave canges appear, e “rreguary rreguar” ear rae and rym o ara braon. ncudng ragmenaon and oss o myocye conrace bers. I e arovenrcuar node s dysuncona, var yng degrees o ear ere oten are scaered oc o nerceuar bross, represenng bock occur ses o myocye dropou due o scema. Inay e ckened et venrcuar wa becomes sf, mparng dasoc ng and eadng Pat h o g e n e s  s. A c q u i re d myocardial diseases and inherited o et ara daon, bu w progresson o congesve ear aure disorders of ion transport a re important causes of rhythm venrcuar daon appears. disorders. Acqured acors a dsurb myocarda sgna conducon ncude scema, nlammaon or scarrng, and deposon o exra- ceuar maera beween myoc yes (e.g., cardac amyodoss). e Clncal Features. E ary yperensve ear dsease s asympomac mos mporan rsk acor s coronar y arer y dsease and assoc- and s suspeced ony  rom e dscover y o eevaed bood pressure aed scemc njur y. In mos cases, ere s no assocaed myocar- or ncdenay dscovered et venrcuar yperropy. Poory con- da narcon, and arryma us appears o be rggered by e roed yperenson ncreases e rsk or scemc ear dsease eecrca “rraby” o abnorma myocardum. Inered orms o (by poenang coronar y aerosceross), rena damage, cerebro- arrymas are ess common and are usuay due o muaons n vascuar sroke, ara braon, ear aure, and sudden dea. genes a encode cardac on cannes (so-caed canneopaes). Efecve yperenson conro greay essens e rsk o a o ese e prooypca canneopay s e ong QT sy ndrome, caused mos compcaons. oten by a muaon afecng a poassum canne. Many commony Right-Sided (Pulmonary) Hypertensive Heart Disease used medcaons can rgger arrymas n paens w ong QT syndrome. Canneopaes are dagnosed by genec esng, yp- Right-sided hypertensive heart disease may be caused by primary cay perormed n paens w a amy sor y or an unexpaned disorders of the lung parenchyma or vasculature, or may occur nonea arryma. secondary to left-sided ventricular failure or congenital heart dis- ease associated with left-to-right shunts. Causes o soaed rg-sded yperensve ear dsease (aso Clncal Features. Ar ry m a may be asy mpoma c, be s ens e d as known as cor pumonae) ncude dverse dsorders afecng pumo- abnor ma  b e as (paptatons) or a rapd e ar  rae, or c aus e sy mp- nar y ar excange or e pumonar y vascuaure (Caper 10). A oms re ae d o nade qu ae c ard ac oupu, suc as an ng (sy n- produce ncreased pumonar y vascuar ressance, eadng o yperen- cope). Sudden de a  c aus e d by ven r c u  ar br    a on or asysoe son, rg venrcuar yperropy (Fg. 8.11B), and evenuay rg- o cc urs n roug  y 400,000 p e ope e ac ye ar n  e Une d S aes. I sded ear aure. he mos common suc dsorders are: s due o coronar y ar er y ds e as e n 80% o 90% o c as es and may    Dseases of pumonary parencyma, suc as cronc obsrucve pu- be  e rs manes a on o coronar y ar er y ds e as e. In younger monar y dsease and dfuse nersa bross p a ens, nona eros cero c c aus es are more common, ncudng    Dseases of pumonar y vesses, suc as recurren romboembosm canneop a es, congen a  abnor ma  es n va ves or coronar y and prmar y pumonar y yperenson ar er es, myo c ard s and nl ammaor y ds orders, c ardomyop a-    Dseases afecng ches movemen, suc as kyposcooss and obesy  es, and myo c ard a  yp er  ropy s e cond ar y o yp er enson and    Dseases causng pumonary vascuar consrcon, suc as obsruc- o er ac ors. ve seep apnea Rg-sded ear aure may be acue n onse (e.g., w pumo- nar y embosm) or may appear sowy and nsdousy because o pro- HYPERTENSIVE HEART DISEASE onged pressure overoad n e seng o cronc pumonar y dsease. Hyperenson ncreases e cardac workoad and aso as deeerous efecs on arera vesses (see Caper 7). he cardac compcaons ncude congesve ear aure and aa arryma. Aoug e et VALVULAR HEART DISEASE sde o e ear s mos commony afeced due o e requency o sys- emc yperenson, rg-sded yperensve canges (cor pumonae) Valvular disease results in cardiac dysfunction by causing stenosis aso occur n some dsease sengs and/or insufciency (regurgitation or incompetence). Senoss s e aure o a vave o open compeey, obsrucng or- Systemic (Left-Sided) Hypertensive Heart Disease ward low, amos aways due o a cronc process (e.g., caccaon Systemic hypertens i v e he a rt d i s ea s e is d e ne d by left ventric or vave scarrng) a afecs one or more vave cusps. Insuicency ular hypertrophy s eco n d a ry to d o c ume nt e d h y p er t e n s i o n in resus rom aure o a vave o cose compeey, aowng bood o the absence of other ca r d i o v a s cu l a r p a t h o lo g y (e. g. , v a lv u l a r regurgae (backlow). Vavuar nsuicenc y can resu rom dsease stenosis). o e vave cusps (e.g., endocards) or o e supporng srucures (e.g., e endnous cords or papar y musces). Insuicenc y may Pathogeness. Even md yperenson (>140/90 mm Hg),  proonged, appear abrupy (e.g., rom corda rupure) or nsdousy due o nduces et venrcuar yperropy as an adapaon o e ncreased eale scarrng and reracon. Vavuar dsease s muc more com- workoad agans ressance (Fg. 8.11A). I e yperensve sress s pro- mon on e et sde o e ear and s usuay acqured. Causes o onged or severe, e ear may no onger be abe o adap efecvey and acqured vavuar dsease are summarzed n Tabe 8.2 may begn o a. Abnorma low roug dseased vaves produces abnorma ear sounds caed murmurs; severe low abnormaes may be exernay papaed as hrs. he ocaon, quay, and mng o e murmur are Morphology. he ear s eavy and e et venrcuar wa s ck- deermned by e vave afeced, e efec o e eson (regurgaon ened. Mcroscopcay, myocyes and myocye nuce are ncreased versus senoss), and e severy o e deec.  CHAPTER 8 Heart 127 * A B Fig. 8.11 Hypertensive heart disease. (A) Systemic (left-sided) hypertensive heart disease. There is marked concentric thickening of the left ventricular wall, causing a reduction in lumen size. The left ventricle and left atrium are shown on the right in this four-chamber view of the heart. A pacemaker is present incidentally in the right ventricle (arrow). Note also the left atrial dilation (asterisk) due to stiffening of the left ventricle and impaired diastolic relaxation, leading to atrial volume overload. (B) Chronic cor pulmonale. The right ventricle (shown on the left) is markedly dilated and hypertrophied with a thickened free wall and hypertrophied trabec- ulae. The shape and volume of the left ventricle have been distorted by the enlarged right ventricle. Table 8.2 Etiology of Acquired Heart Valve Disease D egenera ve canges n c ard  ac v a ves are re ae d o rep e   ve me canc a  s ress es  a re qure sub s an  a  va ve d eor ma on w   Mitral Valve Disease Aortic Valve Disease e ac nor ma  op enng. T e mos c om mon d ege ne ra ve canges are : Mitral Stenosis Aortic Stenosis    Cacicaons, wc can be cuspa (n e aorc vave) (Fg. 8.12A Postinflammatory scarring Postinflammatory scarring and B) or annuar (n e mra vave) (Fg. 8.12C and D). (rheumatic heart disease) (rheumatic heart disease)    Aeraons n e exraceuar marx. here can be ncreased pro- Calcification of mitral ring Senile calcific aortic stenosis eogycan and dmnsed brar coagen and easn (myxoma- Calcification of congenitally ous degeneraon) or bross and scarrng. deformed valve Mitral Regurgitation Aortic Regurgitation Calcific Aortic Degeneration Abnormalities of leaflets and Intrinsic valvular disease Calcic aortic degeneration is the most common cause of aortic commissures Postinflammatory scarring stenosis. Postinflammatory scarring (rheumatic heart disease) Cacc degeneraon usuay s asympomac, bu  may be severe Infective endocarditis Infective endocarditis enoug o cause senoss, necessang surgca nervenon. e nc- Mitral valve prolapse Aortic disease dence ncreases w age, and mos paens presen a e age o 70 years “Fen-phen”–induced valvular Degenerative aortic dilation or greaer. An mporan rsk acor s bcuspd aorc vave, a congen- fibrosis Syphilitic aortitis a dsorder n wc e vave conans wo uncona cusps nsead Abnormalities of tensor apparatus Ankylosing spondylitis Rupture of papillary muscle Rheumatoid arthritis o ree. Bcuspd aorc vave occurs n 1% o 2% o a ve brs. I s Papillary muscle dysfunction Marfan syndrome generay asympomac eary n e bu s prone o caccaon eadng (fibrosis) o aorc senoss 1 o 2 decades earer an norma rcuspd vaves. Rupture of chordae tendineae Abnormalities of left ventricular Pathogeness. Rsk acors or aorc vave degeneraon and cac- cavity and/or annulus caon ncude mae sex, g ow-densy poproen coesero, Left ventricular enlargement yperenson, and smokng, a o wc are aso assocaed w a- (myocarditis, dilated cardiomy- erosceross. e accumuaon o poproens nduces oca nlamma- opathy) on, wc may be exacerbaed by low abnormaes (e.g., bcuspd Calcification of mitral ring vave, yperenson) a aer endoea ce uncon. e resung Fen-phen, Fenfluramine-phentermine. njur y predsposes e vave or caccaon. Data from Schoen FJ: Surgical pathology of removed natural and prosthetic valves, Hum Pathol 18:558, 1987. Morphology. Heaped-up caced masses on e oulow sde o e cusps prorude and mecancay mpede vave openng, causng Degenerative Valve Disease senoss (Fg. 8.12A and B). e cusps oten sow ckenng due Degenerative valve disease is an umbrella term that describes o bross. changes in the valvular extracellular matrix that negatively affect valve function.