VALVULAR HEART DISEASECausesa) stenosisi) “narrowing” and failure of forward flowb) insufficiency (regurgitation, incompetence) i) failure of valve to close completely- allowing reverse flow
c) Pure i) stenosis or regurgitation d) mixed i) stenosis and regurgitation coexist in same valve - usually 1 defect predominates e) isolated i) 1 valve f) combined i) more than 1 valve dysfunctional
g) flow anomalies through valves produce turbulent flow patterns h) acquired valvular heart disease
iii) most frequent causes:- AS calcification of congenitally deformed valve- AI dilation of ascending aorta (e.g., hypertension and aging)- MS RHD- MI mitral valve prolapse(myxomatous degeneration)
Myxomatous Degeneration of Mitral Valve (Mitral Valve Prolapse) ballooning back during systole one of most common valvular heart diseasesa) incidence in womenb) usually presents as incidental finding on physical exam
c) affected leaflets are thickenedi) due to mucoid deposits (“Myxomatous”)ii) cords are usually elongated thinned and often rupturediii) annular dilation characteristic- leaflets balloon- rare in other mitral insufficienciesiv) thrombi formation - behind ballooned cusps (on leaflets)
d) clinical: i) most asymptomatic ii) ~3 % develop complications:
Rheumatic Fever and Heart Disease RF is acute inflammation a) within weeks following group A streptococcal pharyngitis i) cross reaction of Ab directed at M proteins of Strep. proteins with glycoprotein Ag in heart, etc. b) acute carditis (RF) may develop to chronic RHDc) consequence of RF is chronic valvular deformities (fibrosis) - mitral and aortic - mainly mitral stenosis - permanent
Pathology:a) RF focal inflammatory lesions i) “Aschoff” bodies pathognomonic for RF- swollen eosinophilic collegen- found is any layer of the heart (“pancarditis” - in pericardium fibrinous or serofibrinous exudateii) “Anitschkow” cells- swollen activated macrophages and/or plasma cells
b) RHD – chronici) organized acute inflammation- fibrosis ii) leaflet thickeningiii) commissure fusion (stenosis)- “buttonhole” or “fishmouth” stenosesiv) cord fusion / thickening v) Aschoff bodies replaced with fibrous scar
Stenotic mitral Valve seen from left atrium. Both commissures are fused; the cusps Are severely thickened.The left atrium is huge. The valve is both incompetent and stenotic
Opened stenotic mitral valve showing thickening distorted cusps, adherent commissures with calcification and thrombus deposition, and thickening, fusion and shortening of chordae tendinae
vi) major cause of mitral stenosis - ~ 99% - mitral valve alone ~ 70% - mitral / aortic valve ~ 25%
Clinical (major criteria):a) migratory polyarthritisi) large jointsb) carditisc) s.c. nodulesd) erythema marginatume) Chorea movements (CNS) (Sydenham Chorea) (“St. Vitus Dance”)Minor criteria - Fever - Arthralgia - High ESR
s.c. nodule
erythema marginatumInfective Endocarditis Most cases are bacterial Classification based on clinical grounds a) acute i) destructive (necrotic, ulcerative) valvular infections ii) Friable, bulky, vegetation contiaing fibrin, inflammatory cells and m.o. iii) highly virulent (S. aureus) iv) frequently of healthy valve v) ~ 50% lethal: days to weeks - despite antibiotics/surgery
b) Subacute i) low virulence (causative organisms)ii) recovery with antibiotic Txiii) vegetative growths show signs of healing iv) colonizing a previously abnormal heart valves. v) Splenomegaly is common. vi) The aortic and mitral valves are the most common sites of infection
Common Manifestations of Infective Endocarditis. Splinter hemorrhages are normally seen under the fingernails. Systemic emboli with septic infarcts
Predispossing factors for infective endocarditis i) Prosthetic heart valves ii) Pre-existing cardiac disease iii) indwelling vascular catheters iv) Host factors such as neutropenia, immunodeficiency, malignancy, D.m, alcohol or intravenous drug abuse.
Non Infective Endocarditis Nonbacterial Thrombotic Endocarditis (NBTE) a) sterile, nondestructive b) small masses of fibrin, platelets, etc. - on leaflets of cardiac valves c) often seen in debilitated pts - cancer d) may produce emboli - stroke in brain, heart, etc.
e) frequently occur with DVT and PE - common origin with hypercoagulable states
Disease of the Myocardium A. Cardiomyopathy B. Myocarditis Cardiomyopathy This term refers to diseases of the heart muscle that are non-inflammatory and are not associated with hypertension, congenital heart disease, valvular disease, or coronary artery disease. Usually, these diseases are characterized by otherwise unexplained ventricular dysfunction (heart failure unresponsive to digitalis, ventricular enlargement, ventricular arrhythmias.)There are three general pathophysiologic categories of cardiomyopathy : Dilated (90%). Hypertrophic Restrictive (least common) Dilated cardiomyopathy It results in systolic (contractile dysfunction) It may be acquired, for example following myocarditis, toxic exposures (e.g. alcohol) or pregnancy (peripartum), in (25-35%) of the cases genetic defects in cytoskeletal proteins are causal.
Hypertrophic cardiomyopahty It results in diastolic (relaxation) dysfunction.The vast majority of cases are due to autosomal dominant mutations in the genes encoding the contractile apparatus, in particular β-myosin heavy chain .Restrictive cardiomyopathy1. It results in a stiff, noncompliant myocardium and can be due to depositions (e.g. amyloidosis and hemochromatosis), increased interstitial fibrosis caused by radiation
B- Myocarditis Myocarditis results from muscle injury caused by an inflammatory process that may be secondary to infections or immune reactions . Coxsackievirus A and B are the most common cause in the U.S. In Chagas myocarditis which is distinctive by the parasitization of scattered myofibers by trypanosomes accompanied by an inflammatory infiltrate of neutrophils, lymphocytes, macrophages, and occasional eosinophils .
Diseases of the Pericardium A. Acute pericarditis Serous pericarditis is associated with systemic lupus erythematosus, rheumatic fever, and a variety of viral infections. It is characterized by production of a clear, straw-colored, protein-rich exudates containing small numbers of inflammatory cells. Fibrinous or serofibrinous pericarditis is characterized by a fibrin-rich exudates. It may be caused by uremia, myocardial infraction, or acute rheumatic fever.
Purulent or suppurative pericarditis is characterized by a grossly cloudy or frankly purulent inflammatory exudates. It is almost always caused by bacterial infection. Hemorrhagic pericarditis is characterized by a bloody inflammatory exudates. It usually result from tumor invasion of the pericardium but can also result from tuberculosis or other bacterial infection.
B. Chronic (constrictive) pericarditis This disease is usually of tuberculous or pyogenic staphylococcal etiology. Characteristics include thickening and scarring of the pericardium with resultant loss of elasticity. This prevents the pericardium form stretching and thus interferes with cardiac action and venous return, often mimicking the signs and symptoms of right-sided heart failure.
Tumors of the heart A. Primary tumors Myxoma of the left atrium is the most frequently occurring benign cardiac tumor and is found most often in adults. Rhabdomyoma is most common in infants and young children and is notable for its association with tuberous sclerosis. B. Metastatic tumors : Are more frequent than primary tumors (from Bronchogenic carcinoma or Melanoma)