Diseases of the Heart 2 PDF

Diseases of the heart 2  Valvular diseases and deformities Valvular diseases are various forms of congenital and acquired diseases which cause valvular deformities. Many result in cardiac failure. Rheumatic heart disease is the most common form of acquired...

Diseases of the heart 2  Valvular diseases and deformities Valvular diseases are various forms of congenital and acquired diseases which cause valvular deformities. Many result in cardiac failure. Rheumatic heart disease is the most common form of acquired valvular disease. Valves of the left side of the heart are involved much more frequently than those of the right side of the heart. The mitral valve is affected most often, followed in descending frequency, by the aortic valve, and combined mitral and aortic valves. The valvular deformities may be of 2 types: stenosis and insufficiency:..Stenosis is the term used for failure of a valve to open completely during diastole resulting in obstruction to the forward flow of the blood...Insufficiency or incompetence or regurgitation is the failure of a valve to close completely during systole resulting in back flow or regurgitation of the blood. – Valvular deformities Impose hemodynamic burden and Increase susceptibility to infective endocarditis – Lesions of tricuspid and pulmonic valves less common that those of mitral and aortic  Valvular diseases and deformities Various acquired valvular diseases that may deform the heart valves are listed below: 1. RHD, the commonest cause 2. Infective endocarditis 3. Non-bacterial thrombotic endocarditis 4. Libman-Sacks endocarditis 5. Syphilitic valvulitis 6. Calcific aortic valve stenosis 7. Calcification of mitral annulus 8. Myxomatous degeneration (floppy valve syndrome) 9. Carcinoid heart disease.  AORTIC STENOSIS The most common of all valvular abnormalities, calcific aortic stenosis is usually the consequence of age-associated “wear and tear” of either anatomically normal valves or congenitally bicuspid valves. Occurs in 7th to 9th decade. 1. Non-calcific aortic stenosis The most common cause of non- calcific aortic stenosis is chronic RHD. 2. Calcific aortic stenosis senility, various causes include healing by scarring followed by calcification of aortic valve such as in RHD, bacterial endocarditis, Brucella endocarditis, Mönckeberg’s calcific aortic stenosis. EFFECTS obstruction to left ventricular outflow…..increasing pressure gradient across the calcified valve…. LVH…. Angina pectoris and ischemia…. cardiac decompensation and CHF  MITRAL STENOSIS Mitral stenosis occurs in approximately 40% of all patients with RHD. About 70% of the patients are women. The latent period between the rheumatic carditis and development of symptomatic mitral stenosis is about two decades. Generally, the valve leaflets are diffusely thickened by fibrous tissue and/or calcific deposits, button-hole’ or ‘fish-mouth’ mitral orifice. Patients present with exertional dyspnea, orthopnea, fatique weakness, reduced left ventricular output.  MITRAL STENOSIS EFFECTS 1. Dilatation and hypertrophy of the left atrium. 2. Normal-sized or atrophic left ventricle due to reduced inflow of blood. 3. Pulmonary hypertension resulting from passive backward transmission of elevated left atrial pressure which causes: i) chronic passive congestion of the lungs; ii) hypertrophy and dilatation of the right ventricle; and iii) dilatation of the right atrium when right heart failure supervenes.  AORTIC INSUFFICIENCY About three-fourth of all patients with aortic insufficiency are males with some having family history of Marfan’s syndrome. The aortic valve cusps are thickened, deformed and shortened and fail to close. There is generally distension and distortion of the ring. EFFECTS As a result of regurgitant aortic orifice, there is increase of the left ventricular end-diastolic volume. This leads to hypertrophy and dilatation of the left ventricle producing massive cardiac enlargement so that the heart may weigh as much as 1000 gm. Failure of the left ventricle increases the pressure in the left atrium and eventually pulmonary hypertension and right heart failure occurs.  MITRAL INSUFFICIENCY Mitral insufficiency is caused by RHD in about 50% of patients EFFECTS : 1. Dilatation and hypertrophy of the left ventricle. 2. Marked dilatation of the left atrium. 3. Features of pulmonary hypertension such as:  (MITRAL VALVE PROLAPSE) floppy valve syndrome , one or both mitral valve leaflets are “floppy” and prolapse, or balloon back, into the left atrium during systole The condition is common and seen in 5% of general adult population young patients between the age of 20 and 40 years. More common in females The cause of the condition is not known but in some cases it may be genetically determined collagen disorder ( Marfan syndrome, Ehlers Danlos syndrome, myotonic dystrophy) A significant feature is the ballooning or aneurysmal protrusion of the affected leaflet The enlarged cusp shows loose connective tissue with abundant mucoid or myxoid material due to abundance of mucopolysaccharide it is most often an incidental finding on physical examination, but in a small minority of affected individuals may lead to serious complications mid-systolic clicks, sometimes followed by a mid to late systolic murmur. Increased risk for infective endocarditis, mitral insufficiency, arrhythmias, sudden death.  (MITRAL VALVE PROLAPSE) Although the great majority of persons with MVP have no untoward effects, approximately 3% develop one of four serious complications: (1) infective endocarditis; (2) mitral insufficiency, sometimes with chordal rupture; (3) stroke or other systemic infarct, resulting from embolism of leaflet thrombi; (4) arrhythmias, both ventricular and atrial. Rarely, MVP is the only finding in sudden cardiac death  RHEUMATIC FEVER AND RHEUMATIC HEART DISEASE Rheumatic fever (RF) is a systemic, post- streptococcal, non-suppurative inflammatory disease, principally affecting the heart, joints, central nervous system, skin and subcutaneous tissues. The acute stage of RF involves all the layers of the heart (pancarditis) causing major cardiac sequelae referred to as rheumatic heart disease (RHD). In spite of its name suggesting an acute arthritis migrating from joint to joint, it is the heart rather than the joints which is first and major organ affected.  RHEUMATIC FEVER AND RHEUMATIC HEART DISEASE The disease appears most commonly in children between the age of 5 to 15 years when the streptococcal infection is most frequent and intense. Both sexes are affected almost equally Etiologic role of preceding throat infection (pharyngitis) with b- hemolytic streptococci of group A. However, the mechanism of lesions in the heart, joints and other tissues is not by direct infection but by induction of hypersensitivity or autoimmunity in a susceptible host supported by observing that symptoms is 2 to 3 weeks after infection, and absence of bacteria in lesions Proposed that antibodies directed against M proteins of streptococci cross-react with glycoproteins of heart, joints, etc. Acute rheumatic fever results from host immune responses to group A streptococcal antigens that cross-react with host proteins  RHEUMATIC FEVER AND RHEUMATIC HEART DISEASE Acute rheumatic fever Chronic rheumatic heart disease (valvular abnormality)  RHEUMATIC FEVER AND RHEUMATIC HEART DISEASE Clinical diagnosis of RF and RHD is made in a case with antecedent laboratory evidence of streptococcal throat infection in the presence of any two of the major criteria, or occurrence of one major and two minor criteria Major: (1) migratory polyarthritis of the large joints, (2) pancarditis, (3) subcutaneous nodules, (4) erythema marginatum of the skin (5) Sydenham chorea Minor: fever, arthralgia, or elevated blood levels of acute phase reactants  RHEUMATIC FEVER AND RHEUMATIC HEART DISEASE – Diffuse cellular infiltrate or localized fibrinoid necrosis inflammation fibrosis synovium joints skin Heart  Cardiac manifestations Pancarditis: focal inflammatory involvement of the interstitial tissue of all the three layers of the heart. The pathognomonic feature of pancarditis in RF is the presence of distinctive Aschoff nodules or Aschoff bodies. Aschoff bodies, consist of foci of T lymphocytes, occasional plasma cells, and plump activated macrophages called Anitschkow cells along with fibrinoid necrosis (pathognomonic for RF). Cardiac manifestations  Cardiac manifestations Endocardium – Inflammation of the endocardium and the left-sided valves (most pronounced in mitral & aortic valves) typically results in fibrinoid necrosis within the cusps or tendinous cords. Overlying these necrotic foci and along the lines of closure are small (1 to 2 mm) vegetations, called verrucae (small excrescences). Vegetative endocarditis. – Subendocardial lesions, perhaps exacerbated by regurgitant jets, can induce irregular thickenings called MacCallum plaques, usually in the left atrium. – Lesions may resolve or undergo fibrosis  Cardiac manifestations Pericardium – Fibrinous pericarditis (at times serous or serosanguineous)  Extracardiac manifestations 1. POLYARTHRITIS Acute and painful inflammation of the synovial membranes of some of the joints, especially the larger joints of the limbs, is seen in about 90% cases of RF in adults and less often in children. As pain and swelling subside in one joint, others tend to get involved, producing the characteristic ‘migratory polyarthritis’ involving two or more joints at a time. Usually Self-limited with no chronic deformity 2. SUBCUTANEOUS NODULES The subcutaneous nodules of RF occur more often in children than in adult. These nodules are small (0.5 to 2 cm in diameter), spherical or ovoid and painless. They are attached to deeper structures like tendons, ligaments, fascia or periosteum and therefore often remain unnoticed by the patient. 3. ERYTHEMA MARGINATUM This non-pruritic erythematous rash is characteristic of RF. The lesions occur mainly on the trunk and proximal parts of the extremities. / Aschoff bodies. Extracardiac manifestations 4. RHEUMATIC ARTERITIS Arteritis in RF involves not only the coronary arteries and the aorta but also occurs in arteries of various other organs such as renal, mesenteric and cerebral arteries. 5. CHOREA MINOR Chorea minor or Sydenham’s chorea or Saint Vitus’ dance is a delayed manifestation of RF as a result of involvement of the central nervous system. 6. RHEUMATIC PNEUMONITIS AND PLEURITIS Involvement of the lungs and pleura occurs rarely in RF. Pleuritis is often accompanied with serofibrinous pleural effusion.  chronic RHD The chronic stage of RHD is characterized by permanent deformity of one or more valves, especially the left sided valves, mitral (in 98% of cases alone or along with other valves) and aortic. – Chronic rheumatic heart disease most common cause of mitral stenosis – Stenosis more common than regurgitation Gross appearance of chronic healed mitral valve in RHD is characteristically ‘fish mouth’ or ‘button hole’ stenosis. May result in: hypertrophied and dilated left atrium mural thrombi chronic passive congestion of lungs hypertrophy and dilation of right ventricle and atrium in long standing cases Mitral stenosis and insufficiency are commonly combined in chronic RHD; calcific aortic stenosis may also be found.  chronic RHD The major causes of death in RHD are cardiac failure, bacterial endocarditis and embolism  Infective Endocarditis is a microbial infection of the heart valves or the mural endocardium that leads to the formation of vegetations composed of thrombotic debris and organisms, often associated with destruction of the underlying cardiac tissues Mostly bacterial IE has been classified on clinical grounds into acute and subacute forms. Acute endocarditis: High virulence organisms -Staphylococcus aureus may affect normal valves Subacute Endocarditis: Lower virulence organisms- alpha-hemolytic streptococci affects previously abnormal valves The characteristic pathologic feature in both ABE and SABE is the presence of typical vegetations or verrucae on the valve cusps or leaflets  Infective Endocarditis Acute bacterial endocarditis is fulminant and destructive acute infection of the endocardium by highly virulent bacteria in a previously normal heart and almost invariably runs a rapidly fatal course in a period of 2-6 weeks. the most common causative organisms are virulent strains of staphylococci, chiefly Staphylococcus aureus. Others are pneumococci, gonococci, b-streptococci and enterococci. Subacute bacterial endocarditis (SABE) is caused by less virulent bacteria in a previously diseased heart and has a gradual downhill course in a period of 6 weeks to a few months and sometimes years. the commonest causative organisms are the streptococci with low virulence, predominantly Streptococcus viridans, which forms part of normal flora of the mouth and pharynx. Other less common etiologic agents include other strains of streptococci and staphylococci. most cases of ABE as well as SABE occur over 50 years of age. Males are affected more often than females.  IE- Predisposing factor 1. Bacteraemia, septicaemia and pyaemia: many procedures seed the microbe to the heart  IE- Predisposing factor 2. Underlying heart disease: i) Chronic rheumatic valvular disease in about 50% cases. ii) Congenital heart diseases in about 20% cases. iii) Other causes are syphilitic aortic valve disease, atherosclerotic valvular disease, floppy mitral valve, and prosthetic heart valves. 3. Impaired host defenses: All conditions in which there is depression of specific immunity, deficiency of complement and defective phagocytic function, predispose to BE. 4. IV DRUG Abuse… Rt sided valves effect  IE- Predisposing factor Causative Organisms – Native (non prosthetic) valves 50% - 60% alpha-hemolytic streptococci (previously damaged valves) 10% - 20% S. aureus (damaged or healthy valves) Oral cavity flora – coagulase-negative staphylococci (prosthetic valves) – Staph. aureus in drug abusers – Enterococci and HACEK group ( haemophilus, actinobacillus, cardiobacterium, eikenella and kingenella) – Fungi  IE- Predisposing factor – Prosthetic valve endocarditis (PVE): Early PVE which occurs in the first two months of surgery: is generally caused by Most commonly – Coagulase negative staphylococcus: S. epidermidis Less commonly: – Coagulase positive staphylococcus – Gram negative bacteria – Fungi Late PVE: after two months of the postoperative period, the organism resemble those of NVE: – Streptococcus viridans (S. salvarius, S. mutans, S. sanguis) is the most common. These are normal oral, GI, GU tract flora – Staphylococcus aureus – Coagulase negative staphylococcus is the cause in less than 20% of cases  IE features The lesions are found commonly on the valves of the left heart, most frequently on the mitral, followed in descending frequency, by the aortic, simultaneous involvement of both mitral and aortic valves. The vegetations of BE vary in size from a few millimeters to several centimeters, grey-tawny to greenish, irregular, single or multiple, and typically friable. They may appear flat, filiform, fungating or polypoid. Valvular Vegetations Containing Microorganisms may lead to: – Rupture of leaflets, chordae or papillary muscle – Perivalvular ring abscesses Fragmented vegetation showing inflammatory cells, fibrin, and the blue color represents the colonies of microorganisms  IE clinically fever, chills, weakness, and lassitude. Weight loss, and a flulike syndrome. Murmurs are present in 90% of patients with left-sided IE, either from a new valvular defect or from a preexisting abnormality. Duke criteria  Diagnosis: based on Duke university criteria: – Two major criteria – One major and three minor criteria – Five minor criteria  IE complications Complications of IE generally begin within the first few weeks of onset, and can include glomerular antigen antibody complex deposition causing glomerulonephritis Earlier diagnosis and effective treatment has nearly eliminated some previously common clinical manifestations of long-standing IE—for example, microthromboemboli (manifest as splinter or subungual hemorrhages), erythematous or hemorrhagic nontender lesions on the palms or soles (Janeway lesions), subcutaneous nodules in the pulp of the digits (Osler nodes), and retinal hemorrhages in the eyes (Roth spots).  Noninfected (sterile) vegetations occur in nonbacterial thrombotic endocarditis and the endocarditis of systemic lupus erythematosus (SLE), called Libman-Sacks endocarditis  NBTE is characterized by the deposition of small sterile thrombi on the leaflets of the cardiac valves The lesions are 1 to 5 mm in size, and occur as single or multiple vegetations along the line of closure of the leaflets or cusps, chiefly in mitral, and less often aortic and tricuspid valve. Histologically, they comprise bland thrombi that are loosely attached to the underlying valve; the vegetations are not invasive and do not elicit any inflammatory reaction ( no tissue destruction). Thus, although the local effect of the vegetations is usually trivial, they can be the source of systemic emboli that produce significant infarcts in the brain, heart, or elsewhere.  NBTE in debilitated patients, such as those with cancer or sepsis marantic endocarditis there is a striking association with mucinous adenocarcinomas, potentially relating to the procoagulant effects of tumor-derived mucin or tissue Endocardial trauma, as from an indwelling catheter, is another well-recognized predisposing condition, and right-sided valvular and endocardial thrombotic lesions frequently track along the course of pulmonary artery catheters.  NBTE: irregular yellow tan vegetations present on mitral valve. Unlike the valve in rheumatic carditis, this valve shows normal thin leaflets, and chordae tendineae are thin and glistening Bland thrombus with virtually no inflammation in the valve cusp or the thrombotic deposit. The thrombus is loosely attached to the cusp (LIBMAN-SACKS) ENDOCARDITIS Characterised by sterile endocardial vegetations which are distinguishable from the vegetations of RHD and bacterial endocarditis. is one of the manifestations of ‘collagen diseases’. Characteristic lesions of Libman- Sacks endocarditis are seen in 50% cases of acute systemic lupus erythematosus (SLE); along with other connective tissue diseases Sterile vegetations on ventricular surface of mitral and tricuspid valves may seen on both surfaces of the same valve No predilection for the lines of closure  Prosthetic valves There are two types of valvular prostheses: Mechanical valves. These consist of different configurations of rigid nonphysiologic material, such as caged balls, tilting disks, or hinged semicircular flaps (bi- leaflet tilting disk valves). Tissue valves (bioprostheses). Porcine aortic valves or bovine pericardium are preserved in a dilute glutaraldehyde solution and then mounted on a prosthetic frame. Alternatively, frozen human valves from deceased donors (called cryopreserved “homografts”) can also be used. Approximately 60% of substitute valve recipients develop a serious prosthesis-related problem within 10 years after the surgery.  Prosthetic valves Thromboembolism is the major consideration with mechanical valves Structural deterioration rarely causes failure of mechanical valves in current use. However, virtually all bioprostheses eventually become incompetent due to calcification and/or tearing Infective endocarditis is a potentially serious complication of any valve replacement. The major organisms causing such infections are staphylococcal skin contaminants (e.g., S. epidermidis), S. aureus, streptococci, and fungi. Others: paravalvular leak due to inadequate healing, obstruction due to overgrowth of fibrous tissue during healing, valve-orifice disproportion (where the effective valve area is too small for the needs of the patient, leading to a relative stenosis), intravascular hemolysis due to high shear forces, or excessive noise owing to hard contacts of moving rigid parts.  Myocardial disease Involvement of the myocardium occurs in three major forms of diseases already discussed— ischaemic heart disease, hypertensive heart disease and rheumatic heart disease. In addition, there are two other broad groups of isolated myocardial diseases: I. Myocarditis i.e. inflammatory involvement of the myocardium II. Cardiomyopathy i.e. a non-inflammatory myocardial involvement  MYOCARDITIS Inflammation of the heart. The heart muscle itself is incredibly resistant to bacterial infections unless they extend from endocarditis. Most myocarditis is probably viral and/or autoimmune. The only systemic bacterial infection that is likely to produce a neutrophilic myocarditis is meningococcemia, and this seems to be the exception even with this dread micro-organism.  MYOCARDITIS Morphology – Dilated flabby heart – Small areas of hemorrhage – Abscesses in bacterial – Lymphocytic infiltrate in acute viral – Myocyte degeneration and necrosis Clinical – Asymptomatic – CHF – arrhythmias  Cardiomyopathy Cardiomyopathy is intrinsic cardiac muscle disease; there may be specific causes, or it can be idiopathic (primary) It is subdivided into the following 3 pathophysiologic categories: dilated (90%), hypertrophic, and restrictive (least common).  DILATED (CONGESTIVE) CARDIOMYOPATHY – weak flappy This type of cardiomyopathy is characterized by gradually progressive cardiac failure along with dilatation of all the four chambers of the heart. The condition occurs more often in adults (20-60) , and the average survival from onset to death is less than 5 years. ETIOLOGY i) Possible association of viral myocarditis. ii) Association with toxic damage from cobalt and chemotherapy , anthracyclin, doxrubucin. iii) Inherited mutations. ( abnormal cytoskelon genes) - dystrophies iv) Chronic alcoholism. v) Peripartum association. The heart is enlarged and increased in weight (up to 1000 gm). The most characteristic feature is prominent dilatation of all the four chambers giving the heart typical globular appearance. The endomyocardial biopsies or autopsy examination of the heart reveal non-specific and variable changes. There may be hypertrophy of some myocardial fibres and atrophy of others.  DILATED (CONGESTIVE) CARDIOMYOPATHY Clinical features: – Major defect is ineffective contraction. Ejection fraction is 25% (normal 50-65%) – Therefore the clinical manifestation will be progressive CHF, which becomes refractory to therapy S/S: – dyspnea, orthopnea – Eventually right heart failure with dependent edema Causes of death: – Intractable heart failure – Embolic complications – Ventricular arrhythmias  Arrhythmogenic right ventricular cardiomyopathy is an autosomal dominant disorder that classically manifests with right-sided heart failure and rhythm disturbances, which can cause sudden cardiac death Morphologically, the right ventricular wall is severely thinned owing to myocyte replacement by fatty infiltration and lesser amounts of fibrosis Defect in genes encoding desmosomal junctional proteins at the intercalated disk (e.g., plakoglobin), as well as proteins that interact with the desmosome (e.g., the intermediate filament desmin). Arrhythmogenic right ventricular cardiomyopathy  HYPERTROPHIC CARDIOMYOPATHY This form of cardiomyopathy is known by various synonyms like asymmetrical septal hypertrophy, The disease occurs more frequently between the age of 25 and 50 years. Myocardial hyeprtrophy, abnormal diastolic filling, intermittent outflow obstruction ETIOLOGY 50% - abnormalities in genes encoding for contractile proteins, (AD inheritance) The characteristic features are cardiac enlargement, increase in weight, normal or small ventricular cavities and myocardial hypertrophy. The hypertrophy of the myocardium is typically asymmetrical and affects the interventricular septum ( mainly LV)more than the free walls of the ventricles. The classical feature is the haphazard arrangement of hypertrophied, abnormally branching myocytes HYPERTROPHIC CARDIOMYOPATHY – Clinical Inadequate filling of hypertrophied left ventricle  forceful but ineffective ejection Dynamic obstruction to LV ouflow Secondary increase in pulomonary venous pressure  exertional dyspnea Anginal pain Arrhythmias and suddent death ( especially in young athletes) Increased risk on infective endocarditis Myocardial fibrosis  CHF RESTRICTIVE CARDIOMYOPATHY This form of cardiomyopathy is characterized by restriction in ventricular filling due to reduction in the volume of the ventricles. results in a stiff, noncompliant myocardium and can be due to deposition (e.g., amyloid), increased interstitial fibrosis (e.g., due to radiation), endomyocardial scarring, Eosinophilic endomyocardial fibrosis ( Loffler), Genetic The common feature is abnormal diastolic function. – Clinical Fatigue, Exertional dyspnea, Chest pain Arrhythmias and block, especially with fibrosis  Pericarditis Causes: – Most common cause is viral infections – Bacteria, mycobacteria, fungi are less common – MI – Cardiac surgery – Radiation to the mediastinum Less common causes: 1-rheumatic fever 2-SLE 3-metastasis: is associated with bloody effusion 4-uremia  Pericarditis outcome: – If effusion is significant that may cause hemodynamic complications – May resolve without significant complications – Progress to chronic fibrosing complication Morphology: – The exudate due to rheumatic fever or uremia is fibrinous, and gives a rough (bread and butter) appearance – It’s fibrinopurulent in cases of viral and bacterial endocarditis – In tuberculosis, the pericardium will contain caseous material – Pericardial metastasis the effusion will be fibrinous and bloody  – When there is extensive suppuration healing gives rise to chronic pericarditis Chronic pericarditis: the lesion in chronic cases ranges from delicate adhesions to dense fibrotic scars that may obliterate the pericardial space In such cases the heart can not expand, a condition called constrictive pericarditis  Clinical manifestation: – Atypical chest pain: worst on reclining, and results in a friction rub type of sound on auscultation – Signs of cardiac tamponade: Distant heart sounds Distended neck veins Declining cardiac output shock  Pericardial effusions Serous: CHF, hypoalbuminemia Serosanguineous: blunt chest trauma, malignancy Chylous: mediastinal lymphatic obstruction Hemopericardium: rupture aortic aneurysm, or ruptured MI, or penetrating trauma Treatment: cardiac tamponade is a cardiac emergency. It should be treated by pericardiocentesis, or pericardiostomy The fluid drained should be examined for cytology, protein, and microorganism Fibrinous pericarditis, note the strands, gross. Microscopic picture shows the surface of the pericardium with pink fibrinous strands extending from the epicardial surface Hemorrhagic Purulent pericarditis pericarditis  Cardiac tumors Primary tumors of the heart are rare; in contrast, metastatic tumors to the heart occur in about 5% of persons dying of cancer. (lung, breast, melanoma, hematological) The most common primary cardiac tumors, in descending order of frequency (overall, including adults and children) are myxomas, fibromas, lipomas, papillary fibroelastomas, rhabdomyomas, Most common primary malignant tumor is: angiosarcomas  Cardiac tumors MYXOMA This is the most common primary tumour of the heart comprising about 50% of all primary cardiac tumours. Majority of them occur in the age range of 30 to 60 years. 90% of them are situated in the left atrium. They are often single but may be multiple. They range in size from less than 1 to 10 cm, polypoid, pedunculated, spherical, soft and haemorrhagic masses resembling an organising mural thrombus. Composed of multinucleated stellate cells, smooth muscle cells may be present, the cells are suspended in a mucopolysaccharide rich stroma  Cardiac tumors Cardiac rhabdomyomas: – Rhabdomyomas are the most frequent primary tumor of the pediatric heart, and are commonly discovered in the first years of life because of obstruction of a valvular orifice or cardiac chamber – Approximately half of cardiac rhabdomyomas are due to sporadic mutations; the other 50% of cases are associated with tuberous sclerosis with mutations in the TSC1 or TSC2 tumor suppressor gene. – Present as myocardiac mass that project into the ventricular lumen – May be solitary or multiple Histopatholgy: – Composed of eosinophilic, polygonal cells, many of which contain large, glycogen rich cytoplasmic granules. Myofibrils can be demonstrated in such cells under the microscope  Cardiac tumors Lipomas: – May occur anywhere in the heart – mature fat cells that can occur in the subendocardium, subepicardium, or myocardium – They most likely represent malformation than true neoplasm – Lipoma like accumulation in the ventricular septum is quite common – Though morphologically benign, they may be implicated in sudden cardiac death  Cardiac tumors SECONDARY TUMOURS Metastatic tumours of the heart are more common than the primary tumours. About 10% cases with disseminated cancer have metastases in the heart. Most of these result from haematogenous or lymphatic spread.