Cardiovascular Flashcards
Arteriosclerosis is classified into what 3 lesions?
Atherosclerosis, Monckeberg medial calcific sclerosis, and arteriolosclerosis. Atherosclerosis is a disease of elastic and large muscular arteries in which the atheroma is the characteristic lesion. The lesions of atherosclerosis enlarge the arterial intima with variable amounts and types of lipids, connective tissues, inflammatory cells, and a variety of extracellular components including matrix proteins and enzymes and calcium deposits. Although “sclerosis” means hardening, atherosclerotic vessels may not be harder than normal and may even be softer. “Athero” literally means gruel-like, so the term atherosclerosis is a misnomer. Monckeberg medial calcific sclerosis is a calcification process that affects the media of large and medium-sized arteries. By Monckeberg’s definition, the calcific lesions involve only the tunica media of arteries without any compromise of the arterial lumen. However, sometimes the term is used when there is calcification of the tunica media and internal elastic lamina, or even just the internal elastic lamina; since the internal elastic lamina is part of the intima, “medial” calcific sclerosis would be a misnomer. Arteriolosclerosis is a lesion of arterioles, small arterial vessels with 1 or 2 layers of smooth muscle cells. It is most typically associated with HTN and DM. The 2 subtypes of arteriolosclerosis are the hyperplastic type and the hyaline type.
Carney Complex. AKA (3)?
AKA LAMB syndrome (Lentigenes, Atrial myxomas, Mucocutaneous myxomas, Blue nevi), NAME syndrome (Nevi, Atrial myxomas, Myxoid neurofibroma, Ephelides), or Swiss syndrome. AD condition. The majority (Carney Complex type I) are caused by mutations in the PRKAR1-alpha gene on 17q24, which has been suggested to function as a tumor-suppressor gene. Carney Complex type II involves chromosome 2. 7% of all cardiac myxomas are associated with Carney complex. M=F. Mean age at Dx: 10-20 years.
Dieulafoy disease.
AKA Dieulafoy lesion, Dieulafoy ulcer, caliber persistent artery, gastric aneurysm, gastric arteriosclerosis, submucosal arterial malformation, cirsoid aneurysm, and solitary exulceration simplex. Defined as an abnormally large artery that retains a large caliber as it approaches the mucosa. The mean diameter of pathogenic arteries at the level of the muscularis mucosae is ~1mm, versus normal arteries having a diameter of ~0.1mm. There is also an accompanying vein. MC location is the lesser curvature of the stomach, b/c the submucosal arteries of the lesser curvature are direct branches of the left gastric artery, whereas in the rest of the stomach, the submucosal vessels are of much smaller caliber b/c of their serial branching. The disease usually occurs in males, and there is a wide age range at time of occurrence.
Examples of pseudoneoplastic lesions in the cardiovascular system and their related neoplastic mimes.
Rhabdomyomatous hamartomas of myocardium (hamartoma of mature cardiac myocytes) [true adult rhabdomyoma]. Endodermal choristoma of interatrial cardiac septum [metastatic adenocarcinoma]. Lipomatous hypertrophy of the heart (lipomatous hypertrophy of the atrial septum) [lipoma]. Mesothelial-monocytic intracardiac excrescences (mesothelial/monocytic incidental cardiac excrescences) [metastatic adenocarcinoma or mesothelioma]. Endocardial and myocardial lymphocytic infiltrates post transplant (aka quilty lesions) [lymphomas]. Florid pericardial mesothelial hyperplasia [epithelial mesothelioma]. Other pseudoneoplasms include inflammatory myofibroblastic tumor and calcified amorphous tumor.
What are Weibel-Palade bodies?
Weibel-Palade bodies are characteristic inclusions of endothelium measuring up to 3 um in maximum dimension. These membrane-bound structures contain up to 25 parallel tubular arrays. These bodies are the site of storage of von Willebrand factor.
What immunostain reacts with the endothelium of cerebral capillaries, placental vasculature, and juvenile capillary angiomas?
GLUT-1.
Examples of pseudoneoplastic lesions in the mediastinum and their related neoplastic mimes.
Sclerosing mediastinitis (sclerosing carcinomas, lymphomas, or germ-cell tumors). Thymic dysplasia (thymoma). Benign mesothelial inclusions in mediastinal lymph nodes (metastatic carcinoma).
Papillary endothelial hyperplasia.
Papillary endothelial hyperplasia is a pattern of organizing thrombus that may occur within a vessel or hematoma. It may be seen incidentally in a surgical specimen or represent a symptomatic small mass by itself, in which case it is called a Masson’s tumor. It is composed of tiny papillae made of fibrin and red blood cells (but no true fibrovascular cores) covered by thin, bland endothelial cells.
What are the HACEK organisms?
Haemophilus (H. parainfluenzae, H. aphrophilus, H. paraphrophilus), Actinobacillus (A. actinomycetemcomitans, Aggregatibacter aphrophilus), Cardiobacterium hominis, Eikenella corrodens, Kingella kingae. These are all slow growing Gram negative bacteria that form part of the normal oropharyngeal flora. They account for 5-10% of infective endocarditis involving native valves, are the most common Gram negative cause of endocarditis among non-IVD users, and are a frequent cause of culture-negative endocarditis. In addition to valvular infections in the heart, they can also produce other infections such as bacteremia, abscess, peritonitis, otitis media, conjunctivitis, pneumonia, arthritis, osteomyelitis, and periodontal infections.
What is Austrian syndrome?
Austrian syndrome was first described by Robert Austrian in 1957. The classical triad consists of meningitis, pneumonia, and endocarditis all caused by Streptococcus pneumoniae. It is associated with alcoholism, due to the presence of hyposplenia, and can been seen in males between 40–60 years old.
Coxsackie A virus causes (conditions). Coxsackie B virus causes (conditions).
Coxsackie A virus causes hand-foot-mouth disease and herpangina. Coxsackie B virus causes myocarditis, pericarditis, and epidemic pleurodynia (the grippe).
What are Quilty lesions?
QLs are collections of inflammatory cells usually found along the endocardium, but sometimes extending deeper into tissues, that can mimic acute rejection. QLs are also known as endocardial infiltrates and have been the subject of more than a dozen different studies, and there is still no consensus as to their etiology or significance. They have been associated with the use of cyclosporine and waxing and waning levels of immunosuppression. It has also been suggested that QLs represent a “benign” form of rejection, or an analogue of vascular rejection. More recent studies in experimental animals suggest that they may be sites of antigen processing and low grade immune stimulation. In human and experimental animals, QLs are comprised predominantly of T cells, with the CD4 subset predominating over CD8 cells by a ratio of 2-3:1. QLs have been subclassified on the basis of whether they infiltrate the underlying myocardium. In type A lesions, the border with the underlying myocardium is smooth. In type B lesions, the mononuclear cells infiltrate between myocytes in the underlying myocardium, but myocyte necrosis is not seen. On a practical level, QLs are generally not considered in the grading of cardiac allograft rejection, but mentioned in the diagnosis as a separate finding.
What is Twiddler’s syndrome?
Twiddler’s syndrome is a rare but potentially dangerous complication of device therapy for arrythmias. It refers to the intentional or unintentional twisting of the generator within the pacemaker pocket by the patient, resulting in either lead dislodgement or fracture without damage to the generator itself. Patients are risk for this condition are usually elderly, obese and often female, presumably due to their relaxed subcutaneous tissue that facilitates the rotation. Diagnosis is often incidental but can also present as problems on device interrogation such as loss of capture or stimulation of the pectoral muscle or diaphragm. Clinically it can manifest as twitching or the pectoral or abdominal muscles, chest pain, hiccups, change in voice, dysrhythmias, syncope or pre-syncope.
What are the 4 subtypes of hemangioendothelioma?
Epithelioid, spindle cell, retiform, kaposiform.
How are podoplanin and D2-40 different?
Basically, podoplanin is the protein, and D2-40 is the antibody against that protein. Podoplanin is a mucin-type transmembrane glycoprotein that is expressed in lymphatic endothelial cells (and several other cell types). The mouse monoclonal antibody D2-40 was originally raised against an oncofetal antigen, M2A antigen, which is an O-linked sialoglycoprotein with a simple mucin-type carbohydrate epitope associated with germ cell neoplasms, but then this antibody clone was found to be reactive with other antigens/cell types as well. D2-40: = anti-podoplanin.
In what clinical situations may endomyocardial biopsies be taken, and for each clinical situation, should light microscopy (LM), electron microscopy (EM), immunofluorescence (IF), and viral nucleic acid studies (NuAc) be done?
New-onset heart failure 3-month duration (LM, EM). Heart failure with dilated cardiomyopathy (LM, EM). Heart failure associated with anthracycline use (LM, EM). Heart failure associated with restrictive cardiomyopathy (LM, EM, IF). Suspected cardiac tumors (LM, EM). Cardiomyopathy in children (LM, EM, NuAc). Heart failure associated with hypertrophic cardiomyopathy (LM, EM). Suspected arrhythmogenic right ventricular dysplasia/cardiomyopathy (LM). Plasma cell dyscrasia and cardiac symptoms (LM, EM, IF). Surveillance for cardiac rejection after transplantation (LM, IF).
Grossing and processing of endomyocardial biopsies.
For light microscopy, an adequate specimen for diagnostic interpretation usually consists of three or more pieces of endomyocardium, each measuring at least 1-2 mm^3. Specimens for light microscopy evaluation should be placed in room temperature 10% buffered formalin. EM, IF, and nucleic acid studies can be accomplished with a single piece of myocardium for each study. The one exception is to increase the number of pieces for EM evaluation of anthracycline toxicity. Tissue for EM should be placed in glutaraldehyde fixative; tissue for IF should be frozen in Optimal Cutting Temperature compound or placed in Zeus solution, and tissue for viral nucleic acid studies should be frozen or placed in RNAlater RNA stabilizing solution. Specimens taken for EM should be processed to generate thick sections at which time the pathologist can determine if EM will add additional information to the case. If tissue was not originally submitted for EM processing and EM is desired, formalin-fixed tissue can be processed for EM, or paraffin-embedded tissue can be reprocessed for EM. Tissue taken for IF can be held and used when appropriate. IF can be useful for subtyping amyloid deposits and in the determination of cardiac nonamyloidotic Ig deposition disease. When viral myocarditis is suspected, tissue may be frozen or placed in RNAlater and then sent to a laboratory that has expertise in viral genome detection by assessment of nucleic acids.
What sectioning methods and stains are used for endomyocardial biopsies?
A general consensus is that multiple sections (three or more) should be stained with H&E at different levels through the biopsy. For diseases that have a patchy distribution (sarcoidosis, myocarditis, etc.), even further sectioning can be performed if the entity is not seen on the initial slides. Intervening sections between H&E stains should be used for HC or IHC staining. A typical panel includes a collagen stain (Masson trichrome, Azan-Mallory, or Sirius red) for fibrosis, an elastic stain (Movat pentachrome, Verhoeff-Van Gieson) for endocardial fibroelastosis, a lymphocyte marker (CD3, CD8) for myocarditis, a macrophage marker (CD68) for myocarditis/myocyte injury, a glycogen stain (PAS) for glycogen storage disease, an amyloid stain (Congo red, thioflavin T, methyl violet, modified sulfated Alcian blue) for amyloid deposition, and an iron stain (Prussian blue) for hemochromatosis.
What is the rationale for why ventricular myectomy specimens are taken?
Myectomy specimens are taken from the left ventricular septum for relieve outflow obstruction. Traditionally, these specimens are taken from patients with hypertrophic cardiomyopathy, although additional reasons for this resection include age-related angulation of the ventricular septum, sigmoid septum, and discrete subaortic stenosis. While these specimens are removed primarily for structural reasons to improve left ventricular outflow, they may be utilized to diagnose cardiac disorders.
What is the rationale for why cardiac apical core segment specimens are taken?
Apical cores of ventricular myocardium are obtained at the time of ventricular assist device (VAD) placement. With the advent of smaller and simpler VADs, their use as either a bridge to transplantation or as destination therapy in heart failure patients is increasing. Apical core tissue is removed when a device cannula is placed in the ventricular apex. While this material is not taken specifically for diagnostic purposes, useful information can be obtained from pathologic evaluation.
What is the rationale for why cardiac papillary muscle specimens are taken?
The most important cause of papillary muscle dysfunction is myocardial ischemia. Rupture of papillary muscle as a complication of acute myocardial infarction results in abrupt onset of severe mitral regurgitation and CHF. Rarely, papillary muscle avulsion has been reported as a consequence of blunt chest trauma. Distortion of the normal spatial relations of the papillary muscles may also be seen in left ventricuar dilatation and hypertrophic cardiomyopathy and can result in mitral regurgitation. In some instances, mitral valve mobility is restricted by anomalous direct insertion of the papillary muscle to the leaflet or via shortened chordae. The gross specimen usually consists of the papillary muscle tip with attached segment of mitral valve leaflet and chordae.
What is the rationale for why atrial appendage specimens are taken?
Atrial appendages from either the right of left atrium may be surgically resected from patients with atrial fibrillation or atrial dilation to prevent embolic episodes, or from patients with congenital atrial aneurysms. The routine histology of the atrial myocardium in these patients differs from the ventricular myocardium. The myocardium in resected atrial appendages frequently displays profound myocyte hypertrophy and vacuolization, interstitial fibrosis, and not uncommonly amyloid deposition.
What is the rationale for why pericardial biopsies/resections are done?
Parietal pericardium may be removed as a diagnostic biopsy particularly in cases of suspected purulent, tuberculous or malignant pericarditis, or as a partial or radical pericardiectomy in cases of constrictive pericarditis. In the specimen, the degree of calcification and fibrosis should be assessed as well as the presence of purulent exudates and fibrin. If purulent infective pericarditis is suspected, sterile portions should be sent for culture.
What is the rationale for why aortic resections are done?
Segments of aorta are typically resected during the surgical repair of an aortic aneurysm, an aortic dissection, or a congenital anomaly such as coarctation. Such aortic resection specimens may contain diagnostic pathologic features that impact patient care, such as infectious or noninfectious artitis, or may show features suggesting an inherited connective tissue disease. Less commonly, segments of aorta may be surgically removed due to the presence of a neoplasm.
Temporal artery biopsy rationale, processing, sectioning, and staining.
Superficial temporal arteries are biopsied to evaluate for vasculitis, particularly giant cell arteritis. Since this disorder affects arteries in a discontinuous fashion with skip lesions, it is essential to extensively sample cross-sections of the specimen. Although classified as medium-sized arteries, the superficial temporal artery is small enough to pose difficulty with tissue orientation if it is sectioned prior to processing. Thus, sectioning and embedding of the artery are typically performed by the histotechnologist after routine processing. After processing, the artery is serially sectioned at 1- to 2-mm intervals and embedded as cross-sections. All of the artery cross-sections can be embedded in the same paraffin block. Multiple H&E-stained slides should be evaluated. For each 1-mm cross-section of artery, it is recommended that a minimum of five levels (slides) be obtained, which may be serial sections or step sections. Each slide may contain a ribbon of 8 sections, to alow for the evaluation of 40 sections per artery cross-section. In borderline cases with inflammation limited to the adventitia, additional levels should be considered. An elastic stain should be evaluated to assess for fragmentation of the internal elastic lamina. CD68 and CD3 stains are helpful to deliniate subtle involvement of the arterial wall by inflammation. Temporal arteries may be involved by systemic amyloidosis, which can mimic the clinical presentation of giant cell arteritis, so if amyloid is suspected on the H&E stain, an amyloid stain such as Congo red should be assessed.
What are the 2 most widely used synthetic vascular grafts made of?
Polyethylene terephthalate (PET; Dacron) and polytetrafluoroethylene (PTFE; Gore-Tex). Synthetic grafts are used in aortic and large diameter peripheral arterial bypass surgeries. Dacron is a type of polyester that is manufactured in either woven or knitted form, and it often has a crimped pattern for greater flexibility. Gore-Tex is made from fluorocarbon polymer sheets and has a smooth surface.
How should vascular grafts and stents be grossed and processed?
Grafts and stents should be examined for integrity of the wall and stenosis or thrombosis of lumen. The soft tissue around the graft may be included in the specimen and should be sampled. In infected grafts or stents, cultures are ideally obtained by the clinical team preoperatively or intraoperatively from blood, wound, sinus tract or perigraft fluid. Explanted stent grafts are examined grossly for evidence of structural graft failure such as fabric tears, fractures, kinks, or collapse. Synthetic vascular grafts can be sectioned easily with a surgical blade and submitted for microscopic evaluation along with its luminal contents and soft tissue.
What is the rationale for why microscopic examination of blood clots is done?
Blood clots located inside cardiac chambers or blood vessels (thrombi and emboli) may be removed as either part of an open procedure or by catheter embolectomy. Blood clots outside cardiac chambers and blood vessels (hematomas) may also be evacuated surgically. Blood clots in general and thrombi in particular should be evvaluated to assess for organization as an indication of the age of the clot and to exclude infection and embolic neoplasm. Clinicians also on occasion request verification if a thrombus is a platelet-rich thrombus, so-called “white clot,” consistent with heparin-induced thrombocytopenia.
Several named syndromes are associated with eosinophilia and eosinophilic infiltration of specific organs: eosinophilic cellulitis (__ syndrome), eosinophilic pneumonia (__ syndrome), eosinophilic fasciitis (__ syndrome), and eosinophilic vasculitis (__ syndrome).
Several named syndromes are associated with eosinophilia and eosinophilic infiltration of specific organs: eosinophilic cellulitis (Well syndrome), eosinophilic pneumonia (Loeffler syndrome), eosinophilic fasciitis (Shulman syndrome), and eosinophilic vasculitis (Churg-Strauss syndrome).
The gene that encodes troponin __ is expressed in both cardiac and skeletal muscle, whereas troponin __ and troponin __ have separate cardiac and skeletal muscle genes.
The gene that encodes troponin C is expressed in both cardiac and skeletal muscle, whereas troponin T and troponin I have separate cardiac and skeletal muscle genes. cTnI is marginally more cardiac-specific than cTnT.
Hypovolemic hyponatremia is often due to ___. Euvolemic hyponatremia is often due to ___. Hypervolemic hyponatremia is often due to ___.
Hypovolemic hyponatremia is often due to water loss either through the kidneys or GI tract. Euvolemic hyponatremia is often due to drugs. Hypervolemic hyponatremia is often due to CHF, nephrotic syndrome, or cirrhosis.
The differential diagnosis of hypertrophic cardiomyopathy includes several syndromes that typically manifest with multiorgan involvement but that can also present with isolated or predominant left ventricular hypertrophy. What syndromes are in the DDx?
Metabolic (storage) cardiomyopathies such as Danon disease and Wolff-Parkinson-White syndrome, and the lysosomal storage disorder Fabry disease. LVH in these conditions is not accompanied by myocyte disarray or fibrosis but by a characteristic accumulation of glycogen or glycospingolipids in cellular vacuoles. LVH is also part of the phenotypic spectrum of Noonan syndrome and Friedreich ataxia.
Pathogenic variants for hypertrophic cardiomyopathy have been described in eight genes encoding sarcomere proteins, with most (∼80%) present in the ___ and ___ genes. As is typical for structural proteins, most sarcomere variants are believed to act in a dominant negative manner (ie, by adversely affecting the normal gene product). Loss-of-function variants leading to haploinsufficiency occur less frequently but are prevalent in the ___ gene. Collectively, sarcomere variants are identified in up to 60% of patients with HCM who also have a family history and in ∼40% of patients with sporadic HCM.
Pathogenic variants for HCM have been described in eight genes encoding sarcomere proteins, with most (∼80%) present in the MYH7 and MYBPC3 genes. As is typical for structural proteins, most sarcomere variants are believed to act in a dominant negative manner (ie, by adversely affecting the normal gene product). Loss-of-function variants leading to haploinsufficiency occur less frequently but are prevalent in the MYBPC3 gene. Collectively, sarcomere variants are identified in up to 60% of patients with HCM who also have a family history and in ∼40% of patients with sporadic HCM.
Pathogenic variants for hypertrophic cardiomyopathy have been described in eight genes encoding sarcomere proteins, with most (∼80%) present in the ___ and ___ genes. Storage cardiomyopathies masquerading as HCM are caused by mutations in ___ (Danon disease), ___ (Wolff-Parkinson-White syndrome), and ___ (Fabry disase).
Pathogenic variants for HCM have been described in eight genes encoding sarcomere proteins, with most (∼80%) present in the MYH7 and MYBPC3 genes. Storage cardiomyopathies masquerading as HCM are caused by mutations in LAMP2 (Danon disease), PRKAG2 (Wolff-Parkinson-White syndrome), and GLA (Fabry disase).
2011 clinical guidelines for hypertrophic cardiomyopathy recommend comprehensive testing for what five HCM genes?
2011 clinical guidelines for hypertrophic cardiomyopathy recommend comprehensive testing for five HCM genes (MYBPC3, MYH7, TNNI3, TNNT2, and TPM1).
Dilated cardiomyopathy is defined by LV dilatation and systolic dysfunction (a reduction in myocardial force generation characterized by an ejection fraction of
DCM is defined by LV dilatation and systolic dysfunction (a reduction in myocardial force generation characterized by an ejection fraction of
Compared with hypertrophic cardiomyopathy, which is mainly a disease of the sarcomere, dilated cardiomyopathy shows a considerably higher degree of locus heterogeneity with a steadily growing number of genes implicated (currently ∼40, with HCM
Compared with HCM, which is mainly a disease of the sarcomere, DCM shows a considerably higher degree of locus heterogeneity with a steadily growing number of genes implicated (currently ∼40, with HCM
Overview of arrhythmogenic right ventricular cardiomyopathy.
ARVC is defined by myocyte loss and fibrofatty infiltration of the myocardium is associated with an increased susceptibility to arrhythmias and sudden death and accounts for a significant portion of sudden deaths in athletes and young adults. Initially thought to affect only the right ventricle, LV involvement is now becoming increasingly recognized. The prevalence of ARVC is estimated to be 1 in 2000 to 5000 individuals, with 30% to 50% of cases being familial. ARVC is typically inherited in an autosomal dominant pattern with reduced penetrance and variable expressivity and affects men more frequently than women. ARVC is commonly described as a disease of the desmosome. Molecular mechanisms of ARVC include impaired cell-cell adhesion and defective transmission of the contractile force.
Most pathogenic arrhythmogenic right ventricular cardiomyopathy variants are present in what five genes?
Most pathogenic ARVC variants are present in five genes encoding desmosomal proteins [plakoglobin (JUP), desmoplakin (DSP), desmocollin-2 (DSC2), desmoglein-2 (DSG2), and plakophilin-2 (PKP2)].
Overview of left ventricular noncompaction.
Isolated LVNC is characterized by a heavily trabeculated or spongy appearance of the LV myocardium. An arrest of myocardial compaction during the first trimester of embryonic development is widely believed to be a cause. The left ventricle is typically affected, but 50% of patients with LVNC also have right ventricular involvement. There is a suggestion that LVNC is frequently associated with mitochondrial disorders, followed by Barth syndrome. Because LVNC is rare, its genetic etiology is not well understood. Variants have been described in known DCM and HCM genes encoding components of the sarcomere (ACTC1, MYH7, MYBPC3, and TNNT2), the Z-disk (LDB3), the nuclear lamina (LMNA), the dystrophin-associated glycoprotein complex (DTNA), as well as the Barth syndrome gene tafazzin (TAZ), a nuclear-encoded mitochondrial protein.
Aorta - large to medium-sized artery - small artery - arteriole - capillary - venule - vein. What parts of the vessel do these entities affect: Giant cell (temporal) arteritis and Takayasu arteritis. Polyarteritis nodosa and Kawasaki disease. Cutaneous leukocytoclastic angiitis. Henoch-Schonlein purpura and essential cryoglobulinemic vasculitis. Microscopic polyangiitis (microscopic polyarteritis). Wegener’s granulomatosis and Chrug-Strauss syndrome.
Giant cell (temporal) arteritis and Takayasu arteritis: aorta and large to medium-sized artery. Polyarteritis nodosa and Kawasaki disease: Large to medium-sized artery and small artery. Cutaneous leukocytoclastic angiitis: capillary and venule. Henoch-Schonlein purpura and essential cryoglobulinemic vasculitis: arteriole, capillary, and venule. Microscopic polyangiitis (microscopic polyarteritis): small artery, arteriole, capillary, and venule. Wegener’s granulomatosis and Chrug-Strauss syndrome: small artery, arteriole, capillary, venule, and vein.
Movat’s stain is a pentachrome stain originally developed to highlight the varous constituents of connective tissue, especially cardiovascular tissue. What are the 5 colors and the 5 tissue types stained by them?
Black: nuclei, elastic fibers. Yellow: collagen fibers, reticular fibers. Blue: ground substance, mucin. Red: fibrin. Bright red: muscle.
Does sarcoidosis cause restrictive or dilated cardiomyopathy?
Either.
Is cardiac involvement by sarcoid diffuse or patchy?
Patchy; endomyocardial biopsy makes the diagnosis in fewer than half of patients and a negative biopsy does not exclude the disease.
True or false. Arrhythmogenic cardiomyopathy involves only the right ventricle.
False. Arrhythmogenic cardiomyopathy typically involves the right ventricle (pulmonary infundibulum, apex, inferior wall) but may also involve the left ventricle and septum.
At least 12 genes encoding sarcomeric proteins, involving thick and thin filaments, with over 400 mutations have been implicated in the pathogenesis of hypertrophic cardiomyopathy. Of these mutations, those involving the (protein) are most commonly involved and account for 35% of all cases of HCM.
At least 12 genes encoding sarcomeric proteins, involving thick and thin filaments, with over 400 mutations have been implicated in the pathogenesis of hypertrophic cardiomyopathy. Of these mutations, those involving the beta-myosin heavy chain are most commonly involved and account for 35% of all cases of HCM. Other common mutations involve genes encoding myosin binding protein C (20%) and cardiac troponin T (15%).
VSDs account for __% of congenital cardiac defects, and ASDs account for __%.
VSDs account for 40% of congenital cardiac defects, and ASDs account for 10%.
Which type(s) of Streptococcus cause rheumatic heart disease, and which cause infective endocarditis?
Streptococcus pyogenes (group A or beta-hemolytic streptococcus) is the causative agent of rheumatic heart disease. Viridans streptococci are a common cause of infective endocarditis.
What is the most common cause of mitral stenosis?
Rheumatic heart disease. In 65-70% of cases, the mitral valve is the only valve affected. The mitral and aortic valves are affected in ~25% of cases.
Why is “arrythmogenic right ventricular cardiomyopathy” a misnomer?
Because it is not only the right ventricle that can be affected - left ventricle and septum can be affected too. The preferred term is “arrhythmogenic cardiomyopathy.”
Of the 3 CK isoenzymes, which is the fastest migrating and which is the slowest migrating?
The fastest is CK-BB (CK1). The slowest is CK-MM (CK3).
