Conversion prepared and presented by Marc Imhotep Cray, M.D. Basic Medical Sciences Teacher A Basic PowerPoint conversion : For study, sharing and download as a tool in preparation to sit for the USMLE Step 1 Source of Images Webpath- University of Utah Hypermedia Image Source Tables included
IVMS ACVBMS is an upper-level undergraduate course designed for Pre-Med, Medical Students and Biomedical Science Majors. IVMS ACVBMS examines the basic medical science behind the uses of Autonomic and Cardiovascular drugs, covering a variety of common prescription medications. There clinical use, mechanism of action, and important side effects of each class of drugs are explored within the context of the body's organ systems.
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Transcript
Conversion prepared and presented by
Marc Imhotep Cray, M.D.
Basic Medical Sciences Teacher
A Basic PowerPoint conversion :
For study, sharing and download as a tool in preparation to
• Here is an example of an atherosclerotic aneurysm of the aorta in which a large "bulge" appears just above the aortic bifurcation.
• Such aneurysms are prone to rupture when they reach about 6 to 7 cm in size.
• They may be felt on physical examination as a pulsatile mass in the abdomen.Most such aneurysms are conveniently located below the renal arteries so that surgical resection can be performed with placement of a dacron graft
• A coronary artery has been opened longitudinally.
• The coronary extends from left to right across the middle of the picture and is surrounded by epicardial fat. Increased epicardial fat correlates with increasing total body fat.
• There is a lot of fat here, suggesting one risk factor for atherosclerosis.
• This coronary shows only mild atherosclerosis, with only an occasional yellow-tan lipid plaque and no narrowing
• The anterior surface of the heart demonstrates an opened left anterior descending coronary artery.
• Within the lumen of the coronary can be seen a dark red recent coronary thrombosis.
• The dull red color to the myocardium as seen below the glistening epicardium to the lower right of the thrombus is consistent with underlying myocardial infarction
• Here, the dissection went into the muscular wall. In any case, an aortic dissection is an extreme emergency and can lead to death in a matter of minutes.
• The blood can dissect up or down the aorta.
• Blood dissecting up around the great vessels can close off the carotids.
• Blood can dissect down to the coronaries and shut them off
• The right carotid artery is compressed by blood dissecting upward from a tear with aortic dissection.
• Blood may also dissect to coronary arteries.
• Thus patients with aortic dissection may have symptoms of severe chest pain (for distal dissection) or may present with findings that suggest a stroke (with carotid dissection) or myocardial ischemia (with coronary dissection).
• This is infective endocarditis. The aortic valve demonstrates a large, irregular, reddish tan vegetation.
• Virulent organisms, such as Staphylococcus aureus, produce an "acute" bacterial endocarditis, while some organisms such as Streptococcus viridans produce a "subacute" bacterial endocarditis
• Microscopically, the valve in infective endocarditis demonstrates friable vegetations of fibrin and platelets (pink) mixed with inflammatory cells and bacterial colonies (blue).
• The friability explains how portions of the vegetation can break off and embolize
• The left atrium has been opened to reveal the most common primary cardiac neoplasm--an atrial myxoma.
• These benign masses are most often attached to the atrial wall, but can arise on a valve or in a ventricle.
• They can produce a "ball valve" effect by intermittently occluding the atrioventricular valve orifice. Embolization of fragments of tumor may also occur. Myxomas are easily diagnosed by echocardiography 57
• Ventricular Septal Defect (VSD) There is a hole within the membranous or muscular portions of the intraventricular septum that produces a left-to-right shunt, more severe with larger defects
• Atrial Septal Defect (ASD) A hole from a septum secundum or septum primum defect in the interatrial septum produces a modest left-to-right shunt
•
• Patent Ductus Arteriosus (PDA) The ductus arteriosus, which normally closes soon after birth, remains open, and a left-to-right shunt develops
Mechanism • Tetralogy of Fallot Pulmonic stenosis results in right ventricular
hypertrophy and a right-to-left shunt across a VSD, which also has an overriding aorta
• Transposition of Great Vessels The aorta arises from the right ventricle and the pulmonic trunk from the left ventricle. A VSD, or ASD with PDA, is needed for extrauterine survival. There is right-to-left shunting
• .
• Truncus ArteriosusThere is incomplete separation of the aortic and pulmonary outflows, along with VSD, which allows mixing of oxygenated and deoxygenated blood and right-to-left shunting
Mechanism • Hypoplastic Left Heart Syndrome There are varying
degrees of hypoplasia or atresia of the aortic and mitral valves, along with a small to absent left ventricular chamber
• Coarctation of Aorta Either just proximal (infantile form) or just distal (adult form) to the ductus is a narrowing of the aortic lumen, leading to outflow obstruction
• Total Anomalous Pulmonary Venous Return (TAPVR) The pulmonary veins do not directly connect to the left atrium, but drain into left innominate vein, coronary sinus, or some other site, leading to possible mixing of blood and right-sided overload
vessels, diagram • In the diagram, transposition of the
great vessels is shown
• occurs when the trunco-conal septum does not spiral down. Instead, it descends straight down. As a result, outflow of right ventricle is into aorta and outflow from left ventricle is into the pulmonic trunk.
• In order for this system to work, there must be a connection between the system and pulmonic circulations.
• Sometimes this is through a ventricular septal defect or an atrial septal defect.
• In the diagram at the left, this is through a patent ductus arteriosus
• Dilated (Congestive) All four chambers are dilated, and there is also hypertrophy. The most common cause is chronic alcoholism, though some may be the end-stage of remote viral myocarditis.
• Hypertrophic The most common form, idiopathic hypertrophic subaortic stenosis (IHSS) results from asymmetric interventricular septal hypertrophy, resulting in left ventricular outflow obstruction.
• Restrictive The myocardium is infiltrated with a material that results in impaired ventricular filling. The most common causes are amyloidosis and hemochromatosis.
• This very large heart has a globoid shape because all of the chambers are dilated.
• It felt very flabby, and the myocardium was poorly contractile.
• This is an example of a cardiomyopathy.
• This term is used to denote conditions in which the myocardium functions poorly and the heart is large and dilated, but there is no specific histologic finding 74
• There is marked left ventricular hypertrophy, with asymmetric bulging of a very large interventricular septum into the left ventricular chamber.
• This is hypertrophic cardiomyopathy. About half of these cases are familial, though a variety of different genes may be responsible for this disease.
• Both children and adults can be affected, and sudden death can occur. Seen here is the explanted heart. Pacemaker wires enter the right ventricle.
• The atria with venous connections, along with great vessels, remained behind to connect to the transplanted heart (provided by someone who cared enough to make transplantation possible).
• The prominent veins shown here on the lower leg are varicosities. Varicose veins are a common problem with aging. The venous valves become incompetent.
• There may be muscular atrophy with less tone to provide a massage effect on the large superficial veins, and skin becomes less elastic with time.
• Hydrostatic pressure from standing for long periods exacerbates the problem