8-9 Blood Vessels & Arteriosclerosis Questions
A 57-year-old woman has had episodes of abdominal pain following meals for the past year. Her BMI is 31. She has hypertension. Her total serum cholesterol is increased. Which of the following types of blood vessel is the most likely location for the pathologic abnormality causing her pain? A Artery B Arteriole C Capillary D Venule E Vein
Artery She has abdominal angina from vascular insufficiency. She has multiple risk factors for atherosclerosis. Atherosclerosis occurs in muscular arteries, because the level of blood pressure in arteries predisposes to endothelial dysfunction.
A study of persons with essential hypertension is performed. They have blood pressures in the range of 140/90 to 160/100 mm Hg. Laboratory studies show normal serum electrolyte values. Which of the following physiologic abnormalities is most likely to account for their hypertension? A Hyperreninemia B Hyperaldosteronism C Decreased natriuretic peptide D Decreased angiotensin converting enzyem E Sodium retention F Catecholamine excess
Sodium retention The causes for essential hypertension are obscure. The 'set point' for sodium diuresis is probably increased at a higher blood pressure in affected persons. Diuretics that promotes natriuresis are effective in treating essential hypertension.
An epidemiologic study seeking to determine possible risk factors for neoplasia is reviewing patient cases of neoplasms reported to tumor registries. Analysis of the data shows that one type of neoplasm is seen in two widely disparate situations: (1) the liver of individuals exposed to polyvinyl chloride and (2) the soft tissue of the arm ipsilateral to a prior radical mastectomy. The pathology reports about the neoplasms in these two groups of patients show a similar gross appearance—an irregular, infiltrative, soft reddish mass—and a similar microscopic appearance—pleomorphic spindle cells positive for CD31. Which of the following neoplasms is most likely to be described by these findings? (A) Angiosarcoma (B) Hemangioendothelioma (C) Hemangioma (D) Hemangiopericytoma (E) Kaposi sarcoma (F) Lymphangioma
(A) Angiosarcoma Angiosarcomas are aggressive malignancies. Knowledge of the association with vinyl chloride has virtually eliminated this occupational exposure. In the past, when radical mastectomies were more common, angiosarcomas arose in the setting of chronic lymphedema of the arm; the tumor probably arose from dilated lymphatics. Most angiosarcomas are sporadic neoplasms that occur rarely in older adults. Hemangioendotheliomas exhibit biologic behavior intermediate between the very localized, slow-growing hemangioma and the aggressive angiosarcoma; they may recur after excision. Hemangiopericytomas are rare soft-tissue neoplasms that can metastasize. Kaposi sarcoma (KS) was previously a rare endemic neoplasm involving the lower extremities; however, with the advent of AIDS, KS has become associated with HIV infection. KS is driven by human herpesvirus-8 infection. Lymphangiomas are benign, and when formed of capillary-like channels, are usually small and localized. Cavernous lymphangiomas can be ill-defined, however, and difficult to remove.
A 61-year-old man had a myocardial infarction 1 year ago, which was the first major illness in his life. He now wants to prevent another myocardial infarction and is advised to begin a program of exercise and to change his diet. A reduction in the level of which of the following serum laboratory findings 1 year later would best indicate the success of this diet and exercise regimen? (A) Cholesterol (B) Glucose (C) Potassium (D) Renin (E) Calcium
(A) Cholesterol Reducing cholesterol, particularly LDL cholesterol, with the same or increased HDL cholesterol level, indicates a reduced risk of atherosclerotic complications. Atherosclerosis is multifactorial, but modification of diet (i.e., reduction in total dietary fat and cholesterol) with increased exercise is the best method of reducing risk for most individuals. Glucose is a measure of control of diabetes mellitus. Potassium, calcium, and renin values can be altered with some forms of hypertension, one of several risk factors for atherosclerosis.
A study of atheroma formation leading to atherosclerotic complications evaluates potential risk factors for relevance in a population. Three factors are found to play a significant role in the causation of atherosclerosis: smoking, hypertension, and hypercholesterolemia. These factors are analyzed for their relationship to experimental models for atherogenesis. Which of the following events is the most important direct biologic consequence of these factors? (A) Endothelial injury and its sequelae (B) Conversion of smooth muscle cells to foam cells (C) Alterations of hepatic lipoprotein receptors (D) Inhibition of LDL oxidation (E) Alterations of endogenous factors regulating vasomotor tone
(A) Endothelial injury and its sequelae Atherosclerosis is thought to result from a form of endothelial injury and the subsequent chronic inflammation and repair of the intima. All risk factors, including smoking, hyperlipidemia, and hypertension, cause biochemical or mechanical injury to the endothelium. Formation of foam cells occurs after the initial endothelial injury. Although lipoprotein receptor alterations can occur in some inherited conditions, these account for only a fraction of cases of atherosclerosis, and other lifestyle conditions do not affect their action. Inhibition of LDL oxidation should diminish atheroma formation. Vasomotor tone does not play a major role in atherogenesis
A 35-year-old man is known to have been HIV-positive for the past 10 years. Physical examination shows several skin lesions with the appearance shown in the figure. These lesions have been slowly increasing for the past year. Which of the following infectious agents is most likely to play a role in the development of these skin lesions? (A) Human herpesvirus-8 (B) Epstein-Barr virus (C) Cytomegalovirus (D) Hepatitis B virus (E) Adenovirus
(A) Human herpesvirus-8 Human herpesvirus-8 has been associated with Kaposi sarcoma and can be acquired as a sexually transmitted disease. Kaposi sarcoma is a complication of AIDS. Individuals with HIV infection can be infected with various viruses, including Epstein-Barr virus (EBV) and cytomegalovirus (CMV), but these have no etiologic association with Kaposi sarcoma. EBV is a factor in the development of non-Hodgkin lymphoma, and CMV can cause colitis or retinitis or can be disseminated. Hepatitis B virus can be seen in HIV-infected patients as well, particularly patients with a risk factor of injection drug use. Adenovirus, which, although rare, can be seen in HIV-infected individuals, tends to be a respiratory or gastrointestinal infection
For more than a decade, a 45-year-old man has had poorly controlled hypertension ranging from 150/90 mm Hg to 160/95 mm Hg. Over the past 3 months, his blood pressure has increased to 250/125 mm Hg. On physical examination, his temperature is 36.9°C. His lungs are clear on auscultation, and his heart rate is regular. There is no abdominal pain on palpation. A chest radiograph shows a prominent border on the left side of the heart. Laboratory studies show that his serum creatinine level has increased during this time from 1.7 mg/dL to 3.8 mg/dL. Which of the following vascular lesions is most likely to be found in this patient's kidneys? (A) Hyperplastic arteriolosclerosis (B) Granulomatous arteritis (C) Fibromuscular dysplasia (D) Polyarteritis nodosa (E) Hyaline arteriolosclerosis
(A) Hyperplastic arteriolosclerosis This patient has malignant hypertension superimposed on benign essential hypertension. Malignant hypertension can suddenly complicate less severe hypertension. The arterioles undergo concentric thickening and luminal narrowing. A granulomatous arteritis is most characteristic of Wegener granulomatosis, which often involves the kidney. Fibromuscular dysplasia can involve the main renal arteries, with medial hyperplasia producing focal arterial obstruction. This process can lead to hypertension, but not typically malignant hypertension. Polyarteritis nodosa produces a vasculitis that can involve the kidney. Hyaline arteriolosclerosis is seen with long-standing essential hypertension of moderate severity. These lesions give rise to benign nephrosclerosis. The affected kidneys become symmetrically shrunken and granular because of progressive loss of renal parenchyma and consequent fine scarring.
The development of atheromatous plaque formation with subsequent complications is observed in an experiment. Atherosclerotic plaques are shown to change slowly but constantly in ways that can promote clinical events, including acute coronary syndromes. In some cases, changes occurred that were not significantly associated with acute coronary syndromes. Which of the following plaque alterations is most likely to have such an association? (A) Thinning of the media (B) Ulceration of the plaque surface (C) Thrombosis (D) Hemorrhage into the plaque substance (E) Intermittent platelet aggregation
(A) Thinning of the media Atheromatous plaques can be complicated by various pathologic alterations, including hemorrhage, ulceration, thrombosis, and calcification. These processes can increase the size of the plaque and narrow the residual arterial lumen. Although atherosclerosis is a disease of the intima, in advanced disease, the expanding plaque compresses the media. This causes thinning of the media, which weakens the wall and predisposes it to aneurysm formation.
A 49-year-old man is feeling well when he visits his physician for a routine health maintenance examination for the first time in 20 years. On physical examination, his vital signs are temperature, 37°C; pulse, 73/min; respirations, 14/min; and blood pressure, 155/95 mm Hg. He has had no serious medical problems and takes no medications. Which of the following is most likely to be the primary factor in this patient's hypertension? (A) Increased catecholamine secretion (B) Renal retention of excess sodium (C) Gene defects in aldosterone metabolism (D) Renal artery stenosis (E) Increased production of atrial natriuretic factor
(B) Renal retention of excess sodium This patient has essential hypertension (no obvious cause for his moderate hypertension). Renal retention of excess sodium, which is thought to be important in initiating this form of hypertension, leads to increased intravascular fluid volume, increase in cardiac output, and peripheral vasoconstriction. Increased catecholamine secretion (as can occur in pheochromocytoma), gene defects in aldosterone metabolism, and renal artery stenosis all can cause secondary hypertension. Hypertension secondary to all causes is much less common, however, than essential hypertension. Increased production of atrial natriuretic factor reduces sodium retention and reduces blood volume.
After falling down a flight of stairs, a 59-year-old woman experiences mild intermittent right hip pain. Physical examination shows a 3-cm contusion over the right hip. The area is tender to palpation, but she has full range of motion of the right leg. A radiograph of the pelvis and right upper leg shows no fractures, but does show calcified, medium-sized arterial branches in the pelvis. This radiographic finding is most likely to represent which of the following? (A) Long-standing diabetes mellitus (B) Benign essential hypertension (C) An incidental observation (D) Increased risk for gangrenous necrosis (E) Unsuspected hyperparathyroidism
(C) An incidental observation Older adults with calcified arteries often have Mönckeberg medial calcific sclerosis, a benign process that is a form of arteriosclerosis with no serious sequelae. Such arterial calcification is far less likely to be a consequence of atherosclerosis with diabetes mellitus or with hypercalcemia. Hypertension is most likely to affect small renal arteries, and calcification is not a major feature, although hypertension also is a risk factor for atherosclerosis.
For the past 3 weeks, a 70-year-old woman has been bedridden while recuperating from a bout of viral pneumonia complicated by bacterial pneumonia. Physical examination now shows some swelling and tenderness of the right leg, which worsens when she raises or moves the leg. Which of the following terms best describes the condition involving the patient's right leg? (A) Lymphedema (B) Disseminated intravascular coagulopathy (C) Thrombophlebitis (D) Thromboangiitis obliterans (E) Varicose veins
(C) Thrombophlebitis Thrombophlebitis is a common problem that results from venous stasis. There is little or no inflammation, but the term is well established. Lymphedema takes longer than 3 weeks to develop and is not caused by bed rest alone. Disseminated intravascular coagulopathy more often results in hemorrhage, and edema is not the most prominent manifestation. Thromboangiitis obliterans is a rare form of arteritis that results in pain and ulceration of extremities. Varicose veins are superficial and can thrombose, but they are not related to bed rest.
A 12-year-old boy died of complications of acute lymphocytic leukemia. The gross appearance of the aorta at autopsy is shown in the figure [It shows fatty streaks]. Histologic examination of the linear pale marking is most likely to show which of the following features? (A) Cap of smooth muscle cells overlying a core of lipid debris (B) Collection of foam cells with necrosis and calcification (C) Granulation tissue with a lipid core and areas of hemorrhage (D) Lipid-filled foam cells and small numbers of T lymphocytes (E) Cholesterol clefts surrounded by proliferating smooth muscle cells and foam cells
(D) Lipid-filled foam cells and small numbers of T lymphocytes The slightly raised, pale lesions shown in the figure are called fatty streaks and are seen in the aorta of almost all children older than 10 years. They are thought to be precursors of atheromatous plaques. T cells are present early in the pathogenesis of atherosclerotic lesions and are believed to activate monocytes, endothelial cells, and smooth muscle cells by secreting cytokines. Fatty streaks cause no disturbances in blood flow and are discovered incidentally at autopsy. All of the other lesions described are seen in fully developed atheromatous plaques. The histologic features of such plaques include a central core of lipid debris that can have cholesterol clefts and can be calcified. There is usually an overlying cap of smooth muscle cells. Hemorrhage is a complication seen in advanced atherosclerosis. Foam cells, derived from smooth muscle cells or macrophages that have ingested lipid, can be present in all phases of atherogenesis.
After a mastectomy with axillary node dissection for breast cancer 1 year ago, a 47-year-old woman has developed persistent swelling and puffiness in the left arm. Physical examination shows firm skin over the left arm and "doughy" underlying soft tissue. The arm is not painful or discolored. She developed cellulitis in the left arm 3 months ago. Which of the following terms best describes these findings? (A) Thrombophlebitis (B) Subclavian arterial thrombosis (C) Tumor embolization (D) Lymphedema (E) Vasculitis
(D) Lymphedema A mastectomy with axillary lymph node dissection leads to disruption and obstruction of lymphatics in the axilla. Such obstruction to lymph flow gives rise to lymphedema, a condition that can be complicated by cellulitis. Thrombophlebitis from venous stasis is a complication seen more commonly in the lower extremities. An arterial thrombosis can lead to a cold, blue, painful extremity. Tumor emboli are generally small but uncommon. Vasculitis is not a surgical complication.
A 23-year-old man experiences sudden onset of severe, sharp chest pain. On physical examination, his temperature is 36.9°C, and his lungs are clear on auscultation. A chest radiograph shows a widened mediastinum. Transesophageal echocardiography shows a dilated aortic root and arch, with a tear in the aortic intima 2 cm distal to the great vessels. The representative microscopic appearance of the aorta with elastic stain is shown in the figure. Which of the following is the most likely cause of these findings? (A) Scleroderma (B) Diabetes mellitus (C) Systemic hypertension (D) Marfan syndrome (E) Wegener granulomatosis (F) Takayasu arteritis
(D) Marfan syndrome This is a description of cystic medial degeneration, which weakens the aortic media and predisposes to aortic dissection. In a young patient such as this, a heritable disorder of connective tissues, such as Marfan syndrome, must be strongly suspected. Scleroderma and Wegener granulomatosis do not typically involve the aorta. Atherosclerosis associated with diabetes mellitus and hypertension are risk factors for aortic dissection, although these are seen at an older age. Takayasu arteritis is seen mainly in children and involves the aorta (particularly the arch) and branches such as the coronary and renal arteries, causing granulomatous inflammation, aneurysm formation, and dissection
An experiment studies early atheromas. Lipid streaks on arterial walls are examined microscopically and biochemically to determine their cellular and chemical constituents and the factors promoting their formation. Early lesions show increased attachment of monocytes to endothelium. The monocytes migrate subendothelially and become macrophages; these macrophages transform themselves into foam cells. Which of the following is most likely to produce these effects? (A) C-reactive protein (B) Homocysteine (C) Lp(a) (D) Oxidized LDL (E) Platelet-derived growth factor (F) VLDL
(D) Oxidized LDL Oxidized LDL can be taken up by a special "scavenger" pathway in macrophages; it also promotes monocyte chemotaxis and adherence. Macrophages taking up the lipid become foam cells that begin to form the fatty streak. Smoking, diabetes mellitus, and hypertension all promote free radical formation, and free radicals increase degradation of LDL to its oxidized form. About one third of LDL is degraded to the oxidized form; a higher LDL level increases the amount of oxidized LDL available for uptake into macrophages. C-reactive protein is a marker for inflammation, which can increase with more active atheroma and thrombus formation and predicts a greater likelihood of acute coronary syndromes. Increased homocysteine levels promote atherogenesis through endothelial dysfunction. Lp(a), an altered form of LDL that contains the apo B-100 portion of LDL linked to apo A, promotes lipid accumulation and smooth muscle cell proliferation. Platelet-derived growth factor promotes smooth muscle cell proliferation. VLDL is formed in the liver and transformed in adipose tissue and muscle to LDL.
A 10-year-old boy is brought to the physician for a routine health maintenance examination. The physician notes a 2-cm spongy, dull red, circumscribed lesion on the upper outer left arm. The parents state that this lesion has been present since infancy. The lesion is excised, and its microscopic appearance is shown in the figure. [The figure shows dilated, endothelium-lined spaces filled with RBCs]. Which of the following is the most likely diagnosis? (A) Kaposi sarcoma (B) Angiosarcoma (C) Lymphangioma (D) Telangiectasia (E) Hemangioma
(E) Hemangioma The figure shows dilated, endothelium-lined spaces filled with RBCs. The circumscribed nature of this lesion and its long, unchanged course suggest its benign nature. Kaposi sarcoma is uncommon in its endemic form in childhood, and it is best known as a neoplastic complication associated with HIV infection. Angiosarcomas are large, rapidly growing malignancies in adults. Lymphangiomas, seen most often in children, tend to be more diffuse and are not blood-filled. A telangiectasia is a radial array of subcutaneous dilated arteries or arterioles surrounding a central core that can pulsate
A 68-year-old woman has survived multiple episodes of pulmonary thromboembolism during the past three months. On physical examination there are no abnormal findings. Which of the following is the most likely underlying condition leading to this patient's recurrent pulmonary thromboembolism? A Micronodular cirrhosis of the liver B Adenocarcinoma of the pancreas C Thrombocytopenia D Familial hypercholesterolemia E Mitral valve endocarditis F Type II diabetes mellitus
Adenocarcinoma of the pancreas The recurrent episodes suggest a hypercoagulable state, and carcinomas can do this (Trousseau syndrome) by releasing substances that act as thromboplastins.
A 70-year-old healthy woman has a check of her health status. On examination her blood pressure is 125/80 mm Hg and BMI 24 kg/m2. Laboratory studies show her serum total cholesterol is 180 mg/dL with LDL cholesterol 90 mg/dL. There is a family history of cancer. Which of the following is a constitutional risk factor for atherosclerotic vascular disease in this woman? A Age B Blood pressure C Family history D Gender E Hyperlipidemia F Weight
Age Her age is a risk factor for atherosclerosis. However, a healthy lifestyle can negate this risk. Many older persons are not pursuing a healthy lifestyle.
A 49-year-old woman has experienced marked pain in her lower extremities on ambulation more than 300 meters for the past 5 months. On physical examination, her lower extremities are cool and pale, without swelling or erythema. No dorsalis pedis or posterior tibial pulses are palpable. Her body mass index is 32. She is a smoker. Which of the following abnormalities of the vasculature is most likely to account for these findings? A Lymphatic obstruction B Arteriolosclerosis C Atherosclerosis D Medial calcific sclerosis E Venous thrombosis
Atherosclerosis She has claudication from severe peripheral arterial atherosclerosis, most likely from the iliac arteries down. Her major risk factor is obesity that promotes insulin resistance and diabetes mellitus that leads to atherosclerosis.
A 62-year-old man has experienced substernal chest pain upon exertion with increasing frequency over the past 6 months. An electrocardiogram shows features consistent with ischemic heart disease. He has a total serum cholesterol of 262 mg/dL. By angiography, there is 75% narrowing of coronary arteries. In which of the following locations is a mural thrombus most likely to occur in this man? A Left atrium B Left ventricle C Right atrium D Right ventricle E Aorta F Vena cava
B Left ventricle The left ventricle is the major user of oxygen and nutrients and requires a good blood supply. A complication of ischemic heart disease with infarction is development of overlying mural thrombus. Such mural thrombi are likely to result from damage to the left ventricle from ischemic heart disease, either acutely with an underlying myocardial infarction, or with a left ventricular aneurysm formed following resolution of a large myocardial infarction
A 73-year-old woman who exercises regularly falls down the stairs and injures her right hip. A radiograph is taken of the pelvis. There is no fracture but the radiograph reveals calcification of the small muscular arteries lateral to her uterus. What is the probable vascular lesion which accounts for this calcification? A Ulcerative atherosclerosis B Calcific medial sclerosis C Metastatic calcification D Trauma E Dystrophic calcification
Calcific medial sclerosis Monckeberg calcific medial sclerosis is a benign, incidental finding most often seen in the elderly. Small arteries in pelvis, breast, neck, and extremities are typically involved. The vascular lumen is not compromised.
A 71-year-old woman experiences a transient ischemic attack (TiA). She had an acute myocardial infarction 5 years ago. Which of the following physical examination findings is most likely to be associated with her TIA? A Blood pressure 140/90 mm Hg B Carotid bruit C Heart rate of 100/minute D Leg swelling E Pulsatile abdominal mass F Radial pulse 1+
Carotid bruit Atheromatous plaques tend to form initially where there is vascular turbulence, and a bruit is indicative of arterial narrowing at the carotid bifurcation. The turbulence drives endothelial injury that contributes to atheroma formation.
A 56-year-old reports reduced exercise tolerance over the past 5 years. In the past year he has noted chest pain after ascending a flight of stairs. He smokes 2 packs of cigarettes per day. On examination he has a blood pressure of 155/95 mm Hg. His body mass index is 30. Laboratory findings include a total serum cholesterol of 245 mg/dL with an HDL cholesterol of 22 mg/dL. Which of the following vascular abnormalities is he most likely to have? A Hyperplastic arteriolosclerosis B Lymphedema C Medial calcific sclerosis D Atherosclerosis E Deep venous thrombosis F Plexiform arteriopathy
D Atherosclerosis He has multiple risk factors for atherosclerosis, including his weight, smoking, hypertension, and high total cholesterol with low 'good' HDL cholesterol. His findings suggest coronary artery disease with risk for an acute coronary syndrome.
A study of atherogenesis is performed. There is a propensity for atheromas to form at muscular arterial branch points, such as the carotid and aortic bifurcations. Which of the following events in the arteries at these locations is most likely to initiate atherogenesis? A Collagen synthesis B Endothelial dysfunction C Lactic acidosis D Cholesterol breakdown E Hypoxemia
Endothelial dysfunction A variety of stressors may affect endothelial cells, including the shear stress from turbulent flow at arterial branch points. Endothelial dysfunction is the initiating event that allows insudation of lipids to promote atherogenesis.
A 25-year-old man experiences chest pain on exercise when he attempts to climb three flights of stairs. This pain is relieved by sublingual nitroglycerin. He is 178 cm tall and weighs 101 kg. His blood pressure is 130/85 mm Hg. Laboratory studies show a total serum cholesterol of 550 mg/dL with an HDL cholesterol component of 25 mg/dL. The blood glucose is 120 mg/dL. He is worried about these findings because his brother died of a myocardial infarction at age 34. Which of the following conditions is this man most likely to have? A Diabetes mellitus, type II B Malignant hypertension C Familial hypercholesterolemia D Cushing syndrome E Morbid obesity
Familial hypercholesterolemia The very high cholesterol with symptoms of coronary artery disease at such a young age, coupled with the family history, are all consistent with familial hypercholesterolemia. In most persons with hypercholessterolemia from multifactorial causes, including diet and exercise patterns, the cholesterol rarely exceeds 400 mg/dL.
An autopsy study reveals that evidence for atheroma formation can begin even in children. The gross appearances of the aortas are recorded and compared with microscopic findings of atheroma formation. Which of the following is most likely to be the first visible gross evidence for the formation of an atheroma? A Thrombus B Fatty streak C Calcification D Hemorrhage E Exudate F Ulceration
Fatty streak A fatty streak on the arterial intimal surface is the first grossly visible sign of atheroma formation. It is benign and reversible, but it may be the precursor to more severe plaques.
A 57-year-old woman has experienced episodes of altered mental status for the past month. On physical examination, she has bilateral carotid artery bruits. She is given folic acid supplementation. Which of the following laboratory test findings is she most likely to have? A Factor V Leiden mutation B Factor VIII deficiency C Increased carcinoembryonic antigen D Homocysteinemia E Increased HDL cholesterol
Homocysteinemia An elevated plasma homocysteine level is a risk for atherosclerosis as well as thrombosis. Her findings point to transient ischemic attacks (TIAs) with risk for stroke. The carotid bruits represent arterial narrowing as the result of atherosclerosis.
A 57-year-old man has had blood pressure measurements in the range of 160/95 to 180/110 mm Hg for many years. He has taken no medications. A renal scan reveals kidneys of normal size for age. These findings with benign nephrosclerosis are most likely to occur with which of the following vascular changes? A Hyaline arteriolosclerosis B Monckeberg's medial calcific sclerosis C Complex calcified atherosclerosis D Arterial mural thrombosis E Hyperplastic arteriolosclerosis
Hyaline arteriolosclerosis Hyaline arteriolosclerosis is a feature of long-standing hypertension and is part of benign nephrosclerosis which may go on for many years with no complications. The small arterioles are thickened with pink (hyaline) proteinaceous deposits.
A 70-year-old man has noted coldness and numbness of his lower left leg, increasing over the past 4 months. He also experiences pain in this extremity when he tries walking more than the distance of half a city block. On physical examination, his dorsalis pedis, posterior tibial, and popliteal artery pulses are not palpable. Which of the following laboratory test findings is he most likely to have? A Protein S deficiency B Blood culture with Staphylococcus aureus C Decreased arterial oxygen saturation D Hyperglycemia E Hypercalcemia
Hyperglycemia This is peripheral arterial vascular disease from severe atherosclerosis, which is promoted by diabetes mellitus. The absence of pulses defines this as an arterial process, as does the claudication (pain with exercise). Thrombophlebitis is a venous process and leads to swelling and pain in the leg, but not loss of pulses.
A 44-year-old African-American man has had elevated blood pressure for years which has not been treated. He now has severe headaches. On physical examination his blood pressure is 275/150 mm Hg. Laboratory studies show Hgb 13.8 g/dL, serum glucose 76 mg/dL, and creatinine 3.5 mg/dL. These findings are most likely to be associated with which of the following pathologic lesions involving his kidneys? A Hyperplastic arteriolosclerosis B Hyaline arteriolosclerosis C Monckeberg medial calcific sclerosis D Atherosclerosis E Thrombophlebitis
Hyperplastic arteriolosclerosis Hyperplastic arteriolosclerosis is seen in the setting of malignant hypertension, and renal failure is common.
An autopsy study is conducted involving the gross appearance of the aorta of adults ranging in age from 60 to 90. In some of these patients, the aorta demonstrates atheromatous plaques covering from 70 to 95% of the intimal surface area, mainly in the abdominal portion, with ulceration and calcification. Which of the following contributing causes of death are these patients most likely to have? A Hyperparathyroidism B Hypertension C Marfan syndrome D Thrombophlebitis E Vasculitis F Colonic adenocarcinoma G Systemic lupus erythematosus
Hypertension Hypertension is a risk factor that accelerates atheromatous plaque formation.
A 30-year-old man goes to his physician for a routine health checkup. On physical examination there are no abnormal findings. Laboratory test findings include serum glucose 80 mg/dL, hemoglobin A1C 4%, total cholesterol 240 mg/dL, LDL cholesterol 180 mg/dL, and HDL cholesterol 20 mg/dL. Through which of the following mechanisms is endothelial vascular injury in this patient most likely to occur? A Accumulation of sorbitol B Insudation of lipid C Inflammation with neutrophils D Deposition of immunoglobulins E Activation of complement
Insudation of lipid He has hypercholesterolemia with more of the 'bad' LDL cholesterol that can become oxidized and taken up by modified arterial wall LDL receptors. The lipid collects in macrophages that transform to foam cells. These foam cells accumulate and becomes a lipid lesion--the precursor to more serious atheromatous plaques.
A 29-year-old woman is involved in a motor vehicle accident that results in severe lacerations to her lower extremities, along with blunt abdominal trauma. In the emergency room she is noted to have cool, pallid skin. She has vital signs showing T 36.9°C, P 110/minute, RR 26/minute, and BP 70/30 mm Hg. She has decreased urine output. Which of the following laboratory findings on a blood sample from this patient is most likely to be present? A Hematocrit of 54% B Glucose of 181 mg/dL C PaO2 of 20 mm Hg D Lactic acid of 4.8 mmol/L E Troponin I of 4 ng/mL
Lactic acid of 4.8 mmol/L She has marked blood loss with shock. There will be vasoconstriction in skin and soft tissue in response to the hypovolemia. Decreased renal blood flow from shock may lead to acute tubular necrosis. The lack of tissue perfusion with shock leads to increased anaerobic glycolysis and lactic acidosis.
A 53-year-old man has the sudden onset of chest pain. He is found to have a serum troponin I of 5 ng/mL. A year later he has reduced exercise tolerance. An echocardiogram reveals an akinetic segment of left ventricle, and he has reduced cardiac output, with an ejection fraction of 25%. He then experiences a transient ischemic attack (TIA). His serum troponin I is now <0.5 ng/mL. Thrombus formation involving which of the following locations is most likely to have put him at greatest risk for the TIA? A Cerebral vein B Vertebral artery C Superior vena cava D Left ventricle E Coronary artery F Saphenous vein
Left ventricle Mural thrombi can form over the damaged area of ventricular wall following myocardial infarction. This can happen acutely overlying the necrotic myocardium; it can occur remotely in a ventricular aneurysm. Portions of the mural thrombus can break off and embolize via the systemic arterial circulation to places such as the cerebral circulation.
During hospitalization, a 40-year-old woman develops thrombophlebitis. She recovers and is discharged. She returns to her job as an electrician. A couple of months later, which of the following terms would best describe the process seen in a femoral vein after recovery from her thrombophlebitis: A Acute inflammation B Rupture C Embolization D Organization E Propagation
Organization Thrombi may either lyse or will organize over time, with much of the clot eventually removed and the vascular lumen restored.
A 66-year-old woman has the sudden loss of movement on part of the left side of her body. She has smoked a pack of cigarettes a day for the past 45 years. She has vital signs including T 37.1°C, P 80/minute, RR 16/minute, and BP 160/100 mm Hg. A cerebral angiogram reveals occlusion of a branch of her middle cerebral artery. Laboratory findings include a hemoglobin A1C of 9%. Which of the following components of blood lipids is most important in contributing to her disease? A Chylomicrons B Lipoprotein lipase C Oxidized LDL D VLDL E HDL cholesterol
Oxidized LDL She has had a 'stroke' which is most often a consequence of cerebral atherosclerosis or embolic disease from the heart as a consequence of ischemic heart disease from atherosclerosis. LDL brings cholesterol to arterial walls, and when increased LDL is present or when there is hypertension, smoking, and diabetes, there is more degradation of LDL to oxidized LDL which is taken up into arterial walls via scavenger receptors in macrophages to help form atheromas.
A 58-year-old woman has the sudden onset of severe dyspnea with chest pain and diaphoresis. A chest CT scan shows areas of decreased attenuation within the main pulmonary arteries. Her D-dimer assay is elevated. Her acute event is most likely to be a consequence of which of the following? A Placement of a hip prosthesis B Marked thrombocytopenia C Chronic alcoholism D Infection with the human immunodeficiency virus E Rheumatoid arthritis
Placement of a hip prosthesis Immobilization is a major risk for the development of venous thrombosis and subsequent pulmonary embolization (the areas of diminished attenuation). Immobilization occurs following surgery. The postoperative goal: get the patient mobile as soon as possible, and meanwhile employ methods to reduce the risk for thrombosis.
A 53-year-old woman is found on a routine physical examination to have vital signs with T 37°C, P 78/minute, RR 16/minute, and BP 165/110 mm Hg. There are no other significant findings. She has an abdominal ultrasound examination that shows the right kidney to be atrophic. Angiography reveals markedly reduced blood flow to the right renal artery from an occlusion at the orifice in the abdominal aorta. Which of the following laboratory findings is she most likely to have? A Serum sodium of 161 mmol/L B Serologic evidence of anti-cardiolipin antibody C Prothrombin time of 25 seconds D Plasma renin activity of 4.8 ng/mL/hr supine E Serum lactic acid of 5.5 mmol/L
Plasma renin activity of 4.8 ng/mL/hr supine She has renal artery stenosis that is reducing renal blood flow on the right and simulating the JG cells to secrete renin to try and raise blood pressure to increase renal blood flow.
A 45-year-old man dies suddenly and unexpectedly. The immediate cause of death is found to be a hemorrhage in the right basal ganglia region. On microscopic examination his renal artery branches have concentric endothelial cell proliferation which markedly narrows the lumen, resulting in focal ischemia and hemorrhage of the renal parenchyma. An elevation in which of the following substances in his blood is most likely to be associated with these findings? A Ammonia B Calcium C Cholesterol D Renin E Troponin I F Triglyceride G C-reactive protein
Renin The findings suggest hyperplastic arteriolosclerosis, which accompanies malignant hypertension. Reduced renal blood flow increases renin, driving hypertension.
A 52-year-old woman has experienced marked substernal, crushing chest pain for the past 3 hours. Her vital signs show T 36.9°C, P 90/minute, RR 18/minute, and BP 100/60 mm Hg. Laboratory studies include a serum creatine kinase MB fraction of 10 microgm/L as well as a serum troponin I of 4.5 ng/mL. Which of the following findings is the best evidence for the presence of a coronary arterial thrombus as the etiology for her chest pain? A Total serum cholesterol of 300 mg/dL B Large size of the infarction by scintigraphic scanning C 80% coronary occlusion by angiography D Response to thrombolytic therapy E Hemoglobin A1C of 10.1%
Response to thrombolytic therapy The purpose of thrombolytic therapy is to lyse the thrombus and restore blood flow. Many acute coronary events are the result of thrombus formation on pre-existing atheromas. Low dose aspirin therapy helps prevent such events.
