1、Cardiology 1題庫Q 31An 18-year-old Caucasian female is referred to the cardiologist because her primary care physician heard a cardiac murmur during a routine check-up. The patient is healthy and has no complaints. Her past medical history is unremarkable. Careful questioning of the patient and her mo

2、ther reveals that several family members have been told that they have murmurs. Auscultation reveals a mid systolic click which is followed by a short late systolic murmur. The murmur disappears on squatting. This patients condition is most likely related to an abnormality of:A. Endocardial lining B

3、. Cardiac muscle C.Connective tissue D.Coronary vessels E. Parietal pericardiumA 31Correct answer:DSmall (1-5 mm), sterile, non-destructive fibrinous vegetations along the lines of closure of cardiac valve cusps are characteristic of non-bacterial thrombotic endocarditis (NBTE). Histologically, thes

4、e vegetations consist of bland thrombus without accompanying inflammation or valvular damage. They are typically the result of a hypercoagulable state, although they may also be caused by endothelial injury. When caused by hypercoagulability, NBTE is most often related to some underlying disease, su

5、ch as a cancer. There is a particularly strong association of NBTE with mucinous adenocarcinomas of the pancreas and adenocarcinomas of the lung, which may relate to procoagulant effects of circulating mucin. NBTE associated with disseminated cancer is termed , marantic(or marasmic) endocarditis, de

6、rived from the term for cancer-related wasting of body tissues (marasmus). By a similar mechanism, tumor-associated release of procoagulants is thought responsible for the migratory thrombophlebitis (Trousseau syndrome) sometimes seen in patients with disseminated cancers.(Choice A) Humoral hypercal

7、cemia of malignancy, the most common cause of hypercalcemia in hospitalized patients, is due to the production of a parathyroid hormone (PTH)-like substance by tumors. This paraneoplastic syndrome would not cause a hypercoagulable state or vegetations of the sort described in this patient.(Choice B)

8、 Cancer metastases to the heart usually involve the pericardium or myocardium. Valve metastases are less frequent and would probably have shown invasive characteristics on histologic examination.(Choice C) Lambert-Eaton syndrome is an autoimmune paraneoplastic myasthenic syndrome that affects the pr

9、esynaptic calcium channels, resulting in decreased presynaptic acetylcholine release. Lambert-Eaton syndrome is associated in most cases with oat cell carcinoma of the lung.(Choice E Raynauds phenomenon involves episodic，ischemic attacks of the digits that produce pallor and numbness. These episodes

10、 may be induced by cold or emotional stimuli. The pathophysiology is thought to involve abnormal sensitivity of digital arteries/arterioles to vasoconstrictive influences. Raynauds phenomenon occurs in the absence of any hypercoagulable state.Q 32A 73-year-old Caucasian male with advanced visceral c

11、ancer dies of extensive myocardial infarction. Autopsy also reveals sterile non-destructive vegetations along the mitral leaflet edges. The pathogenesis of this patients vegetations is most similar to that of:A.Hypercalcemia of malignancy B.Distant metastases C.Lambert-Eaton syndrome D.Trousseau syn

12、drome E.Raynaud phenomenonA 32Correct answer:DThis patient exhibits signs and symptoms consistent with acute transmural myocardial infarction. Typical symptoms include severe chest pain not relieved by rest or nitroglycerin, diaphoresis, dyspnea, nausea, lightheadedness，and/or palpitations. Peaked T

13、-waves are the first ECG sign (reflecting localized hyperkalemia), and ST-segment elevation follows within minutes to hours. Within hours to days, Q-waves appear in the involved leads.The patient in the vignette has likely suffered a transmural infarct of the anterolateral left ventricle, as evidenc

14、ed by the ECG changes in the anterior (V1-V3) and lateral (I, aVL) chest leads. Transmural infarction is most commonly caused by an acute plaque change (e.g. rupture) which produces a superimposed thrombus that completely occludes the involved coronary artery. In this patient, the thrombus may be co

15、mpletely occluding the left main coronary artery.(Choice A) An atherosclerotic plaque obstructing 50% of the lumen and without any overlying thrombus would be unlikely to produce symptomatic myocardial ischemia. Symptoms of stable angina do not become prominent until at least 75% of the cross-sectio

16、nal area of the coronary artery lumen is occluded(Choice B) The patient in the vignette is suffering an acute coronary syndrome. Acute coronary syndromes are generally the result of an acute change in a coronary artery plaque, including ulceration, fissuring, or rupture, with formation of an overlyi

17、ng thrombus. The lesion described in answer choice B is a stable plaque producing a fixed obstruction. This sort of fixed obstruction occluding more than 75% of a coronary artery lumen would tend to produce stable angina.(Choice C) An ulcerated atherosclerotic plaque with a partially obstructive thr

18、ombus would tend to produce unstable angina, subendocardial myocardial infarction, or sudden cardiac death.(Choice E) Coronary artery vasospasm occurs in Prinzmetals (or variant) angina, an uncommon condition of episodic angina that generally occurs at rest. The spasm may occur at sites of coronary

19、atherosclerosis and can result in transient transmural ischemia with ST-segment elevations on ECG. In some cases, the spasm may cause Q-wave transmural myocardial infarction, even in the absence of atherosclerotic lesions on coronary angiography. However, the vasospasm of Prinzmetals angina generall

20、y responds promptly to vasodilators, such as nitroglycerin. Thus, a patient with Prinzmetals angina who received an adequate dose of nitroglycerin would be very unlikely to develop a transmural infarct.Q 33A 23-year-old Caucasian male with a three week history of fatigue and a new cardiac murmur on

21、physical exam is found to have mild proteinuria and microscopic hematuria. His serum creatinine level is 2.3 mg/dL and examination of his urine sediment reveals red cell casts. The urine findings are most likely explained by:A. Hematogenous metastatic infection focusB. Thromboembolic eventC. Circula

22、ting immune complex-mediated injuryD. Anti-glomerular basement membrane antibodies E. Endotoxin-induced renal tubular injuryA 33Correct answer:CBacterial endocarditis (BE) is the most common cause of fatigue and new onset cardiac murmur in a young adult. This patient also has a roughly two-fold elev

23、ation of serum creatinine, indicating a 50% reduction in his GFR. The accompanying hematuria and proteinuria suggest that this mild renal insufficiency is due to a nephritic syndrome. In some patients, BE may be complicated by acute diffuse proliferative glomerulonephritis secondary to circulating i

24、mmune complexes and their mesangial and/or subepithelial deposition in the glomeruli.(Choice A) Septic emboli from infected endocardial vegetations in BE can produce metastatic foci of infection via hematogenous spread. These may cause infarcts in the brain, kidneys, myocardium, and other tissues. S

25、ince the emboli contain large numbers of virulent organisms, abscesses may develop at the sites of such infarcts (septic infarcts). However, in order to decrease GFR by 50%, 75% of all renal glomeruli would have to be affected. This degree of involvement would be unlikely to result from one or even

26、several focal septic renal infarcts. The widespread glomerular involvement here favors a circulating immune complex pathogenesis.(Choice B) Microemboli from endocardial vegetations in BE can produce systemic thromboembolic events in the brain, kidneys, myocardium, and other tissues. Janeway lesions

27、- small, erythematous or hemorrhagic, macular, nontender lesions on the palms and soles - are an example of this process. Thromboembolism to the kidneys is unlikely to have produced the clinical picture here, however, given the degree of renal involvement indicated by this patients urine studies. In

28、 order to decrease GFR by 50%, 75% of all renal glomeruli would have to be affected. This would be unlikely with one or even several microembolic infarcts of the kidney due to BE. This patients widespread glomerular involvement favors a circulating immune complex pathogenesis.(Choice D) Anti-glomeru

29、lar basement membrane autoantibodies can cause an acute nephritic type syndrome of the sort seen in this patient. However, this process would not cause a new cardiac murmur, as these antibodies do not affect cardiac tissues. It is possible for these autoantibodies to attack the pulmonary alveolar ba

30、sement membrane (Goodpastures syndrome).(Choice E) First, infective endocarditis is rarely caused by gram negative organisms, the producers of endotoxin. Furthermore, while endotoxin production can cause acute tubular necrosis as part of sepsis, it is unlikely to cause glomerulonephritis.Q 34A 9-yea

31、r-old Caucasian girl experiences swelling and pain of several joints three weeks after an untreated sore throat. There is no significant past medical history. A new holosystolic murmur is heard on cardiac auscultation and the patient is hospitalized for further work-up and treatment. Her AS titer is

32、 400. If the patient dies during the hospitalization, the most likely cause of death would be:A.Mital stenosisB.Severe myocarditisC.Cardiac tamponadeD.Renal failureE. CNS involvementQ 34Correct answer:BIn a 9-year-old patient with arthritis and a new-onset heart murmur three weeks after an episode o

33、f pharyngitis, acute rheumatic fever (ARF) is the most likely diagnosis. ARF typically occurs 10 days to 6 weeks after group A streptococcal pharyngitis in about 3% of patients. Children between the ages of 5 and 15 are most often affected. The main clinical manifestations of ARF are acute arthritis

34、 and carditis. Signs of acute rheumatic pancarditis include: weak heart sounds, tachycardia, pericardial friction rubs, and arrhythmias. The myocarditis may produce cardiac dilation that can evolve into functional mitral regurgitation (MR) and even heart failure. Functional MR could explain this pat

35、ients heart murmur. Only about 1 % of patients die from fulminant ARF_ The overall prognosis for the primary attack is generally good.(Choice A) Fibrosis of the valve leaflets in chronic rheumatic heart is the most frequent cause of mitral stenosis, accounting for up to 99% of cases. However, the fi

36、brosis responsible for mitral stenosis in rheumatic heart disease requires years or even decades to develop after the initial episode of acute rheumatic fever.(Choice C) Although acute rheumatic fever (ARF) can cause a pancarditis, including fibrinous or serofibrinous pericarditis, progression of a

37、consequent pericardial effusion to the point of tamponade would be a rare occurrence in /XFRF- (Choice D) Although acute poststreptococcal glomerulonephritis (PSGN) could follow streptococcal pharyngitis and potentially result in temporary acute renal failure, PSGN is rarely, if ever, fatal. Moreove

38、r, the presence of a heart murmur in this case makes acute rheumatic fever more likely. Acute rheumatic fever and PSGN rarely occur concomitantly.(Choice E) ARF may involve the CNS in the form of Sydenham1 chorea. However, we are not told of any skeletal motor abnormalities in this child. Moreover,

39、Sydenham chorea itself is generally not a lethal condition.Q 35The autopsy of a 78-year-old Caucasian male who died of esophageal cancer reveals a small heart without significant coronary artery atherosclerosis. Myocardial cells show prominent intracytoplasmic granules that are tinged yellowish-brow

40、n. Which of the following most likely accounts for the observed microscopic changes?A.Iron overload B.Tyrosine oxidation C.Lipid peroxidation D.Glucose polymerizationE.Protein accumulationF.Exogenous pigment endocytosisA 35Correct answer:CAn insoluble pigment composed of lipid polymers and protein-c

41、omplexed phospholipids, lipofuscin is considered a sign of Hwear and tear or aging. This yellow-brown, finely granular perinuclear pigment is the product of free radical injury and lipid peroxidation. It is commonly seen in the heart and liver of aging or cachectic, malnourished patients.(Choice A)

42、Iron overload results in the deposition of iron-containing brown pigmented granules called hemosiderin.(Choice B) Melanin is an oxidation product of tyrosine metabolism and typically appears as dark brown to black pigmented granules.(Choice D) Glycogen is a glucose polymerization product and typical

43、ly appears as clear vacuoles within the cytoplasm.(Choice E) Hyaline is a form of protein accumulation, typically appearing as a glassy, homogeneous pink deposit.(Choice F) A common example of exogenous pigment endocytosis occurs when urban-residing individuals inhale carbon or coal dust that is tak

44、en up by macrophages within the lung parenchyma (HanthracosisH).Q 36A 19-year-old Caucasian male presents to your office for a routine check-up. His body habitus is pictured below. This patient is most likely to die from:A.Myocardial infarction B.Renal failure C.Aortic diseaseD.Overwhelming infectio

45、n E.Liver diseaseA 36Correct answer:CThis patients upper body (head to pubis) is disproportionately short compared to his leg length. Additionally, the image shows spinal scoliosis and kyphosis (posterior convex angulation of the spine), long extremities, and long tapering fingers, all examples of t

46、he skeletal manifestations of Marfan syndrome.Marfan syndrome is an autosomal dominant defect in the connective tissue glycoprotein fibrillin-1, which causes abnormalities in the skeleton, eyes (lens dislocation), and cardiovascular system. The cardiovascular lesions are the most potentially life-th

47、reatening. The two most common cardiac abnormalities are mitral valve prolapse and cystic medial degeneration of the aorta. Cystic medial aortic degeneration may lead to aortic dilatation and dissection. Aortic dissection is the cause of death in 30% to 45% of patients with Marfan syndrome, followed

48、 by cardiac failure (which may be secondary to mitral and/or aortic regurgitation). The average age at death in Marfan syndrome is between 30 and 40 years.Q 37A 3-year-old Caucasian male is brought to your office because of recurrent episodes of dyspnea and turning blue, to which the boy responds by

49、 assuming a squatting posture. This patient most likely suffers from:A.Primum-type atrial septal defect B.Secundum-type atrial septal defect C.Ventricular septal defect D.Patent ductus arteriosus E.Coarctation of the aorta F.Tetralogy of FallotA 37Correct answer:FThe major physiological problem in c

50、yanotic TOF is stenosis of the pulmonary outflow tract due to asymmetric division of the embryonic truncus arteriosus. The result is right-to-left intracardiac shunting. Cyanotic spells occur when there are episodic decreases in lung blood flow due to increased right-to-left shunting. Squatting incr

51、eases total systemic vascular resistance (SVR), thereby raising mean arterial pressure. If the ductus arteriosus is patent, this increases pulmonary blood flow via the ductus (compensatory left-to-right shunt). Any decrease in the ratio of total pulmonary vascular resistance to SVR decreases right-t

52、o-left shunting.(Choices A, B, C, and D) Atrial septal defect (ASD), VSD, and patent ductus arteriosus (PDA) are noncyanotic congenital heart diseases. These initially cause left-to-right intracardiac shunting, without cyanosis. Cyanosis may occur later in the course of the disease, if there is shun

53、t reversal due to chronic pulmonary hypertension-induced pulmonary vascular sclerosis (Eisenmenger syndrome).(Choice E) Coarctation of the aorta (COA) is also a noncyanotic congenital heart disease. CA accounts for about 7% of congenital heart disease cases. In infants presenting with COA, the defec

54、t is preductal (i.e. proximal to the ductus arteriosus). The ductus arteriosus usually remains patent, permitting some right-to-left shunting (i.e. ductal-dependent systemic perfusion). The degree of arterial desaturation in these patients is not severe enough to cause cyanotic spells.Q 38A 57-year-

55、old man dies 30 minutes after the onset of chest pain while driving to the emergency department. His past medical history was significant for hypertension, diabetes mellitus, and hypercholesterolemia. His medications included metformin, simvastatin, and enalapril. A cross-section of his left anterio

56、r descending coronary artery is shown in the image below.A.Contractile dysfunction B.Ventricular septal rupture C.Cardiac free wall rupture D.Ventricular fibrillation E.Embolic stroke F. Atrial fibrillationQ 38Correct answer:DSCD is defined as cardiac arrest that begins within 1 hour of a precipitat

57、ing event and ultimately proves fatal. Approximately 80% of SCDs are due to coronary artery disease (CAD). In the majority of CAD-related SCD, the pathogenesis involves an acute plaque change resulting in acute myocardial ischemia. Ischemia then induces electrical instability in the heart, which can

58、 generate a potentially lethal arrhythmia. Ventricular fibrillation is usually the first arrhythmia to appear as the result of acute myocardial ischemia and is the most common cause of lethal cardiac arrest in CAD-related SCD. Ventricular fibrillation is also the most common cause of death in patien

59、ts suffering from myocardial infarction (Ml) during the prehospital phase (ie, prior to arrival in the emergency department).Ventricular tachycardia and ventricular fibrillation are the most lethal arrhythmias in patients with acute ML Atrial flutter and atrial fibrillation usually do not result in

60、sudden cardiac death.(Choice A) Terminal ventricular failure can sometimes result shortly after an extensive ML However, heart failure caused by an Ml usually develops gradually as the infarct extends over the next 2-10 days. Ventricular failure is the most common cause of death due to Ml during the