Week 1 Block 6: PCR

Question 1

(1) Dx & Explain: vomiting, prolonged oliguira, marked ballooning and vacuolar degeneration of proximal renal tubules, anion gap metabolic acidosis, increased osmolar gap, presence of calcium oxalate crystals in urine

Answer 1

Ethylene glycol ingestion led to acute renal failure due to precipitation of calcium oxalate crystals in renal tubules and subsequent damage to tubular epithelium. Note: Sx of acute renal failure (oliguria, anorexia, flank pain) characteristic of ethylene glycol poisoning and occur 24-72 hours after ingestion.

Question 2

(1) Left ventricular (LV) free wall rupture: (a) complication of what condition, and in what % of cases (b) time of onset (c) mechanism (relate to onset) (d) protective factors against it. (2) Most common cause of in hospital death due to MI, % cases (3) Most frequent complication of coronary artery fibronolysis

Answer 2

(1) (a) Complicates transmural MI in less than 10% of cases (b) 3 to 7 days after onset of MI, (c) when coagulative necrosis and neutrophil infiltration have sufficiently weakened the infarcted myocardium (d) LV hypertrophy and prior MI protect against LV rupture (2) LV failure/cardiogenic shock, which complicates 10 to 15% of cases (3) Systemic bleeding

Question 3

Atherosclerotic plaques: (1) description and examples of vessels predominantly affected (2) Most heavily involved vessels in humans

Answer 3

(1) Develop predominantly in large elastic arteries (e.g., aorta, carotid, and iliac arteries), and in large or medium-sized muscular arteries (e.g., coronary and popliteal arteries). (2) Abdominal aorta, followed by coronary arteries, popliteal arteries, internal carotid arteries, and circle of Willis

Question 4

A. Precursor proteins or peptides responsible for localized amyloidosis: (1) Cardiac Atria (2) Thyroid gland (3) Pancreatic islets (4) Cerebrum/Cerebral blood vessels (5) Pituitary gland; B. Amyloid in Primary systemic amyloidosis

Answer 4

(1) Atrial natriuretic peptide (2) Calcitonin (3) Islet amyloid protein (amylin) (4) Beta-amyloid protein (5) Prolactin; B. Immune globulin light chains (multi-organ)

Question 5

Nephrotic syndrome: (1) Coagulability state & mechanism (2) Dx & Explain: Sudden onset abdominal flank pain, hematuria, and left-sided varicocele (3) Anatomy correlation to Dx

Answer 5

(1) Hypercoagulable - Loss of anticoagulant factors, especially ATIII, responsible for thrombotic and thromboembolic complications of nephrotic syndrome (2) Together suggest renal vein thrombosis, a well-known complication of nephrotic syndrome (3) Left testis drains through left renal vein then to IVC (right testis drain directly to IVC), so left-sided varicocele more common secondary to left renal vein thrombosis

Question 6

(1) Dx: 7 yo boy, 2 d. hx colicky abdominal pain now develops bloody stools, urine also appeared red today, PE: palpable skin lesions on buttocks (2) Typical presenting population and/or historical context (3) Mechanism (4) Other signs/sx expected

Answer 6

(1) Henoch-Schonlein (most common small vessel vasculitis in children) (2) Young children and classically preceded (few weeks) by upper respiratory infection (3) IgA mediated hypersensitivity (4) Commonly causes abdominal pain, joint pain, lower extremity palpable purpura, and hematuria

Question 7

Infective endocarditis: (1) Predisposing conditions/factors (2) Characteristic appearance grossly and/or echocardiogram

Answer 7

(1) Valvular inflammation, damge, and scarring (2) Presence of valvular vegetations

Question 8

Mechanism/Development of vegetations in bacterial endocarditis

Answer 8

Represent fibrin and platelet deposition at site of bacterial colonization (underly endothelial damage is key predisposing insult in development of infective endocarditis)

Question 9

(1) General Dx: unprovoked syncope in previously asymptomatic young person (2) 2 most important dx’s within this general dx (3) Mechanism (4) Distinguishing between the 2 (5) Related cardiac condition & effects

Answer 9

(1) Congenital QT prolongation syndrome (2) Two most important congenital syndromes with QT prolongation - Romano-Ward syndrome and Jevell and Lange-Nielsen syndrome (3) Thought to result from mutations in K+ channel protein that contributes to delayed rectifier current (I k) of the cardiac action potential (4) JLN (autosomal recessive, sensorineural deafness) & RW (autosomal dominant, no deafness) (5) Both may predispose to torsades de pointes (ventricular tachyarrhythmia) at a young age, causing syncopal episodes and possible sudden cardiac death

Question 10

(1) Dx: Mid-systolic click followed by murmur for remainder of systole, murmur disappears with squatting (2) Cause (3) Result/Mechanism

Answer 10

(1) Mitral valve prolapse (MVP) (2) Often caused by defects in mitral valve connective tissue proteins that predispose to myxomatous degeneration (3) Results in stretching and elongation of valve leaflets and chordae tendinae by chronic hemodynamic stress

Question 11

(1) Dx: significant endocardial thickening due to dense fibrous deposits around tricuspid and pulmonary valves as well as moderate pulmonary valve stenosis, left cardiac chambers and valves normal (2) Lab measurement & correlation to severity

Answer 11

(1) Carcinoid syndrome can cause predominately right-sided endocardial fibrosis which may progress to pulmonic stenosis and/or restrictive cardiomyopathy (2) Severity of carcinoid heart disease correlates with plasma levels of serotonin and urinary excretion of the serotonin metabolites, 5-hydroxyindoleacetic acid

Question 12

(1) Dx: fever lasting 5 days, more irritable than usual & episodes of vomiting, bilateral conjunctivitis, bright red tongue with cracked lips, skin desquamation of fingertips (2) Most serious complication of this Dx

Answer 12

(1) Kawasaki disease - vasculitis of medium-sized arteries that presents with presistent fever, bilateral conjunctivitis, cervical LAD, and mucocutaneous involvement (2) Formation of coronary artery aneurysms

Question 13

(1) Dx: gross hematuria in elderly man, worked at rubber plant for 35 years (2) Risk factors

Answer 13

(1) Transitional cell carcinoma of bladder - typically presents as gross hematuria in elderly man (2) Hx of smoking or occupational exposure to rubber, plastics, aromatic amine-containing dyes, textiles, or leather increases risk

Question 14

Important prognostic factor in poststreptococcal glomerulonephritis

Answer 14

Age - 95% of affected children, but only 60% affected adults, recovery completely

Question 15

(1) Cause of almost all cases of mitral stenosis (2) Other causes of mitral valve conditions & distinguishing between them in terms of mitral effects

Answer 15

(1) Chronic rheumatic heart disease (2) a) Infective endocarditis of mitral valve tends to cause destruction and regurgitation. b) Congenital heart defects may produce mitral regurgitation, but are generally not associated with stenosis. c) Mitral valvular calcinosis generally not impair valve function. d) Rheumatoid arthritis and tertiary syphilis only rarely affect cardiac valves.

Question 16

(1) Dx: jugular venous distention, muffle heart sounds (2) Other sx (3) Lung examination & its use in distinguishing this disorder from related disorder

Answer 16

(1) Cardiac tamponade (2) Tachycardia and pulsus pardoxus also frequently seen (3) Lung exam normal, which can help distinguish cardiac tamponade from tension pneumothorax (absent breath sounds & hyperresonance to percussion on affected side)

Question 17

(1) Pathophysio of systolic bp drop in cardiac tamponade (2) Name of this phenomenon (3) Other conditions in which it is seen

Answer 17

(1) During inspiration, press in pleural space and lung interstitium decreases, increasing pulmonary vascular capacitance. This causes fall in venous inflow to left heart, resulting in decreased left ventricular stroke volume and drop in systolic blood pressure (normally < 10 mmHg). The inspiratory drop in systolic blood pressure is exacerbated in cardiac tamponade due to extrinsic compression of ventricles, which acts to equalize left and right ventricular diastolic pressures, allowing intraventricular septum to bulge into left ventricl as a result of inspiratory increase in right ventricular filling. This further reduces left ventricular stroke volume, leading to drop in systolic bp > 10 mmHg. (2) Pulsus paradoxus (3) Constrictive pericarditis, chronic obstructive pulmonary disease, asthma, and pulmonary embolism

Question 18

Hypertrophic cardiomyopathy (HCM): (1) characteristic heart findings (2) Type of murmur it can produce & why (3) enhancement of murmur

Answer 18

(1) asymmetric ventricular septal hypertrophy & variable dynamic left ventricular outflow tract obstruction, which may produce (2) systolic ejection murmur. (3) Decreases in LV end diastolic volume increase the obstruction, causing murmur of HCM to be enhanced. Actions like standing suddenly from supine position and Valsava maneuver decrease venous return and accentuate the murmur

Question 19

(1) Dx: fatigue, new onset cardiac murmur in young adult (2) Complication: If add mild proteinuria and microscopic proteinuria to this picture, urine red cell casts as well

Answer 19

(1) Bacterial endocarditis (BE) (2) Acute, diffuse, proliferative glomerulonephritis secondary to circulating immune complexes may complicate BE and can result in acute renal insufficiency

Question 20

Hypertrophic cardiomyopathy: (1) Significant histology (2) Specific cause

Answer 20

(1) Extreme myofiber disarray with interstitial fibrosis on cardiac histology (2) Almost 100% cases of HCM result from mutations in genes encoding cardia sarcomere proteins (most commonly beta-myosin heavy chain)

Question 21

Jervell and Lange-Nielsen: (1) Type of syndrome (2) other main sx

Answer 21

(1) congenital long-QT syndromes (2) neurosensory deafness

Question 22

(1) Underlying etiology in most cases of sudden cardiac death (SCD) (2) Most likely cause of death assoc. with this (3) Most likely mechanism behind this cause of death prehospital vs. in hospital (4) Other later-onset, potentially lethal complications of this

Answer 22

(1) Coronary artery disease (2) Acute plaque change will result in acute myocardial ischemia, which may precipitate ventricular fibrillation (3) Cardiac arrhythmia is most common cause of death in MI patients during prehospital phase. Ventricular failure is most common cause of death during pre-hospital phase. (4) Ventricular rupture & mural thrombosis

Question 23

(1) DDx: dilation of 1 or both ventricles, contractile (systolic) dysfunction (2) Cause & mechanism of diastolic dysfunction (3) Gross heart findings of HCM

Answer 23

(1) Congestive heart failure due to dilated cardiomyopathy or chronic ischemic heart disease (2) Hypertensive heart disease, which causes concentric ventricular hypertrophy and decrease left ventricular chamber size. Diastolic dysfunction occurs with impaired left ventricular filling due to reduced LV compliance. (3) Asymmetric septal hypertrophy & dynamic ventricular outflow tract obsruction

Question 24

Aschoff bodies: (1) Definition (2) Typical clinical context (3) Histology

Answer 24

(1) Interstitial myocardial granulomas (2) Acute rheumatic carditis (3) Contain plump macrophages with abundant cytoplasm and central, round-to-ovoid nuclei with central, slender ribbons of chromatin (Anitschkow cells)

Question 25

(1) Renal Dx: MVA victim, multiple fractures, internal bleeding, successfully resuscitated but develops oliguria (2) Most likely outcome of this Dx & mechanism by which it occurs (3) Other option for outcome & its context as well as its histology

Answer 25

(1) Acute tubular necrosis (ATN) (2) Most patients with ATN experience tubular re-epithelization and regain renal function. (3) When ATN assoc. w/ multi organ failure, renal fxn may be permanently impaired (foci of interstitial scarring can be seen on light microscopy)

Question 26

Most likely in HCM patients: (1) Type of obstruction (2) cause of obstruction

Answer 26

(1) Dynamic left ventricular outflow tract obstruction (2) due to abnormal systolic anterior motion of the anterior leaflet of mitral valve toward a hypertrophied interventricular spetum

Question 27

(1) Dx: 73 yo male with advanced visceral cancer dies of extensive myocardial infarction, autopsy reveals sterile non-destructive vegetations along mitral leaflet edges (2) Pathogenesis (3) Pathogenesis similar to what other disorder

Answer 27

(1) Nonbacterial thrombotic endocarditis (NBTE) (2) often involves hypercoagulable state. when hypercoagulability is result of procoagulant effects of circulating products of cancer, resulting cardiac valve vegetations may also be called marantic endocaridtis. (3) Pathophysiology of NBTE similar to Trousseau’s syndrome (migratory thrombophlebitis) which may also be induced by disseminated cancers

Question 28

(1) Dx: right-sided flank pain that radiates to groin shortly after undergoing surgery for invasive cervical carcinoma, palpable mass deep in right upper abdominal quadrant (2) Mechanism

Answer 28

(1) Hydronephrosis (2) Ureters pass under uterine artery so may be transected/ligated. Kidney will continue to produce urine, but urine cannot drain into bladder. Pressures within ureter and calyceal system increase, causing distention of renal pelvis and kidney. Distention causes flank pain that radiates to groin and often a palpable mass (the kidney) on deep abdominal palpation

Question 29

Predominant light microscopic changes at the following times following MI: (1) 0-4 hrs (2) 4-12 hrs (3) 12-24 hrs (4) 1-5 days (5) 5-10 days (6) 10-14 days (7) 2 wks to 2 mo.

Answer 29

(1) minimal change (2) early coagulation necrosis, edema, hemorrhage, wavy fibers (3) coagulation necrosis and marginal contraction band necrosis (4) coagulation necrosis and neutrophilic infiltrate (5) macrophage phagocytosis of dead cells (6) granulation tissue and neovascularization (7) collagen deposition / scar formation