Davidson medicine and mini Harrison?
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Here's what's currently available in the medical library:
Found:
- Harrison's Principles of Internal Medicine, 22nd Edition (2025, McGraw Hill Medical) - internal medicine, 56 blocks
Not found:
- Davidson's Principles and Practice of Medicine - not currently in the library
- Mini Harrison (Harrison's Manual of Medicine) - not currently in the library
Only the full Harrison's 22e is available. Davidson's and the Harrison's Manual (pocket/mini version) are not in the collection at this time.
Would you like me to look up a specific topic from Harrison's 22e that's available?
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Answers exam oriented
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Here are complete exam-oriented answers for all the circled questions (3, 6, 8, 9, 10):
Q3. Pathological Characteristics of Congenital Heart Diseases
Classification
Congenital heart disease is classified based on the presence or absence of cyanosis.
A. CYANOTIC CONGENITAL HEART DISEASE
Mechanism: Right-to-left shunting → deoxygenated blood enters systemic circulation → cyanosis
Mnemonic: "5 T's"
| Condition | Key Feature |
|---|---|
| Tetralogy of Fallot | VSD + pulmonary stenosis + overriding aorta + RVH |
| Transposition of Great Arteries | Aorta arises from RV; pulmonary trunk from LV |
| Truncus Arteriosus | Single arterial trunk from both ventricles |
| Tricuspid Atresia | No tricuspid valve; right heart hypoplasia |
| Total Anomalous Pulmonary Venous Return (TAPVR) | All 4 pulmonary veins drain to systemic veins |
Pathological features:
- Central cyanosis (present at rest)
- Polycythemia (compensatory)
- Clubbing of fingers and toes
- Eisenmenger syndrome (reversal of shunt with pulmonary hypertension)
- Boot-shaped heart on X-ray (ToF)
B. ACYANOTIC CONGENITAL HEART DISEASE
Mechanism: Left-to-right shunting → pulmonary overcirculation → no cyanosis initially
| Condition | Key Feature |
|---|---|
| VSD (most common CHD) | Harsh pansystolic murmur at left sternal border |
| ASD | Fixed split S2; pulmonary plethora on X-ray |
| PDA | Continuous "machinery" murmur; bounding pulse |
| Coarctation of Aorta | Hypertension in upper limbs; rib notching on X-ray |
| Pulmonary Stenosis | Ejection systolic murmur; right heart hypertrophy |
| Aortic Stenosis | Ejection systolic murmur; syncope on exertion |
Pathological features:
- Present as heart failure in infancy (pulmonary congestion)
- Increased pulmonary blood flow / vascularity on X-ray
- Can progress to Eisenmenger syndrome (become cyanotic later - "Eisenmenger reversal")
- Left-to-right shunt initially → volume overload of left heart
Tintinalli's Emergency Medicine, p. 862
Q6. Diagnosis of Rheumatic Fever (Jones Criteria)
Prerequisite (Mandatory)
Evidence of prior Group A Streptococcal infection:
- Positive throat culture OR
- Elevated/rising ASO titre OR
- Positive rapid strep antigen test
DIAGNOSIS = 2 Major OR 1 Major + 2 Minor criteria
MAJOR CRITERIA (JONES - mnemonic: SPACE)
| Criterion | Details |
|---|---|
| Sydenham's Chorea | Involuntary, purposeless movements; emotional lability |
| Pancarditis (Carditis) | Most serious; clinical or subclinical (echo valvulitis); new murmur, pericarditis, CCF |
| Arthritis | Migratory polyarthritis (large joints); very painful; responds to aspirin |
| Cutaneous nodules (subcutaneous) | Firm, painless nodules over bony prominences |
| Erythema marginatum | Pink rings on trunk; not on face; evanescent |
MINOR CRITERIA
| Low-Risk Populations | Moderate/High-Risk Populations |
|---|---|
| Polyarthralgia | Monoarthralgia |
| Fever ≥38.5°C | Fever ≥38.5°C |
| ESR ≥60 mm/h AND/OR CRP ≥3.0 mg/dL | ESR ≥30 mm/h AND/OR CRP ≥3.0 mg/dL |
| Prolonged PR interval | Prolonged PR interval |
Note: Arthralgia cannot be a minor criterion if arthritis is already counted as a major criterion.
Goldman-Cecil Medicine, p. 483
Q8. Pathognomonic Features of Infective Endocarditis
Duke Criteria (Modified) - for Diagnosis
MAJOR CRITERIA:
- Positive blood cultures - typical organisms (S. aureus, Streptococcus viridans, HACEK group) in 2 separate cultures
- Echocardiographic evidence - vegetation, abscess, dehiscence of prosthetic valve, new valvular regurgitation
PERIPHERAL / EMBOLIC SIGNS (Exam Favourites)
| Sign | Description | Mechanism |
|---|---|---|
| Osler's nodes | Tender, raised, red/purple nodules on finger/toe pulps and thenar eminence | Immune complex deposition |
| Janeway lesions | Non-tender, hemorrhagic macules on palms and soles | Septic emboli |
| Roth spots | Retinal hemorrhages with pale (white) centre | Immune complex vasculitis |
| Splinter hemorrhages | Linear hemorrhages under fingernails | Microemboli to nail bed vessels |
| Clubbing | In subacute IE | Chronic hypoxia |
| Petechiae | Conjunctival, palatal, skin | Microemboli/vasculitis |
Other Features:
- Fever (most common symptom)
- New or changing heart murmur
- Splenomegaly
- Anaemia of chronic disease
- Elevated ESR, CRP
- Microscopic haematuria (embolic glomerulonephritis)
Memory Aid for peripheral signs: "JORE + Splinter"
- Janeway lesions (non-tender palms/soles)
- Osler's nodes (tender fingers)
- Roth spots (retina)
- Emboli (splenic, renal, cerebral)
Frameworks for Internal Medicine; Goldman-Cecil Medicine
Q9. Deep Venous Thrombosis (DVT)
A. Virchow's Triad
The three factors predisposing to thrombosis:
| Component | Mechanism | Examples |
|---|---|---|
| 1. Endothelial injury | Most important for arterial thrombosis; exposes vWF & tissue factor | Surgery, trauma, IV catheter, atherosclerosis |
| 2. Stasis (abnormal blood flow) | Most important for venous thrombosis; prevents dilution of activated clotting factors | Immobility, prolonged bed rest, heart failure, atrial fibrillation |
| 3. Hypercoagulability | Imbalance of procoagulant vs anticoagulant factors | Malignancy, OCP, pregnancy, Factor V Leiden, antiphospholipid syndrome |
Robbins Basic Pathology, p. 3.12
B. Sites of DVT (in order of frequency)
- Calf muscle sinuses - gastrocnemius and soleus sinusoids = most common site of origin
- Posterior tibial and peroneal veins
- Popliteal vein
- Femoral vein (superficial femoral vein)
- Iliac veins (ilio-femoral DVT = most dangerous, highest PE risk)
- Upper limb - axillary-subclavian (especially with central lines)
Clinical significance:
- Proximal DVT (popliteal and above) → high risk of pulmonary embolism → treat with anticoagulation
- Isolated distal/calf DVT → can be observed (lower PE risk)
C. High-Predilection Sites
DVT favours valvular sinuses because:
- Stasis of blood behind valve cusps
- Low oxygen tension → endothelial activation
- Gastrocnemius/soleus sinuses are valveless → maximum stasis
Imaging Anatomy: Vessels and Nerves
Q10. Varicose Veins + Differentials of Unilaterally Swollen Leg
Varicose Veins - Pathophysiology
- Dilated, tortuous superficial veins due to incompetent valves
- Most common: Sapheno-femoral junction incompetence → great saphenous vein dilation
- Also: Sapheno-popliteal incompetence → small saphenous system
- Cycle: valve incompetence → venous dilation → more valves become incompetent → entire saphenous system affected
Sites of valvular incompetence:
- Sapheno-femoral junction (most common)
- Mid-thigh perforating veins
- Sapheno-popliteal junction
Differentials of Unilaterally Swollen Leg
The key question in exams is to distinguish causes systematically:
Vascular Causes:
- DVT - most important to exclude; warm, red, tender, pitting oedema; Homan's sign positive
- Post-thrombotic syndrome - chronic oedema after DVT
- Venous insufficiency/varicosities
- Arterial insufficiency (claudication; cold, pale limb)
Inflammatory/Infective:
- Cellulitis - warm, erythematous, tender; fever
- Lymphangitis - red streaking
- Septic arthritis (knee/ankle)
Musculoskeletal:
- Ruptured Baker's cyst - sudden onset, posterior knee; mimics DVT clinically
- Muscle/tendon tear (gastrocnemius tear)
- Hematoma (post-trauma)
Other:
- Lymphoedema - non-pitting; peau d'orange skin; no pain
- Malignancy - pelvic mass compressing iliac vein
- Asymmetric oedema from heart failure or liver disease
Distinguishing DVT from Baker's Cyst (Common Exam):
| Feature | DVT | Ruptured Baker's Cyst |
|---|---|---|
| Location | Whole leg/thigh | Mainly calf/posterior knee |
| History | Risk factors for thrombosis | Previous knee pathology/arthritis |
| Diagnosis | Doppler US | Ultrasound (shows cyst) |
Rosen's Emergency Medicine, Box 74.1
Quick Memory Summary for Exam:
- Q3 = Cyanotic (5Ts, R→L shunt) vs Acyanotic (VSD/ASD/PDA, L→R shunt)
- Q6 = Jones: 2 Major OR 1 Major + 2 Minor + evidence of prior Strep
- Q8 = IE signs: Osler (tender, immune) + Janeway (non-tender, embolic) + Roth + Splinters
- Q9 = Virchow's Triad: Injury + Stasis + Hypercoag; Calf sinuses = commonest DVT site
- Q10 = Swollen leg DDx: DVT > Cellulitis > Baker's cyst > Lymphoedema > Malignancy
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