Here you go β the complete summary notes, all 7 topics in one place! π―
π« CARDIOVASCULAR SYSTEM β COMPLETE SUMMARY NOTES
(Ref: Merck Manual 20th Ed, Section 7)
TOPIC 1 β CARDIOVASCULAR TESTS & PROCEDURES
(Ch. 75)
β‘ ECG (Electrocardiography)
- Records heart's electrical activity
- P wave = atrial depolarization | QRS = ventricular depolarization | T wave = ventricular repolarization
| ECG Finding | Think of... |
|---|
| ST elevation | STEMI / Pericarditis |
| ST depression | NSTEMI / Ischemia |
| PR depression | Pericarditis |
| Wide QRS | Bundle branch block |
| Electrical alternans | Cardiac Tamponade |
| Delta wave | WPW syndrome |
| Deep Q waves (lateral) | HCM (pseudo-infarct) |
π Echocardiography
- Ultrasound of heart - shows structure + function
- TTE (transthoracic) = standard bedside
- TEE (transesophageal) = better image; used for valves, aorta, thrombus
- Tells you: EF, wall motion, valve function, pericardial effusion
Normal EF = 55-70% | EF <40% = HFrEF
π¬ Cardiac Catheterization
- Catheter inserted via femoral/radial artery β guided to heart
- Left heart cath = coronary angiography (finds blockages)
- Right heart cath (Swan-Ganz) = measures pulmonary pressures, cardiac output
- Used pre-CABG, valve disease workup, chest pain evaluation
π Stress Testing
- Heart stressed via treadmill exercise or pharmacologic (dobutamine / adenosine)
- Positive test = ST depression β₯1mm during exercise β ischemia
- Nuclear stress test = adds perfusion imaging (better sensitivity)
π PCI (Percutaneous Coronary Intervention)
- Balloon angioplasty + stent in blocked coronary artery
- First-line for STEMI ("primary PCI within 90 min")
πͺ CABG (Coronary Artery Bypass Grafting)
- Surgical bypass using saphenous vein or internal mammary artery
- For: multi-vessel disease, left main stenosis, failed PCI, diabetics
β’οΈ Radionuclide Imaging
- Radioactive tracer (Tc-99m or Thallium) shows myocardial perfusion
- Cold spot on stress only = reversible ischemia
- Cold spot at rest + stress = fixed infarct (scar)
π Tilt Table Test
- Patient tilted 60-80Β° upright; BP and HR monitored
- Used for: unexplained recurrent syncope (reproduces vasovagal episodes)
TOPIC 2 β ARTERIOSCLEROSIS
(Ch. 77)
Arteriosclerosis = umbrella term for "hardening of arteries"
Four Types:
| Type | Vessel | Key Feature |
|---|
| Atherosclerosis | Large/medium arteries | Plaque (lipid core + fibrous cap) |
| Arteriolosclerosis | Arterioles | Hyaline or hyperplastic thickening; linked to HTN/DM |
| MΓΆnckeberg's Sclerosis | Medium muscular arteries | Calcification in media; lumen NOT affected |
| Fibromuscular Hyperplasia | Medium arteries | Intimal SMC proliferation; post-injury or stents |
Atherosclerosis β Pathogenesis
Endothelial injury β inflammation β plaque β rupture β thrombosis
- Endothelial injury (HTN, smoking, DM, high LDL)
- LDL enters intima β gets oxidized
- Monocytes β macrophages β engulf ox-LDL β foam cells
- Foam cells accumulate β fatty streak (earliest lesion; reversible)
- SMCs migrate from media β fibrous cap forms
- Atheromatous plaque = lipid core + fibrous cap
- Plaque rupture β thrombus β MI / stroke / sudden death
A = vascular response to injury (SMC recruitment) | B = atheromatous plaque anatomy
Risk factors:
- Modifiable: HTN, smoking, dyslipidemia, DM, obesity, sedentary lifestyle
- Non-modifiable: Age, male sex, family history
Complications:
- Stenosis β Stable angina
- Plaque rupture β ACS (UA / NSTEMI / STEMI)
- Carotid plaque β Stroke
- Weakened media β Aneurysm
MΓΆnckeberg's Sclerosis (Non-Atheromatous)
- Calcification of tunica media of muscular arteries
- Lumen NOT affected β usually clinically silent
- Seen in diabetics, >50 yrs
- X-ray: "pipe-stem" arteries | Mammogram: "railroad track" calcification
TOPIC 3 β ENDOCARDITIS, MYOCARDITIS & PERICARDIAL DISEASES
(Ch. 82 & 86)
π¦ Infective Endocarditis (IE)
Common organisms:
| Organism | Context |
|---|
| Strep viridans | Dental procedures, Sub-acute IE |
| Staph aureus | IV drug users, prosthetic valves, Acute IE |
| Enterococcus | GI/GU procedures |
| Strep bovis | Colon cancer (screen the gut!) |
| HACEK organisms | Culture-negative IE |
Clinical features:
- Fever + new regurgitation murmur
- Osler's nodes = painful nodules on fingers/toes
- Janeway lesions = painless macules on palms/soles
- Roth spots = retinal hemorrhages with pale center
- Splinter hemorrhages under nails
- Splenomegaly, embolic events (stroke, renal infarcts)
π Memory: "From Jane's Roth Spot, Osler Splints"
Diagnosis: Blood cultures Γ3 + Echocardiography (TEE preferred)
Treatment: IV antibiotics 4-6 weeks; surgery if valve destruction or refractory
π« Non-Infective Endocarditis
| Type | Feature | Association |
|---|
| Libman-Sacks | Sterile vegetations on both sides of mitral valve | SLE |
| NBTE (Marantic) | Small thrombus on valve leaflets | Malignancy, chronic illness |
| Rheumatic | Aschoff bodies; later mitral stenosis | Group A Strep pharyngitis |
β€οΈβπ₯ Myocarditis
- Inflammation of the myocardium
- Causes: Viral (Coxsackievirus B = most common in USA), autoimmune, drugs (doxorubicin), Chagas disease (Trypanosoma cruzi)
- Features: Chest pain, fever, dyspnea, arrhythmias, sudden cardiac death
- Diagnosis: Echo (wall motion abnormalities), cardiac MRI (gold standard), biopsy (Dallas criteria)
- Risk: Can evolve into dilated cardiomyopathy
ECG in Myocarditis/Perimyocarditis:
Diffuse ST elevation + tachycardia β seen in perimyocarditis
π« Pericardial Diseases
Acute Pericarditis
- Causes: Viral (most common), TB, post-MI (Dressler's), uremia, autoimmune
- Pain: Sharp, pleuritic β worse lying flat, better leaning forward
- Friction rub on auscultation (scratchy sound)
ECG β 4 Stages:
| Stage | ECG change |
|---|
| 1 | Diffuse concave (saddle-shaped) ST elevation + PR depression |
| 2 | ST returns to baseline |
| 3 | T-wave inversion |
| 4 | Normalization |
π Pericarditis vs STEMI: Pericarditis = diffuse + concave ST | STEMI = localized + convex ST
Treatment: NSAIDs + colchicine (first-line); steroids only if refractory
Pericardial Effusion
- Fluid in pericardial sac (normally <50 mL)
- Slowly accumulating β can reach 2L (pericardium stretches)
- Rapidly accumulating β tamponade with even 200-300 mL
Cardiac Tamponade
- Fluid compresses heart β obstructive shock
- Beck's Triad: Hypotension + Muffled heart sounds + JVD
- ECG: Electrical alternans (QRS height alternates beat to beat)
- Treatment: Pericardiocentesis (emergency needle drainage)
Constrictive Pericarditis
- Fibrous scarring β rigid shell around heart β diastolic restriction
- Causes: TB (most common globally), radiation, post-cardiac surgery
- Features: JVD, Kussmaul's sign (JVP increases on inspiration), ascites, edema
- Treatment: Pericardiectomy (surgical stripping)
TOPIC 4 β CARDIOMYOPATHY
(Ch. 79)
Dilated = big floppy | Hypertrophic = thick septum | Restrictive = stiff but normal size
Comparison Table:
| Feature | Dilated | Hypertrophic | Restrictive |
|---|
| Problem | Systolic (can't squeeze) | Diastolic (can't relax) | Diastolic (can't fill) |
| Wall thickness | Thin | Thick (asymmetric septum) | Normal or mildly thick |
| Chamber size | All 4 dilated | Normal/reduced LV cavity | Normal |
| EF | β | Normal or β | Normal |
| Most common cause | Alcohol / viral / genetic | Autosomal dominant (sarcomere mutation) | Amyloid / sarcoid |
| Classic patient | Middle-aged alcoholic | Young athlete with syncope | Elderly with HF + low voltage ECG |
1. Dilated Cardiomyopathy (DCM) β Most Common (90%)
-
All 4 chambers dilate β thin walls β systolic dysfunction
-
Causes (ABC):
- Alcohol (most common toxin)
- Babies (peripartum cardiomyopathy)
- Coxsackie (post-myocarditis)
- Drugs (doxorubicin, cocaine)
- Encoded (genetic - titin mutations; AD in 50% of familial cases)
-
Signs: S3 gallop, pulmonary edema, mitral/tricuspid regurgitation (annular dilation)
-
Treatment: ACEi + beta-blocker + diuretics + ICD if EF <35%; heart transplant
2. Hypertrophic Cardiomyopathy (HCM)
- Asymmetric septal hypertrophy β LVOTO (outflow obstruction)
- Genetics: Autosomal dominant; beta-myosin heavy chain mutation (most common)
- Classic: Young athlete + syncope on exertion / sudden cardiac death
Murmur trick:
- Increases with: Valsalva / standing (β preload β worse obstruction)
- Decreases with: Squatting / leg raise (β preload β less obstruction)
- (Opposite of most murmurs!)
ECG: LVH + deep narrow Q waves (lateral leads) β looks like MI but isn't
Treatment: Beta-blockers / verapamil; avoid nitrates + digoxin; ICD for high-risk; septal myomectomy or alcohol ablation
3. Restrictive Cardiomyopathy β Least Common
- Stiff, non-compliant myocardium β can't fill β elevated filling pressures
- Causes: Amyloidosis (apple-green birefringence on Congo red), sarcoidosis, hemochromatosis, radiation
- ECG: Low voltage + conduction defects (amyloid deposits disrupt conduction)
- Signs of both left and right HF; Kussmaul's sign may be present
- Treatment: Treat underlying cause; supportive HF therapy
TOPIC 5 β SHOCK, DISEASES OF THE AORTA & ITS BRANCHES
(Ch. 74, 81; Sec. 6, Ch. 71, 72)
π΅ Syncope
- Transient LOC from cerebral hypoperfusion β self-limiting, full recovery
| Type | Mechanism | Clue |
|---|
| Vasovagal | Vagal surge β bradycardia + vasodilation | Pain/emotion/prolonged standing trigger |
| Orthostatic | BP drops on standing | Elderly, dehydration, antihypertensives |
| Cardiac | Arrhythmia / structural | Exertional syncope, sudden onset |
| Carotid sinus | Sinus hypersensitivity | Tight collar / head turning |
β οΈ Syncope during exertion = CARDIAC until proven otherwise (think AS, HCM, arrhythmia)
Workup: ECG, Holter, Echo, Tilt table test, Carotid sinus massage
β‘ Shock
= Inadequate tissue perfusion β cellular hypoxia β organ failure
| Type | Cause | CO | SVR | CVP/PCWP |
|---|
| Hypovolemic | Hemorrhage, dehydration | β | β | β |
| Cardiogenic | MI, severe HF, tamponade | β | β | β |
| Distributive (Septic) | Sepsis, anaphylaxis | β (early) | β | β |
All shock: Hypotension + tachycardia + altered consciousness
- Hypovolemic/cardiogenic: cold, clammy skin
- Distributive (early septic): warm, flushed skin
Treatment:
- Hypovolemic β IV fluids / blood
- Cardiogenic β Dobutamine, norepinephrine, IABP, revascularize
- Septic β Fluids + broad-spectrum antibiotics within 1 hour + norepinephrine
π΅ Aortic Aneurysm
-
AAA (Abdominal): Dilation >3 cm, below renal arteries
- Risk: Males >65, smokers, HTN, atherosclerosis
- Screening: Abdominal USS in males >65 who ever smoked
- Repair: >5.5 cm, or rapid growth >1 cm/yr, or symptomatic
-
TAA (Thoracic): Associated with Marfan's, bicuspid aortic valve, syphilis
π₯ Aortic Dissection
- Intimal tear β blood enters media β false lumen
- Pain: Sudden, severe, tearing chest-to-back pain β max intensity at onset
- Signs: Unequal BP in both arms, pulse deficit, aortic regurgitation murmur
Stanford Classification:
| Type | Where | Treatment |
|---|
| Type A | Ascending aorta (Β±arch) | Emergency surgery |
| Type B | Descending aorta only | Medical (IV beta-blockers, BP control); TEVAR if complications |
Imaging: CT angiography (best); urgent MRI or TEE if CT unavailable
Initial Rx: IV labetalol/esmolol β target systolic BP <120, HR <60
π Takayasu's Arteritis (Aortic Arch Syndrome)
- Granulomatous vasculitis of the aorta and major branches
- Who: Young women <40; Asian populations
- Nickname: "Pulseless disease"
Two phases:
- Inflammatory: Fever, fatigue, myalgia, βESR/CRP
- Fibrotic/Occlusive: Absent radial pulses, BP difference between arms, bruits, limb claudication, renovascular HTN
Diagnosis: MR angiography; biopsy if accessible vessel
Treatment: Corticosteroids first line; methotrexate / tocilizumab for refractory; angioplasty / bypass for occlusion
π©Έ Abdominal Aortic Branch Occlusion
| Vessel | Syndrome | Features |
|---|
| Renal arteries | Renovascular HTN | Resistant HTN, elevated creatinine, flank bruit |
| SMA / Celiac | Intestinal ischemia | Postprandial pain + weight loss ("mesenteric angina") |
| Aortic bifurcation (Iliac) | Leriche Syndrome | Buttock claudication + erectile dysfunction + absent femoral pulses |
TOPIC 6 β PERIPHERAL ARTERIAL DISORDERS
(Ch. 87)
𦡠Peripheral Arterial Disease (PAD)
- Atherosclerosis of limb arteries (mostly lower limb)
Stages of severity:
| Stage | Symptom |
|---|
| Asymptomatic | No symptoms |
| Intermittent claudication | Calf pain on walking β relief with rest |
| Rest pain | Foot pain at night; relieved by dangling leg |
| Critical limb ischemia | Ulcers / gangrene |
Signs: Cool pale limb, absent pulses, hair loss on legs, non-healing ulcers at toes
Key Diagnostic Test β ABI (Ankle-Brachial Index):
| ABI Value | Interpretation |
|---|
| >0.9 | Normal |
| 0.7-0.9 | Mild PAD |
| 0.4-0.7 | Moderate PAD |
| <0.4 | Severe / Critical ischemia |
| >1.3 | Non-compressible vessels (calcification) |
ABI = ankle systolic BP Γ· arm systolic BP
Treatment:
- Stop smoking (most important)
- Antiplatelet: aspirin or clopidogrel
- Statins (stabilize plaque)
- Cilostazol (improves claudication)
- Revascularization: Angioplasty / bypass for critical ischemia
βοΈ Raynaud's Syndrome
- Episodic digital vasospasm from cold or stress
- Color sequence: White β Blue β Red
- White = ischemia (vasospasm)
- Blue = cyanosis (stagnant blood)
- Red = reactive hyperemia (reperfusion)
| Type | Feature |
|---|
| Primary (Raynaud's disease) | Young women; no underlying disease; benign |
| Secondary (Raynaud's phenomenon) | Associated with scleroderma (most common), SLE, drugs (beta-blockers) |
Treatment: Avoid cold; calcium channel blockers (nifedipine); sympathectomy if severe
π₯ Thromboangiitis Obliterans (Buerger's Disease)
- Segmental inflammatory thrombosis of small/medium arteries AND veins
- Classic patient: Young male, heavy smoker
- Affects fingers, toes, hands, feet β ulcers, gangrene
- No atherosclerosis but strongly linked to tobacco
- Hallmark: Migratory superficial thrombophlebitis
- Only effective treatment: Absolute smoking cessation
- Other: Prostaglandins (iloprost), amputation if needed
π Acrocyanosis
- Persistent, painless, bluish discoloration of hands and feet
- Benign vasospasm of cutaneous arterioles
- Worsens with cold; improves with warmth
- No tissue ischemia, no ulcers, no episodic attacks
- Distinguished from Raynaud: persistent (not episodic) + painless
π΄ Erythromelalgia
- Opposite of Raynaud: Burning, red, hot extremities
- Triggered by warmth; relieved by cold water immersion
- Associated with polycythemia vera and myeloproliferative disorders
- Treatment: Aspirin (especially if polycythemia vera); avoid heat
π©Έ Fibromuscular Dysplasia (FMD)
- Non-inflammatory, non-atherosclerotic disease of medium arteries
- Affects: Renal arteries β renovascular HTN | Carotid arteries β stroke/TIA in young women
- Angiography: Classic "string of beads" appearance
- Treatment: Percutaneous transluminal angioplasty (PTA)
π΅ Peripheral Arterial Aneurysms
- Popliteal artery = most common peripheral aneurysm
- Complications: Thrombosis / embolism β acute limb ischemia
- Repair when >2 cm or symptomatic
TOPIC 7 β PERIPHERAL VENOUS & LYMPHATIC DISORDERS
(Ch. 88)
π©Έ Deep Venous Thrombosis (DVT)
Virchow's Triad (risk factors):
| Factor | Examples |
|---|
| Stasis | Immobility, long flights, pregnancy, post-op |
| Hypercoagulability | OCP, malignancy, Factor V Leiden, antiphospholipid syndrome |
| Endothelial injury | Surgery, trauma, IV cannula |
Symptoms: Unilateral leg swelling + pain + warmth + redness
Diagnosis:
- D-dimer β highly sensitive; negative D-dimer rules OUT DVT
- Compression ultrasound β gold standard; non-compressible vein = DVT
Left: Vein does NOT compress (DVT present) | Right: Normal vein collapses with probe pressure
Complication β Pulmonary Embolism (PE):
- Clot travels to pulmonary artery β dyspnea, pleuritic chest pain, hypoxia, tachycardia
- Massive PE β obstructive shock + RV strain on ECG (S1Q3T3)
- Treatment: Systemic thrombolysis (tPA) for massive PE; anticoagulation for submassive/non-massive
DVT Treatment:
- DOACs (rivaroxaban, apixaban) = first line
- LMWH in cancer-associated DVT
- Warfarin (INR 2-3) if DOACs unavailable
- Duration: 3-6 months provoked; β₯12 months or lifelong unprovoked/recurrent
- IVC filter if anticoagulation is contraindicated
π΄ Superficial Venous Thrombosis (SVT)
- Clot in superficial veins; visible, tender, cord-like
- Usually in varicose veins or around IV cannulas
- Less dangerous than DVT; can extend to DVT especially near saphenofemoral junction
- Treatment: NSAIDs, compression; fondaparinux if high risk of DVT extension
π Varicose Veins
- Dilated, tortuous superficial veins from incompetent venous valves
- More common: Women, pregnancy, prolonged standing
- Symptoms: Aching, heaviness, visible bulging, ankle swelling
- Complications: Lipodermatosclerosis, venous eczema, venous ulcers (medial ankle)
- Treatment: Compression stockings; sclerotherapy; laser/radiofrequency ablation; vein stripping
𦡠Chronic Venous Insufficiency & Post-Phlebitic Syndrome
- Long-term venous hypertension + valve damage (often after DVT)
- Features: Edema, hemosiderin pigmentation (brown skin), lipodermatosclerosis, venous ulcers
Venous Ulcer vs Arterial Ulcer β Key Differences:
| Feature | Venous Ulcer | Arterial Ulcer |
|---|
| Location | Medial ankle (gaiter area) | Toes / pressure points |
| Appearance | Shallow, irregular, wet | Deep, punched-out, dry |
| Pain | Relatively painless | Very painful |
| Pulses | Present | Absent |
| Surrounding skin | Pigmented, indurated | Pale, atrophic, hairless |
| ABI | >0.9 | <0.9 |
π§ Lymphedema
- Impaired lymphatic drainage β protein-rich fluid accumulates β non-pitting edema
| Type | Cause |
|---|
| Primary | Congenital (Milroy's disease) or idiopathic |
| Secondary | Breast cancer surgery/radiation (most common in developed world), filariasis (Wuchereria bancrofti - globally) |
Features:
- Starts pitting β becomes non-pitting over time
- Skin thickens (peau d'orange texture)
- Stemmer's sign = cannot pinch skin at base of 2nd toe
- Complications: Recurrent cellulitis, lymphangiosarcoma (Stewart-Treves syndrome)
Treatment: Complex decongestive physiotherapy (CDT) + compression garments + pneumatic compression (no cure)
π΅ Idiopathic Telangiectasia (Spider Veins)
- Dilated superficial capillaries/venules
- Usually cosmetic; may be hereditary (HHT = Osler-Weber-Rendu)
- HHT features: Epistaxis + GI bleeding + pulmonary AVM
- Treatment of spider veins: Sclerotherapy or laser
π Arteriovenous Fistula (AVF)
- Abnormal connection between artery and vein (bypasses capillary bed)
- Congenital or acquired (trauma; dialysis access is deliberately created)
- Features: Continuous machine-like murmur over site; distal ischemia ("steal"); high-output cardiac failure if large
- Treatment: Surgical ligation or endovascular embolization (except dialysis AVF)
β‘ MASTER QUICK REVISION TABLE
| Topic | One-Liner to Remember |
|---|
| ECG | P-QRS-T = atria depolarize β ventricles depolarize β repolarize |
| Echocardiography | EF <40% = HFrEF; EF >50% = HFpEF |
| Stress test | ST depression β₯1mm = positive for ischemia |
| Atherosclerosis | Foam cells β fatty streak β plaque β rupture β MI |
| MΓΆnckeberg's | Calcified media; lumen intact; "pipe-stem" on X-ray |
| IE | Osler = painful (fingers) |
| Tamponade | Beck's triad + electrical alternans |
| Pericarditis ECG | Diffuse concave ST elevation + PR depression |
| DCM | Big floppy heart; systolic failure; EF β |
| HCM | Murmur β with Valsalva; young athlete; septal hypertrophy |
| Restrictive CMP | Low voltage ECG + HF signs = think amyloid |
| Vasovagal syncope | Most common; triggered by emotion/pain/standing |
| Cardiac syncope | Exertional = dangerous; rule out HCM / arrhythmia |
| Shock types | Hypovolemic = βCO βSVR βCVP; Septic = βCO βSVR βCVP |
| Aortic dissection | Tearing chest-to-back pain; Type A = surgery; Type B = medical |
| Takayasu's | Young Asian woman + pulseless disease |
| Leriche syndrome | Bilateral buttock claudication + erectile dysfunction + no femoral pulses |
| PAD | ABI <0.9 = PAD; <0.4 = critical ischemia; #1 fix = stop smoking |
| Raynaud | White β Blue β Red; cold trigger; nifedipine |
| Buerger's | Young smoker + digital gangrene; STOP SMOKING = only treatment |
| DVT | Non-compressible vein on USS; treat with DOACs |
| Venous ulcer | Medial ankle, shallow, painless, pigmented skin |
| Arterial ulcer | Toes, deep, punched out, very painful, absent pulses |
| Lymphedema | Non-pitting; Stemmer's sign; secondary to breast Ca surgery |
| AVF | Machine-like murmur; high output HF if large |
Reference: Merck Manual on Diagnosis & Therapy, 20th Ed (2018), Section 7 β Cardiovascular Disorders. Supplemented by Robbins Pathology & Braunwald's Heart Disease.