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Cardiovascular Disorders - Full Clinical Reference

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1. ISCHEMIC HEART DISEASE (IHD) / CORONARY ARTERY DISEASE (CAD)

Pathophysiology

• Traditional: Hypertension, hyperlipidemia (especially LDL), smoking, diabetes mellitus, family history, age, male sex
• Non-traditional: High-sensitivity CRP (hsCRP), lipoprotein(a) [Lp(a)], fibrinogen, obesity (visceral adiposity generates IL-6, TNF-α promoting atherogenesis)

Clinical Presentations

A. Stable Angina (Stable IHD)

• Predictable chest pain on exertion, relieved by rest or nitrates
• Fixed atherosclerotic plaque causing >70% stenosis
• ECG: ST depression during symptoms; normal at rest
• Dx: Stress test (exercise ECG, nuclear, stress echo), coronary angiography
• Rx: Nitrates, beta-blockers, CCBs, aspirin, statins; revascularization (PCI or CABG) if refractory

B. Unstable Angina (UA) / NSTEMI (Acute Coronary Syndrome)

• Plaque rupture with partial coronary occlusion, thrombus formation, microembolization, or vasoactive substance release causing localized spasm
• UA defined as: (1) Rest angina ≥20 min within 1 week, OR (2) New-onset class III angina within 2 months, OR (3) Previously stable angina that worsened by ≥1 CCS class in the prior 2 months
• Prolonged rest angina (>30-60 min) typically causes myocardial necrosis = NSTEMI
• Cardiac Biomarkers:
  • Myoglobin: rises in 1-2 hr, remains elevated 7-12 hr; sensitive but not specific
  • CK-MB: 90% accurate at 6 hr; peaks at ~24 hr; normalizes by 72 hr
  • Troponin I: most specific; rises 10-14 hr after onset; sensitivity 58%/specificity 94% at 6 hr; 92%/95% at 10 hr; remains elevated for days
• High-risk features requiring admission: Age >70, prior SIHD/revascularization, ECG ischemia (ST deviation, new T-wave changes, new LBBB), ongoing chest pain >20 min, hemodynamic instability, CHF, elevated biomarkers
• ECG: ST depression or T-wave inversions in contiguous leads (can be silent)
• Rx: Antiplatelet (aspirin + P2Y12 inhibitor), anticoagulation (heparin), nitrates, beta-blockers, oxygen; early invasive strategy if high-risk; revascularization by PCI or CABG

C. ST-Elevation Myocardial Infarction (STEMI)

• Complete occlusion of a coronary artery; transmural necrosis
• ECG: ST elevation in contiguous leads; later Q waves
• Rx: Emergent reperfusion - primary PCI within 90 min (door-to-balloon); fibrinolysis if PCI unavailable within 120 min
• Complications: Arrhythmias, cardiogenic shock, papillary muscle rupture (MR), free wall rupture, ventricular septal defect, Dressler syndrome (post-MI pericarditis, weeks later)

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2. HEART FAILURE (HF)

Definition and Epidemiology

Types

Pathophysiology

1. A precipitating injury (CAD, MI, hypertension, valvular disease, diabetes, anemia, alcohol) triggers LV remodeling (stretching and dilation)
2. Neurohormonal activation follows: RAAS (angiotensin II, aldosterone) and SNS (catecholamines) are upregulated
3. Angiotensin II causes cardiomyocyte apoptosis, hypertrophy, and ventricular fibrosis
4. Aldosterone "escapes" RAAS suppression - requiring separate aldosterone blockade
5. Catecholamines suppress beta-adrenergic receptors and have direct myocardial toxicity
6. Inflammatory cytokines (endothelin-1, MMPs) cause cardiac fibrosis and collagen deposition
7. Calcium flux alterations and shift to glycolytic metabolism impair function

Causes / Precipitants

Clinical Features

• Dyspnea (on exertion, then at rest), orthopnea, paroxysmal nocturnal dyspnea
• Fatigue, exercise intolerance
• Fluid retention: peripheral edema, ascites, elevated JVP, S3 gallop
• Pulmonary congestion: bibasilar crackles
• Note: Pulmonary congestion may be absent even in established HF

Diagnosis

• Echocardiogram (measure EF, wall motion, diastolic function) - key test
• BNP/NT-proBNP (elevated in HF, inversely proportional to EF)
• CXR: cardiomegaly, Kerley B lines, pulmonary vascular congestion
• ECG: may show prior MI, LVH, arrhythmias

Treatment

• ACE inhibitors or ARBs - block angiotensin II; reduce apoptosis, hypertrophy, fibrosis
• Beta-blockers (carvedilol, metoprolol succinate, bisoprolol) - reverse SNS toxicity
• Aldosterone antagonists (spironolactone, eplerenone) - needed alongside ACEi/ARBs due to aldosterone escape
• ARNI (sacubitril/valsartan - entresto) - replaces ACEi in stable HFrEF
• SGLT2 inhibitors (dapagliflozin, empagliflozin) - reduce HF hospitalizations and CV death
• Diuretics (furosemide) - symptom relief, fluid management
• Digoxin - reduces hospitalizations; no mortality benefit
• ICD - for EF <35% to prevent sudden death
• CRT (cardiac resynchronization therapy) - for LBBB with EF <35%

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3. HYPERTENSION

Classification (AHA/ACC 2017)

Primary (Essential) Hypertension (~95% of cases)

• No single identifiable cause
• Polygenic predisposition + environmental (salt, obesity, sedentary lifestyle, stress)
• Neurohormonal (RAAS, SNS activation), endothelial dysfunction

Secondary Hypertension (~5%)

Target Organ Damage

• Heart: LVH, HF, CAD, MI
• Brain: Stroke, hypertensive encephalopathy
• Kidney: Nephrosclerosis, CKD, microalbuminuria
• Eyes: Hypertensive retinopathy (AV nicking, flame hemorrhages, papilledema)
• Vessels: Accelerated atherosclerosis, aortic aneurysm

Treatment

• Lifestyle: DASH diet, weight loss, sodium restriction (<2.4 g/day), aerobic exercise, limit alcohol
• Drug therapy:
  • Thiazide diuretics (chlorthalidone preferred over HCTZ), CCBs - first-line, especially in Black patients
  • ACE inhibitors/ARBs - first-line in diabetes, CKD, HF, proteinuria
  • Beta-blockers - preferred in CAD, HF, post-MI, arrhythmias
  • Aldosterone antagonists - useful in resistant hypertension
• Hypertensive urgency (no end-organ damage): Oral agents, lower BP over 24-48 hr
• Hypertensive emergency (end-organ damage): IV agents (labetalol, nicardipine, nitroprusside); lower MAP by 25% in 1st hour

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4. ARRHYTHMIAS AND CONDUCTION DISORDERS

Atrial Arrhythmias

Atrial Fibrillation (AF) - Most Common Sustained Arrhythmia

• Disorganized rapid atrial activity (350-600 impulses/min); irregular ventricular response
• Causes: Hypertension (most common), valvular disease (especially MS), hyperthyroidism, alcohol ("holiday heart"), CAD, HF, post-cardiac surgery, sleep apnea, obesity
• Risks: Stroke (5x increased risk), HF, hemodynamic compromise
• ECG: Absent P waves, irregularly irregular rhythm
• Stroke prevention: CHA₂DS₂-VASc score guides anticoagulation
  • Score ≥2 (men) or ≥3 (women): oral anticoagulant indicated
  • NOACs (apixaban, rivaroxaban, dabigatran) preferred over warfarin (except mechanical valves/MS)
• Rate control: Beta-blockers, CCBs (diltiazem/verapamil), digoxin
• Rhythm control: Cardioversion (electrical or pharmacologic), antiarrhythmics (flecainide, amiodarone), catheter ablation

Atrial Flutter

• Reentrant circuit in right atrium; rate ~300 bpm with 2:1 block → ventricular rate ~150 bpm
• ECG: Sawtooth flutter waves (F-waves) in II, III, aVF
• Rx: Similar to AF; catheter ablation highly effective

Ventricular Arrhythmias

Ventricular Tachycardia (VT)

• ≥3 consecutive ventricular beats at >100 bpm; wide QRS complex (>120 ms)
• Sustained VT (>30 sec or hemodynamic compromise): Cardiovert if unstable; amiodarone/lidocaine if stable
• Causes: CAD/scar, cardiomyopathy, electrolyte abnormalities, long QT, Brugada syndrome
• Treatment of recurrent VT: ICD + antiarrhythmics (amiodarone, sotalol), catheter ablation

Ventricular Fibrillation (VF)

• Chaotic ventricular activity; no effective cardiac output = cardiac arrest
• Rx: Immediate defibrillation (unsynchronized shock); CPR; ACLS protocol; ICD for secondary prevention

Long QT Syndrome

• Prolonged ventricular repolarization → risk of torsades de pointes (TdP)
• Congenital: Ion channel mutations (LQT1: KCNQ1; LQT2: KCNH2; LQT3: SCN5A)
• Acquired: Drugs (sotalol, quinidine, amiodarone, antipsychotics, macrolides), hypokalemia, hypomagnesemia
• Rx: Avoid QT-prolonging drugs; beta-blockers (LQT1, LQT2); ICD in high-risk patients

Bradyarrhythmias and Conduction Disorders

Sick Sinus Syndrome (SSS)

• Sinus node dysfunction: sinus bradycardia, sinus arrest, sinoatrial block, tachycardia-bradycardia syndrome
• Rx: Permanent pacemaker if symptomatic

Atrioventricular (AV) Block

Bundle Branch Blocks

• LBBB: QRS >120 ms; broad notched R in V5/V6, I, aVL; always investigate underlying cause (IHD, cardiomyopathy)
• RBBB: RSR' (M-shape) in V1; broad S in I, V5/V6; may be normal variant

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5. VALVULAR HEART DISEASE

Aortic Stenosis (AS) - Most Common Valvular Disorder in Adults

• Causes: Calcific/degenerative (most common; elderly), bicuspid aortic valve (younger adults), rheumatic heart disease
• Pathophysiology: Pressure overload → concentric LVH → diastolic dysfunction → eventually systolic dysfunction
• Classic Triad of Symptoms (occur late, bad prognosis when they appear):
  • Angina (average survival ~5 yr)
  • Syncope (average survival ~3 yr)
  • Heart failure (average survival ~2 yr)
• Signs: Harsh systolic ejection murmur (SEM) at RUSB radiating to carotids; diminished and delayed carotid pulse (pulsus parvus et tardus); soft/absent S2; S4
• ECG: LVH; Echo: reduced AVA, high gradient
• Rx: Valve replacement - SAVR (surgical) or TAVR (transcatheter, for high-risk/elderly); no proven medical therapy; avoid vasodilators in severe AS

Aortic Regurgitation (AR)

• Causes (Acute): Infective endocarditis, aortic dissection - surgical emergency
• Causes (Chronic): Bicuspid aortic valve, rheumatic, Marfan syndrome, aortitis (syphilis, ankylosing spondylitis), hypertension
• Pathophysiology: Volume overload → eccentric LVH → LV dilation
• Signs: High-pitched diastolic decrescendo murmur at LUSB; wide pulse pressure; bounding peripheral pulses (Corrigan water-hammer pulse); de Musset's sign (head bobbing); Quincke's pulse; Austin Flint murmur (diastolic rumble)
• Rx: Vasodilators (ACEi, nifedipine) in chronic AR; surgical repair/replacement when symptomatic or EF declining

Mitral Stenosis (MS)

• Cause: Almost exclusively rheumatic heart disease (streptococcal pharyngitis → autoimmune valve damage)
• Pathophysiology: Obstruction of LA-LV flow → elevated LA pressure → pulmonary HTN → RV failure
• Signs: Low-pitched mid-diastolic rumble at apex; opening snap (OS); loud S1; OS-S2 interval shorter = more severe; AF is common complication
• Rx: Anticoagulation if AF; diuretics; beta-blockers for rate control; balloon mitral valvuloplasty (BMV) for suitable anatomy; mitral valve replacement for severe/unsuitable anatomy

Mitral Regurgitation (MR)

• Causes (Acute): Papillary muscle rupture post-MI, infective endocarditis, chordae tendineae rupture - emergency
• Causes (Chronic): Mitral valve prolapse (most common in developed world), rheumatic, dilated cardiomyopathy, Marfan syndrome
• Signs: Holosystolic murmur at apex radiating to axilla; S3 gallop in severe MR; LV dilation on echo
• Rx: Vasodilators; surgical/transcatheter repair (MitraClip) when severe or symptomatic

Mitral Valve Prolapse (MVP)

• Myxomatous degeneration; posterior leaflet billows into LA during systole
• Most common valvular disorder overall; 2-3% of population; often benign
• Signs: Mid-systolic click + late systolic murmur; earlier with Valsalva/standing; later with squatting
• Complications: MR, arrhythmias, rarely sudden death
• Rx: Reassurance if asymptomatic; surgery if significant MR

Tricuspid and Pulmonary Valve Disease

• Tricuspid regurgitation (TR): Most commonly functional (RV dilation from pulmonary HTN); systolic murmur at LLSB that increases with inspiration; treat underlying cause
• Pulmonary stenosis (PS): Often congenital; systolic murmur at LUSB; balloon valvuloplasty if severe

Infective Endocarditis (IE)

• Infection of valvular endothelium; vegetation formation
• Organisms: Streptococcus viridans (subacute, native valve, dental), Staphylococcus aureus (acute, IV drug users, prosthetic valves), Enterococcus, HACEK group
• Risk factors: IV drug use, structural heart disease, prosthetic valves, poor dentition, intravascular catheters
• Clinical features: Fever, new regurgitant murmur, embolic phenomena (stroke, splenic infarct), Janeway lesions (painless), Osler's nodes (painful), Roth's spots (retinal), splinter hemorrhages, splenomegaly
• Duke Criteria: Major (blood cultures, echo vegetation/abscess/new valvular regurgitation) + minor criteria for diagnosis
• Dx: Blood cultures (≥3 sets before antibiotics), transesophageal echocardiogram (TEE > TTE)
• Rx: Prolonged IV antibiotics (4-6 weeks); surgery for severe valvular dysfunction, persistent bacteremia, abscess, emboli

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6. CARDIOMYOPATHIES

Dilated Cardiomyopathy (DCM)

• LV and/or RV dilation with systolic dysfunction; EF typically <40%
• Causes: Idiopathic (most common, often genetic), viral myocarditis (Coxsackievirus B), alcohol, cocaine, peripartum cardiomyopathy, doxorubicin toxicity, thyroid disease, hemochromatosis, sarcoidosis
• Genetics: ~35% familial; mutations in sarcomere proteins (titin - most common, lamin A/C), cytoskeletal proteins
• Clinical: HF symptoms (dyspnea, edema), dilated LV on echo with reduced EF, functional MR, S3 gallop
• Rx: Standard HF therapy (ACEi/ARBs/ARNI, beta-blockers, aldosterone antagonists, SGLT2i, diuretics); ICD if EF <35%; cardiac transplant for refractory cases

Hypertrophic Cardiomyopathy (HCM)

• Asymmetric (usually septal) LV hypertrophy without a hemodynamic cause; sarcomere protein mutations
• Genetics: Autosomal dominant; MYH7 (beta-myosin heavy chain), MYBPC3 (myosin binding protein C) most common
• Obstructive HCM (HOCM): Dynamic LVOT obstruction due to systolic anterior motion (SAM) of mitral valve
• Clinical: Dyspnea, chest pain, syncope (exertional); harsh systolic murmur at LLSB
  • Murmur increases with: Valsalva, standing (decrease preload = worse obstruction)
  • Murmur decreases with: squatting, lying down (increase preload)
• Most common cause of sudden cardiac death in young athletes
• ECG: LVH, deep Q waves (pseudo-infarction) in lateral leads
• Rx: Beta-blockers or non-dihydropyridine CCBs; avoid vasodilators, digoxin, high-intensity exercise; mavacamten (cardiac myosin inhibitor) - novel therapy; septal reduction (surgical myectomy or alcohol septal ablation) for refractory obstructive disease; ICD for high-risk features

Restrictive Cardiomyopathy (RCM)

• Impaired ventricular filling with normal/near-normal systolic function; stiff, non-compliant myocardium
• Causes: Amyloidosis (most common; TTR or AL), sarcoidosis, hemochromatosis, radiation, eosinophilic heart disease (Löffler endocarditis), endomyocardial fibrosis
• Clinical: HFpEF picture; exertional dyspnea, elevated JVP, Kussmaul sign; preserved EF on echo
• Must distinguish from constrictive pericarditis (both cause similar physiology but different treatment)
• Rx: Treat underlying cause; diuretics; avoid digoxin in amyloidosis; tafamidis for TTR amyloidosis; anticoagulation if AF

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)

• Fibrofatty replacement of RV myocardium; autosomal dominant (desmosomal gene mutations - PKP2 most common)
• Clinical: VT with LBBB morphology (RV origin), palpitations, syncope; SCD in young adults
• ECG: Epsilon wave in V1-V3; T-wave inversions in right precordial leads; prolonged QRS
• Rx: ICD; beta-blockers; catheter ablation; avoid competitive sports

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7. PERICARDIAL DISEASES

Acute Pericarditis

• Inflammation of the pericardium; most common pericardial disease
• Causes: Viral (most common; Coxsackievirus A/B, EBV, echovirus), idiopathic, post-MI (Dressler syndrome), uremia, autoimmune (SLE, RA), malignancy, tuberculosis (most common worldwide cause of constrictive pericarditis)
• Clinical: Sharp pleuritic chest pain, relieved by sitting forward; worse supine; pericardial friction rub (3-component)
• ECG: Diffuse saddle-shaped ST elevation with PR depression (pathognomonic); evolution through 4 stages
• Dx: Elevated inflammatory markers (CRP, ESR); echo for effusion
• Rx: NSAIDs + colchicine (reduces recurrence); restrict activity until asymptomatic; steroids only for specific causes (autoimmune, uremic); hospitalize if: high-risk features (fever >38°C, large effusion, tamponade, immunocompromised, trauma)

Pericardial Effusion and Cardiac Tamponade

• Accumulation of fluid in pericardial space; rate of accumulation matters (acute >150 mL can cause tamponade; chronic >1L may be tolerated)
• Tamponade: External compression of the heart impairing cardiac filling
• Clinical (Beck's Triad): Hypotension, elevated JVP (distended neck veins), muffled heart sounds
• Pulsus paradoxus: >10 mmHg fall in systolic BP with inspiration (hallmark)
• ECG: Electrical alternans (alternating QRS amplitude) + sinus tachycardia
• Rx: Emergent pericardiocentesis; drainage catheter; pericardiectomy for recurrent/malignant effusions

Constrictive Pericarditis

• Fibrous scarring and calcification of pericardium impairing diastolic filling
• Causes: Post-viral, post-radiation, TB (developing world), post-cardiac surgery, post-pericarditis
• Clinical: Progressive RHF (JVD, ascites, edema); Kussmaul sign (JVP rises with inspiration - opposite of normal); pericardial knock (high-pitched early diastolic sound); normal EF on echo with pericardial thickening/calcification
• CT/MRI: Best for demonstrating pericardial thickening/calcification
• Rx: Pericardiectomy (surgical stripping) - definitive; diuretics for symptom relief

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8. CONGENITAL HEART DISEASE (CHD)

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9. HYPERTENSIVE HEART DISEASE

• Sustained hypertension → increased afterload → concentric LVH (pressure overload)
• LVH is an independent risk factor for MI, HF, stroke, sudden death
• Systemic hypertensive heart disease: LVH; diastolic dysfunction; eventually systolic dysfunction and HF
• Pulmonary hypertensive heart disease (Cor Pulmonale): Pulmonary HTN → RV pressure overload → RVH → RV failure
  • Causes of pulmonary HTN: Chronic lung disease (COPD, IPF), recurrent PE, primary pulmonary arterial hypertension (PAH), left heart disease, connective tissue disease
  • PAH Treatment: Endothelin receptor antagonists (bosentan, ambrisentan), PDE5 inhibitors (sildenafil, tadalafil), prostacyclin analogues (epoprostenol), soluble guanylate cyclase stimulators (riociguat)

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10. AORTIC DISEASES

Aortic Aneurysm

• Thoracic Aortic Aneurysm (TAA): Associated with cystic medial necrosis, Marfan syndrome, Ehlers-Danlos, bicuspid aortic valve, syphilis (luetic aortitis), aortitis
• Abdominal Aortic Aneurysm (AAA): >90% infrarenal; associated with atherosclerosis; risk factors: male sex, smoking, age >65
  • Screening: one-time abdominal ultrasound for men ≥65 who have ever smoked
  • Repair: open surgery or EVAR when ≥5.5 cm (men) or ≥5.0 cm (women), or expanding >0.5-1 cm/year, or symptomatic
• Rupture: Sudden tearing abdominal/back pain, hypotension, pulsatile mass; 80% mortality

Aortic Dissection

• Intimal tear → blood enters media creating false lumen
• Risk factors: Hypertension (most common), Marfan syndrome, bicuspid aortic valve, aortitis, pregnancy, cocaine
• Stanford Classification:
  • Type A: involves ascending aorta - surgical emergency
  • Type B: descending aorta only - medical management (IV beta-blockers first, then vasodilators); endovascular repair for complications
• Clinical: Sudden tearing/ripping chest pain radiating to the back; unequal BP between arms; aortic regurgitation murmur (Type A); neurological deficits
• Dx: CT angiography of chest (gold standard in stable); TEE (unstable)
• Rx Type A: Emergency surgery; avoid fibrinolytics; control HR and BP

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11. PERIPHERAL VASCULAR DISEASE (PVD)

Peripheral Arterial Disease (PAD)

• Atherosclerotic narrowing of non-coronary arteries; lower extremities most commonly affected
• Risk factors: Smoking (strongest modifiable), diabetes, hypertension, hyperlipidemia, male sex, age; hsCRP independently predicts PAD
  • Note: Lp(a) is an atherogenic LDL subspecies that impairs fibrinolysis and may contribute to PAD
  • Initial data suggested men develop IC ~10 years before women but more recent studies do NOT support gender-based timing differences
• Clinical: Intermittent claudication (reproducible leg pain/cramping with exertion, relieved by rest); critical limb ischemia (rest pain, non-healing ulcers, gangrene)
• ABI (Ankle-Brachial Index): ≤0.9 = PAD; ≤0.4 = critical limb ischemia; >1.4 = non-compressible vessels (diabetes/CKD)
• Rx: Lifestyle modification; antiplatelet therapy (aspirin or clopidogrel); statins; cilostazol (claudication); revascularization (PTA/stenting or bypass) for critical limb ischemia or disabling claudication

Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE)

• See Virchow's triad: stasis, endothelial injury, hypercoagulability
• DVT: Unilateral leg swelling, pain, erythema, warmth; Homan's sign unreliable
• PE: Dyspnea, pleuritic chest pain, hemoptysis, tachycardia; massive PE → hypotension/shock
• Dx: D-dimer (sensitive, not specific); Doppler ultrasound (DVT); CTPA (gold standard for PE); V/Q scan if contrast contraindicated
• ECG in PE: Sinus tachycardia (most common); S1Q3T3; right heart strain pattern
• Rx: Anticoagulation with LMWH/heparin bridging to DOAC or warfarin; thrombolysis for massive PE; catheter-directed therapy; IVC filter if anticoagulation contraindicated

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12. MYOCARDITIS

• Inflammatory disease of myocardium; most commonly viral
• Causes: Viral (Coxsackievirus B, parvovirus B19, HIV, COVID-19), autoimmune (giant cell myocarditis - aggressive), sarcoidosis, drug-induced (immune checkpoint inhibitors increasingly recognized), Chagas disease (T. cruzi - most common infective cause worldwide)
• Clinical: Chest pain, dyspnea, palpitations, arrhythmias; mimics ACS; mild to fulminant
• Dx: Elevated troponin; ECG (diffuse ST changes); echo (regional or global LV dysfunction); MRI (gold standard - late gadolinium enhancement); endomyocardial biopsy (Dallas criteria - definitive but low sensitivity)
• Rx: Supportive; treat HF; immunosuppression for giant cell/autoimmune myocarditis; IVIG in selected pediatric cases; MCS (mechanical circulatory support) for cardiogenic shock

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13. CARDIAC TUMORS

Primary Cardiac Tumors (Rare)

Metastatic Cardiac Tumors

• Far more common than primary tumors
• Most common sources: lung, breast, esophagus, melanoma (highest tendency), lymphoma, leukemia
• Pericardial effusion most common manifestation

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Summary Table: Key Cardiovascular Disorders

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