Summary These notes provide a comprehensive overview of various heart pathologies, covering ischemic heart disease, myocardial infarction, heart failure, and di
Summary These notes provide a comprehensive overview of various heart pathologies, covering ischemic heart disease, myocardial infarction, heart failure, and diverse cardiomyopathies. It details valvular heart diseases, endocarditis, rheumatic heart disease, and congenital cardiac defects. Additionally, the content addresses pericardial and aortic diseases, cardiac tumors, and a summary of vasculitides, highlighting key clinical features and high-yield facts. Key Points - Ventricular fibrillation is the leading cause of early death following myocardial infarction. - Cardiogenic shock represents the primary overall cause of death in myocardial infarction. - Free wall rupture is a serious complication occurring 3-7 days post-MI, leading to tamponade. - Dressler syndrome is an autoimmune pericarditis that can develop weeks after an MI. - Hypertrophic Cardiomyopathy (HOCM) is the most common cause of sudden cardiac death in young athletes. - Myxoma is the most common primary cardiac tumor found in adults. - Ventricular Septal Defect (VSD) is the most common congenital heart defect. - Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease. - Mitral stenosis is the most common late complication of rheumatic fever. - Intravenous drug users frequently develop tricuspid valve endocarditis, often caused by S. aureus. - Libman-Sacks endocarditis is associated with Systemic Lupus Erythematosus (SLE) and affects both sides of the mitral valve. - Berry aneurysms are associated with Autosomal Dominant Polycystic Kidney Disease (ADPKD). - A "boot-shaped heart" is a characteristic radiographic finding in Tetralogy of Fallot. - An "egg-on-a-string" appearance on CXR is indicative of Transposition of Great Arteries (TGA). - Troponin is considered the most specific biomarker for myocardial infarction. Detailed Notes ISCHEMIC HEART DISEASE (IHD) Pathophysiology - Cause: Imbalance between myocardial O₂ supply and demand - 1 cause: Atherosclerosis → plaque rupture → thrombus → occlusion - Risk factors: HTN, DM, smoking, hyperlipidemia, obesity, family history Atherosclerosis - Affects the tunica intima - Starts as fatty streak (foam cells = macrophages engulfing oxidized LDL) - Progresses to fibrous plaque → complicated plaque (calcification, ulceration, rupture) - Foam cells → release cytokines → smooth muscle migration → fibrous cap Coronary Artery Territory Artery Territory -------- ----------- LAD Anterior LV, anterior septum (most common) RCA Posterior LV, SA node, AV node LCx Lateral LV wall MYOCARDIAL INFARCTION (MI) Types - STEMI — full thickness (transmural), complete occlusion - NSTEMI — partial thickness (subendocardial), partial occlusion Timeline of Changes ⚡ (HIGH YIELD) Time Gross Microscopy ------ ------- ------------ 0–30 min Nothing Nothing (reversible) 1–4 hrs Nothing Wavy fibers, contraction bands 4–12 hrs Slight pallor Early coagulative necrosis 24–48 hrs Pale/yellow Coagulative necrosis, neutrophil infiltration 3–5 days Hyperemic border Macrophages appear 1–2 weeks Yellow, soft Granulation tissue, fibroblasts 4–6 weeks White scar Dense fibrous scar Biomarkers ⚡ Marker Rises Peaks Returns to normal -------- ------- ------- ------------------- Troponin I/T 2–4 hrs 24 hrs 7–10 days CK-MB 4–6 hrs 24 hrs 48–72 hrs Myoglobin 1–2 hrs 6 hrs 24 hrs (first to rise, not specific) Complications by Time ⚡ (VERY HIGH YIELD) Time Complication ------ -------------- 0–24 hrs Arrhythmia (VF) — 1 cause of early death 1–3 days Fibrinous pericarditis (friction rub) 3–5 days Papillary muscle rupture → MR; VSD rupture; free wall rupture 1–2 weeks Mural thrombus → embolism Weeks later Dressler syndrome (autoimmune pericarditis, fever) Months later Ventricular aneurysm, heart failure HEART FAILURE Left Heart Failure - Causes: IHD, HTN, aortic/mitral valve disease - Effects: Pulmonary congestion → dyspnea, orthopnea, PND, hemoptysis - Lungs show hemosiderin-laden macrophages ("heart failure cells") Right Heart Failure - Most common cause: Left heart failure - Effects: Systemic venous congestion → JVD, pitting edema, hepatomegaly, ascites - Liver shows "nutmeg liver" (centrilobular congestion) Hypertrophy Types Type Cause Mechanism ------ ------- ----------- Concentric Pressure overload (HTN, AS) Sarcomeres in parallel → thick wall Eccentric Volume overload (AR, MR, DCM) Sarcomeres in series → dilated chamber CARDIOMYOPATHIES ⚡ Dilated Cardiomyopathy (DCM) - Most common cardiomyopathy - All 4 chambers dilated, systolic dysfunction (↓EF) - Causes: ABCDE — Alcohol, Beriberi, Coxsackievirus B, Drugs (doxorubicin), Ectopic (peripartum), also Chagas (Trypanosoma cruzi) - Presents: Progressive HF, S3 gallop, MR/TR (dilated annuli) Hypertrophic Cardiomyopathy (HCM/HOCM) - Autosomal dominant — beta-myosin heavy chain mutation (MYH7) - Asymmetric septal hypertrophy + myofiber disarray - Dynamic LVOT obstruction — worsens with decreased preload (standing, Valsalva) - 1 cause of sudden cardiac death in young athletes - Auscultation: harsh systolic murmur at left sternal border - Murmur increases with: standing, Valsalva, dehydration - Murmur decreases with: squatting, leg raise, fluids Restrictive Cardiomyopathy - Stiff, non-compliant ventricles → diastolic dysfunction , normal EF - Causes: - Amyloidosis — most common in developed world; "sparkling" on echo - Endomyocardial fibrosis — most common worldwide (tropical Africa) - Sarcoidosis, hemochromatosis, radiation fibrosis VALVULAR HEART DISEASE ⚡ Mitral Stenosis - 1 cause: Rheumatic heart disease - Obstruction of LV filling → LA enlargement → pulmonary HTN - Signs: Opening snap + mid-diastolic rumble at apex - Complications: AF, pulmonary HTN, hemoptysis, systemic emboli Mitral Regurgitation - Causes: MVP, rheumatic fever, papillary muscle rupture (post-MI), DCM - Holosystolic murmur at apex radiating to axilla - Volume overload → eccentric LVH Mitral Valve Prolapse (MVP) - Most common valvular disease in developed world - Billowing of leaflets into LA during systole - Midsystolic click + late systolic murmur - Associated with Marfan syndrome Aortic Stenosis - Most common valvular disease in developed world (in elderly) - Causes: Age-related calcification ( 1 in elderly), bicuspid aortic valve ( 1 in young), rheumatic fever - Classic triad: SAD — Syncope, Angina, Dyspnea - Harsh systolic ejection murmur at right upper sternal border radiating to carotids - Prognosis: 2–3 years after symptom onset without treatment Aortic Regurgitation - Causes: Marfan, syphilis, aortic dissection, rheumatic fever, bicuspid AV - High-pitched early diastolic decrescendo murmur at left sternal border - Wide pulse pressure — many eponymous signs: - Corrigan pulse (water-hammer pulse) - De Musset sign (head bobbing) - Quincke sign (nail bed pulsations) ENDOCARDITIS Infective Endocarditis Feature Acute (S. aureus) Subacute (S. viridans) --------- ------------------ ---------------------- Organism S. aureus S. viridans Valve Normal valve Abnormal/damaged valve Course Rapid, destructive Slow, indolent Vegetations Large, destructive Smaller - IV drug users → Tricuspid valve (right-sided) - Dental procedures → S. viridans → mitral valve - Signs: Fever, new murmur, Osler nodes (painful, fingers), Janeway lesions (painless, palms/soles), Roth spots (retina), splinter hemorrhages, splenomegaly Non-Infective Endocarditis Type Association Location ------ ------------- ---------- Libman-Sacks SLE Both sides of mitral valve Marantic (NBTE) Cancer, debilitating illness Valve edges Carcinoid Carcinoid tumor Right-sided valves (tricuspid + pulmonary) Rheumatic Rheumatic fever Mitral valve, chordae tendineae RHEUMATIC HEART DISEASE - Cause: Group A Strep pharyngitis → autoimmune cross-reaction (type II/III hypersensitivity) - Anti-streptolysin O (ASO) antibodies cross-react with cardiac tissue - Aschoff bodies — pathognomonic granulomas with Anitschkow cells (caterpillar cells) - Jones Criteria (major): Carditis, Polyarthritis, Chorea, Erythema mar