These notes provide a comprehensive overview of various heart pathologies, covering ischemic heart disease, myocardial infarction, heart failure, a
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: sta