Rheumatic Fever and Heart Conditions

Rheumatic Fever

• Definition: An immune-mediated multisystem disease affecting all layers of the heart and extra-cardiac sites.
• Occurs after group A beta-hemolytic streptococcal pharyngitis or tonsillitis, typically affecting children and young adults (5-15 years).
• Pathogenesis:
  • Altered antigenicity: Streptococcal antigen binds to tissues, rendering them antigenic.
  • Antigenic similarity (cross-reactivity): Antibodies against streptococcal antigens (M protein) cross-react with human tissue protein (antigens).

Phases of Rheumatic Fever

• Acute Phase:
  • Heart: Resolves completely.
  • Extra-cardiac tissues: Joint, skin, brain, etc.
• Chronic Phase:
  • Heart only: Valve fibrosis.

Pathology of Rheumatic Fever

• All layers of the heart are affected (Pancarditis).
• Pericardium:
  • Acute Phase: Fibrinous Pericarditis (Bread & Butter).
  • Chronic Phase: Milk spots, Fibrous adhesions.
• Myocardium:
  • Acute Phase: Aschoff bodies (pathognomonic of Rheumatic Fever).
  • Chronic Phase: Fibrosis.
• Endocardium:
  • Acute Phase: Vegetations (small thrombi on valves).
  • Chronic Phase: Valvular deformity (stenosis, incompetence, or both).

Complications of Rheumatic Fever

• Predisposes to subacute infective endocarditis.
• Heart failure (valve lesions): Stenosis or incompetence or both.
• Severe rheumatic myocarditis.
• Pericardial fibrosis and adhesions.
• Extra-cardiac: Pathological changes in joints, brain, skin, and serofibrinous inflammation of pleura and peritoneum.

Endocarditis

• Definition: Inflammation of the valvular endocardium, with or without inflammation of the mural endocardium.
• Types:
  • Non-infective Endocarditis (e.g., Rheumatic endocarditis).
  • Infective Endocarditis:
    • Acute Infective Endocarditis.
    • Subacute Infective Endocarditis.

Acute Infective Endocarditis

• Aetiology and Pathogenesis:
  • Highly virulent organisms (e.g., Staph. aureus, Strept. hemolyticus).
  • Suppurative inflammation (pus) in the valve tissue.
• Pathologic Manifestations:
  • Suppurative inflammation of the valve tissue.
  • Vegetations (detachable, friable, and yellowish).

Subacute Infective Endocarditis

• Aetiology and Pathogenesis:
  • Low virulent organisms (e.g., Strept. viridans).
  • Inflammation of the valve tissue without pus.
• Pathologic Manifestations:
  • Inflammation of the valve tissue.
  • Vegetations (friable, grayish, and detachable).

Clinical Picture

• Acute Infective Endocarditis:
  • Septicemia (fever, chills, and weakness).
  • Embolic lesions (e.g., septic infarctions, pyemia, and pyemic abscesses).
• Subacute Infective Endocarditis:
  • Moderate toxemia (fever, clubbing of fingers).
  • Embolic lesions (e.g., infarction of kidney, brain, and spleen).

Ischaemic (Coronary) Heart Disease (IHD)

• Definition: Cardiac ischaemia results from an imbalance between myocardial oxygen supply and demand.
• Coronary Artery Disease Manifestations:
  • Asymptomatic cases.
  • Angina Pectoris.
  • Myocardial Infarction.
• Classification of IHD:
  • Chronic Ischaemia:
    • Incomplete Coronary Insufficiency (Arteriosclerotic Heart Disease).
  • Acute Ischaemia:
    • Complete Coronary Occlusion.

Myocardial Infarction

• Definition: Complete occlusion of a coronary artery.
• Causes: Complete Sudden Coronary Occlusion.
• Sites of Infarction:
  • Left Ventricle (LV): Anterior, lateral, and posterior infarcts.
  • Right Ventricle (RV): Rare, due to right coronary occlusion.
• Gross and Microscopic Picture:
  • Recent Infarction: Swollen, pale, friable, and hyperemic margins.
  • Healed Infarction: Thin, gray, fibrotic, and may dilate.

Atherosclerosis

• Definition: Patchy thickening of the intima as a result of lipid deposition, covered by a fibrous cap.
• Predisposing Risk Factors:
  • Major Risk Factors:
    • Hyperlipidemia (high level of plasma lipids).
    • Hypertension.
    • Diabetes Mellitus.
    • Smoking.
  • Constitutional Risk Factors:
    • Age.
    • Sex.
    • Hereditary predisposition.
    • Lack of exercise and stressful life.
    • Diet (hyperlipaemia).

Pathogenesis

• Chronic endothelial injury.
• Oxidation of soluble LDL.
• Migration and proliferation of smooth muscle cells.
• Proliferation of fibroblasts and deposition of collagen.

Pathological Features

• Distribution: Large arteries, small arteries, and medium-sized arteries.
• Gross and Microscopic Features:
  • Fatty Streaks.
  • Atheromatous Plaque (Atheroma).
  • Atheromatous Ulcer.

Effects and Complications

• Ischaemia.
• Aneurysms.
• Thrombosis.

Hypertension

• Definition: Persistent elevation of resting blood pressure above 140/90.
• Etiologic Types:
  • Primary (Essential) Hypertension.
  • Secondary Hypertension.

Clinicopathologic Classification

• Primary Essential Hypertension:
  • Benign Essential Hypertension.
  • Malignant Essential Hypertension.

Pathology

• Blood Vessels: Arteriolosclerosis.
• Kidney: Benign Nephrosclerosis, Malignant Nephrosclerosis.
• Heart: Marked Concentric Hypertrophy of Left Ventricle.
• Retina: Thickening of Retinal Arterioles, Papilledema, Retinal Hemorrhage, and Exudate.
• Brain: Microaneurysms of Cerebral Arteries, Thrombosis, and Hemorrhage.

Congenital Heart Diseases

• Complications of Large ASD, VSD, and PDA:
  • Left to Right Shunt.
  • Right-Sided Hypertrophy and Dilatation.
  • Reversal of Shunt (Eisenmenger's Syndrome).

True Aneurysms

• Definition: Localized dilatation of the arterial wall.
• Etiology:
  • Hypertension.
  • Weakening of the Media.
  • Congenital.
  • Atherosclerosis.
  • Medionecrosis.
  • Inflammatory.

Complications of True Aneurysm

• Pressure on the Surroundings.
• Thrombosis and Embolism.
• Rupture and Hemorrhage.

Types of True Aneurysm

• According to Shape:
  • Saccular Aneurysm.
  • Fusiform Aneurysm.
• According to Etiology:
  • Congenital (Berry) Aneurysm.
  • Atherosclerotic Aneurysm.
  • Syphilitic Aneurysm.
  • Mycotic Aneurysm.
  • Dissecting Aneurysm.

Pericarditis

• Definition: An inflammatory reaction involving the visceral and or the parietal layers.

• Types:

  • True Aneurysms.
  • False Aneurysms.
  • Infective Pericarditis.
  • Non-Infective Pericarditis.### Pericarditis

• Serofibrinous pericarditis is a type of pericarditis that occurs in Rheumatic fever, also known as "Bread & Butter pericarditis"

• Fibrinous pericarditis is another type that occurs in Rheumatic fever, also known as "Bread & Butter pericarditis"

• Hemorrhagic pericarditis occurs in Trauma and Tumor

• Suppurative pericarditis occurs in Septicemia

• Tuberculous pericarditis is characterized by Granulomas with caseous necrosis

• Constrictive pericarditis is characterized by Pericardial fibrosis and adhesions

Aortic Stenosis

Aetiology

• Chronic rheumatic valvulitis
• Healed subacute infective endocarditis
• Calcific aortic stenosis in atherosclerosis

Effects and Complications

• Left ventricle hypertrophy
• Hypertrophied myocardium tends to be ischemic due to diminished coronary flow, leading to angina pectoris
• Cardiac decompensation and congestive heart failure