Pathology - Cardiovascular System Lecture 6

What type of infection is rheumatic fever secondary to?

What is the most common form of acquired heart disease in all age groups?

Rheumatic fever is more common in developed countries than in developing countries.

Only ___% of infected patients develop rheumatic fever.

How long after the GAS infection does rheumatic fever usually develop?

Which of the following is a salient feature of acute rheumatic carditis?

Which of the following conditions is characteristic of Sydenham’s chorea?

Rheumatic Fever Overview

Immunologically mediated multisystem inflammatory disease.
Occurs following infection by group A beta-hemolytic streptococci.
Affects multiple systems including heart, joints, skin, and brain.
Rheumatic heart disease is the most prevalent form of acquired heart disease across all age groups.
More frequent in developing countries compared to developed nations.

Pathogenesis

Antibodies formed against group A streptococcal antigens can cross-react with myocardial (heart muscle) antigens of the host.
Only about 3% of those infected with group A streptococci develop rheumatic fever.
Onset of rheumatic fever typically occurs 2-3 weeks post-streptococcal infection.

Salient Features of Acute Rheumatic Carditis

The pericardium may show exudative changes.
Myocarditis—an inflammation of the heart muscle—is a common involvement.
Valve involvement leads to necrosis and deposition of fibrin at closure lines.

Clinical Features of Rheumatic Fever

Pancarditis affects approximately 50% of patients, characterized by:
- Endocarditis presenting with a heart murmur.
- Myocarditis potentially leading to heart failure and death.
- Pericarditis causing pericardial rub and risk of tamponade.
Polyarthritis affects around 80% of patients.
Sydenham’s chorea occurs in about 10% of cases, with involuntary movements appearing 2-6 months after the initial streptococcal infection.
Erythema marginatum is another significant clinical feature noted.

This quiz covers Lecture 6 on Rheumatic Fever, focusing on its immunological aspects and how it can affect the cardiovascular system. It discusses the disease's connection to group A beta-hemolytic streptococci infections and its prevalence in various populations. Understand the implications of rheumatic heart disease in acquired heart conditions across age groups.