Infective Endocarditis and Rheumatic Heart Disease

Question 1

What is (the aetiology of) infective endocarditis

Answer 1

Inflammation of the endocardium
- usually involved the valves

Question 2

What are the predisposing factors of infective endocarditis

Answer 2

• Prosthetic valves
• Cardiac devices (permanent pacemakers, defibrillators)
• Intravenous drug users
• Congenital Heart disease
• Rheumatic valve disease (developing countries)
• Mitral valve prolapse
• Immunosuppression
• Prolonged admission to ITU/hospital (health-care associated IE)

Question 3

What are the most common microorganisms involved in infective endocarditis

Answer 3

• Staphyloccus aureus.
• Streptococci (Viridans, gallolyticus)
• Enterococci

Question 4

Describe the most common signs and symptoms of infective endocarditis

Answer 4

• Fever (90%)
  ~ Chills/Rigors
  ~ Poor appetite
  ~ Weight loss
• Heart murmur (85%)
• Less frequent: myalgia, abdo/back pain, confusion
• Embolic complications (phenomena) 25%.

Question 5

Describe the investigations of the Modified Duke’s Criteria

Answer 5

DEFINITE IE =
- 2 major OR 1 major + 3 minor criteria

POSSIBLE IE =
- 1 major + 1 minor OR 3 minor criteria

MAJOR CRITERIA
- blood culture positive for typical microorganism
- echo showing valvular vegetation

MINOR CRITERIA
- Temperature >38C
- IV drug use
- (4 other minor criterias)

Question 6

Outline the management of infective endocarditis, including the indications for cardiac surgery

Answer 6

ANTIBIOTIC TREATMENT
- penicillin G
- amoxicillin
- (Flu)cloxacillin or oxacillin

INDICATIONS FOR CARDIAC SURGERY
- Heart failure with valvular dysfunction or cardiac complications
- Uncontrolled infection
~ Persistent fever and positive blood cultures
- Prevention of embolism
~ If the vegetation is persistently large (>10mm).
~ One or more embolic episodes

Question 7

Characterise the incidence/prevalence and global distribution of rheumatic heart disease in the world

Answer 7

Very common in low and middle income countries.

Estimated 38-40 million cases/year globally with 300.000 death yearly.

Highest prevalence in Oceania, South Asia and sub-Saharan Africa.

Prevalence
Non-endemic: 3.4/100.000
Endemic >1000/100.000

Question 8

Describe the long term effects of rheumatic heart disease

Answer 8

• Heart failure
• Damaged heart valves
• Stroke

Question 9

Outline investigations and management of rheumatic heart disease

Answer 9

INVESTIGATIONS
- ECG
- CXR
- Echocardiogram

MANAGEMENT
- Penicillin prophylaxis
- Diuretics
- Vasodilators: ACEI/ARB
- Treatment for atrial fibrillation:
~ betablockers
~ anticoagulation
- Balloon mitral valvuloplasty
- Cardiac surgery (when valvuloplasty is not possible