DISORDERS OF THE CARDIOVASCULAR SYSTEM PART 1 (AB) Flashcards
What is the most common cause of acquired heart disease in children?
Acute Rheumatic Fever (ARF)
What is the annual incidence of ARF in developing countries?
Exceeds 50 per 100
What region is ARF common in?
Southeast Asian countries
What bacterial organism causes ARF?
Group A beta-hemolytic streptococcus (GABHS)
What protein produced by GABHS is implicated in ARF?
Streptococcal M protein
What is the specific host marker seen in patients predisposed to ARF?
Alloantigen D8/17
What does Alloantigen D8/17 indicate?
Inherited susceptibility to ARF
What is the proposed mechanism of ARF pathogenesis?
Molecular mimicry between streptococcal antigens and human tissues
Which heart structures are affected by molecular mimicry in ARF?
Heart valves
Which brain area is implicated in ARF-related chorea?
Basal ganglia and caudate nucleus
Which immune components cross-react with human tissues in ARF?
Anti-streptococcal antibodies
What tissues do anti-streptococcal antibodies cross-react with?
Heart
What diagnostic criteria is used for ARF?
Jones Criteria (2015 update)
Name the 5 major manifestations in Jones Criteria.
Carditis
Polyarthritis
Erythema marginatum
Subcutaneous nodules
Chorea
Name 3 minor clinical manifestations in ARF.
Arthralgia
FEVER
Name 2 laboratory minor criteria in ARF.
- Elevated acute phase reactants
- Erythrocyte sedimentation rate
- C-reactive protein - Prolonged P-R interval
- Presence of 1st degree AV block
What evidence supports a recent Group A Streptococcal infection?
Positive throat culture
What is required to diagnose an initial attack of ARF?
2 major or 1 major + 2 minor criteria + evidence of recent GAS infection
What is required to diagnose a recurrent attack of ARF?
2 major or
1 major + 2 minor or
3 minor criteria + evidence of recent GAS infection
What population has a higher cutoff for ESR and fever in Jones Criteria?
Low risk populations (developed countries)
In moderate/high-risk populations
what type of arthritis counts as major criterion?
Monoarthritis (single joint), or Polyarthralgia
What is the most common major manifestation of ARF?
Migratory Polyarthritis
Which joints are most commonly affected in migratory polyarthritis?
Knees
What characterizes ARF arthritis?
Hot
What is the second most common major manifestation of ARF?
Carditis
What is subclinical carditis?
Valvulitis detected only by echocardiography
What defines clinical carditis?
Carditis with audible valvulitis murmur
What percentage of ARF cases have carditis?
50-60%
What is pancarditis?
Inflammation of all heart layers: endocardium
What type of murmur is heard with mitral insufficiency in ARF?
High-pitched apical holosystolic murmur radiating to axilla
What type of murmur is heard with aortic insufficiency in ARF?
High-pitched decrescendo diastolic murmur at the left sternal border
What is the hallmark of rheumatic carditis?
Endocarditis/valvulitis
Which valves are most commonly affected in ARF?
Mitral and Aortic valves
Which side of the heart is more commonly involved in ARF?
Left side
What does mitral stenosis typically result from?
Chronic inflammatory damage years after ARF
What is the most serious manifestation of ARF?
Carditis
What percentage of ARF patients develop chorea?
10-15%
What is the pathogenesis of chorea in ARF?
Autoimmune attack on basal ganglia and caudate nuclei
Do ASO titers remain elevated in patients with chorea?
No
What is Milkmaid’s Grip?
Irregular contractions and relaxations of finger muscles when squeezing the examiner’s finger
What is the Spoon & Pronation test for chorea?
Patient extends hands showing spooning of fingers and tendency to pronate
What is Wormian Darting Tongue?
Involuntary darting movements of tongue on protrusion
What type of rash occurs in ARF?
Erythema marginatum
What are the characteristics of erythema marginatum?
Serpiginous
What percentage of ARF patients develop erythema marginatum?
0.01
Where are subcutaneous nodules typically found?
Extensor surfaces: knees
What size are ARF subcutaneous nodules?
0.5-2 cm
Are ARF subcutaneous nodules tender?
No
What defines chronic active carditis in ARF?
Ongoing inflammation lasting more than 6 months with persistent symptoms and elevated acute phase reactants
What is the most common valvular lesion in ARF?
Mitral regurgitation
What is the typical age for onset of mitral stenosis after ARF?
Years to decades after initial attack
What cardiac findings are seen in massive pericardial effusion from ARF?
Low voltage QRS
What is the classic auscultatory finding for mitral regurgitation in ARF?
Holosystolic murmur at the apex
What is the classic auscultatory finding for aortic regurgitation in ARF?
Decrescendo diastolic murmur at left sternal border
What is a key feature distinguishing arthritis in low vs high risk populations?
Low risk = Polyarthritis; High risk = Monoarthritis or Polyarthralgia
What is the common presentation of ARF in low-risk populations?
Polyarthritis involving multiple joints
What is the common presentation of ARF in high-risk populations?
Monoarthritis or Polyarthralgia
What is the cutoff fever for low-risk populations in ARF?
> 38.5°C
What is the cutoff fever for moderate/high-risk populations in ARF?
> 38°C
What is the recommended secondary prophylaxis for ARF?
Benzathine penicillin
What is the most characteristic component of rheumatic carditis?
Endocarditis/valvulitis involving AV and semilunar valves
Which population group has earlier onset and faster progression to stenosis in ARF?
Developing countries
Why is echocardiography important in ARF diagnosis?
Detects subclinical carditis especially in young children
What is the pathognomonic finding for chorea in ARF?
Autoimmune attack on basal ganglia and caudate nuclei
What clinical maneuver checks for chorea in the fingers?
Milkmaid’s grip
What happens to chorea movements during sleep?
They disappear
What is the significance of poor school performance in a child with ARF?
May be due to subtle chorea
What type of arthritis is unusual in ARF?
Monoarticular arthritis (except in high-risk populations)
Which acute phase reactants are elevated in ARF?
ESR and CRP
What is the most common cause of recurrent ARF?
Non-compliance with secondary prophylaxis
What defines sleeping tachycardia in ARF?
Heart rate >100 bpm during sleep
What is the usual duration of acute rheumatic activity?
<3 months
What are the acute phase reactants elevated in Acute Rheumatic Fever?
ESR and CRP
What imaging modalities are used for evaluating Acute Rheumatic Fever?
15-lead ECG, Chest X-ray (CXR), 2D Echocardiogram
What are the laboratory tests used to detect antecedent streptococcal infection in Acute Rheumatic Fever?
Throat culture, Rapid Streptococcal Antigen Detection Test, Streptococcal Antibody Test (ASO titer and anti-Dnase B)
What percentage of Acute Rheumatic Fever patients have positive throat cultures?
0.25
What is the significance of a positive ASO titer in Acute Rheumatic Fever?
Indicates recent streptococcal infection; titers peak 3-4 weeks after infection and remain elevated for 2-3 months
What is the threshold for a positive ASO titer in adults and children?
Adults: 250 Todd units; Children: 330 Todd units
What are the threshold values for Anti-Dnase B titers in adults and children?
Adults: 120 Todd units; Children: 240 Todd units
What are the main goals of Acute Rheumatic Fever management?
- Anti-infective therapy, 2. Anti-inflammatory therapy, 3. Long-term prevention of recurrent attacks
What is the drug of choice for eradicating streptococcal infection in Acute Rheumatic Fever?
Penicillin
What antibiotics can be used if the patient is allergic to penicillin?
Erythromycin (Macrolide)
What is the recommended duration of antibiotic therapy for streptococcal eradication in Acute Rheumatic Fever?
Minimum of 10 days
What is the first-line anti-inflammatory drug for polyarthritis or mild carditis in Acute Rheumatic Fever?
Aspirin
What is the loading dose of aspirin in Acute Rheumatic Fever?
50-70 mg/kg/day QID for 3-5 days
How is aspirin tapered in Acute Rheumatic Fever management?
After initial high dose, 50 mg/kg/day QID for 2-3 weeks, then 25 mg/kg/day QID for 2-4 weeks with gradual weekly taper
When are corticosteroids indicated in Acute Rheumatic Fever?
Moderate to severe carditis or heart failure, unresponsive to aspirin
What is the typical corticosteroid dose for Acute Rheumatic Fever?
Prednisone 1-2 mg/kg/day QID (max 80 mg/day) for 2-3 weeks, then taper over 2-3 weeks
What is the purpose of secondary prophylaxis in Acute Rheumatic Fever?
To prevent recurrent streptococcal infections and recurrent attacks of Acute Rheumatic Fever
What are the options for secondary prophylaxis in Acute Rheumatic Fever?
Penicillin G benzathine (IM), Penicillin V (oral), Sulfadiazine, Sulfisoxazole
What is the preferred route of prophylaxis in Acute Rheumatic Fever?
Intramuscular (IM) due to better compliance
In the Philippines, how often is Penicillin G benzathine given for secondary prophylaxis?
Every 21 days
What is the recommended duration of prophylaxis for patients with rheumatic fever without carditis?
5 years or until 21 years old, whichever is longer
What is the recommended duration of prophylaxis for patients with rheumatic fever with carditis but no residual heart disease?
10 years or until 21 years old, whichever is longer
What is the recommended duration of prophylaxis for patients with rheumatic fever with carditis and residual heart disease?
10 years or until 40 years old, sometimes lifelong
What is the dose of Benzathine Penicillin for patients ≤60 lbs (27 kg)?
600,000 units
What is the dose of Benzathine Penicillin for patients >60 lbs (27 kg)?
1.2 million units
What is the bed rest recommendation for Acute Rheumatic Fever?
4-6 weeks, especially with carditis
What medication is used to manage chorea in Acute Rheumatic Fever?
Phenobarbital (16-32 mg every 6-8 hours PO)
What are alternative drugs for chorea if Phenobarbital is ineffective?
Haloperidol or Chlorpromazine
What medications are used to manage heart failure in Acute Rheumatic Fever?
Digoxin, Diuretics, ACE inhibitors
What are common valvular lesions in Rheumatic Heart Disease?
Mitral regurgitation, Mitral stenosis, Aortic regurgitation, Tricuspid regurgitation
What is the key to preventing permanent cardiac damage in Acute Rheumatic Fever?
Careful diagnosis, appropriate management, patient/guardian education, and prevention of recurrent attacks
What level of prevention involves improving living conditions to prevent streptococcal infections?
Primordial prevention
What level of prevention involves treating streptococcal sore throat to prevent Acute Rheumatic Fever?
Primary prevention
What level of prevention involves long-term antibiotic prophylaxis to prevent recurrent Acute Rheumatic Fever?
Secondary prevention
What level of prevention involves early identification and management of heart failure and other complications?
Tertiary prevention
What is the prognosis for patients with carditis on initial attack if compliant with treatment?
50-70% recover with no residual heart disease
Which patients are at highest risk for developing residual heart disease with recurrent Acute Rheumatic Fever?
Patients with initial carditis
What condition is the long-term sequela of Acute Rheumatic Fever?
Rheumatic Heart Disease
What factors contribute to the development of Acute Rheumatic Fever?
Genetic susceptibility, overcrowding, poor hygiene, exposure to Group A beta-hemolytic streptococci
What are the primary ways to prevent recurrent episodes of Acute Rheumatic Fever?
Long-term penicillin prophylaxis, patient education, regular follow-ups
Which heart valves are most commonly affected in Rheumatic Heart Disease?
Mitral and aortic valves
