Cardiac Path 6 (RHD/Endocarditis) Flashcards
What condition?
- A systemic, immunologically mediated disease related to a Streptococcal infection
- A delayed non-suppurative sequelae to an URI with Group A. beta-hemolytic Streptococcus.
Acute Rheumatic Fever
What condition?
Typically occurs ~2 weeks after a Strept throat infection.
Acute Rheumatic Fever
The following describes the immune rxn to which dz:
- The immune response elicited by the Strep antigens provides the body w/ a defense mechanism against Strept. Pyogenes
- @ the same time, the immune rxn damages the connective tissue of the heart and several other organs and tissues.
- The antibodies against the Strept antigens may cross-react with similar antigens found in the heart.
Acute Rheumatic fever
The following antibodies develop in all pts w/ ________:
Antibodies to the Streptococcal antigen O, called Antistreptolysin O (ASLO or ASO)
Rheumatic Fever
The following describes the susceptibility of which condition?
- Principally a disease of children (median age: 9-11y/o)
- can occur in adults
- No differences in susceptibility related to sex, race, or ethnicity
- Present rate in the U.S.= ~2 per 100,000
Acute Rheumatic Fever
Is Acute Rheumatic fever still prevalent in the US today?
in first 1/2 of 20th century- RF was almost epidemic in US but has decreased dramatically since due to abx and improved socioeconomic conditions
Is Acute Rheumatic fever still prevalent in the world today?
Still the leading cause of death of heart dz in ppl b/w 5-25 years worldwide
What disease involves the following
- the heart
- the joints
- subcutaneous CT of the skin
- blood vessels
- occasionally the brain
Rheumatic Heart Disease
What is a major feature and complication of Acute Rheumatic Fever?
Rheumatic Heart Disease
What is the chief cause of heart disease in persons under the age of 50 still today?
Rheumatic Heart Disease
The pathology of what disease is characterized by non-bacterial, sterile, inflammatory lesions and granulomas throughout the connective tissue of the body.
Rheumatic Heart Disease
What is the characteristic heart pathology in RHD?
RHD causes a Pancarditis, involving all three layers of the heart.
- Pericarditis
- Myocarditis
- Endocarditis
Which disease?
Recognized clinically by a pericardial friction rub and in severe cases can lead to an adhesive pericarditis.
Rheumatic Pericarditis
(“Bread and Butter” Pericarditis)
The following is pathology of which disease?
- Myocarditis:
- Usually heart is dilated
- Aschoff Bodies (aggregates of lymphocytes and macrophages around a central zone of fibrinoid necrosis) w/in the myocardium–> w/ time it assumes a granulomatous appearance–> eventually replaced by a scar
Rheumatic heart disease
Which pathology of RHD is responsible for the majority of deaths in the acute phase due to conduction system fibrosis.
Myocarditis
The following is pathology of what conditon?
- Endocarditis: the most prominent changes are seen on the valves of the left heart.
* This valvulitis begins with inflammation of the valve surfaces, leading to an ulceration.
Pathology of RHD:
What is characteristic about the heart valve ulcerations with time?
***This was a prior board question***
The surface defects are covered with fibrin thrombi, which progressively grow and assume the form of larger vegetations along the lines of closure of the valve leaflets.
Characteristics about the ____________ of RHD:
- There are no bacteria within the ___________
- Ongoing inflammation inside the valves leads to destruction, followed by fibrous scarring–> causes valve deformities.
- The chordae tendinae inserting into the mitral valve are typically shortened and thickened and becomes fused to one another (“Fish-Mouth Stenosis”)
Vegetations
Which side of the heart is most affected by RHD?
The left
How does the valve changes in RHD affect the heart?
- deformity of the leaflets + the changes in the chordae= the valves become incompetent and do not close completely during systole (valvular insufficiency).
- Orifice may also become stenotic
The following is the end result of valve insufficiencies in which disease?
- Mitral Valve Insufficiency: causes reflux of blood across the mitral valve from the L ventricle–> L atrium during systole.
- Aortic Insufficiency: blood flows back from aorta to LV during diastole–> leads to LVH and dilation.
RHD
End result of what?
- Mitral Stenosis–> Ultimately leads to Cor Pulmonale (R heart failure)
- Aortic Stenosis (Impedes the blood flow from the LV into the aorta)
End result of the valve stenoses (pathology of RHD)
___________ causes:
- stagnation of blood in the L atrium, w/ possible clot formation–> later transmitted into the pulmonary circulation and RV
- This leads to left atrial, pulmonary, and right ventricular HTN–> all leading to Cor Pulmonale (right heart failure).
Mitral stenosis (an end result of valve stenoses in RHD)
The following is the end result of what?
- To overcome the increased resistance at its outflow tract, the LV increases the ejection pressure, causing left ventricular hypertrophy
- When the heart fails, the back pressure of the blood is transmitted from the LV to left atrium and into the pulmonary circulation–> again resulting in Cor Pulmonale
The end result of aortic stenosis (pathology of RHD)
**The _______ is responsible for the most deaths after the acute phase (of RHD)**
endocarditis
The following are major extracardiac findings in _______:
- Polyarthritis (migratory arthritis- lasts 1-4 wks)
- Subcutaneous Nodules- Firm, non-tender nodules, urually recurrent. Overlies extensor tendons of the extremities (MC in children)
- Erythema Marginatum (migratory maculopapular rash on trunk and proximal etremities; sparing face)
- Sydenhams Chorea
Extracardiac findings in RHD
What extracardiac finding of RHD is described by the following:
A neurologic disorder characterized by:
- Involuntary movements that are continuous, non-repetitive, purposeless, jerky movements of the limbs, trunk and face muscles.
- Causes impaired speech and gait
Sydenhams Chorea
The following are the characteristic lab findings of what disease?
- Sxs occur 2-3 weeks after strep throat–> culture is usually neg by this time
- Increasing serum antibodies to Group A strep antigens (ASO titers)
- Increased sedimentation rate
- Leukocytosis
- Positive C-reactive protein
Lab findings of RHD
*Positive ASO titers + increased sedimentation rate + pos CRP= good justification for dx of RHD
What lab finding provides concrete evidence of a recent infection with St. pyogenes and is a laboratory finding in RHD?
Increasing titers of serum antibodies to Group A Strept antigens (ASO titers)
What disease?
Clinical diagnosis is based on “Jones Criteria” - subclassified into both major and minor criteria needed for dx
Dx of RHD
The following is criteria for what?
- Pancarditis
- Polyarthritis
- Sydenhams Chorea
- Subcutaneous Nodules
- Erythema Marginatum
MAJOR critera of “Jones Criteria” which is used to dx RHD
The following is criteria for what?
- A previous history of Rheumatic Fever
- Fever
- Arthragias
- EKG signs of heart damage
- Evidence of prior Strept infection (ASO titers, C-reactive protein, increased sed. rate)
MINOR critera of “Jones Criteria” which is used to dx RHD
When is a diagnosis of RHD made using “Jones Criteria”?
The clinical diagnosis is made when 2 major OR 1 major + 2 minor criteria are fulfilled
Complications of what disease?
- secondary bacterial endocarditis b/c the thrombotic vegetations on valve can become infected (MC complication)
- Valvular vegetations–> give rise to emboli, which can cause infarcts of the brain, kidney or the extremities.
RHD
Can RHD be cured?
No
Most of the lesions are irreversible and can only be tx w/ surgery
Treatment of which dz?
- The calcified, deformed valves can be excised and replaced by artificial valves
- Prompt tx of Strep throat w/ abx prevents the initial attack of RF and a recurrence of the disease.
RHD
What is the #1 complication of RHD?
Vegetations on the valve can be come secondarily infected w/ bacteria
The following are causes of __________:
- Bacteria (MC= pyogenic bacteria)
- Fungi
- Rickettsia
- Chlamydiae
Infective Endocarditis
How is Infective Endocarditis is classified clinically?
- Acute (ABE)
- Subacute (SBE)
Characteristics of what?
- A highly destructive infection of the valves.
- Frequently of a previously normal heart valve.
- May also be seen in prosthetic heart valves.
- Usually due to highly virulent organisms (i.e. Staph aureus or Gram neg)–> can lead to death w/in days, despite abx
- Develops in the course of intense bacteremia.
- Produces necrotizing, valvular lesions with chance of perforation of the valve
Acute Bacterial Endocarditis (ABE)
Characteristics of____:
- slower
- less virulent disease
- caused by organisms of less virulence (i.e. St. viridans)
- Can cause infection in previously abnormal heart valves.
- longer course: weeks to months–> most pts recover after appropriate abx therapy
- The lesions are less destructive and show evidence of healing.
Subacute Bacterial Endocarditis (SBE)
Pre-existing Causes for_______:
1. Artificial (prosthetic) valves
2. Congenital defects
3. Degenerative calcified valvular stenosis
4. Bicuspid aortic valves
5. Myxomatous mitral valve (mitral valve prolapse)
***All are red on the slide*****
Endocarditis
What organism is responsible for the most cases of Prosthetic Valve Endocarditis?
Staph epidermidis
Causative agents of _____:
1. Staph epidermidis (Most Common)
- Enterococci
- Gram neg bacteria
- Fungi
Endocarditis
Clinical Effects of ________:
- Fever (present in almost all pts)
- In ABE: quick onset + chills, night sweats and weakness
- Murmur
- Embolization
- SBE: low grade fever + fatigue and flu-like sxs
Infective Endocarditis
Complications of Endocarditis: What are complications of the __________?
- _________episodes (in 1/3 of pts): includes retinal (blindness), coronary (MI), cerebral (strokes), splenic, pulmonary (from IVDA’s) and renal (from renal abscesses to glomerulonephritis) complications in the form of infarcts or abscesses
- CHF due to valve destruction, ruptured chordae tendonae, and myocardial muscle abscesses or MI’s may also complicate the course.
Septic emboli
Dx of what condition is based on:
- clinical presentation of the pt, or the common complications of this condition, or ultrasound of the vegetations
- positive blood cultures are required for conformation.
- With repeated blood samples, positive blood cultures can be obtained in about 90% of cases.
Diagnosis of Endocarditis
- Bacteremia from cellulitis or phlebitis at the injection site or drug contamination is the pathogenesis of this type of endocarditis.
- The Tricuspid valve is infected in over 50% of pts w/ signs and symptoms of pulmonary emboli and abscesses leading to Pneumonia.
Endocarditis in IVDA’s
St. aureus is responsible for 50-60% of cases, followed by Strept. species and Candida (or any skin commensal)
Endocarditis in IVDA’s
