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Case 3: Anat. Path. Infective Endocarditis, image The image above is…
Case 3: Anat. Path. Infective Endocarditis
Endocardium
Define Endocardium
Endocardium is the inner surface lining of the heart including the Cardiac Valves and the Chordae Tendinea
Infective Endocarditis
Define Infective Endocarditis
Infective endocarditis is the colonization/infection of the endocardium of the heart by infective organisms resulting in the formation of bulky, friable vegetations
The leaflets of the infected endocardium have bulky, friable vegetations
Vegetations are located on the lines of Valvular Closure
Aetiology
Outline the Aetiology of Infective Endocarditis
Infective endocarditis may be caused by many different organisms
Many of these organisms originate from the normal flora of the body surfaces liberated into the blood stream in many different ways
In order to survive in the Bloodstream these organisms need to resistant to the killing action of the Antibodies and Complement
List the Causes of Infective Endocarditis
Infective Endocarditis may be caused by the following organisms
Bacteria
Low Virulence
High Virulence
Fungi
Fungal Endocarditis can occur in situations of IV Drug Use and extreme Immunosuppression
Rarely Viruses
Origin of Infection
List the Origins of infection (Infective Endocarditis)
Poor Dental Hygiene
Systemic Sepsis
Localized Suppurative Inflammation
Long-term Haemodialysis
Recent Surgery or Non-Surgical Invasive Procedure
IV Drug Use
Contributory Conditions
List the Contributory Conditions of Infective Endocarditis
Host factors that are Contributory Conditions:
Immunodeficiency
Neutropaenias
Malignancy
Intracardiac Factors
List the Intracardiac Factors (Infective Endocarditis)
Chronic Rheumatic Heart Disease
Congenital Cardiac Anomalies
Mitral Valve Prolapse
Degenerative Calcific Stenosis
Bicuspid Aortic Valves
Prosthetic Valves
Indwelling catheters
Classification of Bacterial Infective Endocarditis
Outline the Classification of Bacterial Infective Endocarditis
Bacterial Infective Endocarditis is classified into 2 categories:
Acute Bacterial Infective Endocarditis
Subacute Bacterial Infective Endocarditis (SBE)
This classification reflects the range of disease Severity and Tempo
Which are determined by the Virulence of the infecting microorganism and the presence of underlying Cardiac Diseases
Acute Bacterial Infective Endocarditis
Outline Acute Bacterial Infective Endocarditis
Acute Bacterial Infective Endocarditis is caused by Highly Virulent organism such as Staphylococcus aureus
It can affect Normal valves or Damaged valves
It is a highly destructive disease process
With more than 90% mortality if disease is not rapidly treated
And a 50% mortality even after intensive treatment
Effects of Acute Bacterial Infective Endocarditis
Outline the effects of Acute Bacterial Infective Endocarditis
Vegetations
Vegetations are located at line of Valve Closure
And at the edges of the defect
Vegetations
Vegetations are large and friable and are more than 5 mm in size
Vegetations can easily dislodge and embolise
Fibrin, proliferating bacteria and Suppurative Inflammation
Abscess Formation
Abscess Formation results in:
Valve destruction
Cardiac/Major artery abscesses
Arrhythmias
Rupture of Papillary Muscles or Chordae Tendinea
Subacute Bacterial Infective Endocarditis
Outline Subacute Bacterial Infective Endocarditis
Subacute Bacterial Infective Endocarditis is caused by Low Virulence Organisms such as Streptococci viridans group of Bacteria
Streptococci viridans form a major part of the normal microbial flora of the Oropharynx
Subacute Bacterial Infective Endocarditis can affect the following
Damaged Valves
Valves may have been damaged by Rheumatic valvulitis or previous Infective Endocarditis
Intracardiac Congenital Defects or Iatrogenic Defects
Such as Atrial Septal Defect, Ventricular Septal Defect, Aorta overrides Ventricular Septal Defect
Prosthetic Valves
Subacute Bacterial Infective Endocarditis has a protracted course over a period of months
With a fair response to antibiotic
And a Low mortality
Effects of Subacute Bacterial Infective Endocarditis
Outline the Effects of Subacute Bacterial Infective Endocarditis
Vegetations
Vegetations are located at the Valve Closure
Vegetations are located at the edge of defects
Vegetations
Vegetations are Large, Friable BUT smaller than vegetations of Acute Bacterial Infective Endocarditis
Vegetations may easily dislodge and embolise
Fibrin and Bacteria
Valve Damage
Picture in the lecture
Caption:
Large vegetations growing on Chordae Tendinea and extending on to Papillary Muscles
Vegetations will also induce Thrombosis by alteration of Virchow's triad: Change in vessel wall and subsequent Change in blood flow
In Upper image there is a Super added Thrombus attached to the vegetations
Images in Lecture
Name the biological effects on the image and the cause of the biological effects
Image A
Endocarditis of the Mitral valve
Cause: Subacute Bacterial Infective Endocarditis by Streptococci viridans
Image B
Endocarditis of the Aortic Valve
Cause: Acute Bacterial Infective Endocarditis by Staphylococcus aureus
With Cusp destruction & Ring abscesses
Image C
Histologic appearance of vegetation of Infective endocarditis with Acute Inflammatory cells and Fibrin
Bacterial organism are demonstrated by tissue gram stain
Image D
Healed Infective endocarditis demonstrating mitral valvular destruction
BUT no active vegetations
1 more item...
Clinical Features of Infective Endocarditis
List the Feature of the types of Infective Endocarditis
Acute IE
Rapid onset, Fever, Rigors and Malaise
Chest pain, Shortness of Breath and Rapid Fatigue
Sudden Death
Subacute IE
Slower onset compared to Acute IE
Fever, Malaise, Fatigue and Loss of Weight
Others
Clubbing
Murmurs
Diagnostic Criteria
Outline the diagnostic criteria for Infective Endocarditis
The diagnostic criteria for Infective endocarditis is the Duke Criteria
The Duke Criteria is made up of the:
Clinical Criteria
Pathological Criteria
Duke Criteria: Clinical Criteria
Outline the Duke Criteria: Clinical Criteria
According to the Duke Criteria: Clinical Criteria for a diagnosis there needs to be:
2 Major Criteria met or
1 Major and 3 Minor Criteria met or
5 Minor Criteria met
Outline the Major Criteria in the Duke Criteria: Clinical Criteria
The Major Criteria of the Duke Criteria are:
Positive Blood culture(s) indicating characteristic organisms or the persistence of an unusual organism
Echocardiographic Findings, including Valve-related or Implant-related mass or abscess, Or Partial separation of Artificial Valve
New Valvular Regurgitation
Minor Criteria in the Duke Criteria: Clinical Criteria
Outline the Minor Criteria in the Duke Criteria: Clinical Criteria
The Minor Criteria of the Duke Criteria are:
Predisposing heart lesion or Intravenous Drug Use
Fever
Vascular Lesions such as: Petechiae, Splinter Haemorrhages, Septic Infarcts, Janeway Lesions
Immunological phenomena such as: Glomerulonephritis, Roth Spots, Osler nodes
Single culture showing uncharacteristic organism
Echocardiographic findings consistent with BUT NOT diagnostic of Endocarditis including New Valvular regurgitation, or Pericarditis
Duke Criteria: Pathologic Criteria
Outline the Duke Criteria: Pathologic Criteria
The Pathologic Criteria for Duke Criteria are:
Microorganism demonstration by Culture or Histology in vegetation
Histologic Confirmation of an active endocarditis in a Vegetation or Intracardiac Abscess
Complications of Infective Endocarditis
List the complications of Infective Endocarditis
Complications of Infective Endocarditis
Ring abscess
Systemic Embolisation
Valve or Chord Rupture
Septicaemia
Immune Complex Formation
Outline the complications of Infective Endocarditis
Complications of Infective Endocarditis
Ring Abscess
Ring abscess which erodes into underlying Myocardium
Systemic Embolisation for example:
Brain Abscess, Splenic/Renal Infarctiotion with Septic Infarcts
Right side- Pulmonary Septic Infarcts
Valve/Chord rupture
Septicaemia
Immune Complex Formation
Outline the Complications and Clinical Manifestations of Infective Endocarditis
Cerebral and Retinal Emboli
Bronchopneumonia
Pulmonary Infarct (Tricuspid valve endocarditis)
Myocarditis
Splenomegaly with Infarcts
Renal Infarcts and Glomerulonephritis
Anaemia
Haematuria
Clubbing
Splinter Haemorrhages
Endocarditis in Unusual Hosts
List the Unusual Hosts in which Endocarditis may present
Endocarditis may also present in unusual hosts such as:
Patients with Prosthetic Heart valves
The Elderly
Drug Addicts
Outline the Presence of Endocarditis in Unusual Hosts such as Patients with Prosthetic Heart Valves
Endocarditis may also present in unusual hosts such as:
Patients with Prosthetic Heart valves
2-3% of patients with Artificial Heart Valves develop endocarditis
Staphylococci accounts for at least 50% of these Cases
Initial presenting symptom is Post-Operative Fever
If Wound sepsis, Lung and UTI are excluded consider Valve Endocarditis
Blood cultures are essential in the diagnosis of Endocarditis secondary to Prosthetic Heart Valves
Mortality rate of endocarditis in patients with artificial heart vales is as high as 70%
The Elderly
Outline the Presence of Endocarditis in Unusual Hosts such as The Elderly
In the elderly, Calcific Valve disease is usually the underlying condition
Predisposing factors include:
UTI
Diabetes Mellitus
Tooth Extraction
Pressure Sores
Surgical procedures
Staphylococcus aureus is a frequent pathogen
Presenting signs may be masked by co-existing diseases
Drug Addicts
Outline the Presence of Endocarditis in Unusual Hosts such as Drug Addicts
Most common pathogens are:
Staphylococcus aureus
Staphylococcus epidermis
Candida
The Valves are usually normal BUT can undergo possible damage by foreign material in the drugs
Right-sided valves such as the Tricuspid Valves and Pulmonary Semi-Lunar Valve are usually involved are usually involved
Often associated with large vegetation that may Dislodge and Embolise in the Lungs
Management of Infective Endocarditis
Outline the Management of Infective Endocarditis
Once diagnosis of Infective Endocarditis is considered: 2 investigations are essential:
Echocardiography that is Transthoracic or Transesophageal
Blood cultures - multiple daily
The continued management is as follows:
Identify causative organism on Multiple Chemical Sensitivity (MCS)
Prevent further skin or airborne bacterial contamination of blood samples
Due to episodic release of bacteria, daily cultures are required at least 1 to 3 times a day
Appropriate intravenous antibiotics
Failure to recover causative organisms may be due to:
Walling off of bacteria by Fibrin within vegetation
Antibiotic treatment administered before Blood Culture was taken
Infection with slow-growing or difficult-to culture organism
The image above is of a mechanical Artificial Heart valve with large vegetations occluding the valve mechanism
These vegetations impair valvular outflow
The image above is of a Calcified Heart Valve in elder people due to Endocarditis
