Cardiac pathology Part 2 Endocarditis & cardiomyopathies Flashcards
How does Streptococci viridians cause endocarditis? (aka describe the pathogenesis)
It has low virulence so it can only infect valves that have been damaged previously. It grows vegetations (fibrin & platelets) on valves which then trap more bacteria (because the state of bacteremia) causing further inflammation.
How would you treat bacterial endocarditis in a patient with +ve blood cultures & a history of Chronic rheumatic heart disease?
Patient will have damaged valves from the CRHD,
Causal agent: S. viridians
Rx: prophylactic antibiotics
What is the most common cause of bacterial endocarditis (excluding IV drug abusers)
S. viridians
What is the most common cause of bacterial endocarditis in patients who abuse IV drugs?
S. aureus
How does S. aureus cause endocarditis? (aka describe the pathogenesis)
It is very virulent so it is able to infect healthy valves (especially the tricuspid valve) it causes large vegetations which destroy the valves (acute endocarditis)
How does S. epidermidis cause endocarditis?
It infects prostatic valves
Endocarditis of prostatic valves is due to which organism?
S. epidermidis
What causes endocarditis in patients with colorectal cancer?
S. bovis
How does S. bovis cause endocarditis?
It infects the heart valves of patients with colorectal cancer
What are the HACEK organisms that cause endocarditis with -ve blood cultures?
Hemophilus
Actinobacillus
Cardio bacterium
Eikenella
Kingella
Hemophilus
Actinobacillus
Cardio bacterium
Eikenella
Kingella
Cause endocarditis with which unique feature?
Endocarditis with -ve blood cultures
What are the signs of endocarditis (common to all)
- Fever
- Janeway lesions (painless palmar/soles)
- Osler’s nodes (painful fingers)
- Splinter hemorrhages.
- Roth spots (embolization)
- Anemia of chronic disease
A 54-year-old male presents to the emergency department complaining of fever, fatigue, and shortness of breath that have progressively worsened over the past two weeks. He has a history of intravenous drug use, specifically heroin, but hasn’t used intravenously for the past six months. On physical examination, the patient appears ill and febrile with a temperature of 39.2°C (102.6°F), heart rate of 110 beats per minute, and blood pressure of 120/80 mmHg. Auscultation reveals a new-onset systolic murmur.
Bacterial endocarditis due to an infection with S. aureus
A 62-year-old male with a history of mitral valve prolapse and prior dental procedures presents to the clinic with a complaint of fatigue, low-grade fever, and weight loss over the past few weeks. He reports experiencing episodes of chills and night sweats. On examination, there are multiple small petechiae over the conjunctiva and nail beds. Auscultation reveals a new-onset diastolic murmur.
Bacterial endocarditis due to S. viridians
A 45-year-old male with a history of intravenous drug use presents to the emergency department with a chief complaint of fever, fatigue, and a new-onset heart murmur. He also reports night sweats and weight loss over the past month. On examination, multiple painful, erythematous nodules are found on his fingers. Laboratory tests reveal elevated inflammatory markers and blood cultures are ordered.
Bacterial endocarditis due to S. aureus
What are the lab values to look out for when dealing with bacterial endocarditis?
- +ve blood cultures (except HACEK)
- Anemia of chronic disease (low Hb, TIBC, serum Fe, O2 saturation & high ferritin)
Describe the pathogenesis of Non-Bacterial Thrombotic Endocarditis
It causes sterile vegetations that appear during states of hypercoagulability or adenocarcinomas
Where do the vegetations arise in Non-Bacterial Thrombotic Endocarditis? What is a complication as a result of this?
Usually the mitral valve along the lines of closure which inhibit valve closure resulting in mitral regurgitation
Describe the pathogenesis of Libman-Sacks endocarditis?
It is associated with SLE. It forms sterile vegetations on the surface/underside of the mitral valve resulting in mitral regurgitation/insufficiency
A 55-year-old female with a history of advanced ovarian cancer presents to the clinic with complaints of headache, fatigue, and recurrent episodes of transient ischemic attacks (TIAs). The patient reports experiencing small, painful reddish-purple lesions on her palms and soles. Physical examination reveals a new-onset mitral valve murmur and bilateral retinal emboli.
non-bacterial thrombotic endocarditis due to ovarian cancer.
A 35-year-old female with a known history of systemic lupus erythematosus (SLE) presents to the clinic with complaints of fatigue, shortness of breath, and occasional chest pain. She reports a low-grade fever over the past few weeks and has noticed swelling in her hands and feet. On examination, there is a malar rash, bilateral joint tenderness, and a high-pitched diastolic murmur at the apex of her heart.
Libman-sacks non-bacterial endocarditis
Massive hypertrophy of the left ventricle due to an AUTO DOM mutation in the sarcomere proteins
Describes what type of cardiomyopathy?
Hypertrophic cardiomyopathy
What are the signs of hypertrophic cardiomyopathy?
Decreased cardiac output with diastolic dysfunction (poor ventricular filling) due to the hypertrophy of the left ventricle
What is the major cause of death due to hypertrophic cardiomyopathy?
It can cause sudden death due to ventricular arrythmia, it can even happen in young athletes!
What are the signs of hypertrophic cardiomyopathy?
Syncope with exercise
What are the changes to the aorta in patients with hypertrophic cardiomyopathy?
Subaortic hypertrophy of the ventricular septum results in functional aortic stenosis
What would a biopsy of a patient with hypertrophic cardiomyopathy cause?
Myofiber hypertrophy with disarray
A 45-year-old male presents to the clinic with complaints of shortness of breath, chest pain, and lightheadedness during physical activity. He mentions a family history of sudden cardiac death and recalls episodes of palpitations. On examination, his blood pressure is normal, but a harsh systolic murmur is heard best at the left lower sternal border that increases with the Valsalva maneuver and decreases with squatting
Hypertrophic cardiomyopathy causing functional aortic stenosis
Describe what dilated cardiomyopathy is?
The most common cardiomyopathy, it’s when the heart wall is weak it is unable to pump blood out effectively (Systolic dysfunction).
As a result there is less filling & stretching of the heart chambers leading to biventricular heart failure & complications such as mitral/tricuspid valve regurgitation & arrythmia (stretched conduction systems)
What are the causes of Dilated cardio myopathy?
Most common
Other
Most common:
- AUTO DOM mutations effecting the myocardium
Other:
- Infections with Coxsackie A or B (myocarditis)
- Alcohol abuse
- Pregnancy (late preg or post birth)
- Drugs (Doxorubicin & cocaine)
How do you treat dilated cardiomyopathy?
Heart transplant
A 55-year-old female comes to the emergency room complaining of worsening shortness of breath and fatigue for the past few months. She reports having difficulty doing her daily activities, such as climbing stairs or walking short distances, without feeling extremely tired. She also experienced sudden weight gain and noticed swelling in her ankles and legs. On examination, her blood pressure is low, heart rate is elevated, and her jugular veins are visibly distended. Auscultation reveals a rapid and irregular heartbeat, along with a third heart sound.
What’s the diagnosis & treatment?
Dilated cardiomyopathy & treatment is a heart transplant
What is restrictive cardiomyopathy?
There’s a decrease in ventricular endomyocardial compliance that restricts filling during diastole
What are the signs of restrictive cardiomyopathy?
- CHF (pulmonary edema/dyspnea)
- Low-voltage ECK with diminished QRSs amplitude (less filling)
- CHF (pulmonary edema/dyspnea)
- Low-voltage ECK with diminished QRSs amplitude (less filling)
Are signs of which type of cardiomyopathy?
Restrictive cardiomyopathy
What are the causes of restrictive cardiomyopathy?
Amyloidosis
Sarcoidosis
Endocardial fibroelastosis (children)
Loeffler syndrome
Hemochromatosis
Endocardial fibroelastosis (dense fibrosis & elastic tissue in endocardium children) can cause which cardiomyopathy?
Restrictive cardiomyopathy
What is a Myxoma?
A benign cardiac tumor (adults) made from mesenchymal cells. It has a gelatinous appearance (because of abundant ground substance)
A mesenchymal cardiac tumor with a gelatinous appearance. What’s the tumor? Why is it gelatinous?
A myxoma it’s gelatinous because of the abundant ground substance
What is the cause & signs of a Myoma?
usually caused by a pedunculated mass in the left atrium that obstructs the mitral valve resulting in symptoms like syncope
Syncope due to mitral valve obstruction - what’s the tumor?
Myxoma
What is a Rhabdomyoma?
A benign hamartoma more common in children. It usually manifests in the ventricle & it’s associated with a TB infection
Cardiac tumor associated with TB - What’s the tumor?
Rhabdomyoma
What are metastasis involving the heart? What other organs do they typically involve?
Metastasis tend to involve the pericardium which can result in pericardial effusion
Other organs involved are usually: skin/lymph, breast, & lungs
