USMLE Step 1: Cardiovascular
Pathology
Bacterial Endocarditis - ANS-Symptoms "FROM JANE"
- Fever (most common symptom)
- Roth's spots (round white spots on retina surrounded by hemorrhage
- Osler's nodes (tender raised lesions on finger or toe pads)
- Murmur (new onset)
- Janeway lesions (small, painless, erythematous lesions on palm or sole)
- Anemia
- Nail-bed hemorrhage
- Emboli
Diagnose using blood culture
Acute Bacterial Endocarditis: Staph aureus (high virulence). Large vegetations on
previously normal valves. Rapid onset.
Subacute Bacterial Endocarditis: Strep viridans (low virulence). Smaller vegetations
on congenitally abnormal or diseased valves. Sequelae of dental procedures. More
gradual onset.
Mitral valve is most frequently involved.
Tricuspid valve is associated with IV drug use ("don't try drugs"). Associated with
staph aureus, pseudomonas, and candida
Complications: chordae rupture, glomerulonephritis, suppurative pericarditis, emboli
Endocarditis may be nonbacterial secondary to malignancy, hypercoagulable state,
or lupus. Staph bovis is present in colon cancer. Staph epidermidis on prosthetic
valves.
\Cardiac tumors - ANS-1. Myxomas: most common primary cardiac tumor in adults.
90% occur in the atria (mostly left atrium). Myxomas are usually described as a "ball
valve" obstruction in the left atrium (associated with multiple syncopal episodes)
2. Rhabdomyomas: most frequent primary cardiac tumor in children (associated with
tuberous sclerosis).
Most common heart tumor is a metastasis (from melanoma, lymphoma)
\Compare and contrast transmural infarcts to subendocardial infarcts in terms of
necrosis, location, and ECG readings. - ANS-Transmural infarcts
, - increase necrosis
- Affects entire wall
- ST elevation on ECG, Q waves
Subendocardial infarcts
- ischemic necrosis of < 50% of ventricle wall
- Subendocardium especially vulnerable to ischemia
- ST depression on ECG
\How do you diagnose MI? - ANS-1. In the first 6 hours, ECG is gold standard
2. Cardiac troponin I rises after 4 hours and is elevated for 7-10 days. It is more
specific than other protein markers.
3. CK-MB is predominantly found in the myocardium but can also be released from
skeletal muscle. Useful in diagnosing reinfarction following acute MI because levels
return to normal after 48 hours.
4. ECG changes can include ST elevation (transmural infarct), ST depression
(subendocardial infarct), and pathologic Q waves (transmural infarct)
\Rheumatic Fever - ANS-"FEVERSS"
- Fever
- erythema marginatum
- valvular damage (vegetation and fibrosis)
- ESR increased
- Red hot joints (migratory polyarthritis)
- Subcutaneous nodules
- St. Vitus' dance (Sydenham's chorea)
Rheumatic fever is a consequence of pharyngeal infection with group A
Beta-hemolytic streptococci. Early death due to myocarditis. Late sequelae include
rheumatic heart disease which affects heart valves. High pressure heart valves are
affected the most (mitral>aortic>>tricuspid)
Early lesion is mitral valve regurgitation. Late lesion is mitral stenosis.
Associated with Aschoff bodies (granuloma with giant cells), Anitschkow's cells
(activated histiocytes), and elevated ASO titers
Immune mediated (type II hypersensitivity). Not a direct effect of bacteria. Antibodies
to M protein.
\Syphilitic heart disease - ANS-Tertiary syphilis disrupts the vasa vasorum of the
aorta with consequent atrophy of the vessel wall and dilation of the aorta and valve
ring. May see calcification of the aortic root and ascending aortic arch. It leads to the
"tree bark" appearance of the aorta.
Can result in aneurysm of the ascending aorta or aortic arch and aortic insufficiency.
\What are 3 types of arteriosclerosis? - ANS-1. Monckeberg medial calcific sclerosis
Pathology
Bacterial Endocarditis - ANS-Symptoms "FROM JANE"
- Fever (most common symptom)
- Roth's spots (round white spots on retina surrounded by hemorrhage
- Osler's nodes (tender raised lesions on finger or toe pads)
- Murmur (new onset)
- Janeway lesions (small, painless, erythematous lesions on palm or sole)
- Anemia
- Nail-bed hemorrhage
- Emboli
Diagnose using blood culture
Acute Bacterial Endocarditis: Staph aureus (high virulence). Large vegetations on
previously normal valves. Rapid onset.
Subacute Bacterial Endocarditis: Strep viridans (low virulence). Smaller vegetations
on congenitally abnormal or diseased valves. Sequelae of dental procedures. More
gradual onset.
Mitral valve is most frequently involved.
Tricuspid valve is associated with IV drug use ("don't try drugs"). Associated with
staph aureus, pseudomonas, and candida
Complications: chordae rupture, glomerulonephritis, suppurative pericarditis, emboli
Endocarditis may be nonbacterial secondary to malignancy, hypercoagulable state,
or lupus. Staph bovis is present in colon cancer. Staph epidermidis on prosthetic
valves.
\Cardiac tumors - ANS-1. Myxomas: most common primary cardiac tumor in adults.
90% occur in the atria (mostly left atrium). Myxomas are usually described as a "ball
valve" obstruction in the left atrium (associated with multiple syncopal episodes)
2. Rhabdomyomas: most frequent primary cardiac tumor in children (associated with
tuberous sclerosis).
Most common heart tumor is a metastasis (from melanoma, lymphoma)
\Compare and contrast transmural infarcts to subendocardial infarcts in terms of
necrosis, location, and ECG readings. - ANS-Transmural infarcts
, - increase necrosis
- Affects entire wall
- ST elevation on ECG, Q waves
Subendocardial infarcts
- ischemic necrosis of < 50% of ventricle wall
- Subendocardium especially vulnerable to ischemia
- ST depression on ECG
\How do you diagnose MI? - ANS-1. In the first 6 hours, ECG is gold standard
2. Cardiac troponin I rises after 4 hours and is elevated for 7-10 days. It is more
specific than other protein markers.
3. CK-MB is predominantly found in the myocardium but can also be released from
skeletal muscle. Useful in diagnosing reinfarction following acute MI because levels
return to normal after 48 hours.
4. ECG changes can include ST elevation (transmural infarct), ST depression
(subendocardial infarct), and pathologic Q waves (transmural infarct)
\Rheumatic Fever - ANS-"FEVERSS"
- Fever
- erythema marginatum
- valvular damage (vegetation and fibrosis)
- ESR increased
- Red hot joints (migratory polyarthritis)
- Subcutaneous nodules
- St. Vitus' dance (Sydenham's chorea)
Rheumatic fever is a consequence of pharyngeal infection with group A
Beta-hemolytic streptococci. Early death due to myocarditis. Late sequelae include
rheumatic heart disease which affects heart valves. High pressure heart valves are
affected the most (mitral>aortic>>tricuspid)
Early lesion is mitral valve regurgitation. Late lesion is mitral stenosis.
Associated with Aschoff bodies (granuloma with giant cells), Anitschkow's cells
(activated histiocytes), and elevated ASO titers
Immune mediated (type II hypersensitivity). Not a direct effect of bacteria. Antibodies
to M protein.
\Syphilitic heart disease - ANS-Tertiary syphilis disrupts the vasa vasorum of the
aorta with consequent atrophy of the vessel wall and dilation of the aorta and valve
ring. May see calcification of the aortic root and ascending aortic arch. It leads to the
"tree bark" appearance of the aorta.
Can result in aneurysm of the ascending aorta or aortic arch and aortic insufficiency.
\What are 3 types of arteriosclerosis? - ANS-1. Monckeberg medial calcific sclerosis
