Cardiac Pathology Flashcards
What changes occur within 30mins to 4 hours of injury?
Waviness of fibers at the border due to sarcolemmal disruption
What changes occur from 4-12 hours of injury?
Early coagulation necrosis and edema can become prominent
What changes occur from 12-24 hours of injury?
Coagulation necrosis increases Nuclei begin to shrink and become pyknotic Myocytes appear very hypereosinophilic Heart appears darkly mottled Early neutrophilic infiltrate
What changes can be seen at 1-3 days of injury?
Marked neutrophil infiltrate
Coagulation necrosis with loss of nuclei that manifests as a yellow tan infarct surrounding mottling
The period from 3 days to a week are characterized by the presence of what?
Macrophages which are present to phagocytize the dead myofibers
What changes occur from 7-10 days of injury?
Well developed phagocytosis of dead cells
Granulation tissue at margins
What changes occur from 10-14 days?
Well established granulation tissue with new blood vessels and collagen deposition
What changes occur from 2-8 weeks?
Gray white scar develops
Increased collagen deposition with decreased cellularity
What changes occur after two months from injury?
Scarring is complete and consists of a dense collagenous scar
Which substance begins to leak out of the dead myocytes after 2-3 hours of injury?
Lactate dehydrogenase which can be seen by staining the heart tissue with triphenyltetrazolium chloride (stains tissue bright red where LDH is present and areas of infarction do not turn bright red)
What is contraction band necrosis?
With repercussion an influx of Ca causes sarcomeres to contract appearing as contraction bands on light microscopy
What is the most common cause of death due to MI?
Fatal arrhythmia
Half of all deaths due to MI occur within 1 hour of onset and are due to fatal arrhythmia (v fib)
(Early complication)
What is the second most common cause of death due to MI?
Contractile dysfunction (early complication) Dependent on size of the infract and associated loss of function Leads to cardiogenic shock
What are the causes of chronic ischemic heart disease?
A healing infarct with fibrosis, Ventricular remodeling and Hypertrophy of the remaining muscle
What is a good way to differentiate between NSTEMI and unstable angina?
NSTEMI will have have elevated troponin and unstable angina will not
Sudden onset of dyspnea, SOB, and crushing stabbing or squeezing CP which radiates to the jaw, less than 3 hours with typical EKG changes (ST elevation) should be assumed to be a what?
Transmural acute MI (STEMI)
What is the MC type of pericarditis?
Fibrinous and serofibrinous pericarditis (bread and butter appearance); Fibrinous inflammatory exudate, variable amount of fluid (serofibrinous)
What are the causes of fibrinous and serofibrinous pericarditis?
Acute MI, Dressler’s syndrome, uremia (CKD with elevated BUN); Others include chest irradiation, RF, SLE, trauma
What is serous pericarditis?
Viral or non infectious inflammatory diseases
An active infection caused by microbial invasion can lead to which type of pericarditis?
Purulent or suppurative pericarditis
What is caseous pericarditis?
Tuberculous in origin
Occasionally fungal
Necrotizing granuloma
What is hemorrhagic pericarditis?
Most commonly caused by the spread of a malignant neoplasm
Also trauma
What is constrictive pericarditis?
Heart is encased in a dense, fibrous or fibrocalcific scar that limits diastolic expansion and CO
Features that mimic a restrictive cardiomyopathy
What are some common benign cardiac tumors?
Myxoma, fibroma, lipoma, papillary fibroelastoma, rhadbomyoma
What is the #1 cardiac tumor in adults?
Myxoma
What is the #1 cardiac tumor in children?
Rhabdomyoma
What is the MC malignant tumor?
Sarcoma (angiosarcoma)
What is a lipoma?
Localized mass composed of mature lobulated fat
Occur throughout the heart (subendocardium, subepicardium, or myocardium)
What is a papillary fibroelastoma?
Typically incidental
Sea anemone like lesions
Often >80% located on valves
Resemble Lambl excrescences (probable remote organized thrombus)
What is a rhadbomyoma?
Considered a hamartoma of developing cardiac myocytes;
50% sporadic mutations;
50% associated with tuberous sclerosis (mutations in TSC1 (hamartin) or TSC2 (tuberin) tumor suppressor genes);
Has spider cell histo appearance;
Gray white mass that protrudes into ventricles
What is angiosarcoma?
Malignant endothelial neoplasm that primarily affects older adults
Which cancers common involve the heart?
Metastatic lung and breast carcinoma, melanoma, lymphoma to the heart are more common than primary tumor
Breast, lung and esophageal can involve through direct extension
Cardiac involvement of a tumor can result in what?
Mass effect (limiting cardiac filing);
Decreased myocardial contractility;
Symptomatic pericardial effusion;
Superior vena cava syndrome
What type of allograft rejection can occur weeks to a couple years after a heart transplant?
Cellular mediated rejection (T cell mediated, lymphocytic response)
Ab mediated rejection (Ab mediated, vascular neutrophilic inflammation)
What is allograft vasculopathy?
Late (many years), progressive, diffusely stenosing intimal proliferation
50% develop in 5 years, in virtually all pts within 10 years
Silent MI: denervated transplanted heart (no angina)
What are the complications due to chronic immunosuppression in transplants?
Infection (hospital acquired, community acquired, reactivated viral infection, opportunistic, etc)
Malignancy
-skin cancers (squamous cell carcinoma, BCC)
-EBV positive lymphoproliferative disorder
What are some general changes that occur in an aging heart?
Reduction in compliance and elasticity occurs in vessels and the heart
What changes occur within the valves of an aging heart?
Fibrous mitral valve —> buckling prolapse during systole —> atrial dilation and arrhythmia
Calcific deposits —> aortic stenosis
Lambl excrescences
What changes occur within the chambers of an aging heart?
Left ventricle cavity sized reduced (esp with HTN) Atrial dilation (fibrous mitral valve)
What are some atherosclerotic changes that occur in an aging heart?
Significant stenosis (MI, aortic dissection, etc)
What are some epicardial and myocardial changes that occur in an aging heart?
Increase in epicardial fat Lipofuscin accumulates Basophilic degeneration Myocyte loss Amyloid deposition (transthyretin) —> senile amyloidosis (heart failure)
