Myocardial Disease

Question 1

Dilated Cardiomyopathy causes

Answer 1

Caused by myocarditis
-Coxsackie virus B

EtOH and metabolites are toxic to myocardium

Thiamine deficiency can cause DCM

Doxorubicin (chemo agent)

Question 2

Gene mutations causing dilated cardiomyopathy

Answer 2

Mitochondrial genes

dystrophin genes

Genes encoding enzymes involved in beta oxidation of FAs

Question 3

DCM clinical

Answer 3

Slowly progressive CHF

50% die within 2 yrs
25% survive longer than 5 years

Death due to progressive cardiac failure or arrhythmia

Question 4

Hypertrophic Cardiomyopathy

Answer 4

Massive myocardial hypertrophy

Abnormal diastolic filling

In 1/3of cases: intermittent LV outflow obstruction

Hypercontracting

• systolic function is preserved
• primarily a diastolic disorder

Question 5

HCM morphology

Answer 5

Massive myocardial hypertrophy without ventricular dilation

Classic: asymmetrical septal hypertrophy

Usually most prominent in subaortic area

Endocardial thickening of LV outflow tract and thickening of ant mitral leaflet

Question 6

HCM microscopic morphology

Answer 6

Myocyte hypertrophy

Haphazard disarray of bundles of myocytes

Interstitial and replacement fibrosis

Question 7

HCM pathogenesis

Answer 7

Mutations in genes that encode sarcomeric proteins

Autosomal dominant with variable expression

Question 8

HCM clinical

Answer 8

Reduced chamber size

Poor compliance, reduced SV due to:

• impaired diastolic filling of LV
• massively hypertrophied LV

Exertion also dyspnea due to decreased CO and increased pulmonary venous pressure

Harsh systolic ejection murmur due to ventricular outflow obstruction

Angina pain

SUDDEN DEATH IN ATHLETES

Question 9

Myocarditis

Answer 9

Inflammatory process plays a primary role in development of myocardial injury

Coxsackie viruses A and B

Trypanosoma Cruzi

Question 10

Myocarditis morphology

Answer 10

Heart normal or dilated

Lesions diffuse or patchy

Ventricular myocardium is flabby

Mural thrombi may be present in any chamber

Question 11

Myocarditis microscopic

Answer 11

Interstitial infiltrate and injury (lymphocytes)

Question 12

Hypersensitivity myocarditis

Answer 12

Perivascular infiltrate- lymphocytes, macrophages and eosinophils

Question 13

Giant Cell myocarditis

Answer 13

Giant cells are present

Poor prognosis

Question 14

Pericardial effusion

Answer 14

Fluid in pericardium

Question 15

Hemopericardium

Answer 15

Blood in pericardium

Question 16

Purulent pericarditis

Answer 16

Pus in pericardium

Question 17

Globular enlargement

Answer 17

Due to slow accumulation of fluid and is < 500 ml

Question 18

Cardiac Tamponade

Answer 18

Due to a large chronic effusion (> 500ml) or accumulate rapidly

Restricts cardiac filling

Question 19

Serous pericarditis

Answer 19

Non infectious inflammation

• rheumatic fever
• systemic lupus erythematosus
• scleroderma
• tumors
• uremia

Question 20

Serous pericarditis morphology

Answer 20

Neutrophils, lymphocytes, and histiocytes on epicardial and pericardial surfaces

Question 21

Acute pericarditis morphology

Answer 21

Fibrinous: surface is dry with a fine granular roughening

Serofibrinous: thick yellow to bloody fluid and fibrin

FIBRINOUS DEVELOPS A LOUD PERICARDIAL FRICTION RUB

Question 22

Purulent pericarditis clinical

Answer 22

Active phase is similar to fibrinous along with signs of systemic infection- spiking temps, chills, fever

Question 23

Hemorrhagic pericarditis

Answer 23

TB or malignant neoplasm ( most common)

bacterial infections

Bleeding diathesis

Cardiac surgery

Question 24

Healed pericarditis

Answer 24

Healing causes adhesive mediastinopericarditis

Pericardial sac in obliterated

Heart adheres to surrounding structures

• systolic retraction of the rib cage and diaphragm
• pulsus paradoxus
• hypertrophy and dilation of heart

Question 25

Constrictive Pericarditis

Answer 25

Encased in dense fibrous or fibrocalcific scar

• limits diastolic expansion
• restricts CO