Introduction to Cardiac Pathology

Question 1

Describe cardiac muscle

Answer 1

branching, striated fibers; organized into parallel units (sarcomeres); sarcolemma arranged to deliver calcium for rapid conduction; intercalated discs; central nuclei; main fuel is fatty acids

Question 2

Where do coronary arteries run

Answer 2

run in connective tissue on surface of heart, supply blood from outer to inner layers of myocardium; originate in coronary ostia behind aortic valve

Question 3

Most of the coronary blood flow occurs during

Answer 3

diastole

Question 4

LAD supplies

Answer 4

apex of heart, anterior left ventricle, anterior two thirds of ventricular septum

Question 5

Right coronary artery supplies

Answer 5

entire right ventricular free wall, posterior third of ventricular septum; posterior left ventricle

Question 6

Left circumflex supplies

Answer 6

lateral left ventricular wall; in 1/5 people, also supplies posterior aspect of left ventricle

Question 7

Results in damage to the left ventricular wall and ventricular septum

Answer 7

occlusions to either the right or left coronary arteries

Question 8

Part of the endocardium at greatest risk of ischemia

Answer 8

subendocardial region

Question 9

Describe the heart’s conduction system

Answer 9

specialized myofibers; myocytes have a certain automaticity; without impulse conduction, will either fire aberrantly or contract in an unorganized fashion

Question 10

SA node

Answer 10

located at the junction of the SVC and right atrium; serves as the pacemaker

Question 11

AV node

Answer 11

near the atrium-ventricular junction; organizes and fires impulse into the bundle of his

Question 12

Bundle of His

Answer 12

runs thru ventricular septum to insure coordinated contraction of both ventricles, movement of contraction in a wave of depolarization to maximize pumping action

Question 13

Pericardial sac

Answer 13

potential space, usually holds 50-60 ml of serous fluid

Question 14

Pericardial sac is lined by

Answer 14

lined on both sides with mesothelial layers of the serous pericardium

Question 15

Visceral layer/epicardium

Answer 15

reflection of the pericardium which covers the surface

Question 16

heart and serous pericardium are encased in what

Answer 16

several layers of the fibrous pericardium

Question 17

Chamber function

Answer 17

left/right synchronous; dependent on directional wave of depolarizaton; sequential upper chamber to lower chamber contraction to help in directional flow

Question 18

Valvular function

Answer 18

essentially one-directional flow valves to prevent backflow; essential for maintaining stroke volume and attaining chamber pressure; passive action

Question 19

Primary causes of cardiovascular dysfunction

Answer 19

hypovolemia; arrhythmia; pressure overload; volume overload; cardiac muscle failure

Question 20

pressure overload caused by

Answer 20

hypertension, valvular stenosis

Question 21

volume overload caused by

Answer 21

fluid overload, valvular insufficiency

Question 22

Cardiac muscle failure caused by

Answer 22

ischemia, metabolic, cardiomyopathy

Question 23

myocardium response to increased work demands

Answer 23

pressure overload -> concentric hypertrophy

volume overload -> eccentric hypertrophy

Question 24

Microscopic changes in hypertrophied myocytes

Answer 24

cellular and nuclear enlargement; increased myocyte size and myofibril content; some disorganization of sarcomeres; expression of fetal proteins

Question 25

Hypertrophy leads to

Answer 25

enlargement/dilation and eventual heart failure; increased myocardial demands for oxygen

Question 26

Mechanisms involved in cardiac decompensation

Answer 26

Starling law; inadequate oxygenation; fibrosis; loss of myocytes; abnormal calcium homeostasis; adrenergic densesitization; amyloidosis

Question 27

Symptoms and signs of left sided heart failure

Answer 27

cardiac enlargement; left atrium enlargement; pulmonary congestion; hypoxic encephalopathy; coronary insufficiency and cardiac ischemia

Question 28

Symptoms and signs of right sided heart failure

Answer 28

engorgement of systemic and portal vasculature; hypoxia; liver congestion; kidney congestion; splenic congestion; dependent peripheral edema

Question 29

Nutmeg liver

Answer 29

right sided heart failure; chronic passive congestion; centrilobular necrosis leading to cardiac sclerosis;local hemorrhage; phagocytosis of red cells

Question 30

Etiology of global heart failure

Answer 30

long-standing right or left-sided failure; constrictive disease; massive infarct; shock

Question 31

Signs and symptoms of global heart failure

Answer 31

degree of symptomology depends on the rapidity of development of cardiac failure

Question 32

Causes of Cor pulmonale

Answer 32

pulmonary hypertension secondary to primary disease of the lungs or pulmonary vasculature; acute: pulmonary embolism; chronic: COPD, compression/obliteration of pulmonary arteries; fibrosis of lungs

Question 33

Criteria for hypertensive heart disease

Answer 33

1. left ventricular hypertrophy (usually concentric) in the absence of other cardiac pathology 2. history of hypertension

Question 34

Microscopic features of myocyte hypertrophy

Answer 34

increased myocyte size with prominent and sometimes reduplicated nuclei; decreased capillary density; increased deposition of ECM

Question 35

Microscopic features of myocardial atrophy/apoptosis

Answer 35

decreased cell numbers; increased fibrosis

Question 36

Microscopic features of cardiac necrosis/inflammation

Answer 36

coagulative necrosis with evolving inflammatory infiltrate; eventual replacement by fibrosis and scar

Question 37

Microscopic features of reperfusion injury

Answer 37

contraction bands

Question 38

Microscopic features of cardiac aging

Answer 38

fewer myocytes; increased collagen; amyloid; basophilic degeneration; brown atrophy (lipofuschin)

Question 39

Microscopic features of acute of chronic inflammatory response to infection of the heart

Answer 39

depends on the nature of the infectious agent; variable infiltration of inflammatory cells and myocyte damage