introduction to cardiac pathology

Question 1

coronary arteries originate from

Answer 1

ostia behind aortic valve

Question 2

coronary arteries

Answer 2

• run in connective tissue on surface of heart

- supply blood from outer to inner layers of myocardium

Question 3

most of coronary blood flow occurs

Answer 3

during diastole

Question 4

LAD

Answer 4

apex of heart
anterior LV
anterior 2/3 of ventricular septum

Question 5

RCA

Answer 5

RV free wall
posterior 1/3 of ventricular septum
posterior LV

Question 6

Left circumflex

Answer 6

lateral left ventricular wall

can also supply posterior aspect of LV

Question 7

left main

Answer 7

both LAD and left circumflex

Question 8

occulsio to what CA(s) results in damage to LV wall and ventricular septum

Answer 8

RCA or LCA

Question 9

endocardium

Answer 9

• thickness varies inversely with myocardium

- subendocardial region at greatest risk of ischemia

Question 10

anatomy of conduction system

Answer 10

• specialized myofibers
• myocytes have a certain automaticity without impulse conduction will either fire an impulse aberrantly (premature complexes) or contract in an unorganized fashion (fibrillation)

Question 11

SA anatomy

Answer 11

location at junction of SVC and right atrium

serves as pacemaker

Question 12

AV anatomy

Answer 12

AV node near atrium-ventricular junction

organizes and fires impulses into Bundle of His

Question 13

bundle of his anatomy

Answer 13

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

Question 14

P wave

Answer 14

atrial contraction

Question 15

Q wave

Answer 15

atrial systole

Question 16

R wave

Answer 16

atrial diastole

Question 17

S wave

Answer 17

ventricular contraction

Question 18

T wave

Answer 18

ventricular systole

Question 19

chamber function

Answer 19

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

Question 20

valvular function

Answer 20

• one directional flow valve to prevent back flow
• essential for maintaining stroke volume and attaining pressure differential across valve
• most passive, mitral valve is assisted papillary muscle and chordae tendonae, tricuspid has similar structures

Question 21

valvular dysfunction

Answer 21

stenosis
insufficiency
anatomic distortion
loss of papillary muscle

Question 22

inflow

Answer 22

• systemic-> inflow through IVC, dependent on systemic blood pressure and ventricular volume
• pulmonary-> interruption of flow secondary to pulmonary emboli

Question 23

outflow

Answer 23

• pulmonary: specialized vessels to pump large volume of blood through lungs under low pressure
• two main problems:
  1. pulmonary HTN resulting in cor pulmonale
  2. pulmonary emboli

-systemic: collective peripheral resistance, blood volume, vessel diameter, elasticity, HTN

Question 24

cardiac cycle

Answer 24

diastole systole
[————————][——————————-]
S2 S1 S2

Question 25

starlings law

Answer 25

stretch versus contractility

Question 26

cardiac dysfunction: primary causes of cardiovascular dysfunction

Answer 26

1. Hypovolemia 2. Arrhythmia 3. Cardiac muscle failure - ischemia (hypertrophy+ cardiac artery disease) - metabolic 4. Decreased end diastole volumes - decreased diastolic relaxation - decreased ventricular volume

Question 27

cardiac failure

Answer 27

hypertrophied muscle may lead to end stage dilation and heart failure

Question 28

left heart failure

Answer 28

->80% ischemia, 1-3% HTN, 1% rheumatic

Question 29

signs and symptoms of left heart failure

Answer 29

1. cardiac enlargement with: LVH-> heart increases in both volume and mass actual cardiac dilatation is end point decompensation 2.Obstruction to venous return-> pulmonary congestion 3. obstruction of systemic outflow -insufficient renal perfusion leads to fluid retention and further exacerbation of problem -hypoxic encephalopathy -coronary insufficiency and cardiac ischemia 4. LA enlargement may be secondary to left ventricular enlargement or may be primary (MS) often associated with atrial fibrillation 5. atrial fibrillation is associated with formation of mural thrombi (stasis of atrial blood flow) increased risk of embolic stroke

Question 30

right heart failure

Answer 30

- occurs in only a few diseases - usually consequence of left sided (global) failure - most common pure form-> cor pulmonale (pul. HTN) - associated with valvular disease

Question 31

right heart failure

Answer 31

1. engorgement of systemic and portal congestion (nutmeg liver, dependent pitting edema) 2. liver congestion: chronic passive congestion (nutmeg liver) - stasis of blood in central vein with hypoxia of adjacent cells - vascular congestion with local hemorrhage, phagocytosis of red cells - fibrosis of long-standing ischemic tissue cardiac sclerosis

Question 32

global heart failure

Answer 32

- long standing right or left sided failure - constrictive disease (tamponade) - massive infarct - shock

Question 33

signs of symptoms of global heart failure

Answer 33

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

Question 34

pressure of volume overload

Answer 34

response: Hypertrophy Microscopic features: - increased myocyte size with prominent and sometimes reduplicated nuclei - decreased capillary density - increased deposition of ECM

Question 35

chronic ischemia

Answer 35

response: myocardial atrophy, apoptosis microscopic changes: - decreased cell numbers - increased fibrosis

Question 36

acute ischemia

Answer 36

response: necrosis, accompanying inflammation around margins microscopic features: coagulative necrosis, with evolving inflammatory infiltrates, eventual replacement by fibrosis and scar

Question 37

reperfusion

Answer 37

response: reperfusion injury microscopic features: contraction bands

Question 38

infection

Answer 38

response: acute inflammation microscopic features: depends on nature of infectious agent, variable infiltration of inflammatory cells and myocyte damage

Question 39

aging

Answer 39

``` microscopic features: fewer myocytes increased collagen senile amyloidosis basophillic degeneration (by product of glycogen metabolism) brown atrophy-> lipofuschin pericardial fat ```