Ischemia And Infarction

Front 1

what is ischemic heart disease?

Back 1

a disease characterized by ischaemia (reduced blood supply) of the heart muscle,

Front 2

myocardial ischemia is most often due to _____

Back 2

atheroschlerois, but also caused by vasospasm, thrombisis, aortic stenosis

Front 3

angina

Back 3

“choking”: paroxysmal chest pain or pressure sensation associated with myocardial ischemia

Front 4

symptoms and duration of angina

Back 4

shortness of breath, nausea
short duration- up to 5 minutes

Front 5

3 classes of angina

Back 5

1. Stable angina
“exercise angina”
fixed atherosclerotic occlusion of coronaries
physical exertion, cold exposure, stress

2. Variant angina
“vasospastic angina”
usually at rest, night, minimal exercise
cause uncertain
treatment: avoid cold, stop smoking, reduce stress

3. Unstable angina
“pre-infarction angina”
probably associated with disruption of unstable atheromatous plaque
may involve thrombus formation --> precipitates infarction

Front 6

non pharmacologic treatment of myocardial ischemia

Back 6

pacing of exercise
avoid smoking, stress, cold exposure
reduce weight

Front 7

pharmacologic treatment of myocardial ischemia

Back 7

vasodilating drugs - nitroglycerin (very fast), isosorbide dinitrate

beta blockers - antagonists of B1 receptors on SA/AV nodes, myocardium
reduces heart’s O2 consumption
Ca++ channel blockers
slows heart rate & force
dilates arterioles (afterload)
increases coronary perfusion

Aspirin - antiplatelet drugs
platelet aggregation stimulated by thromboxane-A2
aspirin inhibits thromboxane A2
recommended dose 75-325 mg /day

Front 8

vasodilators act on ____ and ___ to decreae ___ and ____ therefore reducing work done by the heart

Back 8

veins and arteries
preload and afterload

Front 9

reperfusion treatments

Back 9

angioplasty--> dilatation of coronary atherosclerotic occlusion
-->may include insertion of stainless steel stent


bypass surgery
->uses bypass grapht

Front 10

common name for acute myocardial infarction (AMI)

Back 10

heart attact

Front 11

what kills north americas more than any other illness

Back 11

heart attack

Front 12

why are AMI's more common early in the morning

Back 12

morning surge in catecholamines
platelets have B-adrenergic receptors
common cause: dislodging of unstable plaque
release of platelet activators
thrombus formation

Front 13

clinical manigestations of AMI

Back 13

1. Pain & autonomic responses
abrupt and severe angina, except long-lasting
not relieved by nitroglycerin
tachycardia, anxiety, restlessness
2. Fatigue & weakness (esp. arms & legs)
risk of hypotension & shock

3. EEG changes & dysrhythmias common
abnormal EEG, premature contractions, etc.
dying cells release K+, H+
--> depolarization of surrounding myocardium

4. Dying cells release inflammatory chemicals
fever is common
WBC counts usually rise
inflammation lasts several days

Front 14

emergyency AMI treatment

Back 14

oxygen (ie. nasal prongs)
nitroglycerin (unless BP<90, HR<50, HR>100)
intravenous analgesia
aspirin
beta-blockers (decrease cardiac oxygen consumption)
thrombolytic drugs (given within 1-2 hrs)
streptokinase
tissue plasminogen activator (tPA)

Front 15

fibrillation

Back 15

Fibrillation is the rapid, irregular, and unsynchronized contraction of muscle fibers. An important occurrence is with regards to the heart.

Front 16

complications of AMI

Back 16

fibrillation
heart failure and cardiogenic schock
thromboemboli-blood clots around area of necrosis
rupture of myocardium
ventricular aneurism

Front 17

what is ventricular aneurism

Back 17

They usually arise from a patch of weakened tissue in a ventricular wall, which swells into a bubble filled with blood. This, in turn, may block the passageways leading out of the heart, leading to severely constricted blood flow to the body. Ventricular aneurysms can be fatal. They are usually non-rupturing because they are lined by scar tissue.

Front 18

what is a stroke

Back 18

A stroke, previously known medically as a cerebrovascular accident (CVA), is the rapidly developing loss of brain function(s) due to disturbance in the blood supply to the brain

Front 19

_____ increase the risk of stroke 4x

Back 19

hypertension

Front 20

what is hyperhomocyenimia

Back 20

Hyperhomocysteinaemia is a high level of homocysteine in human blood. A high level of homocysteine makes a person more prone to have blood clots which may result in heart attacks and strokes

Front 21

4 types of stroke

Back 21

1. thrombotic stroke
2. transient ischemic attacks (TIAS)
3. embolic strokes
4. hemorrhagic stroke

Front 22

thrombotic stroke

Back 22

is linked to AS
-->thrombus (blood clot) formation at plaque site
these fragments dislodge and cause a stroke

Front 23

when thrombus breaks off it is called an ___

Back 23

embolus

Front 24

embolic stroke

Back 24

An embolic stroke refers to the blockage of an artery by an arterial embolus, a travelling particle or debris in the arterial bloodstream originating from elsewhere. An embolus is most frequently a thrombus, but it can also be a number of other substances including fat (e.g. from bone marrow in a broken bone), air, cancer cells or clumps of bacteria (usually from infectious endocarditis).

Front 25

hemmorrhagic stroke

Back 25

Hypertension, rutured aneurism, vascular malformation
Expanding blood pool compresses brain

Front 26

stroke manifestations

Back 26

depends on cerebral artery
numbness, weakness
generalized headaches
dysphasia
partial to complete paralysis, paresis
unconsciousness
cerebral edema

Front 27

evaulations and treatments for stroke

Back 27

MRI, angiography (for locating aneurysm, blood clot)
Anticoagulant therapy, aspirin therapy
Hypotensive drugs
Clotting factors (hemorrhagic stroke)
Rehabilitation for motor dysfunction