Perfusions: MI Flashcards
What are the most common causes of atherosclerosis?
reduced flow due to:
high levels of LDL, toxins; atheromas
What is ischemia?
Oxygen supply is inadequate to meet metabolic needs
What are the 3 categories of anginas?
- stable
- unstable
- prinzmetal (variant)
What does ischemia do to the heart and body?
- causes injury to tissues
- it is REVERSIBLE
- causes chest pain
When may a scar be seen from ischemia?
It may not be seen until the third week so the patient will be sensitive to oxygen demands
Define angina
Recurrent chest pain associated with reversible damage to the myocardium
Describe an infarction
IRREVERSIBLE damage to the heart muscle causing necrosis. If extensive, the heart may fail.
What are the AHA recommendations for people experiencing chest pain?
- an individual with unknown chest pain should seek emergency care if chest pain is not relieved by 3 NTG tablets over a 10 min period
- In a person with previously unrecognized coronary disease, the persistence of suspicious chest pain for 2 min or longer may be an indication for emergency medical assistance
What is acute coronary syndrome?
When coronary blood flow is significantly reduced, but not fully occluded.
What can cause acute coronary syndrome?
- rupture or erosion of atherosclerotic plaque
- Coronary artery spasm
- Progressive vessel obstruction
- Inflammation of coronary artery
- Increase in myocardial oxygen demand and/or decrease in supply
What is AMI?
Acute myocardial infarction- blood flow to a portion of cardiac muscle is COMPLETELY blocked causing prolonged tissue ischemia and irreversible cell damage
How are acute myocardial infarctions usually described?
By location of the heart that was damaged.
EX: occlusion of the left anterior descending artery= anterior MI
Left circumflex artery= lateral MI
What drug toxicity can cause an acute MI?
cocaine
What are the nonmodifiable risk factors of an acute MI?
- age
- male gender
- family hx
What are the modifiable risk factors for an acute MI?
- hypertension
- DM
- Hyperlipidemia
- cigarette smoking
- obesity, diet
- physical inactivity
- stress
What are some emerging risk factors for acute MI?
- elevated levels of homocysteine
- inflammatory processes
- metabolic syndrome
What are the risk factors of an acute MI unique to women?
- premature menopause
- oral contraceptive use
- hormone replacement therapy
What are the manifestations of acute coronary syndrome?
- chest pain (substernal or epigastric)
- pain that radiates from the neck, left shoulder, left arm
- pain may occur at rest
- typically lasts longer than 10-20 min
- dyspnea, diaphoresis, pallor, cool skin
- tachycardia and hypotension
What are the manifestations of acute myocardial infarction?
- continuous chest pain, more severe than angina
- onset sudden, not associated with activity
- described as crushing, severe, pressure, heaviness, squeezing
- begins at the center of the chest, then radiates
- lasts more than 15-20 min
- women and older adults have atypical symptoms
- tachycardia, tachypnea, dyspnea
- nausea/vomiting
- anxiety, sweating, cool, mottled skin
- HTN, or hypotension
- Palpitations/dysrhythmias
- signs of left HF
- decreased LOC/orthopnea
- leukocyte count up to 15-20k due to cell damage
- increased sed rate/ increased temp
What are the manifestations of angina pain?
- chest pain typically preceded by an identifiable event
- tight, squeezing, heavy pressure, or constricting sensation
- begins beneath the sternum and radiates
- women often usually have atypical symptoms
What are some complications of acute myocardial infarction?
- dysrhythmias
- pump failure
- cardiogenic shock
- infarct extension
- structural defects
- pericarditis
What are the treatment goals for acute myocardial syndrome and infarction?
- relieve chest pain
- reduce the extent of myocardial damage
- maintain cardiovascular stability
- decrease cardiac workload
- prevent complications
What diagnostic tests may be used to monitor and diagnose acute myocardial syndrome or infarction?
- C-reactive protein
- Ankle-brachial blood pressure index
- exercise ECG testing
- electron beam computed tomography
- myocardial perfusion imaging
- cardiac markers
What diagnostic tests are cardiac markers?
- creatine kinase
- CK-MB
- Troponins
- myoglobin
- CBC
- ABGs
What is CPK and how long does it take to work?
Creatinine phosphokinase
4-6 hour onset; 12-24 hour peak; 3-4 day duration
What is LDH and how long does it take for it to work?
Lactic dehydrogenase
8-12 hour onset; 24-48 peak; 10-14 day duration
LDH1 (primary heart)> LDH2 is significant for MI
note the time drawn, compared to the onset of chest pain and values
What are some significant EKG changes that you would see in an MI?
- elevated ST segment (shows ischemia) w/in the first few hours
- Inverted T wave (seen 8-24 hours post-MI)
- both return to normal w/in 2-3 months
- pronounced U wave always
What are the best ways to prevent acute coronary syndrome or infarction in the future?
- stop smoking
- good diet (reduce saturated fat/cholesterol, Lower LDL level, increase intake soluble fiber, moderate alcohol intake)
- weight reduction if needed
- exercise each week ( at least 30 min moderate-intensity 5-6 days/week; 60-90 min of moderate-intensity daily is recommended)
- maintain BP <140/90
- diabetes: weight loss, reduce fat intake, blood glucose management