Cardiac Pathologies Flashcards
What is a myocardial infarction (MI)?
ischemic event that might result in injury or irreversible tissue death of myocardium
What are the definitive signs and symptoms of MI?
- initial ECG changes of S-T segment elevation, inverted T-wave, & significant Q wave
- signs of cardiac insufficiency
- elevation of cardiac enzymes
How is MI diagnosed or what is called ruled in (R/I) or ruled out (R/O)?
must have 2/3 signs of MI
What is the zone of ischemia?
Tissue is viable & may not have any damage if infant doesn’t extend
what is zone of injury?
viable as long as O2 delivery stays intact. increasing O2 delivery can save this tissue
what is zone of infarct?
tissue is O2 deprived & has irreversible damage
what are the cardiac enzymes that will elevate in instance of MI?
- CPK - MB
- Troponin
- LDH-1
when will the cardiac enzyme CPK-MB elevate?
0-24 hours
when will the cardiac enzyme Troponin elevate?
12 hrs - 4 days
What should be examined in regards to the cardiac enzyme LDH-1?
Ratio LDH-1:LDH-2 greater than 1 suggest MI
When an MI is transmural what deficits are seen?
most wall motion deficits
A transmural MI can be either:
- Hypokinetic
- Dyskinetic
- Akinetic
What is the definition of all 3?
- Hypokinetic: decreased wall motion
- Dyskinetic: unorganized wall motion
- Akinetic: absent wall motion
what is a subendocardial MI?
partial thickness infarct
What is the wall motion and EKG changes with a subendocardial MI?
- Wall motion: may appear normal
- EKG: less changes than transmural
What is cardiomyopathy?
disease where contraction & relaxation of cardiac muscles are impaired
Cardiomyopathy may be the result of what 3 things?
- a progression of fibrous invasion of the cardiac tissue as a result of MI or systemic collagen disorder
- immune dysfunction or unknown (idiopathic) etiology
- secondary to problems in neurotransmission
What are the 3 basic types of cardiomyopathy?
- dilated cardiomyopathy
- hypertrophy
- restrictive
What is dilated cardiomyopathy?
- similar to an aneurysm
- heart wall motion is floppy therefore decreased EF
What hypertrophy cardiomyopathy?
- hyper- contractile left ventricle meaning an increased myocardial O2 demand so rapid ventricular emptying
- decreased EF
What is restrictive cardiomyopathy?
endocardial scarring which restricts heart wall dissension which decreases EF
what can right sided CHF be caused by?
- pulmonary HTN
- right vent infarct
what is right sided CHF initially seen as?
- systemic edema with fluid accumulation in the abdomen (ascitis)
- liver
- legs
what are the sings and symptoms of right CHF?
- primary sign is LE edema
- watch for weight gain (3-5 lbs in 1-2 days)
- JVD (jugular vein distension)
What can left sided CHF be caused by?
resistance from systemic HTN, MV, or LV dysfunction secondary to cardiomyopathy or infarct
what is left sided CHF initially seen as?
pulmonary edema
what are the signs/ symptoms of left CHF?
- primary symptom is dyspnea
- Others: tachypnea, lung or mouth crackles, orthopnea
T/F: Eventually both sides of the heart will become involved with CHF
True by a retrograde progression
What are the signs that may indicate right or left CHF?
- pulmonary edema
- weight gain
- S3 heart sound
- tachycardia
- decreased activity tolerance
describe NYHA I classification
- no limitation of physical activity
- ordinary physical activity does not undue fatigue, palpation or shortness of breath
describe NYHA II classification
- slight limitation of physical activity
- comfortable at rest
- ordinary physical activity results in fatigue, palpitation, SOB or chest pain
describe NYHA III classification
- marked limitation of physical activity
- comfortable at rest
- less than ordinary activity causes fatigue, palpitation, SOB or chest pain
describe NYHA IV classification
- symptoms of heart failure at rest
- any physical activity causes further discomfort
what is the concern of cardiac output in regards to CHF?
low CO is primary concern of R & L CHF
How does the cardiopulmonary system respond to low cardiac output?
- retain fluid
- vasoconstriction to maintain BP
- increase stroke force
- increase HR
- Results is that increased demands, which are counter-productive are placed on an already failing system
medical intervention for CHF is needed to control and reduce what?
- Control: stroke force
- Reduce: vascular pressure & excess fluid to decrease workload on heart
what is the pulmonary impact of CHF?
- heart & lungs are intimately involved in the process of O2 transfer & CO2 elimination
- any significant chronic or acute pulmonary problem would eventually put a strain on the heart
why is hypertrophy of the left ventricular wall a concern when chronic left-sided heart failure is present?
the left ventricle has the largest cardiac muscle mass with subsequently high Os consumption needs, making it increasingly vulnerable to ischemic attack
what are the peripheral changes with CHF in regards to:
- muscle fiber change:
- Skeletal muscle
- muscle fiber change: decreased type I fibers so decrease endurance
- skeletal muscle atrophy
- decrease skeletal muscle blood flow so decreased ability to work
- impaired skeletal muscle metabolism especially decreased ability to break down O2 for use
how does pulmonary edema occur?
factors cause fluid to leak from pulmonary & lymphatic systems interstitially and into the alveoli creating a barrier making gas exchange between capillaries & alveoli difficult
What happens to the heart with pulmonary edema?
- heart has to work much harder to gain sufficient levels of oxygen
- O2 levels are affected most because CO2 is more soluble than O2
