Cardiac Function Flashcards
Describe what occurs when a patient has congestive heart failure.
Inability to pump effectively. Fluid accumulates within the lungs and causes a decreased cardiac output.
What three organs does hypertension affect?
Kidney, brain and heart.
What occurs in hypertensive heart disease?
Increased peripheral resistance and left ventricular workload.
Describe what occurs in acute coronary syndrome.
Reduced blood flow to the heart.
Describe what occurs in ischemic heart disease.
Obstruction of the blood supply resulting in lack of nutrients and oxygen.
What are some risk factors for coronary syndrome?
Age, sex, family history, hyperlipidemia (increased LDL), smoking, hypertension, sedentary lifestyle, diabetes mellitus, and response to stress.
Describe what occurs in acute myocardial infarction.
Blocked blood flow which leads to ischemia and tissue death.
What is the function of Aspartate Aminotransferase (AST)?
The synthesis and degradation of amino acids.
What is the clinical significance of AST?
Indicative of hepatocellular disorders (4X ↑ - cirrhosis; 50-100X ↑ - hepatitis), skeletal muscle disorders, acute myocardial infarction, and pulmonary embolism.
AST > ALT is indicative of what?
Alcohol or drug related hepatic disorders.
What is the function of Lactate Dehydrogenase (LD)?
Glycolysis; catalyzes the interconversion of lactic and pyruvic acid; hydrogen-transfer.
How many isoenzymes are there for LD?
Five.
What are the five different isoenzymes for LD, and where are they most prominent?
LD1 - Heart LD2 - Kidney LD3 - Lungs, spleen, pancreas, lymphs LD4 - Liver, skeletal muscles LD5 - Skeletal muscles
What is the clinical significance of LD?
Highest levels occur during hemolytic anemia, pernicious anemia, shock, and hypoxia.
Moderate levels occur in myocardial infarction: LD1.
What is the function of creatine kinase (CK)?
Catalyzes reversible phosphorylation-dephosphorylation; an enzyme found within the cytoplasm and mitochondria.
What is the clinical significance of creatine kinase?
Myocardial infarction:
- Rise ~ 4 - 8 hours - Peaks ~ 12 - 24 hours - Returns to normal ~48 to 72 hours
What are the three isoenzymes for CK, and where are they located?
CK - MM : Muscle
CK - MB : Hybrid
CK - BB : Brain
How do the cardiac proteins change with cardiac damage?
They increase.
What is the clinical significance of Myoglobin?
2% of total muscle, found in striated skeletal and cardiac.
When would myoglobin be increased?
Acute myocardial infarction and progressive muscular dystrophy.
What are the three different isoenzymes for troponin?
T, I, and C.
What is the function of Troponin?
To regulate muscle contraction.
When can you find Troponin T & I increased?
Acute myocardial infarction and ischemic heart disease.
Why is HS-CRP helpful to monitor heart disease?
It’s a liver protein that increases rapidly with inflammation; small increases predict vascular disease/cardiac events.
Why is homocysteine helpful to monitor heart disease?
Increases cause disulfide bridging with proteins; causes a direct injury to vessels.
What are other helpful serum markers to monitor during acute coronary syndromes?
Fibrinogen, D-Dimer, Ischemia-modified albumin, and Lp-PLA2
Why would Brain-type Natriuretic Peptide (BNP) be helpful when monitoring heart disease?
It is a peptide hormone that is secreted by cardiac vesicles. BNP stimulates excretion of sodium by kidneys and increases urine flow. Elevated levels occur in diseases that expand fluid volume.
