Cardiac function (part 2)

Question 0

Appearance, peak, return to normal values in cardiac enzyme markers
-AST

Answer 0

A: within 12 hrs
p: 18-24 hrs
N: 4-5 days

Question 1

Appearance, peak, return to normal values in cardiac enzyme markers
-total CK

Answer 1

A: 3-8 hrs, P: 10-36 hrs, N: 3-4 days

Question 2

Appearance, peak, return to normal values in cardiac enzyme markers
-LD

Answer 2

A: 8-18 hrs
P: 48-72 hrs
N: 6-10 days

Question 3

Four current laboratory markers for acute MI

Answer 3

Myoglobin, CKMB, Troponin I, Troponin T

Question 4

The principle oxygen carrier protein in the cytoplasm of both skeletal and cardiac muscle cells

Answer 4

Myoglobin

Question 5

Typical appearance time frame of myoglobin in plasma and return to normal after MI

Answer 5

Appears 0.5-2 hrs after the onset of chest pain, peaks at 5-12 hrs, returns to normal on 18-30 hrs

Question 6

Not often used due to non specificity of the elevation to diagnose an AMI, clearance from the blood dependent on renal function so increases may not only be us to cardiac cell death.

Answer 6

Myoglobin

Question 7

CKMB appearance, peak, and return to normal levels in plasma

Answer 7

Increases 1-4 hrs after onset of chest pain, peaks 4-8 hours, return to normal in 24-48 hrs

Question 8

Because CKMB may be of myocardial or skeletal muscle origin, physicians prefer ______ _______

Answer 8

CK Index=CKMB/Total CK

Question 9

Regulates cardiac contraction via the ACTIN filaments

Answer 9

Troponin C, I, and T

Question 10

Calcium binding complement (Troponin)

Answer 10

Troponin C

Question 11

Inhibitory component; binds to actin to inhibit activity of actinomyosin ATPase (breaks down ATP)

Answer 11

Troponin I

Question 12

Tropomyosin-binding component

Answer 12

Troponin T

Question 13

Troponin I appearance, peak, and return to normal levels in plasma

Answer 13

Appears 4-6 hrs after onset of chest pain, peaks 24 hrs, returns to normal 5-15 days

Question 14

Two physical changes to the heart in congestive heart failure

Answer 14

Chambers enlarge to handle increased fluid; walls may thicken to handle the increased strain

Question 15

Four symptoms of congestive heart failure

Answer 15

Dyspnea, orthopnea, paroxysmal nocturnal dyspnea, exercise intolerance, fatigue, fluid retention

Question 16

Contained in Pressure sensing cells in the left ventricle

Answer 16

BNP

Question 17

Stimulus for BNP release

Answer 17

When pressure in the ventricle increases, BNP is released into the blood

Question 18

Effect of BNP on ADH Secretion from the hypothalamus

Answer 18

Decreased sodium inhibits production of ADH by the pituitary gland; increased diuresis results in decreased blood volume, thereby trying to solve the problem

Question 19

Effect of BNP on sodium excretion

Answer 19

In kidney, BNP stimulates natriuresis (sodium excretion) by inhibiting sodium reabsorption

Question 20

Why BNP may be used in the diagnosis of congestive heart failure

Answer 20

Focuses on several goals:

• determine the cause of diagnostic symptoms
• estimate the degree of severity of CHF
• Estimate the risk of disease progression and risk
• screen for a less symptomatic disease