EXAM #2: CONGESTIVE HEART FAILURE

Question 1

What is preload?

Answer 1

Tension developed on the wall of the ventricles before the start of contraction

This is equal to the end diastolic volume, and EDV is equal to the atrial pressure

Question 2

What is the Frank Starling Principle?

Answer 2

More preload = more contractility TO A POINT

Question 3

What is afterload?

Answer 3

The pressure the ventricle has to push against i.e. arterial pressure/ peripheral vascular resistance

Question 4

What is the relationship between afterload and contractility?

Answer 4

Increasing afterload increases contractility to a point

This is called the anrep phenomenon

Question 5

What is the relationship between the contractility and heart rate?

Answer 5

Faster heart rate will be associated with increased contraction

This is called the Bowditch phenomenon*

Question 6

Draw the relationship between ventricular EDV and stroke volume. How is this changed in HF?

Answer 6

N/A

Generally, in HF you need MORE preload to produce the same amount of WORK.

Question 7

Draw the pathophysiology of Heart Failure and the major drug action sites.

Answer 7

N/A

Question 8

What is the main cause of HF?

Answer 8

Cardiac remodeling

Question 9

What is stage A Heart Failure?

Answer 9

High risk for developing HF

• HTN
• CAD
• DM
• FHX of Cardiomyopathy

Question 10

What is stage B Heart Failure?

Answer 10

Asymptomatic HF

• S/p MI
• LV systolic dysfunction
• Asymptomatic valvular disease

Question 11

What is stage C Heart Failure?

Answer 11

Symptomatic HF

• Known structural heart disease
• Dyspnea/ Fatigue
• Reduced exercise tolerance

Question 12

What is stage D Heart Failure?

Answer 12

Refractory End-Stage HF

- Symptoms at rest despite max. medical therapy

Question 13

What drugs classes are used to treat Stage A HF?

Answer 13

1) ACEI or ARB

Question 14

What drugs classes are used to treat Stage B HF?

Answer 14

1) ACEI or ARB

2) Beta-blocker

Question 15

What drugs classes are used to treat Stage C HF?

Answer 15

1) ACEI or ARB
2) Beta-blocker
3) Diuretics

Question 16

What drugs classes are used to treat Stage D HF?

Answer 16

1) ACEI or ARB
2) Beta-blocker
3) Diuretics
4) Digoxin
5) Positive ionotrope

Question 17

What is the effect of diuretics alone on the pathophysiology of HF?

Answer 17

Shift to lower cardiac filling pressure on the same ventricular function curve

Question 18

What is the effect of ionotropes alone on the pathophysiology of HF?

Answer 18

Shift to higher ventricular function curve BUT increased workload

Question 19

What is the effect of vasodilators alone on the pathophysiology of HF?

Answer 19

Shift to improved ventricular function curve AND reduce cardiac filling pressure

Question 20

What is the effect of vasodilators and ionotropes on the pathophysiology of HF?

Answer 20

Shift to improved ventricular function curve AND sight reduction in cardiac filling pressure

Question 21

What is the effect of vasodilators, diuretics, and ionotropes on the pathophysiology of HF?

Answer 21

Shift to improved ventricular function curve AND significant reduction in cardiac filling pressure

Question 22

What are the effects of beta agonists on myocardial contractility?

Answer 22

• Gs stimulation
• Increased cAMP
• Phosphorylation of the Ca++ channel in the sarcolemma
• Increased Ca++ induced Ca++ release

Positive ionotropy

Question 23

How can intrinsic myocardial activity be increased?

Answer 23

1) Increase cytosolic Ca++
2) Increased myocardial cAMP
3) Agonism of B1 receptors
4) Increase B1 density

Question 24

What drugs increase cytosolic Ca++?

Answer 24

Cardiac Glycosides i.e. Digoxin

Question 25

What drugs increase myocardial cAMP?

Answer 25

Phosphodiesterase inhibitors

Question 26

What drugs agonise B1 receptors?

Answer 26

``` Isupreal Dobutamine DA Epi NE ```

Question 27

What drugs increase B1 receptor denisty?

Answer 27

Beta-1 ANTAGONISTS

Question 28

What is the mechanism of action of digoxin?

Answer 28

1) Block Na+/K+ ATPase 2) Accumulation of intracellular Na+ 3) Reduction in Na+/Ca++ exchange 4) INFLUX of Ca++ from extracellular space *****Net ionotropic effect*****

Question 29

What are the cardiac effects of Digoxin?

Answer 29

1) Positive ionotropy 2) Direct vagal effect 3) Increased coronary blood flow 4) Proarrhythmic

Question 30

Why is digoxin used in patients with A-fib w/ RVR?

Answer 30

Direct vagal effect decreases AV conduction

Question 31

What EKG change is characteristic of Digoxin?

Answer 31

Hockey stick ST depression

Question 32

What is the proarrhythmic effect of digoxin related to?

Answer 32

K+

Question 33

What is the half-life of digoxin?

Answer 33

36-48 hours

Question 34

How long does it take to achieve steady-state blood levels of digoxin?

Answer 34

7 days

Question 35

How is digoxin excreted?

Answer 35

Kidney

Question 36

What are the adverse effects of Digoxin?

Answer 36

1) Hypokalemia 2) Acid-base disbalance 3) Arrhythmia (AV block)

Question 37

What are the first symptoms that patients complain of with digoxin that should be concerning to you?

Answer 37

Anorexia Nausea Vomiting Visual distrubance

Question 38

What is the role of Digoxin in the treatment of HF?

Answer 38

Used frequently in HF, especially in CHF and a-fib w/ RVR; however - Improves quality of life but NOT all-cause mortality

Question 39

How is Digoxin overdose reversed?

Answer 39

Cholestyramine

Question 40

List the phosphodiesterase 3 inhibitors.

Answer 40

Inamrione | Milrinone

Question 41

What is the mechanism of action of the phosphodiesterase 3 inhibitors?

Answer 41

- Type III Phosphodiesterase degrades cAMP | - inhibition INCREASES cAMP

Question 42

What is the effect of cAMP in the heart?

Answer 42

Increased intracellular Ca++ leading to enhanced contractility

Question 43

What are the cardiovascular effects of the phosphodiesterase 3 inhibitors?

Answer 43

- Positive ionotrope - Positive lusotropy - Balanced venous and arterial dilation ****All increase CO****

Question 44

What setting are Inamrinone and Milrinone used in?

Answer 44

ICU i.e. only for short-term support of advanced CHF