Heart Week 2: Medicine

Question 1

What classification of drugs reduces preload? Give an example.

Answer 1

diuretics (thiazide).

venodilators (nitro).

Question 2

What classification of drugs reduces afterload? Give an example.

Answer 2

arteriodilators (Ca++ channel blockers, eg- verapamil).

Question 3

What classification of drugs reduces heart rate and contractility? Give an example.

Answer 3

beta-blockers (metoprolol, , carvedilol).

Question 4

What classification of drugs increases contractility? Give an example.

Answer 4

inotropics (digoxin).

Question 5

Does having more epi/norepi correlate to increased or decreased mortality?

Answer 5

increased

Question 6

How can vasodilation reduce preload?

Answer 6

increase venous capacitance which will decrease return to the heart.

Question 7

What part of the cardiac cycle does Ca++ channel blockers affect (preload, afterload, inotropics, HR)?

Answer 7

It decreases afterload by reducing smooth muscle contractions.

Question 8

Is digoxin a Ca++ channel blocker? How does it work?

Answer 8

No. It works by inhibiting the K/Na pump. This keeps more Na inside the cell which changes the gradient for the Na/Ca pump and keeps more Ca inside the cell. Thus increasing contractility.

Question 9

How can K+, Mg+ and Ca++ affect digoxin toxicity?

Answer 9

low K = digoxin toxicity
low Mg = digoxin toxicity
high Ca = digoxin toxicity

Question 10

What do beta1 and beta2 receptors do?

Answer 10

beta1: increase CO, HR and contractility.
beta2: dilates arteries (also has B1 effects, but to a lesser extent)

Question 11

What do alpha1 and alpha2 receptors do?

Answer 11

alpha1: smooth muscle constriction
alpha2: inhibits norepi release (norepi causes vasodilation)

Question 12

What are the symptoms of digitalis overdose?

Answer 12

Increases in intracellular Ca++ leads to DADs which are arrhythmogenic. It can lead to ectopic beats, AV block, and AV jxn rhythms.

Question 13

Is carvedilol a direct vasodilator? How does it function?

Answer 13

Yes. It works through release of nitrous oxide (N2O), and not thru a beta-receptor.

Question 14

What are the 6 steps for treating heart failure?

Answer 14

1. modify activity (“take it easy”), lose weight, decrease hypertension
2. decrease Na
3. diuretics if edema is present
4. ACEI (+/- digitalis)
5. vasodilators: nitrates if dyspnea bc of high preload, arteriodilators if fatigue bc of decreased CO
6. beta-blockers: carvedilol, metoprolol (+/- ACEI and diuretics)