Cardio

Question 1

Class 1 antiarrhythmic block…

Answer 1

Sodium Channels

Question 2

Class 1a antiarrhytmic block…

Answer 2

Rapid sodium channels (slows conduction velocity) and potassium channels (prolongs AP and refractory period)

Question 3

Examples of class 1a antiarrhythmics (3)

Answer 3

Quinidine, procainamide, disopyramide

Question 4

Class 1b antiarrhythmic drugs block ___ and only affects the ____. List 2 examples

Answer 4

Blocks sodium channels at increased heart rate thus slows conduction; only affects the ventricular tissue. Examples - lidocaine and mexilitine.

Question 5

Class 1c antiarrhythmic drugs blocks ____ channels and affects ____ tissue. List most common example.

Answer 5

Affects sodium channel; affects atrial and ventricular; example flecainide

Question 6

Class II antiarrhythmic drugs block ____. List four examples.

Answer 6

Beta adrenergic blockers (SLOW AV nodal conduction). Examples: Atenolol, carvedilol, propanolol, esmolol

Question 7

Class III antiarrhytmic block ____. Which tissue(s) are affected. List 2 examples.

Answer 7

Potassium channel blockers - for refractory arrhythmias only. Affect atrium and ventricle. Examples: Amiodarone, sotolol

Question 8

Class IV antiarrhymic block ____. List 3 examples.

Answer 8

Inhibits the slow calcium channels responsible for AV and SA node depolarization. Examples: diltiazem, veramapil, nifedinpine, amlodipine

Question 9

Amlodipine is a ___ channel blocker; it’s main effects is ____ systemic vascular resistance.

Answer 9

Calcium; decreased systemic vascular resistance

Question 10

ACE inhibitors - inhibit the conversion of ____ to ____, preventing vasoconstriction resulting in vasodilation; casues ___ sodium uptake in the ____. Dec/Inc Aldosterone?

Answer 10

inhibit the conversion of Ang I to Ang II, preventing vasoconstriction resulting in vasodilation; casues decreased sodium uptake in the PCT. Dec Aldosterone.

Question 11

What are some side effects of amidarone, and what time of antiarrhythmic is it?

Answer 11

SE: hepatic disease, neuro, GI, pulmonary fibrosis, thyroid. Class III.

Question 12

What drug slows conduction via the AV node and decreases activity of the NaK-ATPase pump and the Na exchanger – thus increases intracelluarl sodium and calcium.

Answer 12

Digoxin

Question 13

Hydralazine: arteroile or venous dilator? Increased/Decreases renin release so used with diuretics in cardiac patients? Preload or afterload reducer? Aso acts by altering calcium/potassium metobilism in the smooth muscle?

Answer 13

Arterial dilator. Increases renin release. Afterload reducer. Alters calcium.

Question 14

MOA of prazosin?

Answer 14

Alpha 1 adrenergic antagonist.

Question 15

MOA of pimobendan?

Answer 15

Increased calcium sensitization or troponin; also is a phosphodiesterase/PDE III inhibitor.

Question 16

Sildenafil: MOA? Inactivates the enzyme that would breakdown ___ to ____ which are important for the production of _______ and prostacycline.

Answer 16

PDE5 inhibitor. Inactivates the enzyme that would breakdown cAMP to cGMP which are important for the production of Nitric Oxide and prostacycline.

Question 17

Use of nitroglycerin?

Answer 17

Relaxes vascular smooth muscle (primarily venous and coronary artery) –> reduces preload and some afterload.

Question 18

Sodium nitroprusside: Use?

Answer 18

Arterial and venous vasodilator – decreased peripheral resistance, increases heart rate.

Question 19

Breakdown product of sodium nitroprusside?

Answer 19

Cyanide

Question 20

What are the main drugs used for SVT? Drug type and class. What do they slow?

Answer 20

SVT=BCD - beta blocker (class II), calcium channel blocker (class IV), digoxin. All slow conduction through the AV node.

Question 21

What are the main drugs used for ventricular tachycardias?

Answer 21

VT=SPAM; Sotolol (class III), procainamide (class 1a), atenolol (class II), mexilitine (class Ib).