Cardio Flashcards
Class 1 antiarrhythmic block…
Sodium Channels
Class 1a antiarrhytmic block…
Rapid sodium channels (slows conduction velocity) and potassium channels (prolongs AP and refractory period)
Examples of class 1a antiarrhythmics (3)
Quinidine, procainamide, disopyramide
Class 1b antiarrhythmic drugs block ___ and only affects the ____. List 2 examples
Blocks sodium channels at increased heart rate thus slows conduction; only affects the ventricular tissue. Examples - lidocaine and mexilitine.
Class 1c antiarrhythmic drugs blocks ____ channels and affects ____ tissue. List most common example.
Affects sodium channel; affects atrial and ventricular; example flecainide
Class II antiarrhythmic drugs block ____. List four examples.
Beta adrenergic blockers (SLOW AV nodal conduction). Examples: Atenolol, carvedilol, propanolol, esmolol
Class III antiarrhytmic block ____. Which tissue(s) are affected. List 2 examples.
Potassium channel blockers - for refractory arrhythmias only. Affect atrium and ventricle. Examples: Amiodarone, sotolol
Class IV antiarrhymic block ____. List 3 examples.
Inhibits the slow calcium channels responsible for AV and SA node depolarization. Examples: diltiazem, veramapil, nifedinpine, amlodipine
Amlodipine is a ___ channel blocker; it’s main effects is ____ systemic vascular resistance.
Calcium; decreased systemic vascular resistance
ACE inhibitors - inhibit the conversion of ____ to ____, preventing vasoconstriction resulting in vasodilation; casues ___ sodium uptake in the ____. Dec/Inc Aldosterone?
inhibit the conversion of Ang I to Ang II, preventing vasoconstriction resulting in vasodilation; casues decreased sodium uptake in the PCT. Dec Aldosterone.
What are some side effects of amidarone, and what time of antiarrhythmic is it?
SE: hepatic disease, neuro, GI, pulmonary fibrosis, thyroid. Class III.
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.
Digoxin
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?
Arterial dilator. Increases renin release. Afterload reducer. Alters calcium.
MOA of prazosin?
Alpha 1 adrenergic antagonist.
MOA of pimobendan?
Increased calcium sensitization or troponin; also is a phosphodiesterase/PDE III inhibitor.
Sildenafil: MOA? Inactivates the enzyme that would breakdown ___ to ____ which are important for the production of _______ and prostacycline.
PDE5 inhibitor. Inactivates the enzyme that would breakdown cAMP to cGMP which are important for the production of Nitric Oxide and prostacycline.
Use of nitroglycerin?
Relaxes vascular smooth muscle (primarily venous and coronary artery) –> reduces preload and some afterload.
Sodium nitroprusside: Use?
Arterial and venous vasodilator – decreased peripheral resistance, increases heart rate.
Breakdown product of sodium nitroprusside?
Cyanide
What are the main drugs used for SVT? Drug type and class. What do they slow?
SVT=BCD - beta blocker (class II), calcium channel blocker (class IV), digoxin. All slow conduction through the AV node.
What are the main drugs used for ventricular tachycardias?
VT=SPAM; Sotolol (class III), procainamide (class 1a), atenolol (class II), mexilitine (class Ib).
