Ischemic Heart Disease, Heart Failure, Arrhythmias

What is the goal of ischemic heart disease treatment?

reduce workload on heart

decrease O2 demand

increasing O2 supply

increase blood supply to heart

What drug classes are used to treat ischemic heart disease?

Nitrates

CCB

Betal blockers

What are nitrates?

prodrugs for NO

What do nitrates do?

vasodilate

Examples of nitrate drugs

nitroglycerin

isosorbide dinitrate

What is nitroglycerin used for?

acute symptoms of angina

What is the drug of choice for acute symptoms of angina?

nitroglycerin

What is isosorbide mononitrate used over nitroglycerin?

longer acting (longer half life)

Side effects of nitrates?

orthostatic hypotension

reflex tachycardia

throbbing headache

flushing

Why are nitrates used for ischemic heart disease?

they vasodilate, decreasing BP (after load) and also increasing perfusion to heart

What do calcium channel blockers do?

decrease heart rate and force of contraction

vasodilate

What CCB have stronger heart effects?

verapamil

diltiazem

Which CCB predominately affect BVs?

nifedipine

amlodipine

Side effects of CCB?

headache

nausea

edema

flushing

bradycardia for cardiac specific ones

How do CCB treat ischemic heart disease?

decreases heart work by decrease HR + contraction

vasodilates decreasing afterload and increasing blood to heart

What kind of angina are beta blockers used for?

extertional angina only

Why aren't beta blockers used for variant angina?

blocking B2 can cause vasoconstriction, which would worsen variant angina

Why are beta blockers used to treat ischemic heart disease?

decrease workload on heart by decreasing HR + contraction

What are the goals of congestive heart failure treatment?

increase contraction

decrease preload and afterload (BP)

normalize HR and rhythm

How do ACE inhibitors treat heart failure?

decrease afterload (BP)

How do Ang II receptor blockers treat heart failure?

decrease afterload (BP)

How do B-blockers treat heart failure?

stop downward spiral + arrhythmic death (decreasing cardiac workload)

How do vasodilators treat heart failure?

decrease afterload and increase perfusion of heart

Example of vasodilator used to treat heart failure?

hydralazine

Why are diuretics used to treat heart failure?

HF causes a decrease in CO and therefore increase in fluid retention, diuretics combat this fluid retention

diuretics also decrease BP (afterload)

Why are cardiac glycosides used to treat heart failure?

increase heart contraction

How do cardiac glycosides increase heart contraction?

block NKA pump, resulting in an increase in Ca2+ in cell

Example of cardiac glycoside?

Digoxin

Why are beta agonists used to treat HF?

increase contractility

Why are PDE inhibitors used to treat HF?

increase contractility of heart and vasodilate (decrease afterload)

How do PDE inhibitors work?

PDE causes cAMP breakdown, PDE inhibitors inhibit this breakdown, resulting in more cAMP and therefore more contraction in heart and less contraction of BVs (vasodilation)

What are the 3 main ways to treat congestive heart failure?

Decrease cardiac workload

Control excess fluid

Enhance contractility

What does digoxin compete with?

K+ on NKA pump

Why should patients on thiazide or loop diuretics not take digoxin?

They will have low K+ therefore not much to compete with digoxin, resulting in increase sensitivity to the drug and an increased risk for side effects digoxin toxicity

What is an antidote for digoxin toxicity?

K+ (potassium)

What are the three ways arrhythmias occur?

1. hearts pacemaker develops an abnormal rhythm

2. another part of heart takes over as pacemaker

3. normal conduction path is interrupted

What are causes of arrhythmias?

1. cardiac ischemia

2. increase in or sensitivity to autonomic transmitters

3. toxic substances

4. idiopathic

What are the 4 classes of anti-arrhythmics?

Class 1: Na+ channel blockers

Class 2: Beta Blockers

Class 3: K+ channel blockers

Class 4: CCB

How do class 1 Na+ channel blockers work to treat arrhythmia?

slow depolarization in fast AP cells

Which class of anti-arrhythmics focus on rate control?

Class II: beta blockers

Class IV: CCB

Which class of anti-arrhythmics focus on rhythm control?

Class I: Na+ channel blockers

Class II: K+ channel blockers

How to beta blockers (class II) treat arrhythmias?

slow depolarization in slow AP cells by increasing AP and refractory period lengths

decreases HR and contraction

Class II beta blockers are used to treat which type of arrhythmia?

tachyarrhythmias

Side effects of class II Beta blockers to treat arrhythmias?

hypotension

bradycardia

How do class III K+ channel blockers work?

prolong repolarization phase

Class III K+ channel blockers are used to treat what types of arrhythmias?

Afib

ventricular tachycardia

Example of Class III K+ channel blocker?

Amiodarone

Side effects of amiodarone?

corneal deposits

thyroid problems

What kind of drug is Amiodarone? What is it used for?

K+ channel blocker

used to treat arrhythmias

How do Class IV CCB treat arrhythmias?

prolongs repolarization phase in slow AP cells

Class IV CCB are used to treat which type of arrhythmias?

arterial arrhythmias

Example of CCB used to treat arrhythmias?

Diltiazem

Verapamil

What CCB do you not want to use to treat arrhythmias and why?

Amlodipine, Nifidepine (dihydropyridines) because they can cause arrhythmias

What is the DOC for paroxysmal supra ventricular tachycardia?

adenosine

How does adenosine work to treat arrhythmias?

causes hyperpolarization and decrease in NE

What kind of drug is lidocaine?

Na+ channel blocker

Lidocaine is used to treaT what kind of arrhythmia?

acute ventricular arrhythmias, especially after Myocardial Infarction

Side effects of lidocaine?

blurred vision

dizziness

tremor

What kind of drug is Flecainide/Propafenone?

Na+ channel blocker

Flecainide and Propafenone is used for what kind of arrhythmias?

life threatening supraventricular + ventricular arrhythmias

What is a side effect of felcainide and propafenone?

Can be proarrhythmic