20. Chap 14.3, 14.4 Angina and arrythmias

Name the most typical class of anti-anginal medications

Organic nitrates

How is nitroglycerin typically administered? (3 ways)

Sublingual

Creams

Patches

What is the primary indication for nitroglycerin?

Angina pectoris

How do nitrates work to decrease angina?

Dilate peripheral vasculature, decreasing cardiac preload and afterload

What is the effect of decreased cardiac preload and afterload on the heart?

Decreased cardiac workload, decreased O2 demand

How quickly does sublingual nitroglycerin work? How long does it last?

Starts working after 1-3 minutes, works for 30-60 minutes

Does tolerance to nitrates occur? How can we impact tolerance?

Yes, continuous administration can cause tolerance

Effectiveness restored when nitrates discontinued

How can we prevent nitrate tolerance?

Prevent via daily nitrate-free intervals, ex. patch 12 hours on, 12 hours off

What are some potential negative side effects of nitrates? (3)

Headache and dizziness

Orthostatic hypotension

Increased vasolidation

Can pts using nitrate use whirlpools or hottubs?

NO, avoid exposure to heat

What is one strategy to make sure that pts taking nitrates always have them near?

Check the drug viability and have the drug ready before the rehab session

What are the classes of drugs that help decrease cardiac arrhythmias? (4)

1. Sodium channel blockers

2. Beta blockers

3. Drugs that prolong repolarization

4. Calcium channel blockers

How do class 2 (beta blockers) help decrease cardiac arrhythmias?

Decrease HR by decreasing sympathetic stimulation of heart

How do class 4 (calcium channel blockers) help decrease cardiac arrhythmias?

Limit calcium excitation of SA and AV nodes, decreasing HR

What do class 1 (sodium channel blockers) do to decrease cardiac arrhythmias?

Stabilize cardiac cell excitability by inhibiting abnormal sodium channel opening

What are the types of class 1 (sodium channel blocker) cardiac arrhythmia drugs? (3) (just names)

IA

IB

IC

How do class 3 (drugs that prolong repolarization) drugs for cardiac arrhythmia work?

They lengthen the time period before the next AP can be generated in the heart, letting the heart rest between beats

Which of the four classes of cardiac arrhythmia drugs are used for the most serious heart conditions?

Class 3

Define the proarrhythmic effect

A negative side effect of a drug that treats cardiac arrhythmia that causes a new arrhythmia to occur

Drugs that help slow the progression of heart disease generally do what?

Decrease the amount of stress on the heart

How do diuretics help with heart failure?

Decrease fluid accumulation in the body, reducing cardiac workload

How do beta blockers help with heart failure?

Reduce sympathetic stimulation of heart and vasculature, normalizing HR

How do vasodilators help with heart failure?

Decrease pressure in the arterial system

How do RAS drugs help with heart failure?

Decrease harmful effects of Ang-II on heart and vasculature

Define a positive inotropic drug

One that helps increase cardiac output and reduce symptoms of CHF

What is the primary positive inotrope drug? What plant is it derived from?

Digitalis

Derived from foxglove plant

What is the mechanical effect that digitalis uses to assist with CHF?

Brings Na into the cell, more Ca+ in the cell, stronger muscle contractions

What is the autonomic effect of digitalis on the heart? (2 things)

Stimulates vagus nerve

Inhibits sympathetic stimulation to heart

What is the primary problem with digitalis? How common is it? What are some of the symptoms?

Digitalis toxicity, affects 20-25% of hospitalized pts

Common symptoms: GI distress, fatigue, confusion, depression, blurred vision, arrhythmias

What are other positive inotrope drugs? (2) Are they any better than digitalis? When are they typically used?

Phosphodiesterase inhibitors, dopamine

Not better than digitalis

Typically used in acute or severe heart failure