Anti dysrhythmics /certified fixed orthodontic courses by Indian dental academy

INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com


Dysrhythmia


Any deviation from the normal rhythm of the heart

Antidysrhythmics


Drugs used for the treatment and prevention of
disturbances in cardiac rhythm




Inside the cardiac cell, there exists a net
negative charge relative to the outside of
the cell.









This difference in the electronegative charge.
Results from an uneven distribution of ions
(sodium, potassium, calcium) across the cell
membrane.
An energy-requiring pump is needed to
maintain this uneven distribution of ions.
Sodium-potassium ATPase pump




A change in the distribution of ions causes
cardiac cells to become excited.



The movement of ions across the cardiac cell’s
membrane results in the propagation
of an electrical impulse.



This electrical impulse leads to contraction
of the myocardial muscle.


Four Phases


The SA node and the Purkinje cells each have separate
action potentials.




System commonly used to classify
antidysrhythmic drugs




Class 1









Class Ia
Class Ib
Class Ic

Class II
Class III
Class IV
Other


Class I




Membrane-stabilizing agents
Fast sodium channel blockers
Divided into Ia, Ib, and Ic agents, according
to effects


Class I
moricizine




General Class I agent
Has characteristics of all three subclasses
Used for symptomatic ventricular and life-threatening
dysrhythmias


Class Ia
quinidine, procainamide, disopyramide





Block sodium channels
Delay repolarization
Increase the APD
Used for atrial fibrillation, premature atrial
contractions, premature ventricular contractions,
ventricular tachycardia, Wolff-Parkinson-White
syndrome

Class Ib
tocainide, mexiletine, phenytoin, lidocaine





Block sodium channels
Accelerate repolarization
Decrease the APD
Used for ventricular dysrhythmias only
(premature ventricular contractions, ventricular
tachycardia, ventricular fibrillation)


Class Ic
encainide, flecainide, propafenone





Block sodium channels (more pronounced effect)
Little effect on APD or repolarization
Used for severe ventricular dysrhythmias
May be used in atrial fibrillation/flutter


Class II
Beta blockers: atenolol, esmolol, petaprolol,
propranolol





Reduce or block sympathetic nervous system
stimulation, thus reducing transmission of impulses in
the heart’s conduction system
Depress phase 4 depolarization
General myocardial depressants for both
supraventricular and ventricular dysrhythmias


Class III
amiodarone, bretylium, sotalol, ibutilide







Increase APD
Prolong repolarization in phase 3
Used for dysrhythmias that are difficult to treat
Life-threatening ventricular tachycardia or fibrillation,
atrial fibrillation or flutter—resistant to other drugs
Sustained ventricular tachycardia


Class IV
verapamil, diltiazem




Calcium channel blockers
Depress phase 4 depolarization
Used for paroxysmal supraventricular tachycardia; rate
control for atrial fibrillation and flutter


Other Antidysrhythmics
digoxin, adenosine


Have properties of several classes and are not placed
into one particular class


Digoxin


Cardiac glycoside



Inhibits the sodium-potassium ATPase pump



Positive inotrope—improves the strength of cardiac
contraction



Allows more calcium to be available for contraction



Used for CHF and atrial dysrhythmias



Monitor potassium levels, drug levels, and
for toxicity

adenosine (Adenocard)








Slows conduction through the AV node
Used to convert paroxysmal supraventricular
tachycardia to sinus rhythm
Very short half-life
Only administered as fast IV push
May cause asystole for a few seconds
Other side effects minimal


ALL antidysrhythmics can cause
dysrhythmias!!


Hypersensitivity reactions







Nausea
Vomiting
Diarrhea
Dizziness
Blurred vision
Headache







Obtain a thorough drug and medical history.
Measure baseline BP, P, I & O, and
cardiac rhythm.
Measure serum potassium levels before
initiating therapy.







Assess for conditions that may be
contraindications for use of specific agents.
Assess for potential drug interactions.
Instruct patients regarding dosing schedules
and side effects to report to physician.







During therapy, monitor cardiac rhythm, heart
rate, BP, general well-being, skin color,
temperature, heart and breath sounds.
Assess plasma drug levels as indicated.
Monitor for toxic effects.








Instruct patients to take medications as
scheduled and not to skip doses or double up
for missed doses.
Patients who miss a dose should contact their
physician for instructions if a dose is missed.
Instruct patients not to crush or chew any oral
sustained-release preparations.






For class I agents, monitor ECG for QT
intervals prolonged more than 50%.
IV infusions should be administered with
an IV pump.




Patients taking propranolol, digoxin, and other
agents should be taught how to take their own
radial pulse for 1 full minute, and to notify
their physician if the pulse is less than 60
beats/minute before taking the next dose of
medication.




Monitor for therapeutic response:
Decreased BP in hypertensive patients
 Decreased edema
 Regular pulse rate or
 Pulse rate without major irregularities, or
 Improved regularity of rhythm



Leader in continuing dental education


Anti dysrhythmics /certified fixed orthodontic courses by Indian dental academy

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (14)

Similar to Anti dysrhythmics /certified fixed orthodontic courses by Indian dental academy

Similar to Anti dysrhythmics /certified fixed orthodontic courses by Indian dental academy (20)

More from Indian dental academy

More from Indian dental academy (20)

Recently uploaded

Recently uploaded (20)

Anti dysrhythmics /certified fixed orthodontic courses by Indian dental academy