Drugs Flashcards
Chronotropic
Change in HR
positive is increased HR
negative is decreased HR
Example: Adrenaline speeds up SA node=positive chronotopic action
Acetylcholine slows down SA node=negative chronotropic action
Inotropic
Change in the force of the contraction
positive is increased contraction
negative is the decreased contraction
Example: Digitalis=increases force of contraction from calcium loading, making it a positive inotropic action
Calcium channel blockers=decrease calcium levels in the heart, making it a negative inotropic action.
Dromotropic
Change in the speed of impulse
positive is increased velocity
negative is decreased velocity
Example: Adrenaline=increased velocity of conduction on the AV node, resulting in a positive action.
Cardiac glycosides=decreased velocity of conduction, making it a negative action.
Lidocaine
Class 1b Antiarrhythmic
Code Blue Medication
-Blocks NA channels and slows conduction (impulse transmission).
-Reduces automaticity (continuous/spontaneous) repolarization
-Treats: V-tach occurring in acute MI
What are the S/S of toxicity of lidocaine?
S-slurred speech
*paresthesias, numbness of lips and tongue
A-altered mental status
*drowsiness, dizziness, dysrhythmias, restlessness, confusion
M-muscle twitching
S-seizures
*conclusions, respiratory depression, cardiac arrest
What are the nursing implications for lidocaine?
-Monitor VS, LOC, ECG, and O2 saturation
-Do NOT confuse lidocaine with local anesthesia
What do Class IC (congenital) antiarrhythmics treat?
Atrial arrhythmias
What effect do Class IC (congenital) drugs have on the heart?
They slow depolarization by impacting NA+ influx.
Class II Beta Blockers, what do they do?
-Decrease tachycardias
-Decreases SNS in patients with sustained VT
-Decreases MI mortality
What are the indications/uses for Beta Blockers?
-Inappropriate sinus tachycardia
-Paroxysmal atrial tachycardia (PAT) from emotions
-Ventricular arrhythmias from exercise
-Long QT syndrome
-Mitral valve prolapse from arrhythmias
What do potassium blockers do?
They block potassium channels that are responsible for cardiac repolarization.
Amiodarone is used for what types of rhythms?
-Life-threatening arrhythmias
-SVT (particularly a-fib)
-V-tach
-V-fib
Nursing implications of Amiodarone:
-Careful IV administration may cause an inotropic effect
-Monitor ECG, BP, pulmonary status, and neurotoxicity
What can happen in the long-term use of Amiodarone?
Pulmonary dysfunction
What are the side effects of Amiodarone?
-ARDS (acute respiratory distress syndrome) Pulmonary Toxicity
-CHF
-Fatigue, hypotension, bradycardia, dizziness, NV, constipation, dizziness
Calcium Channel Blockers
Verapamil (Calan, Covera, Verelan)
diltiazem (Cardizem)
Why are Calcium channel blockers used?
-slow ventricular rate (a-fib or atrial flutter)
-terminate SVT caused by AV nodal reentrant circuit
Contraindications of Calcium channel blockers
ventricular tachycardias
Adenosine
