Affects of Electrolyte Disturbances and Drugs on ECG’s Flashcards
(20 cards)
What are normal EFC K+ levels
3.5-5.3mEq/L (3.5-5.3mmoles/L)
Hyperkalemia levels of K+ and “symptoms”
greater than 5.3mEq/L (higher than normal extracellular levels)
- peaked T waves
- widening QRS (decrease in conductivity
- cardiac standstill (arrest)
Hypokalemia levels of K+ and “symptoms”
less than 3.5,Eq/L (lower than normal extracellular levels)
- sluggish repolarization (flat T waves, U waves)
- bradycardias
Normal Calcium (Ca2+) levels
2.2-2.6Eq/L (4.4-5.3mmole/L)
Hypercalcemia levels and “symptoms”
greater than 2.6Eq/L
- Heightened depolarizaton and reploarization
- spastic contractions (skeletal)
Hypocalcemia
lower than 2.2Eq/L
- increased excitablility
- Q-T interval gets shorter
- Tachycardias
do we see hypo/hypercalcemia often
no the levels are well regulated by the body
Cardiac Glycosides: example, what do they do
- tend to increase CA+ within the sacroplasmic reticulum
- increases cadiac contractility (force of contraction)
can cause conduction blocks – due to decreased excitability and conduction velocity (SA to AV node)
example of a cardiac glycoside drug?
ex digitalis, digoxin
what do cardiac glycosides treat
- sometimes used to treat Afib, Aflutte
what do beta Adrenergic Sympathomimetics mimic?
sympathetic nervous system
what is a adrenergic sympathomimetic drug treat … what are the side effects
ex isoproterenal
slow heart rate (bradycardia) and blocks
side effects = Tachycardias, ventricular arrythmias
Alpha vs beta stimulation
??
what is a positive inotrope
inotrope is an agent that alters the force or energy of muscular contractions
(increases if positive, decreases if negative)
what is a positive chronotrope
Chronotropic drugs may change the heart rate and rhythm by affecting the electrical conduction system of the heart and the nerves that influence it
what is a negative dromotrope
A dromotropic agent is one which affects the conduction speed (in fact the magnitude of delay) in the AV node, and subsequently the rate of electrical impulses in the heart.
what is a parasympatholytic?
Blocks the parasympathetic system by competing with ACH
eg - ATROPINE
- used to treat bradycardia (drug will speed the heart up)
what is a Sympatholytic?
blocks beta 1 receptors in the heart
- called beta blockers eg INDEROL
- used to TREAT tachyarrythmias and hypertension
- can CAUSE bradycardia, blocks
What are Calcium Channel Blockers
promote smooth muscle relaxation
eg. Verapamil, Nifedipine
to treat ANGINA PECTORIS and HYPERTENSION
can CAUSE conduction problems (blocks)
Antiarrhythmics
Quinidine - used to treat atrial arrhythmia’s by suppression of conduction & automaticity
Lidocaine – used for ventricular arrythmias
can cause numerous ECG changes especially if dose to high
** amiodarone is drug of choice now for treating ventricular arythmias like V.fib and V.tach
