Dysrhythmia Interpretation Flashcards
(42 cards)
Automaticity
creates an electrical impulse
Excitability
ability to respond to outside stimulus
Conductivity
receives an impulse and conducts it to an adjacent cell
Contractility
shortening of fibers in response to impulses
Polarized
resting membrane potential (movement of ions across a membrane)
Depolarization
Sodium goes in, Potassium goes out
electrical activation of cell caused by influx of sodium into cell while potassium exits
Repolarization
Potassium back in, Sodium back out
return of cell to resting state caused by re-entry of potassium into cell while sodium exits
Effective or absolute refractory period
Refractory Period
- phase in which cells are incapable of depolarizing
Relative Refractory period
phase in which cells require stronger-than-normal stimulus to depolarize
Pacemaker Sites
SA node, AV node, Bundle of HIS, Purkinje Fibers
Cardiac Cycle
Atrial depolarization (blood drains into ventricles) -> atrial contraction (atrial kick) -> AV node (impulse delayed ventricles fill) -> impulse moves through the common Bundle of HIS (divides into left and right branches) -> purkinje fibers (ventricular contraction)
Electrocardiogram (EKG)
looking at electrical activity of the heart viewed as “leads”
picked up by sensors placed on the skin (electrodes)
waves on the ECG correlate with the electrical activity conducted to the atria and ventricles
P wave
atrial depolarization
looking at where it leaves the baseline and returns back
want to know if there is a P wave present
QRS Complex
should be
T Wave
ventricular depolarization
Follows QRS complex and is usually in the same direction; coming back to resting state
*Atrial depolarization also occurs but is not visible on the EKG because it occurs at the same time at QRS
PR Interval
0.12 to 0.20 seconds
measured from beginning of P waves to the beginning of the QRS complex
represents time needed for sinus node stimulation, atrial depolarization and conduction through the AV node before ventricular depolarization
ST Segment
represents early ventricular depolarization
End of QRS complex to the beginning of the T wave
normally isoelectric
QT Interval
total time for ventricular depolarization and depolarization
Beginning of the QRS complex to the end of the T wave
varies w/ HR, gender, age and lead
Prolonged: can lead to lethal dysrhythmia Torsades de points
Sinus Tachycardia Intervention
Assessment; worry about perfusion
Want to address underlying causes: fever, pain, hypoxia, CHF, hypovolemia, dehydration, anxiety, drugs
continue to monitor
Six Second Method/Rule of 10
number of complete QRS complexes in 6 seconds of strip multiply by 10 and get the heart rate
ex: 9 QRS complex X 10 seconds = 90HR
Normal Sinus Rhythm
Rate: 60-100bpm Rhythm: atrial and ventricular regular P Waves: uniform, upright, one preceding each QRS PR Interval: 0.12-0.2 seconds QRS: 0.10 seconds or less
Sinus Tachycardia
Rate: usually 100-160bpm Rhythm: atrial and ventricular regular P waves: uniform, upright, one preceding each QRS PR Interval: 0.12-0.2 seconds QRS: 0.10 seconds or less
Sinus Bradycardia
Rate: less than 60 bpm Rhythm: atrial and ventricular regular P waves: uniform, upright, one preceding each QRS PR interval: 0.12-0.2 seconds QRS: 0.10 seconds or less
Vagal Stimulation
bearing down, coughing, sneezing
