Base top of the heart
Apex bottom of the heart
PEA pulseless electrical activity
good looking EKG, but no pulse
Check mechanical function (pumping) of the heart pulse and BP
Systole Contraction of the heart
Diastole Relaxation of the heart
Postive P wave Always sinus rhythm
Q-T interval less then half the R-R
horizontal represents time
Automaticity The ability of the heart to generate and conduct electrical impulses on its own
Excitability ability to respond to stimuli
Conductivity The ability to receive and transmit electrical impulses to adjacent cells.
Contractility ability to shorten and cause muscle contraction
Flat part of EKG Isoelectric line
absoulte refractory period no amount of stimulus can cause the heart to beat again "safe zone"
"absolutely safe"
Stuvia 2026-2027
, Relias Dysrhythmia Basic | Exam Questions & Verified Answers
relative refractory period a strong stimulus can cause the heart to go into a lethal arrythmia "danger zone"
lead 2 neg to postive = postive
SA Node (P wave) pacemaker of the heart
60-100
P wave atrial depolarization
AV node "QRS" 40-60, begins QRS
ventricular depolarization
Purkinje fibers last chance pacemaker
20-40
Ends depolarization
ectopic beat Cardiac beat starting at a point other than the SA node
Inverted P wave not sinus
QRS less than 0.12
(2-3 boxes)
ventricular depolarization
PR interval 0.12-0.20
QT interval less than half the R-R
Artifacts anything on EKG that is non-cardiac, distortions
T wave ventricular repolarization
counting rhythms 300, 150, 100, 75, 60, 50, 40, etc
normal sinus rhythm 60-100 bpm
all complexes normal and evenly spaced (P, QRS, T)
Stuvia 2026-2027