ES 310 Exam 3 11/25/13
1. An EKG is used to diagnose cardiac function (T/F)?
2. What is the best measure of cardiac function? BP???
3. In the normal heart, what does SA node discharge result in?
depolarization of atria (P-wave) -contraction of the heart -Calcium influx
4. What 5 things should you evaluate when interpreting an EKG strip??
-Rate –Rhythm -axis -hypertrophy -infarction
5. mean wave of depolarization heading away from positive electrode, direction will the deflection be (+ or
6. What structure must the atrial wave of depolarization pass through in order for the ventricles to
7 . What structure(s) does the wave of depolarization pass through that allows both ventricles to
depolarize essentially simultaneously?
8 . Atrial depolarization is characterized by what on an EKG tracing? Pwave
9 . Ventricular depolarization is characterized by what on an EKG tracing? QRS complex
10 . What is the PR interval? What is the normal duration? 0.12 – 0.20 normal if 100, irregular ventricular
- no single foci achieve dominance so all of them pace together
Atrial Fibrillation: irregular ventricular rhythm not of a healthy young individual
continuous chaotic atrial spikes
Result of multiple irritable atrial foci
Parasystolic- entrance is blocked so foci cant be overdrive-suppressed= all pace
Escape Rhythms: Atrial Junction Ventricular
Escape Rhythm: foci establishes the overdrive suppression from SA node and paces at
-SA node stops entirely and inherently paces at rate which produces an escape
Escape Beat: foci escapes overdrive suppression to emit one beat.
-Pause in pacing is brief and foci emit one beat before sinus rhythm returns
-atrial escape beat: pause before P-wave
Atrial escape Rhythm occurs after sinus arrest (60-80 bpm) still p-wave but looks
Junctional escape rhythm “isojunctional” (40-60bpm) -no p-wave or inverted p-wave
- inverted p-wave