EKG FINAL Flashcards
Atrial depolarization (contraction)
P wave
Ventricular depolarization, atrial repolarization
QRS complex
Ventricular repolarization (resting phase)
T wave
Each tiny box equals
0.04 seconds
5 tiny boxes = 1 big box (0.20 seconds)
Each big box equals
0.20 seconds
5 big boxes = 1 second
Normal PR interval should be
0.12 to 0.20 seconds
Normal QRS interval should be
0.04 to 0.10 seconds
Questions to ask
1) Is there a P-wave before every QRS?
2) Is each QRS the same distance apart? Do they march out?
3) It is regular or irregular?
4) Is it fast or slow?
Normal sinus rhythm
HR 60-100 bpm
Regular rhythm
P wave for every QRS
PR interval & QRS complex are normal
Sinus bradycardia
HR<60 bpm
Causes: Normal in athletes, response to carotid massage, Valsalva, increased ICP
Sx: pale, cool skin, hypotension, angina, SOB, dizziness, confusion
Treatment: pacing, atropine
First Degree Heart Block
PR interval > 0.20 seconds
MI, CAD, hypothyroid, vagal stim, meds- digoxin, BB, CCBs
Watch/monitor
Precursor to lethal heart blocks
Second Degree Heart Block
Type I - Wenckebach
Progressive prolonged PR interval until P wave is blocked
Dig, BB, CCBs can cause.
May not need treatment, but could progress
Second Degree Heart Block
Type II
Blocked P wave
(Fixed PR, dropped QRS complex)
Ischemia, myocarditis, post cardiac surgery, meds- CCBs & digoxin
May progress to complete heart block
Treat w/ pacemaker
Third Degree Heart Block (Complete)
P wave no relation to QRS
Ischemia, MI, fibrosis, cardiomyopathy
Treat w/ pacemaker
Sinus Tachy
Normal, but fast
HR >100-180
Causes: SNS stim, anxiety, pain, fever, caffeine, alcohol, nicotine, dehydration
Sx: Dizzy, SOB, low BP, pallor
Treatment varies, fix the problem. BB, anxiety meds, etc.