ECG Flashcards
The p wave is?
Atrial depolarization
The PR interval is?
conduction from SA to AV node
QRS interval is
ventricular muscle depolarization
T wave is
ventricular muscle repolarization
Which lead is used for amplitude measurements?
Lead II- right shoulder to left leg
Positive waves are?
waves traveling toward the positive electrode
ECG is best to evaluate?
Heart rate, heart rhythm, and conduction
What are the 4 steps to evaluate and ECG?
- Evaluate for artifacts, quality, and calibrations
- Determine the heart rate
- Name the cardiac rhythm
- Evaluate the P-QRS-T complex configurations and morphologies
What does amplitude increase indicate?
Chamber enlargement
What is standard calibration for ECG?
Gain: 10mm/mV = 1cm/mV
- each small box is 1mm
at 50mm/sec, 1 small box =?
0.02 seconds
Name some artifacts that can render ECG uninterpretable?
purring, respiration movememt, motion, muscle twitches
Normal feline heart rate
140-220
Normal canine heart rate
60-160
What are the two most common cardiac rhythms?
Sinus rhythm and sinus arrhythmia
What is a sinus rhythm?
normal P wave with similar shaped QRS and similar P-P interval
What is sinus arrhythmia?
irregular rhythm originated from the SA node, normal in many species, normal QRS for every P with varying normal heart rate because of high vagal tone, may see varying P height
What is a wandering pacemaker?
varying P height, seen with sinus arrhythmia
How tall should the T wave be
< 1/3 QRS, can even be negative or biphasic
When may you see a sinus bradycardia in cattle?
Lack of food intake