Electrocardiogram (ECG) Flashcards
What is the intrinsic conduction system(nodal system)?
A specialized non-contractile myocardial tissues ensuring that heart muscles depolarizes and repolarizes in a ordered manner from atria to ventricle consisting of:
1) SA node
2) AV node
3) AV bundle (bundle of His)
4) right & left bundle branch
5) purkinje fibers
What is an ECG?
It is a graphic recording of the electrical changes occurring in the muscle tissue during the cardia cycle (a record of voltage & time), it can give info about heart rate, heart rhythm/regularity, impulse conduction time & pathways, Consisting of deflection waves, P wave (atrial depolarization), QRS complex (ventricular depolarization), T wave (ventricular repolarization), it has four aspects:
1) machine (roll paper moves to represent time, stylus moves up & down due to voltage representing the electrical events
2) electrodes (4 limb, 6 chest)
3) grids (x-axis is time in seconds (usually 25mm/s = one small block 0.04s one large block 0.20s), (Y-axis is the electrical impulse 10mm/mV)
4) leads (Bipolar (two electrodes - & + they are the limb leads I, II & III) ,Unipolar (Only + pole - is obtained by mixing other electrodes it has two types Augmented limb leads (aVF, aVL & aVR & precordial/chest leads (V1, V2, V3, V4, V5, & V6), ground lead) it shows a view of the heart electrical activity, 12 leads are used to record a comprehensive picture of the electrical activity of the heart for diagnostic purposes & the
What is meant by bradycardia?
Slow heart beat
What is tachycardia?
Fast heart rhythm
What is meant by ventricular tachycardia?
Fast beating ventricles
What is meant by Ventricular Fibrillation?
Chaotic contraction of the ventricles
What is meant by Atrial Flutter?
Fast regular beating of the atria
What is meant by Atrial Fibrillation?
Irregular rapid rhythm of the atria
What are the Ventricular Ectopic Beats/premature ventricular contraction (PVC)?
Originates from the ventricles, where they contract earlier than usual causing the sensation of a skipped or extra heart beat
Which lead can you use to monitor a patient?
Lead II
What are the different views of the leads?
Lead I: right arm to left arm
Lead II right arm to left foot
Lead III: left arm to left foot
aVR: heat to right arm
aVL: heart to left arm
aVF: heart to left leg
What can you diagnose using the ST segment?
Myocardial infarction
What is the use\age of the 12 leads?
To diagnose the location of the myocardial infarction
The RR interval is used to calculate what?
Heart rate depending on the number of boxes in between 1=300, 2=150, 3=100, 4=75, 5=60, 6=50 given that the paper is moving at a speed of 25mm/s
What can you obtain from an ecg?
Heart rate, heart rhythm, impulse conduction time interval, abnormal conduction pathways
