Week 1 - exam 1 Flashcards
what is a Dysrhythmia?
variation from the normal electrical rate or rhythm of conduction. (synonym: arrhythmia)
What is the difference between ECG and Telemetry?
Electrocardiogram: EKG/ECG; graphic representation of electrical activity in the heart; is a visible record of the individual waves of depolarization and repolarization of the myocardial cells – captures over a short period of time (one second)
Telemetry: the use of electronic devices to record or measure a distant event and transmit the data to a receiver – continuous reading, does not stop until the patient is disconnected
what does ectopic mean?
irritable spot in the electrical cells = abnormal
Electrical System of the Heart
Starts in the SA node (top of atria) – AV node – bundle of his– RLBB – fibers
Mechanical vs electrical cells
Mechanical cells – pumping work – must be stimulated to work = check these by checking circulation (color, pulses, mental status)
Electrical cells – stimulates the mechanical cells = check with ECG or tele
which plane are the leads in
Limb leads or frontal plane Leads I, II, III, aVr, aVl, aVf
Precordial (chest) or horizontal plane leads - V1-V6
ECG lead placement
V1 – fourth intercostal space and the right sternal border
V2 – fourth intercostal space on the left sternal border
V3 – half way between V2 and V4
V4 – fifth intercostal space and the left midclavical line
V5 – fifth inercostal space and the left antierior axillary line
V6 – fifth inercostal space at the left mid axillary line
information about ECG strip? p wave, QRS, etc. what do they mean?
P wave – atrial depolarization = contraction
PR interval – atrial repolarization = resting
QRS - ventricular repolarization = contraction
T wave- vent repolarization = resting
Voltage is measure when you looking by the height
One small box is 0.1 millivolt
Time is measured with looking horizontal – this is important
One small box is 0.04 seconds
Big box is 0.20 seconds
5 steps to reading a rhythm
- Heart Rate
- Heart Rhythm
- P wave
- PR Interval (PRI)
- QRS Complex
Read an ECG; Step 1 – Heart Rate
Normal is 60-100 bpm
Most accurate method of counting – print for a minute and count how many PQRS occur in a minute
Small black line is 3 seconds
Count QRS in 6 seconds (ticks on the paper) and times by 10
Read an ECG Step 2 – Heart Rhythm
Rhythm
Sequence of beats of heart
Can be classified as
Regular pattern: Interval between R waves Regular
Irregular pattern: Interval between R waves is NOT regular
Irregular if it varies by >= 1.5 small boxes
Step 3 – Examine the p-wave
THE P wave! P waves are produced then the left and right atria depolarize
P wave is the first deviation from the isoelectric line
Represents the SA node pacing/firing at regular intervals
Think of P wave & ask the following 5 questions;
- Do I see P waves (look for them prior to the QRS)
- Are P waves regular? (measure P wave to next P wave)
- Is there ONE P wave for each QRS
- Are the P waves smooth, rounded & upright or are the inverted (upside down)
- Does each P wave look like the others?
what is the normal length of a normal P wave
Length of a normal p wave is: 0.06-0.12 seconds
Step 4: PR–interval
The PRI (PR Interval) measures the time “interval” from the beginning of the atrial contraction to the beginning of the ventricular contraction (AKA atrial depolarization is complete)
Measured from onset of P wave to Onset of QRS
Normal Interval is 0.12 – 0.20 (3 to 5 small squares)
what is the normal length of a PR interval?
Normal Interval is 0.12 – 0.20 (3 to 5 small squares)
