ECG Flashcards
What does a 12 lead electrocardiogram do?
Picks up the electrical impulses that travel from the sinoatrial node through the heart and records these into wave forms
What equipment do you need?
ECG machine, paper, electrodes, scissors and gauze swabs
What should you do prior to placing electrodes?
Gain consent
Reassure patient, I have these electrodes which I’m going to place on your chest and limbs which are attached to this machine and it’s going to pick up the electrical impulses that travel from the sinoatrial node through the heart and record it in wave form. There is no electrical current.
Before I start, I need to explain the importance of lying still as muscle movement interferes with the reading
Now that it’s time to place electrodes, what do you do?
-Provide privacy for patient dignity
-Perform hand hygiene
-Assess how well the patient can be still with on pillow, if they are having trouble breathing, lay the patient in semi-fowler’s position ensuring no muscle work is required to maintain the position
-Ask patient to remove clothing and jewelry above the waste and expose upper legs, assisting as needed
Where do you place the stickers?
-aVR/RA: inside of right wrist
-aVL/LA: inside of left wrist
-aVF/LF/LL: left ankle
-Earth/RF/RL: right ankle
-V1: 4th intercostal space at the right sternal border
-V2: 4th intercostal space at the left sternal border
-V3: 5th intercostal space at the left sternal border midway between V2 and V4
-V4: 5th intercostal space at the mid clavicular line
-V5: 5th intercostal space at the anterior axillary line
-V6: 5th intercostal space at the mid axillary line
Once the electrodes have been placed what do you do?
-Turn on machine
-Enter patient name, date of birth, URN
-Remind patient to remain as still and silent as possible
-Allow all traces to appear green on the ECG machine
Print
-Ensure patient details have been printed or apply patient detail sticker
-Remove clips
-Remove electrodes
-Thank patient
-Ensure patient is comfortable
-Clean lead wires and equipment
-Perform hand hygiene
Interpret ECG, sign and date
What should you check before interpreting the ECG reading?
-Make sure it’s the right way up
-The lead in the top left corner
-Check that it has the correct age, name, ID
-Write on the ECG if the patient has chest pain at the time the ECG was recorded
What should you check about the aVR lead
Check that its negative
and that the P wave points down
What should you check about the calibration square
-That it is 0.2 sec (1 large vertical squares)
-1.0 mV (2 large vertical squares)
-Some machines will generate 0.4 second calibration square
What should you check to interpret the reading
-Labeled correctly
-aVR lead is negative (P wave points down)
-Check for calibration square
What are two ways to calculate the rate
-On a standard 10 second 12 lead ECG, count the number of R waves (peaks) on the bottom rhythm lead and multiply by 6
-Or count the number of boxes between each R wave and divide that by 300
What are the average heart rate ranges for adults
-Normal: 60-100
-Tachycardia: greater than 100
-Bradycardia: less than 60
How do you know if the rhythm is regular
Use a blank piece of paper, mark the edge of the paper with small pencil lines that align with two R waves, then move the paper along the rhythm strip. Do your pencil marks still line up? If they do, then it is regular, if they don’t then it is irregular.
What are the main things we look for when interpreting an ECG
-Labeled correctly, name, date, URN
-aVR lead is negative (P wave points down)
-Check for calibration square
-Calculate the rhythm
-Is the rhythm regular
-P wave rounded or upright
-Complex narrow QRS
-ST elevation or depression
-T wave upright or inverted
What features indicate atrial fibrillation
-Atrial rate 400-600 bpm
-ventricular rate usually 100-160 if untreated rapid uncontrolled atrial fibrillation
-ventricular rate usually 60-100 if treated controlled atrial fibrillation
-irregular
-absent P wave
-F waves present
-PR interval absent
-P-P intervals absent
-R-R intervals unequal
-Random conduction ratio
-Normal QRS complex, wide if conduction delay exists
-Pattern can be isolated or occur in group beats or repetitive beats
-Origin is at the atrial sites outside the SA node
