Mod D Tech 12 3 and 12-Lead ECG Placement and Acquisition Flashcards
Basic considerations before ecg
To reduce artifact: Consider ambient temperature and patient dignity Ensure good electrode contact (How?) Shave off excessive hair Make sure electrodes are in date and gel is moist Ensure cable is not pulling on electrodes
Preparation for ecg
Expose the monitoring area Consider temperature and dignity Select and prepare the electrode site Shave excessively hairy areas Attach the electrodes Secure the patient cable Switch the machine on and take a recording Always explain to the patient what & why you are doing this procedure!
12 Views or Leads name groups of leads
3 Standard leads I, II and III
3 Augmented Voltage leads AVR, AVL and AVF
6 Precordial Leads V1,V2,V3,V4,V5 and V6
Electrocardiogram
- A recording of electrical activity in the heart.
- The electrical activity is picked up by electrodes placed on the patients skin
- The positioning of these electrodes allows the ECG to look at the electrical activity from different directions
- Basic monitoring is carried out using three leads
- These leads are normally known as leads I, II, III.
- Lead II is commonly used as a rhythm strip and is normally sufficient to identify arrhythmia
•A normal ECG trace shows five deflections which are named?
P,Q, R, S, and T.
•The P wave arises when the impulse from the ______sweeps over the___and triggers contraction of the ____
The P wave arises when the impulse from the SA node sweeps over the atria and triggers contraction of the atria
•The QRS complex represents the very rapid spread of the impulse from the ____through the ___ ___ and the ________and triggers contraction of the ventricles
•The QRS complex represents the very rapid spread of the impulse from the AV node through the AV bundle and the purkinje fibres and triggers contraction of the ventricles
•The T wave represents the _______ of the _______ muscle
•The T wave represents the relaxation of the ventricular muscle
•The normal ECG originates from the ____ ____ and is known as ____ ____ _____
•The normal ECG originates from the SA node and is known as normal sinus rhythm
PQRST Complex
ECG Rate
lagre sq
- 1 Sq = 300 bpm
- 2 Sq = 150 bpm
- 3 Sq = 100 bpm
- 4 Sq = 75 bpm
- 5 Sq = 60 bpm
- 6 Sq = 50 bpm
ECG Electrical Deflection
- When an electrical impulse flows towards an electrode the ECG will record a _____ or _____ deflection (A)
- When an electrical impulse flows away from an electrode the ECG will record a _____ or _______ deflection (B)
- When an electrical impulse flows towards an electrode the ECG will record a positive or upward deflection (A)
- When an electrical impulse flows away from an electrode the ECG will record a negative or downward deflection (B)
P Wave which part of the ecg
Q wave which part of the ecg
R Wave which part of the ecg
S Wave which part of the ecg
T wave which part of the ecg
Normal Intervals ecg
ST Segment
Denotes end of ventricular contraction to beginning of resting phase
ST Segment
Normal
ST Depression
(Ischaemia)
ST Elevation
(Injury/MI)
Normal Parameters of
•P-R Interval = ___- ___seconds
•
•QRS Complex = ____seconds ___ – ___secs)
•P-R Interval = 0.12 - 0.2 seconds
•
•QRS Complex = <0.12 seconds (0.8 – 0.12 secs)
A 9-Point plan
- Is there any electrical activity?
- Has the patient got a pulse?
- What is the ventricular rate?
- Is the rhythm regular or irregular?
- Is atrial activity present?
- Is the PR interval within normal limits?
- Is the QRS complex normal or prolonged?
- How is atrial activity related to ventricular activity?
- Is the ST Segment elevated or depressed?
10 rules of Chamberlain
1 The PR interval should be no longer than 0.12 – 0.2 seconds (3 to 5 small squares
- The QRS should be no wider than 0.12 seconds (less than 3 small squares
- The QRS should be predominantly positive (Upright) in leads I and II
- The T waves should point in the same direction as the QRS in the limb leads (Standard leads)
- All waves should be negative in aVR
6 The R wave should grow from V1 to at least V4
- The ST segment should start isoelectric except in V1 and V2 where it may be slightly raised
- The P wave should be upright in leads I and II and V2 – V6
- There should be no Q wave greater than 0.03 secs (Less than 1 small square) in leads I, II and V2 – V6
- The T wave should be upright in leads I,II and V2 – V6