Chapter 5 Flashcards
What is evaluated and classified when determining dysrhythmias?
The ECG waveform has various components—such as waves, segments, and intervals—that are evaluated and classified based on their size, length of time, and location on the tracing.
Normal Heart rate:
15-25 lil boxes P-P or R-R intervals
Name the five components that must be evaluated on a rhythm strip.
Rhythm (regularity): taking measure of P to P or R to R or S to S intervlas for at least 6 consecutive seconds Rate P wave configuration PR interval QRS duration and configuration
A regular rhythm has 19 small boxes between the P-P interval. What is the heart rate?
79
After you measure the QRS duration and configuration, what other questions need to be answered?
Are all the QRS complexes of equal length?
What is the actual measurement, and is it within the normal limits?
Do all QRS complexes look alike, and are the unusual QRS complexes associated with an ectopic beat?
The most common monitoring lead
Lead II
P wave represents
atrial depolarization (contraction)
QRS complex represents
ventricular depolarization
The rhythm of atrial contraction is evaluated by assessing
the regularity or irregularity of the occurrence of the P waves
The QRS complexes are assessed to evaluate
ventricular contraction
Atrial is determined by the
P-P wave interval measurement.
The ventricular rate is determined by the
R-R wave interval measurement
If the atrial and ventricular rates are different, there is a problem with the
myocardium
Determining the atrial rate of a regular rhythm tracing
Count the number of small boxes between the P-P intervals, divide into 1500
Determining the ventricular rat of a regular rhythm tracing
Count the number of small boxes between the QRS complexes, divide into 1500
Determining heart rate in an irregular rhythm tracing
6-second rule: Identify 6 seconds on strip (2 vertical lines at the bottom or top of strip), count the number of complete complexes seen in one 6 second interval, multiply the number of complexes by 10.
How to identify the P wave configuration (shape)
Are the shapes and waveforms all the same?
Does each P wave have a QRS complex following it?
What does the PR interval measure?
The time it takes the electrical current to be initiated at the sinoatrial node and travel through the electrical current pathway to cause a ventricular contraction
How to measure the PR interval
Measure form the beginning of the P wave to the beginning of the QRS complex
Normal range of the PR interval
0.12 to 0.20 seconds
What does the QRS complex determine
Duration of time it takes for the ventricles to depolarize or contract
Normal QRS complex duration
0.06 to 0.10 seconds
Hoe to measure the QRS complex duration
Measure between the beginning of the QRS complex and the J point
What does the J point indicate
The ventricular depolarization (contraction) completion and beginning of re-polarization
Primary pacemaker of the heart
SA (sinoatrial) node
Normal conduction pathway
SA node, AV node, bundle of His, bundle branches of the ventricles (contraction!!!)