12-lead ch.8 Flashcards
What are some irregularily, irregular rhythms?
Atrial fibrillation, MAT, WAP
What are some Irregularily, regular rhythms?
a pattern of this would be long long short, short short long such as in wenkebach or atrial flutter patterns.
Which questions should you ask yourself about p waves?
Do you see p waves? Are all the p waves the same? Does each qrs complex have a p wave? Is the PR interval constant?
Which questions should you ask yourself about the qrs?
Are the p waves and qrs associated with each other? Are the complexes wide or narrow? Are the qrs complexes grouped or not? Are there any dropped beats?
What can cause Sinus tachycardia?
medications or conditions that require increased cardiac output such as exercise, hypoxemia, hypovolemia, hemorrhage and acidosis.
What is the difference between a pause/arrest and a block?
A block occurs when the qrs is a dropped beat but the next beat resumes on cycle or is a multiple of the cycle in the case of two dropped beats. A pause would not occur regularily within that cycle.
How does a PAC occur?
What some pacemaker site in the atria fires faster than the SA node
Describe ectopic Atrial tachycardia.
Occurs when an ectopic atrial focus fires more quickly than the underlying sinus rate. ST and T wave abnormalities may be present transiently.
Which patients tend to have WAP/MAT
Patients with severe lung disease such as COPD.
Which HR is indicative of Atrial Flutter 2:1 conduction?
A ventricular rate of 150bpm. (atrial is twice as fast)
Describe Atrial Fibrillation.
Chaotic firing of numerous pacemaker cells in the atria.
Why are PJCs the same morphology of a normal QRS? What patterns can they occur in?
A PJC originates in the AV node and follows down the normal electrical conduction system of the ventricles. They can occur as Bigeminey and Trigeminey.
Describe the difference between a PJC and a junctional escape beat.
An escape beat does not fire prematurely and tends to occur after the regular interval because it allows time for the SA node to fire first, when it does not fire, the escape beat fires to ensure proper heart function.
In what instances would you see a junctional rhythm?
When the function of the SA node is absent or surpressed and can also occur in AV dissociation and third degree heart block.
Describe the difference between a PVC and a ventricular escape beat.
A PVC is a premature beat that should give compensatory pause after it occurred to allow the heart to repolarize. An escape beat however waits for other pacemakers to fire and when it does not, the ventricles kick out and fire a beat and results in no compensatory pause before the next normal beat.
