Chapter 4 Flashcards
TRUE/FALSE
Individuals with preexcitation syndrome are predisposed to tachydysrhythmias.
true
TRUE/FALSE
In atrial fibrillation, the AV node attempts to protect the ventricles from the hundreds of impulses bombarding it per minute by blocking many of the impulses generated by the irritable sites in the atria.
true
TRUE/FALSE
Upon conversion of atrial fibrillation to sinus rhythm, the patient should be observed for signs of a possible stroke.
true
TRUE/FALSE
The presence of an accessory pathway should be considered in atrial fibrillation with a ventricular rate faster than 180 beats/min.
true
TRUE/FALSE
Most patients with type I atrial flutter develop atrial fibrillation.
false
TRUE/FALSE
In atrial fibrillation, fibrillatory waves are referred to as f waves.
true
TRUE/FALSE
Delivery of an electrical current timed for delivery during the QRS complex is called defibrillation.
false
TRUE/FALSE
Multifocal atrial tachycardia is another name for atrial fibrillation.
false
TRUE/FALSE
A macroreentrant circuit is one that involves a small area of heart tissue, usually a few centimeters or less.
false
TRUE/FALSE
The ventricular rhythm in atrial fibrillation is usually “irregularly irregular.”
true
What is meant by the term controlled atrial fibrillation?
The overall ventricular rate is less than 100 beats/min.
Which of the following correctly describes multifocal atrial tachycardia?
Atrial and ventricular rhythms are irregular.
Characteristics of multifocal atrial tachycardia:
Rhythm
Usually irregular as the pacemaker site shifts from the SA node to ectopic atrial locations or AV junction
Rate
Faster than 100 beats/min
P waves
Size, shape, and direction may change from beat to beat; it may be upright, inverted, biphasic, rounded, flat, pointed, notched, or buried in the QRS complex
PR interval
Varies as the pacemaker site shifts from the SA node to ectopic atrial locations or AV junction
QRS duration
0.11 seconds or less unless abnormally conducted
The most common type of supraventricular tachycardia (SVT) is _____.
AV nodal reentrant tachycardia (AVNRT)
Atrial fibrillation is characterized by _____.
an erratic, wavy baseline and irregular ventricular rhythm
Characteristics of atrial fibrillation:
Rhythm
Ventricular rhythm usually irregularly irregular
Rate
Atrial rate usually 400 to 600 beats/min; ventricular rate variable
P waves
No identifiable P waves, fibrillatory waves present; erratic, wavy baseline
PR interval
Not measurable
QRS duration
0.11 seconds or less unless abnormally conducted
How are frequent PACs usually managed?
Correcting the underlying cause
A wandering atrial pacemaker rhythm with a ventricular rate of 60 to 100/min may also be referred to as _____.
multiformed atrial rhythm
To determine whether the ventricular rhythm on an ECG tracing is regular or irregular, compare _____ intervals.
R to R
A 77-year-old woman is complaining of a sudden onset of palpitations. The cardiac monitor reveals atrial fibrillation with a ventricular response of 144 to 210 beats/min while the patient is at rest. In this situation, the ventricular rate associated with this rhythm is considered to be _____.
uncontrolled
Delivery of an electrical current timed for delivery during the QRS complex is called _____ _____.
synchronized cardioversion
Sometimes, when a premature atrial complex (PAC) occurs very prematurely and close to the T wave of the preceding beat, only a P wave may be seen with no QRS after it (appearing as a pause). This type of PAC is termed a _____ PAC.
nonconducted
blocked
PACs associated with a wide QRS complex are called _____ _____ PACs, indicating that conduction through the ventricles is abnormal.
aberrantly conducted
An accessory pathway that has one end attached to normal conductive tissue is called a(n) _____ _____.
bypass tract
