Deck 10: Overview of Dysrhythmias

Question 1

The term dysrhythmia means the:

A) rhythm arises from a site outside the SA node.
B) ECG rhythm differs from normal sinus rhythm.
C) ECG has all the normal characteristics and waveforms.
D) heart is beating in an unusual way.

Answer 1

ECG rhythm differs from normal sinus rhythm.

Question 2

_________ is the ability of the cardiac muscles to depolarize spontaneously.

A) Excitability
B) Conductivity
C) Automaticity
D) Contractility

Answer 2

Automaticity

Question 3

Which of the following describes the generation and conduction of the normal heartbeat?

A) The impulse that generates the heartbeat originates from the SA node.
B) Impulse conduction is accelerated as it passes through the AV node.
C) Impulses normally spread through both ventricles by way of accessory pathways.
D) The impulse that generates the heartbeat progresses through the heart from the ventricles upward to the atria.

Answer 3

The impulse that generates the heartbeat originates from the SA node.

Question 4

In the polarized state:

A) cells have a high concentration of cations on the inside of the cell.
B) there is a high concentration of negatively charged ions, proteins, and organelles on the outside of the cells.
C) the resting membrane potential is negative.
D) the resting membrane potential is sustained by the cell membrane's ability to prevent cations, such as K+, from entering the cell and the anions from leaving the cell.

Question 5

SA node depolarization includes:

A) ion channels opening and allowing the slow inward movement of Na+ currents called "funny" currents
B) a resting membrane potential that begins at around -55 to -60 mV and becomes less negatively charged until it results in a gradual depolarization
C) the gradual depolarization of the SA node that occurs because of a slow inflow of Ca++ into the cell without a corresponding outflow of K+.
D) All of these

Question 6

Depolarization of nonpacemaker myocytes

A) occurs spontaneously.
B) takes over three phases.
C) occurs during Phase 0.
D) results from the rapid influx of Ca++ through the fast Ca++ channels.

Question 7

________ is/are the most common symptom of cardiac dysrhythmias.

A) Hypotension
B) A racing heart
C) Shortness of breath
D) Palpitations

Question 8

If the patient has a fast heart rate that is producing a low blood pressure, we would describe it as

A) atrial tachycardia.
B) symptomatic tachycardia.
C) tachycardia with low blood pressure.
D) sympathomimetic reflex.

Question 9

Cardiac output is defined as ________________.

A) blood pressure x stroke volume
B) peripheral resistance x heart rate
C) heart rate x stroke volume
D) blood pressure plus systole

Question 10

Match the following types of dysrhythmias with the corresponding characteristics:

-Early beats

A)Having a heart rate greater than 100 BPM
B)Having a heart rate less than 60 BPM
C)Occurs when the SA node fails to initiate an impulse or from a partial or intermittent block at the AV node
D)Impulses that occur early in the cardiac cycle

Question 11

Match the following types of dysrhythmias with the corresponding characteristics:

-Tachycardia

A)Having a heart rate greater than 100 BPM
B)Having a heart rate less than 60 BPM
C)Occurs when the SA node fails to initiate an impulse or from a partial or intermittent block at the AV node
D)Impulses that occur early in the cardiac cycle

Question 12

Match the following types of dysrhythmias with the corresponding characteristics:

-Dropped beats

A)Having a heart rate greater than 100 BPM
B)Having a heart rate less than 60 BPM
C)Occurs when the SA node fails to initiate an impulse or from a partial or intermittent block at the AV node
D)Impulses that occur early in the cardiac cycle

Question 13

Match the following types of dysrhythmias with the corresponding characteristics:

-Bradycardia

A)Having a heart rate greater than 100 BPM
B)Having a heart rate less than 60 BPM
C)Occurs when the SA node fails to initiate an impulse or from a partial or intermittent block at the AV node
D)Impulses that occur early in the cardiac cycle

Question 14

Characteristics of sinus rhythm include:

A) an irregular rhythm.
B) progressively longer P-R intervals.
C) an inverted P wave which follows each QRS complex.
D) a rate of between 60 and 100 beats per minute.

Question 15

Triggered activity:

A) is a problem with impulse conduction.
B) is known as before depolarization.
C) can bring about atrial or ventricular tachycardia.
D) occurs when an impulse is delayed along a slow conduction pathway

Question 16

Reentry occurs when:

A) the atrial cells spontaneously depolarize and initiate impulses before the SA node has a chance to generate a normal impulse.
B) an electrical impulse goes back into a conduction pathway rather than moving from one end of the heart to the other and then terminating.
C) problems occur at the level of the ion channels in individual heart cells leading to partial repolarization which causes repetitive ectopic firing.
D) b and c

Question 17

Dysrhythmias that arise from the ventricles include

A) junctional escape.
B) atrial fibrillation.
C) sinus arrest.
D) idioventricular rhythm.

Question 18

AV heart blocks include

A) 1st degree AV block.
B) sinoatrial exit block.
C) wandering atrial pacemaker.
D) accelerated junctional rhythm.

Question 19

The preferred lead for identifying cardiac dysrhythmias is lead

A) I.
B) II.
C) MCL6.
D) V3.

Question 20

In lead II, the deflection of the QRS complex is characteristically:

A) upright.
B) flat.
C) biphasic.
D) downward.

Question 21

Defibrillation is used to treat

A) bradycardia.
B) symptomatic tachydysrhythmias.
C) ventricular fibrillation.
D) AV heart block.

Question 22

Normally, myocardial cells do not require an electrical stimulus in order to contract.

Question 23

The primary electrolytes responsible for initiating electrical charges are the positively charged ions (cations) sodium (Na+), potassium (K+), and calcium (Ca++).

Question 24

In order for pacemaker cells to be the self-initiators of the heartbeat, they depolarize differently than the myocardial cells.

Question 25

Early beats that arise from the ventricles can result in a decreased or absent heartbeat.

Question 26

Sometimes the first clinical manifestation of a cardiac dysrhythmia is sudden death.

Question 27

Stimulation of the parasympathetic nervous system increases the firing rate of the SA node while stimulation of the sympathetic nervous system decreases it.

Question 28

Tachycardia that arises above the ventricles is called supraventricular tachycardia, whereas tachycardia that arises in the ventricles is called ventricular tachycardia.

Question 29

Increased automaticity is commonly caused by ischemia, hypoxia and atrial stretching or dilation.