Arrhythmias

Question 1

Normal Sinus Rhythm (NSR)

Answer 1

Pacemaker originates in the sinus node and travels through the normal conduction pathways within normal time frames

Question 2

How does the electrical impulse travel in a NORMAL rhythm? (Normal pathway of impulse from SA node)

Answer 2

1.Electrical impulse originates in SA node, travels through the intermodal tract to cause the atria to contract.
2. The impulse then travels to the AV node, through the AV bundle and into the bundle of His.
3. The bundle of His then splits into two sections
4. The left bundle branch travels around the left ventricle and into the purkinje fibers. The right branch travels around the right ventricle and ends in the purkinje fibers.
5. Once the impulse reaches the purkinje fibers, the ventricles then contract forcing the blood out of the heart.

Question 3

Sinus Bradycardia

Answer 3

This rhythm follows all the rules for normal sinus rhythm except for the rate. In this rhythm the rate is lower than 60bpm

Question 4

Sinus tachycardia

Answer 4

This rhythm follows all the rules for a normal sinus rhythm except that the rate is too fast. In this arrhythmia, the rate will be greater than 100bpm

Question 5

Sinus arrhythmia

Answer 5

This rhythm is characterized by a pattern that would normally be considered NSR, except that the rate changes with the patients respirations. When the patient breathes in, the rate increases and when the patient breathes out, the rate decreases.

Question 6

Wandering Atrial Pacemaker (WAP)

Answer 6

Occurs when the pacemaker role switches from beat to beat from the SA node to the atria and back again. The resulting rhythm is made up of interspersed sinus and atrial beats

Question 7

Ectopic

Answer 7

When a single beat arises from an ectopic focus (a site outside the SA node) within the conduction system, that beat is called an ectopic beat. When it occurs from the atria it is called an atrial ectopic. An ectopic beat arises when a site somewhere along the conduction system becomes irritable and overrides the SA node for a single beat

Question 8

Premature Atrial Contraction (PAC)

Answer 8

A PAC is an ectopic beat that comes early in the cardiac cycle and originates in the atria. Since the PAC comes early in the cardiac cycle, it will usually fall very close to the end of the preceding QRS complex

Question 9

Atrial tachycardia

Answer 9

This arrhythmia is characteristically very regular. It is usually very rapid with a rate of 150-250bpm. This occurs when a single focus in the atria becomes so irritable that it begins to fire very regularly and thus overrides the SA node for the entire rhythm

Question 10

Atrial flutter

Answer 10

When the atria become so irritable that they fire faster than 250bpm, they are said to be fluttering. It is theorized that an area in the atrium initiates an impulse that is conducted in a repetitive, cyclic pattern, creating a series of atrial waves with a saw tooth appearance

Question 11

Atrial fibrillation

Answer 11

This rhythm results when the atria becomes so irritable that they are no longer beating, but merely quivering ineffectively