EKG certification Chapter 9

For my EKG certification

Electrical Conduction system in order

• Sinoatrial (SA) Node: Primary Pacemaker of the heart

• Atrioventricular (AV) Node: Delays impulse from SA node and relays to Bundle of His

• Bundle of His (AV bundle): Relays impulses to right and left bundle branches

• Right and Left Bundle Branches: Relay Impulses to Purkinje Fibers

• Purkinje Fibers: Relay impulses to ventricular myocardium

What is heart rhythm affected by?

How the cardiac conduction system is generally functioning or problems in the conduction system itself.

Escape Beat

When the SA node doesn’t generate an impulse so another part of the conduction system makes it causing a late heartbeat that may be isolated or may occur regularly.

Escape Rhythm

Created when an area other than the SA node acts as the PRIMARY pacemaker of the heart

Ectopic Focus

AKA Ectopic pacemaker, caused when an irritable area can generate an impulse even when the SA node is working normally, make isolated early beats.

Dysrhythmia

Commonly known as Arrhythmia, means difficult or abnormal rhythm. Rhythms can be too fast or too slow beginning in an area of the conduction system other than the SA node.

Sinus Rhythm

A rhythm that starts in the sinoatrial node

Atrial Rhythm

Rhythms beginning in the atria

Junctional rhythm

Rhythm beginning in the AV junction

Ventricular rhythm

Rhythm beginning in the ventricles

Heart Blocks

AKA AV Blocks, caused by problems in the conduction of electrical impulses between the atria and ventricles

What is VERY important to do before generating the EKG tracing?

Ensuring electrodes are properly attached and in the right positions.

What is the most common limb lead reversal?

The right and left arm electrodes. (This can be seen on the tracing as an error casing a negative deflection of QRS complexes in lead I and positive deflection of QRS complexes in lead aVR.

Underlying Rhythm

The basic rhythm of the patient’s heart

Sinus

Begins in the sinus node (SA node)

Atrial

Begins in the Atria (AV node)

Junctional

Begins in the area of the AV junction

Ventricular

Begins in the ventricles

Supraventricular

Begins somewhere ABOVE the ventricles

Bradycardia

Is slow

Tachycardia

Is fast

Premature

Comes earlier than expected

Escape

Comes later than expected

Multifocal

Originates from multiple locations in the heart

Paroxysmal

Comes and goes in bursts

Uniform

Stays the same

Monomorphic

Has a key feature that stays the same every time (EX. QRS complexes staying the same)

Polymorphic

Has a key feature that changes from beat to beat

Normal Sinus Rhythm

When the heart rhythm is completely normal and healthy

• Name of Rhythm: Normal Sinus Rhythm

• Rate: 60- 100 BPM (In this case it is 70 BPM)

• Rhythm Pattern: Regular

• P wave Characteristics: Upright and Uniform

• PR interval: 0.12-0.20 seconds (0.12 s)

• QRS Duration: 0.12 seconds (0.08 s)

• Unique Identifier: All Complexes, Intervals, rate, and rhythm normal

Sinus Tachycardia

When the heart rate is fast around over 100 beats per minute but everything else is normal

• Name of Rhythm: Sinus Tachycardia

• Rate: 60- 100-160 BPM (107 BPM)

• Rhythm Pattern: Regular

• P wave Characteristics: Upright and Uniform

• PR interval: 0.12-0.20 seconds (0.20 s)

• QRS Duration: <0.12 seconds (0.08 s)

• Unique Identifier: All features normal with fast rate

Sinus Bradycardia

When the heart rate is slow but all characteristics are normal

• Name of Rhythm: Sinus Bradycardia

• Rate: <60 BPM (55 BPM)

• Rhythm Pattern: Regular

• P wave Characteristics: Upright and Uniform

• PR interval: 0.12-0.20 seconds (0.16 s)

• QRS Duration: <0.12 seconds (0.08 s)

• Unique Identifier: All features normal with slow rate

Sinus arrhythmia

Is when all characteristics are normal except for the R-R intervals(They are irregular) Meaning inconsistent pattern timing.

• Name of Rhythm: Sinus arrhythmia

• Rate: 60-100 BPM (70 BPM)

• Rhythm Pattern: Irregular

• P wave Characteristics: Upright and Uniform

• PR interval: 0.12-0.20 seconds (0.16 s)

• QRS Duration: <0.12 seconds (0.10 s)

• Unique Identifier: All complexes normal but rate changes with respiration

Sinus Arrest

sinus arrest/pause occurs when the SA node does not initiate an impulse at the right time, creating pauses in the heart’s electrical activity (It is helpful to note the length of the pause)

• Name of Rhythm: Sinus Arrest

• Rate: Varies due to length and frequency of pause (50 BPM)

• Rhythm Pattern: Irregular

• P wave Characteristics: Upright and Uniform

• PR interval: 0.12-0.20 seconds (0.12 s)

• QRS Duration: <0.12 seconds (0.08 s)

• Unique Identifier: Normal complexes alternating with arrest periods

Can heart rate vary due to activity, stress, medical conditions, and age?

Yes it absolutely can

What heart rate change can be caused by straining during bowel movement?

sinus node firing slowed down by the vagus nerve(Part of the Para symptomatic nervous system but not of clinical concern) This slows down the heart rate

Can Sinus arrhythmia happen naturally?

It can in some children and adults because of different respiration patterns which is totally normal and not of clinical concern unless there has to be extra effort when the patient breathes.

Asymptomatic

Having no symptoms

What makes P waves in Atrial Rhythms different?

Since in atrial rhythms the electrical impulse starts in the atria(contraction) it travels to the AV node on a different path than usual so the P waves may be flattened, pointed, notched or biphasic, sometimes even hidden.

Premature atrial complexes