NCLEX Review & Nursing School

DYSRYTHMIAS

As we all know cardiac dysrhytmia is basically an abnormality and irregularity in the rhythm and
rate in electrical conduction within the system that causes changes in the heart rate and the heart rhythm.

Some causes of dysrhytmias include:
Heart Failure
M.I.
Drug Toxicity
Trauma

Here are the different types of dysrhytmia:

1. SINUS RHYTHM
2. SINUS BRADYCARDIA
3. SINUS TACHYCARDIA
4. ATRIAL FIBRILLATION
5. VENTRICULAR FIBRILLATION (VF)
6. VENTRICULAR TACHYCARDIA (VT)
7. PREMATURE VENTRICULAR CONTRACTION (PVC)
8. FIRST DEGREE AV BLOCK
9. SECOND DEGREE AV BLOCK
10. THIRD DEGREE AV BLOCK

* Lidocaine is the drug of choice in treating ventricuar dysrhytmmias.

SINUS RHYTHM

– is considered a normal rhythm

Rate:

• VENTRICULAR  60- 100
• ATRIAL 60- 100

Rhythm:

• P-R INTERVAL: REGULAR
• P-P INTERVAL: REGULAR

Duration:

• PR INTERVAL .12-.20 SECONDS
• QRS COMPLEX: .6-.10 SECONDS

Normal Sinus Rhythm
– It originates from the SA node
– Atrial and Ventricular rhythms are regular
– Atrial and Ventricular rhythms are between 60-100.

SINUS BRADYCARDIA

The heart rate is usually 60 beats/min. or less.
Some causes of sinus bradycardia includes MI & electrolyte imbalance.

Rate

• VENTRICULAR:  < 60  (LESS THAN 60 BPM)
• ATRIAL: NORMAL

Rhythm

• R-R INTERVAL: REGULAR
• P-P INTERVAL: REGULAR

Duration

• PR INTERVAL: .12- .20 SEC.
• QRS COMPLEX:  .6- .10 SEC.

Sinus Bradycardia
– ♣ Atrial and ventricular rhythm is below 60 bpm
– Treatment maybe be necessary if symptomatic
– Treatment includes: ATROPINE SULFATE
* Main treatment is ATROPINE.
– Monitor Oxygen if prescribed by MD.

SINUS TACHYCARDIA

Occurs when the rhythm of the heart is at least 100-150 bpm.

Rate

• VENTRICULAR:  < 100  (GREATER THAN 100 BPM)
• ATRIAL: NORMAL

Rhythm

• R-R INTERVAL: REGULAR
• P-P INTERVAL: REGULAR

Duration

• PR INTERVAL: .12- .20 SEC.
• QRS COMPLEX:  .6- .10 SEC.

Sinus Tachycardia
– ♣ Sinus Tachycardia rhythm is below 60 bpm
– Treatment the cause.

ATRIAL FIBRILLATION

– an erratic and  chaotic firing within the heart that originates from the atria.
– ♣ THERE IS NO P WAVE AND A CHAOTIC QRS in a patient with A-Fib
SINUS RHYTHM
– is a normal rhythm
Rate:

• VENTRICULAR  80- 160
• ATRIAL > 350 (GREATER THAN 350)

Rhythm:

• P-R INTERVAL: IRREGULAR
• P-P INTERVAL: ABSENT

Duration:

• PR INTERVAL: ABSENT
• QRS COMPLEX: .6-.10 SECONDS

Atrial Fibrillation
– Multiple rapid impulses within the atria at a rate of 350+ per minute
– Atrial quiver can lead to thrombi formation.
– Give O2 and anticoagulants (pt. is risk for thrombus)

VENTRICULAR FIBRILLATION (VF)

– An uncoordinated firing of the ventricles.
– NO QRS COMPLEX CAN BE SEEN
– leads to death, if untreated

Rate:

• VENTRICULAR: UNKNOWN (VARIES)
• ATRIAL > ABSENT

Rhythm:

• P-R INTERVAL: CHAOTIC
• P-P INTERVAL: ABSENT

Duration:

• PR INTERVAL: ABSENT
• QRS COMPLEX: CHAOTIC

Ventricular Fibrillation
– A quivering of the ventricles
– Patient has no Blood Pressure, Heart rate, Heart sounds and Respirations.
– Defibrillate patient STAT up to 3 times:   200, 300 and 360 Joules
– CPR, Oxygen
– Administer Epinephrine, Amidarone (Cordarone) and Lidocaine.

VENTRICULAR TACHYCARDIA

– originates from the ventricles
– at least 3 consecutive ventricular contractions.
– QRS Complex is widened
Rate

• VENTRICULAR:  UNKNOWN
• ATRIAL: ABSENT

Rhythm

• R-R INTERVAL: REGULAR
• P-P INTERVAL: ABSENT

Duration

• PR INTERVAL: ABSENT
• QRS COMPLEX:  CHAOTIC, BIZZARE AND WIDENED

Ventricular Tachycardia
– ♣ Can lead to cardiac arrest or V Fib.
– paroxysm of 3 beats or more.
– Prepare patient for cardioversion.

PREMATURE VENTRICULAR CONTRACTION

– a premature contraction of the ventricles due to unexpected firing within one of the ventricles.
– Abnormal conduction within the ventricles.
– There is no P wave before the PVC.
– Can be Multifocal or Unifocal.

VENTRICULAR TACHYCARDIA

– originates from the ventricles
– at least 3 consecutive ventricular contractions.
– QRS Complex is widened
Rate

• VENTRICULAR:  UNKNOWN
• ATRIAL: ABSENT

Rhythm

• R-R INTERVAL: REGULAR
• P-P INTERVAL: ABSENT

Duration

• PR INTERVAL: ABSENT
• QRS COMPLEX:  CHAOTIC, BIZZARE AND WIDENED

Ventricular Tachycardia
– ♣ Can lead to cardiac arrest or V Fib.
– paroxysm of 3 beats or more.
– Prepare patient for cardioversion.

PREMATURE VENTRICULAR CONTRACTION

– a premature contraction of the ventricles due to unexpected firing within one of the ventricles.
– Abnormal conduction within the ventricles.
– There is no P wave before the PVC.
– Can be Multifocal or Unifocal.

VENTRICULAR TACHYCARDIA

– originates from the ventricles
– at least 3 consecutive ventricular contractions.
– QRS Complex is widened
Rate

• VENTRICULAR:  UNKNOWN
• ATRIAL: ABSENT

Rhythm

• R-R INTERVAL: REGULAR
• P-P INTERVAL: ABSENT

Duration

• PR INTERVAL: ABSENT
• QRS COMPLEX:  CHAOTIC, BIZZARE AND WIDENED

Ventricular Tachycardia
– ♣ Can lead to cardiac arrest or V Fib.
– paroxysm of 3 beats or more.
– Prepare patient for cardioversion.

FIRST DEGREE AV BLOCK

– usually a slow conduction of the impulse by the AV node.
– the PR interval is lengthened.
Rate

• VENTRICULAR:  NORMAL
• ATRIAL: NORMAL

Rhythm

• R-R INTERVAL: REGULAR
• P-P INTERVAL: REGULAR

Duration

• PR INTERVAL: > OR = .20
• QRS COMPLEX:  .6- .10

First Degree AV Block
– usually asymptomatic

SECOND DEGREE AV BLOCK

–   ”WENCKENBACH” also is called.
– often seen after a myocardial infarction
– the PR interval is getting progressively longer until one P wave is not followed by an QRS complex.
Rate

• VENTRICULAR:  SLOW
• ATRIAL: GREATER THAN VENTRICULAR

Rhythm

• R-R INTERVAL: IRREGULAR
• P-P INTERVAL: IRREGULAR

Duration

• PR INTERVAL: NORMAL OR PROLONGED
• QRS COMPLEX:  NORMAL

SECOND DEGREE AV BLOCK  (MOBITZ TYPE)

– ♣ Can lead to cardiac arrest or V Fib.
– paroxysm of 3 beats or more.
– Prepare patient for cardioversion.

THIRD DEGREE AV HEART BLOCK

.

HEMODYNAMIC MONITORING

– Measure the cardiac output and intracardiac pressures through hemodynamic monitoring.

• A CATHETER IS INSERTED INTO THE PULMONARY ARTERY STARTING FROM THE FEMORAL ARTERY AND THROUGH THE HEART VESSELS AND INTO THE CHAMBERS.

SIDE NOTE: FOR THE NCLEX
* When giving Digitalis (lanoxin) tell patient to consume a moderateamount of potassium to avoid toxicity.
* If pulse rate is less than 100 in infants: IMMEDIATELY REPORT FINDINGS AND CALL PHYSICIAN.
* To treat Premature Ventricular Contractions (PVC) :  give pt.LIDOCAINE, AMIODARONE (CORDARONE) AND MAGNESIUM SULFATE.
* For pts. w/ possible thrmbophlebitis: No more assessment of Homan’s Sign, put the client on Bedrest
* DIGITALIS TOXICITY:

• HALOS AROUND LIGHTS
• BRADYCARDIA
• NAUSEA AND VOMITING

THIRD DEGREE AV HEART BLOCK

– A “pacemaker” is usually required
– There is no impulse that can pass from the atria to AV node.
* The client needs to wear an identification tag to indicate having a PACEMAKER.

PACEMAKER

– Major complications includes infection, thrombophlebitis and pacemaker syndrome

Some pacemaker malfunctions: 

• Failure to Output- no pacing spike is pressent  (cause can be battery failure or lead failure)
• Failure to Capture- pacing spike is not followed by ventricular or atrial complex.
• Undersensing
• Oversensing