Cardiac Rhythm Classification and Characteristics

Normal Sinus Rhythm (NSR)

1. Regular Rhythm 2. Rate: 60-100 bpm 3. P wave (sinus) 4. PR-Interval (sinus) 5. QRS (WNL)

Sinus Bradycardia

All the same like NSR except HR less than 60 bpm

Sinus Tachycardia

All the same like NSR except HR between 100-150 bpm

Sinus Dysrhythmia

All the same like NSR except irregular rhythm

Sinus Arrest

All the same like NSR except irregular rhythm because of pause and rate varies depending on electrical activity of S.A. Node

Sinus Exit Block

All the same like NSR except irregular rhythm because of pause(s) caused by S.A. block and rate varies depending on electrical activity of S.A. Node

Premature Atrial Contractions (PAC)

1. Irregular Rhythm 2. Rate: 60-100 bpm 3. P wave - abnormal (flattened, notched, biphasic or unusual) 4. Every beat will have different PR measurements but WNL 5. QRS (WNL)

Wandering Atrial Pacemaker (WAP)

1. Slightly irregular 2. 60-100 bpm 3. P wave morphology continuous change 4. PR interval varies 5. QRS (WNL)

Atrial Flutter (A Flutter)

1. P-P interval constant; R-R usually irregular 2. Rate: Atrial rate 250-300 bpm 3. P wave may not be absent 4. PR interval not identifiable 5. QRS (WNL)

Atrial Fibrillation (A Fib)

1. P-P interval not determinable; R-R interval is irregular 2. Rate: Atrial Rate 375-700 bpm 3. P wave cannot be identified; chaotic electrical activity 4. PR interval cannot be identified 5. QRS is irregular

Premature Junctional Complex (PJC)

1. Irregular depending on underlying rhythm and/or # of PJCs 2. Rate: depends on underlying rhythm 3. P wave: inverted, may proceed, follow or be buried by QRS complex 4. PR interval: depends on location of P wave 5. QRS complex (WNL)

Junctional Escape Rhythm

1. P-P and R-R intervals are regular and similar; P-P interval may be difficult to determine due to location of P wave 2. Ventricular and Atrial rate: 40-60 bpm 3. P wave: usually inverted and may follow, precede, or be hidden by QRS complex 4. PR interval: before the QRS: less than 0.12 second and constant 5. QRS complex: WNL

Accelerated Junctional Rhythm

1. P-P and R-R intervals are regular and similar; P-P interval may be difficult to determine due to location of P wave 2. Rate: 60-100 bpm 3. P wave: usually inverted and may follow, precede, or be hidden by QRS 4. PR interval: before the QRS: less than 0.12 second and constant 5. QRS complex (WNL)

Junctional Tachycardia

1. P-P and R-R intervals are regular and similar; P-P interval may be difficult to determine due to location and increased HR 2. Ventricular and Atrial rate: 100-180 bpm 3. P wave: usually inverted; may follow, precede, or fall within QRS; may not be visible on rhythm strip; may need increased paper speed on cardiac monitor 4. PR interval: before the QRS: less than 0.12 second and constant 5. QRS complex (WNL)

Supraventricular Tachycardia

1. R-R interval regular, P waves usually regular 2. Ventricular rate: 150-250 bpm 3. P wave: usually not identifiable at this HR; may occur before, during, or after QRS complex 4. PR interval: usually unable to determine 5. QRS complex: WNL if duration is 0.06-0.10 seconds and some rhythms result in narrow or wide QRS complexes