Electrocardiography Rhythm

ELECTROCARDIOGRAPHY RHYTHM

1. SINUS RYTHM

Rhythm Regular

Rate Normal (60-100 bpm)

P Wave Normal (positive & precedes each QRS)

PR Interval Normal (0.12-0.20 sec)

QRS Normal (0.06-0.10 sec)

2. ASYSTOLE

Rhythm Not present

Rate Absent

P Wave Absent

PR Interval Absent

QRS Absent

Notes Confirm with multiple leads

3. ATRIAL FLUTTER

Atrial flutter is an abnormally fast heart rate where the atria contract rapidly do not adequately pump blood to the ventricles. These fluttering atrial contractions are out of sync with the ventricles. As a result, the heart does not pump blood effectively. Atrial flutter is a common arrhythmia. It is a type of supra-ventricular tachycardia (SVT) and is similar to atrial fibrillation.

Sawtooth patterns in baseline

Rhythm Regular or irregular

RateFast (250-350 bpm) for Atrial, but ventricular rate is often slower

P WaveNot observable, but saw-toothed flutter waves are present

PR Interval Not measureable

QRS Normal (0.06-0.10 sec)

4. MULTIFOCAL ATRIAL TACHYCARDIAMultifocal atrial tachycardia is caused by electrical signals being sent from multiple (ectopic) locations in the atria rather than from the sinoatrial (SA) node. These multiple signals cause a rapid, inefficient heartbeat. This arrhythmia is more commonly found in patients over 50 years of age, particular in patients with lung disorders. Also see Wandering Atrial Pacemaker, a related abnormality.

Rhythm Irregular

Rate Fast (> 100 bpm)

P WaveOften changing shape and size from beat to beat (at least three differing forms)

PR Interval Variable

QRS Normal (0.06-0.10 sec)

NotesT wave is often distorted Also review wandering atrial pacemaker lesson

5. ATRIAL FIBRILLATION

Atrial fibrillation is a common type of supraventricular tachycardia (SVT) arrhythmia, characterized by chaotic, quivering atria. These atrial fibrillations result in atrial contractions that are ineffective and out of coordination with the ventricles.

P wave missing, replaced by a fine wavy wave

Rhythm Irregular

RateVery fast (> 350 bpm) for Atrial, but ventricular rate may be slow, normal or fast

P Wave Absent - erratic waves are present

PR Interval Absent

QRSNormal but may be widened if there are conduction delays

6. SUPRAVENTRIKULAR TACHYCARDIA

Supraventricular tachycardia (SVT) is a rapid heart rhythm originating at or above the AV node. SVT rates are above 100 beats per minute and are typically 150-250 bpm. SVT is the most common pediatric rhythm problem. SVT’s rapid heart rate does not allow the ventricles to completely fill with blood, decreasing cardiac output.

Rhythm Regular

Rate Fast (150-250 bpm)

P Wave Merged with T wave

PR Interval Normal (0.12 sec)

QRS Normal (.10 sec)

Notes PR interval can be difficult to measure

7. VENTRICULAR TACHYCARDIA

Ventricular tachycardia (VT) is a rapid heartbeat over 100 bpm that originates in the ventricles. The EKG will show three or more irregular heartbeats in a row. Ventricular tachycardia can be classified by type. Several types of VT, including Monomorphic, Polymorphic and Torsade de Pointes are available for review on this website. Ventricular tachycardia requires immediate medical attention.

Rhythm Regular

Rate Fast (100-250 bpm)

P Wave Absent

PR Interval Not measurable

QRS Wide (>0.10 sec), bizarre appearance

7.1. VT MONOMORPHIC

Monomorphic ventricular tachycardia is a form of ventricular tachycardia where the shape of each beat on an ECG match each other. A common cause is tissue scarring from a previous heart attack.

Rhythm Regular

Rate Fast (100-250 bpm)

P Wave Absent

PR Interval Not measurable

QRS Wide (>0.10 sec), bizarre looking

7.2. VT POLYMORPHIC

Polymorphic ventricular tachycardia has changing ECG shapes from beat to beat.

Rhythm Regular or irregular

Rate Fast (100-300 bpm)

P Wave Absent

PR Interval Not measurable

QRS Normal or wide (>0.10 sec), bizarre looking

7.3. TORSADE DE POINTES

Torsade de pointes ventricular tachycardia is a particular type of polymorphic VT. An ECG characterizes it by the QRS complexes twisting around the isoelectric line.

Rhythm Irregular

Rate Fast (200-250 bpm)

P Wave Absent

PR Interval Not measurable

QRS Wide (>0.10 sec), bizarre looking

8. VENTRICULAR PREMATURE BEATS8.1. PREMATURE BEATS BIGEMINY

Premature ventricular contraction bigeminy are extra, abnormal heartbeats originating in the Purkinje fibers of the ventricles. The PVC occurs with every other heart beat. Patients may feel a PVC as a skipped beat or palpitation. Single beat premature ventricular contractions are very common and can often be asymptomatic in healthy patients. PVCs are also called premature ventricular complexes.

Rhythm Irregular

Rate The underlying rate

P Wave Absent

PR Interval Not measurable

QRS Wide (> 0.10 sec), bizarre appearance

Notes PVC appears every second beat

8.2. PREMATURE BEATS TRIGEMINY

Premature ventricular contraction trigeminy are extra, abnormal heartbeats that originate in the Purkinje fibers of the ventricles. The PVC occurs with every third heart beat. Patients may feel a PVC as a skipped beat or palpitation. Single beat premature ventricular contractions are very common and can often be asymptomatic in healthy patients.

Rhythm Irregular

Rate The underlying rate

P Wave Absent

PR Interval Not measurable

QRS Wide (> 0.10 sec), bizarre appearance

Notes PVC appears every third beat

8.3. PREMATURE BEATS QUADRIGEMINY

Premature ventricular contraction quadrigeminy are extra, abnormal heartbeats originating in the Purkinje fibers of the ventricles. The PVC occurs with every fourth heart beat. Patients may feel a PVC as a skipped beat or palpitation. Single beat premature ventricular contractions are very common and can often be asymptomatic in healthy patients.

Rhythm Irregular

Rate The underlying rate

P Wave Absent

PR Interval Not measurable

QRS Wide (> 0.10 sec), bizarre appearance

Notes PVC appears every fourth beat

8.4. PREMATURE BEATS COMPLEX

Premature ventricular contraction couplets are extra, abnormal heartbeats that originating the Purkinje fibers of the ventricles. The PVC occur in pairs. Patients may feel a PVC as a skipped beat or palpitation. Single beat premature ventricular contractions are very common and can often be asymptomatic in healthy patients. PVCs are also called premature ventricular complexes. Premature ventricular contraction (PVCs) are extra, abnormal heartbeats that originating the Purkinje fibers of the ventricles. Patients may feel a PVC as a skipped beat or palpitation. Single beat premature ventricular contractions are very common and can often be asymptomatic in healthy patients. PVCs are also called premature ventricular complexes.

Rhythm Irregular

Rate The underlying rate

P Wave Absent

PR Interval Not measurable

QRS Wide (> 0.10 sec), bizarre appearance

NotesTwo PVCs together are termed a couplet while three PVCs in a row with a fast rhythm is ventricular tachycardia

9. BUNDLE BRANCH BLOCK

A bundle branch block is a partial or total interruption of the heart’s electrical impulse in either the right or left branch of the electrical pathway. This interruption, or block, causes the electrical signals for one of the ventricles to detour, so that one of the ventricles contracts slightly later than the other ventricle. As a result, cardiac output can drop. This condition can be congenital or caused by heart disease.

Rhythm Regular

Rate The underlying rate

P Wave Normal

PR Interval Normal (0.12-0.20 sec)

QRS Wide (>0.12 sec)

10. AV Blok Derajat 1

Rhythm RegularRate The underlying rate

P Wave NormalPR Interval Prolonged (>0.20 sec)

QRS Normal (0.06-0.10 sec)

NotesA first degree AV block occurs when electrical impulses moving

through the Atrioventricular (AV) node are delayed (but not blocked). First degree indicates slowed conduction without missed beats.

11. AV Blok Derajat 211.1. AV Blok Derajat 2 tipe I

Rhythm Irregular but with progressively longer PR interval lengtheningRate The underlying rate

P Wave NormalPR Interval Progressively longer until a QRS complex is missed, then cycle repeats

QRS Normal (0.06-0.10 sec)

11.2. AV Blok Derajat 2 tipe II

Rhythm Regular (atrial) and irregular (ventricular)

Rate Characterized by Atrial rate usually faster than ventricular rate (usually slow)

P Wave Normal form, but more P waves than QRS complexesPR Interval Normal or prolonged

QRS Normal or wide

12. AV Blok Derajat 3

Rhythm Regular, but atrial and ventricular rhythms are independent

Rate Characterized by Atrial rate usually normal and faster than ventricular rate

P Wave Normal shape and size, may appear within QRS complexesPR Interval Absent: the atria and ventricles beat independently.

QRS Normal, but wide if junctional escape focus