Module 4 - Normal Sinus Rhythm and Sinus Arrhythmia

List the required characteristics for sinus rhythm.

• 60-100BPM

• rhythm is regular

• P wave precedes every GRS

• PR interval 0.12-0.2s and constant in length

• QRS identical

• QRS duration <0.12s and constant in length

• QT interval <0.44s and constant in length

What does it mean when an ECG paper reads “unconfirmed”?

ECG machine reads rhythm and makes an assessment that must be verified by an MD.

What is the P:QRS ratio in sinus rhythm?

1:1

Describe the rhythm of this patient.

Normal sinus rhythm.

Define arrhythmia.

Abnormal formation of APs.

Define sinus arrhythmia.

Abnormalities of the SA node.

Provide examples of sinus arrhythmias.

• sinus bradycardia

• sinus tachycardia

• sinus arrhythmia

• sinus arrest

• SA block

• asystole

List the required characteristics of sinus bradycardia. How does it differ from normal sinus rhythm?

• <60BPM

• rhythm is regular

• P wave precedes every GRS

• PR interval 0.12-0.2s and constant in length

• QRS identical

• QRS duration <0.12s and constant in length

• QT interval <0.44s and constant in length

List some possible causes of sinus bradycardia.

• could be normal for patient

• BP medication (B-blockers)

• hypothyroidism

• vasovagal reaction

• hypothermia

Estimate HR.

300/7.2 = 41BPM

Describe the rhythm of this patient.

Sinus bradycardia.

List the required characteristics of sinus tachycardia. How does it differ from normal sinus rhythm?

• >100BPM

• rhythm is regular

• P wave precedes every GRS

• PR interval 0.12-0.2s and constant in length

• QRS identical

• QRS duration <0.12s and constant in length

• QT interval <0.44s and constant in length

List some possible causes of sinus tachycardia.

• exercise

• anxiety

• alcohol/caffeine/drugs

• hypotension/hypovolemia

• hyperthyroidism

• CHF

List the required characteristics for sinus arrhythmia. How does it differ from normal sinus rhythm?

• 60-100BPM

• rhythm is irregular

• P wave precedes every QRS

• PR interval 0.12-0.2s and constant in length

• QRS identical

• QRS duration <0.12s and constant in length

• QT interval <0.44s and constant in length

Describe the rhythm of this patient.

Sinus arrhythmia.

Sinus arrhythmia is common and asymptomatic in…

Children and young adults.

Describe the rhythm of this patient.

Sinus arrest.

Describe sinus arrest.

SA node fails to generate an impulse.

≥1 complete PQRST is dropped

Compare sinus pause, sinus arrest, sinus exit block, and asystole.

Sinus pause: <3s pause

Sinus arrest: >3s pause

Sinus exit block: exactly 1 (or an exact multiple of) PQRST missing

Asystole: absence of any electrical activity

Describe the rhythm of this patient.

Sinus exit block.

Describe the rhythm of this patient.

Sinus arrest.

List some causes of asystole.

• death

• low gain on monitor

• leads are out of place

• possibly missing a fine ventricular fibrillation

Describe the rhythm of this patient.

Sinus arrhythmia.

Describe the rhythm of this patient.

Sinus bradycardia.

Describe the rhythm of this patient.

Normal sinus rhythm.