SCN EKG Review and Strip

Milburn, R.L., & Stech, M. 2015.

Objectives

• Identify regular and irregular neonatal heart rhythms

• Recognize causes of irregular heart rhythms in the neonate

• Match irregular heart rhythms with their appropriate medical treatment

Overview

Basic Neonatal ECG

P wave= atrial depolarization

QRS complex= ventricular depolarization

T wave= ventricular repolarization

Normal Sinus Rhythm

• Heart rate 100-180 bpm• Regular, uniform P wave before each

QRS complex followed by a T wave• No treatments necessary

Sinus Bradycardia

• Heart rate <100 bpm• Slow rate with normal P waves• Caused by:

– Hypoxia– Acidosis– Increased intracranial pressure– Increased vagal tone– Abdominal Distention– Hypoglycemia– Hypothermia– Digoxin

Sinus Bradycardia Treatments

• Treat underlying causes• Administer Oxygen• Resuscitation if appropriate

Sinus Tachycardia

• Heart rate >181 and <220 bpm• Normal P wave that precedes QRS complex• Caused by:

– Heart Failure– Fever– Anemia– Pain– Infections– Hypovolemia

• Treatment:– Treat underlying cause

Atrial Flutter

• “Saw tooth” flutter waves• P waves may be hidden in QRS complex• Heart rate can reach as high as 500 in

neonates• Caused by:

– Damage to Sinus Node– Congenital heart disease– Digoxin Toxicity– Idiopathic

Atrial Flutter Treatments

• If unstable:– Pacing– Electrical cardioversion

• If stable:– Digoxin– Propranolol– Amiodarone

Atrial Fibrillation

• “Irregularly irregular”• No two R to R intervals will look the

same• Absent P waves• Caused by:

– Atrial septal defects– Mitral valve anomalies– Atrial dilatation

Atrial Fibrillation Treatments

• If unstable:– Electrical cardioversion

• If stable:– Digoxin– Propranolol

• Due to risk of thrombus, anticoagulant therapy may be started

Supraventricular Tachycardia(SVT)

• Heart rate >220 bpm• Abnormal P axis• P wave may be seen or hidden• Caused by:

– Cardiac defects– Conduction abnormalities– Myocarditis– Systemic infections– Idiopathic

SVT Treatments

• If unstable:– Adenosine (0.05 mg/kg)– Amiodarone

• If stable:– Propranolol– Amiodarone– Digoxin

• Vagal maneuvers can also treat– Ice

Ventricular Tachycardia

• Lethal arrhythmia• Regular rhythm with no P waves• Wide QRS complex• Caused by:

– Asphyxia– Cardiac Tumors– Hypoxia– Acidosis– Electrolyte Imbalances– Drug toxicity– Cardiac Anomalies– Conduction Disorders

Ventricular Fibrillation

• Lethal Arrhythmia• Chaotic rhythm• Rapid and irregular• Caused by:

– Hypoxia– Acidosis– Electrolyte Imbalances– Cardiac Anomalies

Asystole

• Lethal Arrhythmia• Absence of electrical activity• Rhythm is flat• No P waves or QRS complexes

Treatments for Lethal Arrhythmias

• Defibrillation for Pulseless rhythms (such as Ventricular Tachycardia and Ventricular Fibrillation)

• Cardioversion for rhythms with pulses (such as Ventricular Tachycardia)

Abnormal Beats

• Premature Ventricular Contraction (PVC):• Early with no P wave• Wide QRS complex• T wave inverted• Caused by:

– Acidosis– Electrolyte Imbalances– Cardiac Disease– Irritation from invasive lines (such as UVCs)– May be normal in infants up to 2 months of age

PVC Treatments

• Infant should have cardiac work up including:– BMP– 12 lead EKG– ECHO

References

• Ambulance Technician Study. (2013). ECG rhythms. Retrieved from http://www.ambulancetechnicianstudy.co.uk/rhythms.html.

• New York-Presbyterian Healthcare System. (2011). Neonatal basic dysrhythmia study guide.