What are common newborn cardiac arrhythmias?

From the Guidelines

Common newborn cardiac arrhythmias include sinus tachycardia, sinus bradycardia, premature atrial contractions (PACs), premature ventricular contractions (PVCs), supraventricular tachycardia (SVT), atrial flutter, and ventricular tachycardia (VT). These arrhythmias can be distinguished based on their characteristics, such as heart rate, R-R interval variation, P wave axis, and QRS complex morphology, as outlined in the guidelines for the interpretation of the neonatal electrocardiogram 1. For example, sinus tachycardia typically has a heart rate of less than 230 beats per minute, with visible P waves and a regular R-R interval, whereas SVT has a heart rate of 260-300 beats per minute, with visible P waves in 60% of cases and an extremely regular R-R interval after the first 10-20 beats 1. Atrial flutter, on the other hand, has an atrial rate of 300-500 beats per minute, with variable block giving different ventricular rates, and VT has a heart rate of 200-500 beats per minute, with slight variation over several beats and a QRS complex different from sinus 1. It is essential to accurately diagnose and manage these arrhythmias, as some, such as SVT, require prompt treatment with vagal maneuvers, adenosine, or cardioversion, while others, such as PACs and PVCs, are generally benign and often resolve spontaneously without treatment 1. The management of ventricular arrhythmias in children with a structurally normal heart is also crucial, as medical treatment or catheter ablation is rarely indicated, and most children remain asymptomatic, with PVCs often resolving in time 1. In addition, the guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death emphasize the importance of excluding any associated cardiovascular disease and considering the specific diagnosis and treatment of ventricular arrhythmias in pediatric patients 1. Overall, the diagnosis and management of newborn cardiac arrhythmias require a thorough understanding of their characteristics, as well as the latest guidelines and recommendations for their treatment.

Some key points to consider when evaluating newborn cardiac arrhythmias include:

• The distinction between different types of arrhythmias, such as sinus tachycardia, SVT, atrial flutter, and VT, based on their characteristics and electrocardiogram findings 1
• The importance of prompt treatment for certain arrhythmias, such as SVT, and the use of vagal maneuvers, adenosine, or cardioversion as needed 1
• The generally benign nature of PACs and PVCs, which often resolve spontaneously without treatment 1
• The need to exclude any associated cardiovascular disease and consider the specific diagnosis and treatment of ventricular arrhythmias in pediatric patients 1
• The importance of following the latest guidelines and recommendations for the management of newborn cardiac arrhythmias, such as those outlined by the European Society of Cardiology and the American College of Cardiology/American Heart Association Task Force 1.

From the Research

Types of Newborn Cardiac Arrhythmias

• Benign arrhythmias:
  • Sinus arrhythmia 2
  • Premature atrial contraction (PAC) 2, 3
  • Premature ventricular contraction (PVC) 2, 3
  • Junctional rhythm 2
• Nonbenign arrhythmias:
  • Supraventricular tachycardia (SVT) 2, 3, 4, 5
  • Ventricular tachycardia 2
  • Atrioventricular conduction abnormalities 2
  • Genetic arrhythmia such as congenital long-QT syndrome 2
  • Atrioventricular (AV) block 3
  • Wolff-Parkinson-White syndrome 3

Incidence and Prevalence

• The incidence of neonatal arrhythmias was 0.4% and 0.3% in two NICUs, and was 0.37% in the study population as a whole 3
• Foetal arrhythmias are encountered in 1-2% of pregnancies and 10% of these are associated with some form of foetal mortality or morbidity 4

Diagnosis and Management

• A systematic approach to analyzing the electrocardiogram and the telemetry monitor is often sufficient to diagnose the type of arrhythmia 6
• Echocardiographic evaluation is required to exclude associated structural abnormalities and to decide whether therapy is required 4
• The treatment of fetal tachycardia depends on the type of the tachycardia and several antiarrhythmic agents are available for the perinatal treatment of tachyarrhythmias 4, 5